Energy:  What Exactly Is It?  Pp - 29
Davy Jones

No matter how much you push the envelope – it will always be stationery

About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion was known as the Big Bang.  At the moment of this event all of the matter and energy was contained at one point.  What existed prior to this event is completely unknown and is a matter of pure speculation.  (LaRocco)

The above paragraph is an excerpt from an article, entitled, ‘The Big Bang – It sure was BIG’!  Note the comment: all of matter and energy was contained at one point – not - all of matter and energy was created at one point.  

There’s no great mystery in this statement of course, it is a simple matter of physics, energy, as we ‘know’, cannot be ‘created or destroyed’, it can only be transformed!  The arguable word in the sentence is the inclusion of ‘matter’ being contained at this point.  However, given that energy and matter are, according to Einstein (E=mc2), one and the same, the semantics of the sentence are perhaps neither here nor there.  What is possibly more important in this reflection is the fact that many people actually refer to the Big Bang as the point at which the universe was ‘created’!  That basic misinterpretation muddies the cosmic waters before any logical thought as to the conceivable possibilities surrounding the greatest of all mysteries, can be considered.  Just to underline the immense implications contained in this short paragraph, one should also consider; all energy and matter must mean and include, dark energy and dark matter, or quite simply the basic constituents for everything thereafter!  

My thoughts as I read through the above article drifted to the most basic question: ‘What exactly is energy’?  On the face of it, a simple and certainly most obvious question, which would soon be resolved by a little research?  (I have been known to make naive suppositions from time to time).

Within a short while I found myself frustrated at every new Internet page.  Information categorising energy in its various forms, thermal (heat); chemical; electrical; radiant; nuclear; elastic; sound; mechanical and luminous (light), abounded.  All of the indicated forms of energy can of course be divided into the two generic groups of kinetic and potential energy.  

The Internet also provides an overabundance of data relating to the above classifications, detailing where, when, how, and why they occur.  There is also much made of the fact that energy is a physical measure that expresses the amount of work that can be achieved by a force; it then follows that all forms of energy are measurable through the use of mathematical symbols.  A lot of interesting facts and figures, but no concrete explanation of exactly what energy is!  
Eventually, I stumbled upon a Science Forum discussion page that seemed to offer something I could finally nail down!  The opening question appeared to offer precisely the information I needed: ‘What exactly is energy…without using symbols and metaphors’?  There was no doubt about it, as I waded into the opening comment, the first participant began by stating the obvious that molecules move, and they are ‘hot’ and have lots of kinetic energy.  But, then asked: what exactly is energy?

The discussion progressed along similar fumbling lines as my own research going through all of the categorisation mentioned above, including the mathematical concepts involved.  Several comments into the forum I came across the first glimmer of hope in the following comment: …’energy is the capacity to do work of some sort.  It is categorically not a substance in itself that pervades the universe’.  Naturally a swift rejoinder to this comment followed, which suggested that if the previous writer thought energy was just an abstract concept they should try sticking a fork into an electrical socket.  Whilst amusing, this comment still didn’t assist me in my quest to define ‘energy’ per se.  We all know that ‘electricity’ is a form of energy.  And, as with just about every form of energy I can think of, in certain circumstances, too much of it can do extreme damage to the fragile human atomic structural arrangement!  At its worse, we call that damage death, that being, in terms of physics, just another ‘changed state’ in an apparently endless process!

The next comment suggested that ‘everything’ was energy because all matter, irrespective of state is a form of energy.  A fair enough comment, but it still didn’t answer the basic question!  It is amazing how trains of thought can become bogged down when dealing with oddly esoteric questions.  Further again into the discussion the term: ‘creation of the universe’ inevitably raised its head.  The very use of the word, creation, of course, suggests a creator and therefore moves the discussion from a purely scientific one to a philosophical and or spiritual one.  This manipulation of any discussion seems to be the ultimate human response when frustration and a lack of logical answers set in; a third party is introduced that conveniently provides all the answers.  Even the illustrious Einstein is recorded as resorting to the same conclusion at one very frustrating moment in his quest for answers. 

Despite this natural diversion, the discussion continued in a reasonably focused direction.  Some participants were beginning to show obvious signs of frustration, evident in their comments becoming more personal and derogatory towards other forum participants.  Much was made of the fact that energy determines the path of change, energy is evident through observable change, and the amount of energy determines the rate of change.  

All pertinent points, but still none that addressed the original question: What exactly is energy?

Towards the end of the discussion there were a few comments relating to molecules and particles, and the movement of these ‘producing energy’.  

Finally, a respondent came up with the following explanation:  Energy, he said, has no reality apart from its mathematical dependence on measurable variables.  The respondent noted that an object’s kinetic or potential energies are not measured, but the associated state variables are, velocity and position respectively. (Sic)

This answer was expanded upon, by one I assumed to be the convener, who warned that whilst it wasn’t an easy question to answer, that didn’t make the question impossible to answer.  
He indicated most physicists know exactly what energy is, and continued thus: the concept of energy is ultimately a tool, invented by humans, to understand the world around us.  He stated that whilst this was not a definition of energy, the whole point was, energy can be MANY things and it is this vagueness that makes the concept useful.

As an example, he cites the notion of length, which is close to our primitive perception; length, we understand as being that there is, “here” and “there”.  The concept of energy, however, he describes as being a higher order type of tool.  It doesn’t correspond so simply to our direct experience in that no one can point to a primitive notion and state that it is an example of energy.  Therefore, energy is simply an abstraction.  However, it does enable a unified description of diverse phenomena.  Energy, as such, is simply a tool and an additional way to organise our understanding of the universe.  

The writer wraps up by providing what he describes as an exact definition of energy: “Energy is the generator of time translations”.  Having given this murky definition, he explains that: this is why no one gives the exact definition of energy, because it takes years of intensive training just to comprehend what such a statement really means!

In this instance, I can only agree.  Having put myself through this meticulous research process, I now wonder what ‘diverse phenomena’ are?  I’m sure no one will ever bother to explain it to me, simply because I wouldn’t understand, even if they bothered!  

So, at the moment of the Big Bang, all diverse phenomena were present, or were they? 

Any readers’ comments on this small reflection would be most welcome; particularly if a convincingly simple answer is forthcoming.

Refs:
Encyclopedia, W. T. F. (1999). Energy. Retrieved February 18, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Energy#Forms_of_energy.
LaRocco, C. E. A. The big bang it sure was big. Retrieved February 18, 2011, from University of Michigan: http://www.umich.edu/~gs265/bigbang.htm.
Sciforums, P. (2006). What exactly is energy. Retrieved February 18, 2011, from SciForums.com: http://www.sciforums.com/showthread.php?t=54423.

Comprehending the Incomprehensible
Davy Jones

The most incomprehensible thing about the universe is that it is comprehensible: A. Einstein

In the previous chapter, I made a vain attempt to define energy; as an adjunct to that chapter I felt it worthwhile exploring human scientific thought and development generally. The human pursuit of understanding the natural world and all that surrounds us culminating with the ultimate answers to the ultimate questions: ‘Where did it all come from’?  And - ‘what the heck is it all about’?

Attending an Astronomy Forum in February 2011:  Prof. Fed Watson mentioned in passing recent advances in technology which allow never-before dreamed of results in the areas of amateur and professional astronomy and cosmology.  It seems difficult to believe that for thousands of years, the human race had such an extremely unrealistic view of the universe and our place in it.  Yet, without the historically flawed models, the assumptions and wildly mythological structures, much of what we take for granted today, might remain cloaked in mystery.  It is this human ability to build upon accumulated knowledge – sometimes renewed after a lengthy hiatus – or even transferred across culturally differing societies – that facilitates genuine scientific progress.

Human curiosity is not culturally exclusive; from the earliest times, every culture, worldwide, has had some form of mythical version of the creation story.  Each ‘creation story’ mirrored the situation and society from which it originated; and each story symbolized the ‘supreme truth’ within its own society.  Scientific progress could not truly begin until many of those ancient traditions, bound up in folklore and myth, began to decline.  

In trying to make some sense of order in the various models that have impacted the most on today’s perception of the universe, I think one of the earliest notable hypotheses is the ‘Mesopotamian Model’.  
This model was developed by the inhabitants of the Nile and Tigris-Euphrates valleys.  The Earth was depicted as flat, and surrounded by lofty mountains.  The sky was a solid dome upon which the stars were placed, and water canopies emptied their rainfall.  The planets, the Sun and the Moon, were all imagined to be relatively small, and guided by celestial forces.  Interestingly perhaps, aspects of this model are offered in the Bible (Joshua 10 & Psalm 19).  

Whilst still containing strong mystical overtones, over time the Mesopotamian Model was adopted and modified by other civilizations.  Around the 6th century BC early theorists such as Anaximander (possibly also the founder of evolutionary theory) and Xenophanes appeared on the scene, and whilst their explanations of the natural world were still far removed from modern ideas, they nevertheless did develop theories that didn’t rely on supernatural elements for support. 
 
Those ancient philosophers are recognised as the first true cosmologists, by virtue of the fact that they were genuinely concerned with the scientific study of the physical universe and its genesis.  The ancient Greek word – kosmeo – from which our modern word – cosmology – is derived, literally translates into - to order or to organise. 

Every authentic scientific premise must make a prediction about the universe that can be measured and observed; history recognises Pythagoras as the man who made such scientific enterprise possible through mathematics.  His successors developed and enhanced his ideas, allowing science to become a sophisticated and authoritative discipline capable of some amazing early achievements.  Amongst these early achievements – without which later developments would have been impossible – were the measuring of the dimensions of the Earth – the Moon – and the Sun; and the distances between them.  To quote the author, Simon Singh: “these measurements were a milestone in the history of astronomy, representing as they do the first tentative steps on the road to understanding the entire universe.”

At this point it is worth taking a closer look at how some of those early measurements were achieved, and the human logic that lay behind such discoveries.  
Aristotle (384 BC-322 BC) is acknowledged as being the first to write down a complete set of rules for logical analysis.  Whilst earlier philosophers had merely suspected the Earth was a globe – by drawing on their observations of the Sun and the Moon; Aristotle established those assumptions as fact.  

He observed many eclipses, and obviously recorded his observations over time.  Aristotle noticed that during a lunar eclipse, the shadow of the Earth on the Moon was circular.  Naturally, a flat round object may also cast such a shadow.  However, he noted the shadow remained circular no matter in which direction the eclipse took place – in Aries, Capricorn, Gemini or Sagittarius.  It followed; the only object capable of casting a circular shadow from all directions is a sphere!   Thus, based on his empirical research, Aristotle affirmed the Earth was indeed spherical.  

Eratosthenes (276 BC-195 BC) is reportedly the first person to have used the word ‘geography’; he also ‘invented’ a system of latitude and longitude.  More impressively, he accurately measured the size of the Earth.  His measurement of about 39,250 km was accurate to 2% compared to modern measurements.  How he achieved this feat with the most basic tools available is testimony to human ingenuity.  

Whilst studying at a library, Eratosthenes learned of a water-well with extraordinary properties.  This well was situated near the township of Syene (near modern day Aswan).  Each year, at noon on the 21st June, the day of the summer solstice, the Sun shone directly into the well, illuminating it right to the bottom.  Being an erudite chap, Eratosthenes realised for this to happen, the Sun must be directly overhead.  Eratosthenes, who resided in Alexandria, was aware that such an event didn’t happen in his locality.  

Being aware of the Earth’s curvature, he reasoned that the Sun could not be overhead in Alexandria and Syene (several hundred km south) simultaneously; he decided to exploit his discovery in an attempt to establish the actual size of the Earth.  Today, we call this a ‘problem-solving approach’, in which we take a problem and reduce it to simpler terms before making extrapolations to arrive at our final conclusions.
It is not within the scope of this article to explore too deeply how Eratosthenes arrived at his final results with little more than a stick and a brain; but by coordinating his readings to occur at the same time as the Sun was overhead and shining down the well in Syene, he placed a stick in the ground in Alexandria.  At the appropriate time, Eratosthenes recorded the angle of the shadow cast by the stick at mid-day.  Having established the size of the angle – 7.2° - the rest of the equation became academic.  Using the distance between the two towns, he extrapolated his results to estimate the distance around the Earth.  Having established the size of the Earth – it then became possible to estimate the size of both the Moon and the Sun, and their distances from Earth! 

I can only reiterate this is: ‘a man – with a stick and a brain’!  Human resourcefulness leaves me quite flabbergasted; as does its frequent lapses in common sense!

In fairness to earlier philosophers, it was they who laid much of the foundations relating to the measurements mentioned above.  However, there was always one missing value: the size of the Earth.  Once that value became available, the remaining values were a matter of course.  Using Earth’s shadow cast on the Moon during a lunar eclipse, it didn’t take Eratosthenes long to estimate the Moon’s size as about one-quarter that of Earth.  Thus geometry, logic, and empirical research began to pave the way toward genuine scientific discovery.  Measurements, sizes, distances, all relating to our own solar system became firmly established.  As indicated earlier, those measurements were remarkably accurate and have stood the test of time and advancing technology.  

Other suppositions being made about the universe at that time were not as accurate.  The influences of mythology and religion were, and still are, deeply entrenched in the human psyche.  Those suppositions and the logic that lay behind them will be explored in later discussions.

Refs:
Administrator, D. (2005, March 6). The Ptolemaic system - a short history. Retrieved March 13, 2011, from The Flat Earth Society Forum: http://www.theflatearthsociety.org/forum/index.php?PHPSESSID=8c20b1a28c0eefa7dfb2f4a61e3326d5&topic=14.msg22#msg22.
Encyclopedia, W. T. F. (1999). Eratosthenes. Retrieved March 15, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Eratosthenes.
JJ, O. E. A. (1999, January 1). Pythagoras of Samos. Retrieved March 14, 2011, from School of Mathematics University of St Andres Scotland: http://www-history.mcs.st-and.ac.uk/Biographies/Pythagoras.html.
Singh, S. (2005). Big bang. London: Harper Perennial.

Shedding Some Light -  July, 2011 – Davy Jones

The less one knows about the universe, the easier it is to explain – Leon Brunschvicg 1869-1944

Before moving into the scientific complexities of the 20th century, it is worth consolidating the synoptic view created over the past few chapters.  I began this series by asking: ‘What is Energy’; and continued with an examination of the early growth of human scientific thought.  It became apparent that certain human traits and conditions stymied human logic and the development of scientific reflection.  Identified amongst these traits and conditions were religion and spiritual fantasy, economics, politics, cultural needs or desires, and fluctuating levels of human curiosity; not to mention basic professional envy.  

Our primary interest is astronomy and cosmology, so I don’t intend straying too far down a philosophical or psychological path.  However, to achieve the objective of understanding scientific development, we should be cognizant of human needs.  ‘Maslow’s Hierarchy of Needs’ plays a large part in our intellectual development.  Without going too deeply into this phenomenon, suffice to say, Maslow maintained that without a full belly, and the basic needs of life, humans tend not to be too concerned with deeply intellectual or academic matters.  One can imagine many periods of human history where the sole concern was basic survival – not scientific advancement or idle curiosity.

Another aspect worth considering is the difference between ‘scientific development’ and ‘technological development’; two distinctly differing fields of human enterprise.  The Egyptians, for example, were without doubt technologically advanced.  However, they weren’t necessarily scientifically astute!    Quite simply; they made many items that made life easier, without necessarily understanding the scientific principles underpinning them.   Much the same could be said today; many of us drive technologically advanced vehicles, however, few understand what makes them work! 

One other point worth consideration: in earlier times, it had been possible, if one were among a privileged few, to ‘know all there was to know’.  The sum of human knowledge was such that, without modern day distractions, a person could study to ‘understand everything’.  The last statement must be taken cautiously; but reflects how little was understood scientifically.   As the Enlightenment progressed into the Industrial Revolution, science and physics started to get really serious.  Pandora’s Box inched to open.  Scientists began to specialize in their own areas of interest.  The world was still a large place at the end of the 19th century, with poor infrastructures.  Nevertheless, progress was made and information started to be collated.

By that time, the three classical states of matter, liquid, solids and gas had been investigated seriously.  Those investigations led to study into non-classical states – glass and crystal etc.  With the coming of quantum physics, the field widened again into low temperature states, high-energy states, very-high energy states and ever onward into other proposed states.
  
Hypothesis built on hypothesis as theories were proven or disproved; perfect unadulterated science thrived.  The First and Second World Wars drove further discoveries – some more welcome than others.  Year by year, scientists presented the human race with a growing array of deepening mysteries; mysteries that would stretch ordinary mortal mental capacities beyond normal limits.  Some of those discoveries have led us to rethink reality itself.  Take the following examples; I take the liberty of assuming most readers are aware of the properties of an atom in general terms: 

If one accepts the world human population now to be 6,000,000,000 (6x109) – and the number of atoms in the human body on average to be 7,000,000,000,000,000,000,000,000,000 (7x1027) then the whole human race comprises: 6x109 x 7x1027 = 4.2×1037 atoms.  Now strip away the outer layers of those atoms, leaving only their nuclei - matter.  The space required to ‘store’ the whole human race is now reduced to something akin to the volume of a sugar lump.   

Or conversely:  the density of a neutron star, about 20km in diameter, is such that one teaspoon of its substance has a mass of about 100 million tons, which is about as much weight as a good-sized mountain.  The consequential force of gravity, so powerful, that if an object were to fall from just one metre high it would hit the surface of the star at around 2,000 kms per second, or 6,920,179.2 kmph. 

These statements are tricky for people to comprehend, because they lay outside the confines of ‘common sense’; but remember, ‘common sense’ was once a reason for accepting the geocentric model of the universe!  Today, there are still those who support the notion of a flat earth.  Religion and superstition still retain an iron grip on the human psyche.  Economics often restricts funding for scientific research, and professional jealousy still gets in the way of progress.  Increasingly, politics in this modern age has an unfortunate habit of creating misleading ‘scientific facts’ for purely political ends.  In spite of these negatives, whilst it may have slowed, genuine scientific knowledge continues to develop apace.

Having indulged in a little consolidation, we can now examine some of the specific areas of scientific development concerning the nature of the universe.  As we have seen scientific arguments and debates have raged throughout history.  That is the essential strength of science: one must always question the results.  Darwin’s Theory may be termed ‘only a theory’, but since first proposed, all subsequent evidence has only supported the ‘theory’.  Nothing has cast serious doubt upon Darwin’s empirical evidence and ensuing conclusions.  Conversely, the scientific debate that raged for years over the existence of cosmic ether as the medium by which light moved through the universe, was eventually lost; in spite of assertions - there ‘must be something’ in which light could travel.  Common sense again!  Since the Ancient Greeks, it was speculated that light had a finite speed.  Our old champion, Galileo, actually carried out some crude research attempting to establish the speed of light.  Some 70 years later, the Danish astronomer, Ole Roemer estimated the speed of light at about 220,000 km/s; nearly 26% lower than its correct value.  

It wasn’t until 1849, that Armand-Hippolyte-Louis Fizeau (1819-1896) made a reasonably successful attempt to establish the actual speed of light.  In coming years, eminent scientists from Leon Foucault to Mittelstaedt through to Bergstrand, in 1951, struggled to achieve a correct result.  

The American, Albert Abraham Michelson (1852-1931), typified the calibre of those whose efforts would lead to an accurate assessment of the speed of light.  Michelson is particularly interesting because his greatest claim to fame was a failed experiment, which lasted an agonising seven years.  Michelson initially set out to prove the existence of the enigmatic substance - ‘ether’.  Finally, he proved beyond doubt that ether didn’t exist. (See Michelson-Morley experiment)  Incidentally, in 1880 – Michelson estimated the speed of light to be: 2990,910 km/s.  Although incorrect, it was however a respectable estimate.  In 1921-22, Michelson, in association with Francis Pease, became the first to measure the diameter of a star, other than the Sun.  Using an ‘astronomical interferometer’ at the Mt Wilson Observatory, they successfully measured the super-giant star, Betelgeuse.

In 1905, Albert Einstein demonstrated that the velocity of light was an essential constant and in fact the definitive speed for any object.  In 1951, using a Kerr Cell shutter, an instrument previously used as early as 1875, Erik Bergstrand put the speed of light at 299,793.1 km/s; an error of just 0.3.  Accumulated knowledge and advances in technology were finally closing the gap on the elusive ancient speculation.  In the second half of the 20th century, methods such as cavity resonance techniques, and later laser interferometer techniques ensured increasingly accurate measurements of the speed of light.  In 1983, the metre was redefined to increase the accuracy of various methods of measurement.  The current definition now reads: ‘the metre is the length of the path travelled by light in a vacuum during a time interval of 1/299 792 458 of a second.’  As a consequence of that reclassification the value of the speed of light in a vacuum is now given as 299,792,458 m/s by the International System of Units (SI).  Finally – it is worth remembering, when we talk of the ‘speed of light’ - we are in fact referring to the ‘speed of electromagnetic radiation’.  What we call, visible light is only a small part of that greater electromagnetic spectrum.  

Refs:
Encyclopedi, W. t. (2010). State of Matter. Retrieved June 1, 2011, from Wikipedia: http://en.wikipedia.org/wiki/State_of_matter
Fowler, M. (2009). Galileo and Einstein. Retrieved June 2, 2011, from Uva Dept of Physics: http://galileoandeinstein.physics.virginia.edu/
Fowles, G. (1989). Introduction to Modern Physics. Retrieved June 2, 2011, from Physlink.com: http://www.physlink.com/education/askexperts/ae22.cfm
Gibbs, K. (2010). Speed of Light. Retrieved June 10, 2011, from School Physics: http://www.schoolphysics.co.uk/age16-19/Wave%20properties/Wave%20properties/text/Speed_of%20light/index.html?PHPSESSID=325fe609a38643798b41aced112cbcd0
Singh, S. (2005). Big Bang. London: Harper Perennial.
WikiAnswers. (2011). How much would a spoonful of neutron star weigh. Retrieved June 1, 2011, from Answers.com: http://wiki.answers.com/Q/How_much_would_a_spoonful_of_a_neutron_star_weigh
Wikipedia the Free Encyclopedia. (2011). Speed of Light. Retrieved June 10, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Speed_of_light

Deep Space Pioneers
Davy Jones

Where were you on the 2rd March 1972 (some refs state 3rd of March) – the day Pioneer 10 (AKA Pioneer F) was launched into space on its epic journey to Jupiter and its search for alien life?  

Thirty-seven years is a lifetime away.  Imagine the crudity of the ‘ancient technology’!  Big, clunky, and cutting edge in the broadest sense of the word!  Then consider the mathematical beauty of the successes achieved and how it was so painstakingly accomplished.  As has been said many times; today, in 2011, we have more computing power in a home PC than was available to such complex cosmic endeavours. 

Launched atop an Atlas/Centaur/TE364-4 three-stage launch vehicle; Pioneer 10 carried only 11 instruments – as follows:  1. Plasma Analyzer (P/L) - 2. Charged Particle Instrument - 3. Cosmic Ray Telescope - 4. Geiger Tube Telescope  -           5. Trapped Radiation Detector (P/L) - 6. Meteoroid Detector (ENC) (F) - 7. Asteroid-Meteoroid Experiment (ENC)(F) - 8. Ultraviolet Photometer - 9. Imaging Photopolarimeter (ENC) (P/L) - 10.  Infrared Radiometer (F) and - 11. A Helium Vector Magnetometer.  

This very limited and specific collection of instruments sent back more useful information in its working lifetime than could of ever been hoped for, leading the way for all future deep space exploration.

For the record, the third stage booster was required to gain a speed of 51,810 kph to enable the unit to complete its flight to Jupiter.  At the time, this made Pioneer 10 the fastest manmade body to leave Earth at a speed that would take it past the Moon in just 11 hours; traversing 80 million kilometres of space and crossing the orbit of Mars in only 12 weeks.   

Measuring just 2.9 metres in length, and 2.7 metres at its widest point, Pioneer 10 weighed in at just 258kgs.  Electrical power was supplied by four radioisotope thermoelectric generators (RTGs), each providing just 155 watts of power at launch – decaying to 140w in transit to Jupiter.  The spacecraft required just 100w to power all systems.  

An RTG is a nuclear electrical generator that draws its power from the process of radioactive decay!  Heat released by the decay process is converted into electricity via the Seebeck effect (an explanation of which would take us down the murky road to the magic world of semiconductors).  Put simply, an RTG is a form of battery; a power source long associated with space probes, satellites and even terrestrial unmanned scientific facilities.  The most obvious drawback to their use is the requirement to safely contain the radioisotopes long after the useful ‘battery life’ has been expended.

By July 15th 1972, Pioneer 10 entered the Asteroid Belt – an area 280 million kms wide and 80 million kms thick – located approximately between the orbits of Mars and Jupiter.  The thinly spaced objects within the Asteroid Belt travel at speeds estimated to be 20 km/sec and the objects within, vary in size from mere dust particles to rocks the size of the state of Queensland!  Whilst other spacecraft have since negotiated this area of space, at the time scientist were unsure if Pioneer 10 would be able to safely navigate its way across this possibly terminal minefield.

By the 4th of December, 1973, Pioneer 10 made its first fly-by of the gas giant, Jupiter, achieving a dream first approved in February 1969.  The earliest mission objectives had been outlined as follows: explore the interplanetary medium beyond the orbit of Mars – investigate the environment within the Asteroid Belt and assess the belt’s potential hazards to future outer planet missions – explore the locality around Jupiter – and make a close approach Jupiter to gather information on the possible effects of Jovian radiation on spacecraft instrumentation. 

In just 21 months the textbook mission had been completed beyond all expectations; but the story continued for the tiny probe well beyond that point as for many years a weak signal continued to be traced by the Deep Space Network.  
Right up to 1997 and onward, the probe was employed to train flight controllers on how to obtain radio signals from space!  The final successful telemetry – the technology that allows remote measurement and reporting – from Pioneer 10, was on April 27th 2002.

Amazingly, on the 23rd of January 2003, what is recognised as the very last extremely weak signal was received from the still operating probe.  At that time Pioneer 10 was estimated to be 12 billion kilometres from Earth (80 au).  A further contact effort was made on February 7th 2003 – but that attempt was unsuccessful.  

On March 4th, 2006, the last time the probe’s antenna would be acceptably aligned with Earth, yet one last attempt at contact was made.  No response from Pioneer 10 was forthcoming.  It is thought that sheer distance and lack of power were the reasons for the eventual loss of contact, rather than the destruction of the probe.  It should also be noted that the probe must first be contacted by NASA before it will respond and send back data.

When its last position was recorded, Pioneer 10 was headed in the general direction of Aldebaran, in the constellation of Taurus.  At an estimated speed of 2.6 au per year, assuming Aldebaran has relative zero speed, Pioneer 10 should reach this distant destination in approximately 2 million years.

Pioneer 10 and its twin, Pioneer 11 (AKA Pioneer G), may yet possibly achieve one last duty if they are ever intercepted by ‘alien life’.  Both vehicles carry the famous gold anodized aluminum plaques - suitably shielded from erosion and cosmic dust - which depict the human race in all its naked glory.  Further information, should the extraterrestrials be adventurous or interested enough, and have technology well in advance of that presented to them in the shape of the defunct Pioneer probes, provides the exact location of our ‘Blue Island’ world.

Refs:
Encyclopedia, W. T. F. (2010). Radioisotope thermoelectric generator. Retrieved January 1, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator.
Encyclopedia, W. T. F. (2010). Thermoelectric effect. Retrieved January 1, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Seebeck_effect#Seebeck_effect.
Hamilton, C. J. (N/A). Pioneer 10 & 11. Retrieved December 31, 2010, from NASA Houston TX 77058: http://www.solarviews.com/eng/pn10-11.htm.
Lakdawalla, E. (2006). The final attempt to contact pioneer. Retrieved January 3, 2011, from The Planatary Society: http://www.planetary.org/blog/article/00000477/.
NASA. (2010, April 1). Pioneer 10 & 11. Retrieved December 31, 2010, from NASA  Science Missions: http://science.nasa.gov/missions/pioneer-10-11/.
Stenger, R. (2002, December 1). A distant pioneer whispers to earth. Retrieved January 3, 2011, from CNN - Science and Space: http://edition.cnn.com/2002/TECH/space/12/18/pioneer.contact/index.html.
Today, S. (2003). The pioneers are way out there after 30 years. Retrieved December 31, 2010, from Space Today Online: http://www.spacetoday.org/SolSys/ThePioneers.html.
Ward, M. (2001, April 30). Distant probe phones home. Retrieved January 1, 2011, from BBC News: http://news.bbc.co.uk/2/hi/science/nature/1305068.stm.

All That Is 
Intelligent life stands in awe of the universe, yet the mother of all life cares for nothing! 
 
Gazing into the night sky - you are observing 'all states and phases of energy and matter'.  The very existence of the universe and our inborn curiosity lies at the beating heart of many human intellectual enterprises.  Those enterprises predictably encompass religion, philosophy and the sciences in their various forms.  

Each discipline holds its own particular fascination of course, but, in my humble opinion, only one discipline provides comprehensible, yet always challengeable answers: science.  The historical development of scientific thinking has been the focus of this little writing project.  Whilst we have only skipped over the centuries like a flat stone over water, the background research has provided an informative and enlightening experience for me personally.  However, I'd be the first to admit, I'm no nearer the 'ultimate answers' than I was at the beginning of the venture.  Nonetheless, I do now have a better grasp on the complexity of the issues that face scientists, astronomers, cosmologists and physicists in their various roles.

The men and women of science have battled a lack of technical aids throughout history; the technology it seems, always playing catch-up.  They have also had to contend with another, even more insidious, trait: human incredulity.  Because something appeared beyond human reason or traditional cultural belief - often in spite of significant proof - both the scientific messenger and the message were repeatedly brutally maligned.  Oddly perhaps, the same level of incredulity has not been customarily applied to other disciplines, in spite of their patent lack of empirical evidence and often curious, superstitious claims.  One can only speculate what progress might have been made if human foibles hadn't retarded the natural pace of scientific development.

Our Western ideas of the classical four elements; Earth, Water, Air and Fire stem from Babylonian religious mythology.  Sometimes a fifth element - or quintessence - was added; named Aether (literally - light carrier).  This 'element' attempted to describe that which existed beyond the physical world.  
Likewise, the first mention of the atom was suggested by the Ancient Greeks and is linked to one Leucippus - 5th c BCE - the founder of Atomism.  The Greek word: atomos - translated means uncuttable.  As many readers would be aware, the concept of the Aether (or Ether) was finally discredited by Einstein with his work on General and Special Relativity.

At great personal cost, Galileo Galilei, 1564-1642, finally exposed the myth of Ptolemaic model of our solar system, seriously challenging the entrenched religious dogma surrounding that belief.  

Following this, Sir Isaac Newton, 1642-1727, created a set of scientific principles that held sway for the next 300 years.  Newton, a Master of the Royal Mint circa 1699 until his death in 1727, in fact, wrote more papers on biblical interpretation and occult studies than on scientific topics.  For trivia buffs, it is claimed Newton suffered from Asperger's Syndrome.   

Newtonian science influenced many aspects of scientific experimentation for so many years, and great advancements predictably occurred.  The Classical States of Matter were modernized into the classifications of Solid, Liquid and Gas.  Each of those states of matter has their own story of scientific exploration and explicit identification.  Each also has its associated scientists who focused, often for a lifetime, on the investigation of each particular state and the transformations that occur between those states.

Today we are aware of many other exotic states, described as Non-Classical States, among them: Glass - Crystals - Liquid Crystal states - Copolymers - Superfluids - Bose-Einstein condensates - Fermionic condensates - Rydberg molecules - Quantum Hall states and the aptly named - Strange Matter.  

In addition to these states we now recognise the High Energy states, most commonly - Plasma, the ionized gas state now artificially produced, and regularly employed in much of today's technology.  Examples of natural occurrences of plasma are of course, lightning and stars, such as our own sun.  

Moving into the Large Hadron Collider (LHC) territory, states such as Quark-gluon plasma are shown to exist (baryonic material).  The temperature required to produce such material is up to 2×1012 K.  This type of matter is perhaps more commonly associated with quantum or particle physics and the conditions existing shortly after the period termed - The Big Bang.  Coincidentally, certain pundits suggest the term - The Big Bang - is inappropriate; I agree - it does seem misleading.  This - First Event - is often introduced with the codicil indicating - 'it wasn't actually an explosion as we know it - it is better described as a very rapid expansion'.  However, therein lays a topic for another day perhaps.

Einstein's theory of general relativity predicted the Very High Energy State, described as the gravitational singularity state.  Einstein postulated the environment for such a state may exist at the heart of a black hole.  With so many of Einstein's predictions constantly being upheld - as technology advances allowing scientists to run observable experiments, disproving, or more often, proving his theoretical speculations - this claim may yet prove to be another posthumous tribute to his genius. 

There are now additional proposed states of matter; these include Degenerate Matter - apparently of great interest to astrophysicists because such high pressure conditions that create this type of matter are thought to exist within white dwarf and neutron stars.

Further proposed states include such exotic sounding names as - Supersolid - String-net Liquid and Superglass.  All of the aforementioned states are far removed from the Classical Ancient Greek classifications that satisfied human curiosity for so many years.  Whilst Einstein certainly didn't debunk Newtonian Science in the same way as Galileo debunked Ptolemy, he nevertheless lifted the lid of Pandora's Box much wider than even he perhaps appreciated.

Given the human characteristic of accepting the status quo without question, often for many years, one cannot imagine what spectacular breakthroughs are just over the horizon.  Will we ever know - all there is to know?  
I suspect, with the ever-increasing speed of technological advancement, science is only now on the threshold of as yet unimagined disclosures.  The mystery of Dark Matter and Dark Energy are surely high on that particular wish list.  

Just as a parting thought; have you ever considered that the universe is simply the detritus of that mighty cosmic conflagration - The First Event?  

Rather than a magnificent creation the universe is just: Ashes in a cold, cold, fireplace, swirling endlessly in a mighty celestial up-draught! 

Refs:
IEP. (2001, April 17). Internet Encyclopedia of Philosophy. Retrieved October 9, 2011, from Leucippus 5th c BCE: http://www.iep.utm.edu/leucippu/
Jupiter Scientific. (1997). The Bible According to Einstein. New York: Jupiter Scientific Publishing Company.
Microsoft. (1998). Isaac Newton's Life. Retrieved October 8, 2011, from Isaac Newton Institute for Mathematical Sciences: http://www.newton.ac.uk/newtlife.html
Stanford Encyclopedia of Philosophy. (2005, August 23). Ancient Atomism. Retrieved October 7, 2011, from Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/entries/atomism-ancient/
Wikipedia. (2010). Classical Elements. Retrieved October 6, 2011, from Wikipedia the Free Encyclopedia: http://en.wikipedia.org/wiki/Classical_element
Wikipedia. (2011, September 28). Isaac Newton. Retrieved October 8, 2011, from Wikipedia the Free Encyclopedia: http://en.wikipedia.org/wiki/Isaac_Newton
Wikipedia. (2011, October 5). State of Matter. Retrieved October 8, 2011, from Wikipedia the Free Encyclopedia: http://en.wikipedia.org/wiki/State_of_matter#Solid

Coming Full Circle
Davy Jones

    The Lord set the earth on its foundations; it can never be moved. (Psalm 104:5)

Claudius Ptolemy

Whilst the subject of this chapter may seem familiar, the logic behind the ideas may not be as obvious.  Our modern conceit ensures ‘we know’ how the universe is structured and are confident in our summation because our technology and scientific know-how support our theories beyond a shadow of doubt.  
Singh, pp 20, described how our ancestors studied the sky by night and day to determine changes in weather patterns, measure time, and confirm directions.  The ground on which they stood stayed firm under feet, and the heavens passed overhead in an endless and ‘fairly predictable’ procession; consequently, they assumed the Earth was the centre of the ‘known universe’, and the heavens revolved around it and them.

Notwithstanding those early, Earth-centred assumptions, there were a few early thinkers who quite accurately proposed a heliocentric (sun-centred) ‘universe’.  Whilst the idea of our solar system as just a tiny part of the greater universe was still a long way off, those early heliocentric proposals were uncannily correct.   Here we can observe yet another perfect example of human knowledge and ideas being built upon – handed down – and developed over several generations.   The earliest recognition for presenting a ‘true’ heliocentric model goes to Aristarchus of Samos (310 BC-230 BC); however, it is acknowledged that his proposals were based on the ideas of those who had gone before him.  

Philolaus of Croton (approx 470 BC–385 BC) a pupil of the Pythagorean school, in the fifth century BC, was possibly the first to suggest the Earth orbited the Sun.  In the following century, Heraclides of Pontus (approx 387 BC-312 BC) developed these ideas even further.  For his efforts, he was publically ridiculed, labelled crazy, and given the nickname of Paradoxolog – ‘the maker of paradoxes’.  

Whilst there is some disparity about the dates given from various sources, it is clear that Aristarchus was born about the time of Heraclides’ passing.  Naturally, any of the aforementioned characters are worth further investigation if the reader is so inclined.  It goes without saying; their lives were a rich mosaic of mathematical and philosophical thought.  Truly – no man is an island! 

Having established a viable and reasonably accurate model of a heliocentric ‘universe’ what happened to change that model?  Why did this ‘accurate proposal’ quite plainly disappear for the next 1500 years, until resurrected in the early 1500s by Nicolaus Copernicus, and later, in the face of severe religious persecution, brought to the fore by Galileo Galilei?

Change doesn’t occur easily in the human intellect – egocentrism rules – and the majority, especially if supported by religious or mystical factions in society, tends to hold sway against even the most persuasive scientific arguments.  It appears our old companion – common sense – was partly to blame initially; the very idea of the Sun being at the centre of the universe just ‘seemed ridiculous’ to most people.  Add to this, the ‘fact’ that the heliocentric model did not stand up to rudimentary scientific analysis and did not appear to reflect reality.  Three very specific criticisms appear to have been levelled: 

1.	The Greeks reasoned that if the Earth moved rapidly through space – they would feel a great continuous wind pressure blowing against them.  The Earth, they concluded must be motionless!   This decision was obviously taken on a windless day!  However, far be it for me to interject.  
2.	The Greeks inability to appreciate the effects of gravity in the sense that – to them – everything naturally moved towards the centre of the universe.  Apples fell from trees – stars were seen to ‘fall’ from the sky – and so – as everything ‘fell to earth’ – then Earth MUST be the centre of the universe.  If the Sun were at the centre of the universe – it was fairly obvious to the ancient Greeks – that everything would ‘fly up’ and off in the direction of the Sun.

3.	The third reason given is more understandable in that a lack of instrumentation or technology rather hindered the Greek ability to identify any shift in the positions of the stars.  The stellar parallax – as it is more familiarly now understood - indeed could not be detected with the naked eye, simply because of the vast distances involved. 
(See: http://onlinedictionary.datasegment.com/word/stellar+parallax)

There were however, five celestial bodies that seemed to defy the observations at point 3 above, and those, as we now know, were the five known planets:  Mercury, Venus, Mars, Jupiter and Saturn.  For those who love trivia, the word ‘planet’, originated from the Greek, planetes, meaning, ‘wanderer’.  Those five non-compliant bodies presented problems that would eventually be overcome by sheer human resourcefulness, or determination to appear correct at any price!  Quite simply, one of the core issues in the heliocentric debate was; if the heavens orbit in circles around the Sun, then it followed there would be an obvious predictability in the patterns produced in the cosmos.  The patterns did not appear to concur with the hypothesis. 

Over the course of several centuries many astronomers and mathematicians contemplated the conundrum!   Slowly but surely, a complex answer began to evolve.  The final solution to the problem became associated with the astronomer, Claudius Ptolemy (AD 90-c. AD 168).  Ptolemy’s, astronomical paper on the intricate movements of the stars and planetary paths, the Almagest, is known as one of the most significant scientific documents in human history.  So powerful was Ptolemy’s argument, it held sway from its origins in Hellenistic Alexandria, into the Byzantine and Islamic cultures and on into Western Europe through the Middle-Ages and early Renaissance up until the time of Copernicus!  

One glance at a model of the Ptolemaic system reveals a system so complex as to be almost unbelievable.  Part of the problem that had to be overcome was caused by Mars and the outer planets, which, to observers on Earth, appeared to move sometimes ahead, at other times stop completely, and yet again at other times, to move backwards.  
That apparent anomaly was simply a result of Earth’s position within the solar system and our respective orbits around the Sun.  However, to make the ‘mathematical facts’ fit the geocentric model; Ptolemy devised a complex, but workable solution, known as the epicycle!                                                              (See: http://www.thefreedictionary.com/epicycle) 

The analogy provided for this model compares to a wild fairground waltzer ride, in which the passenger is locked into a cradle joined to a long arm. Whilst the cradled passenger follows a small ‘circular orbit’ the longer arm at the same time describes its own much larger ‘orbit’.  This complex arrangement complied with the demands created by the Earth-centred model and satisfied both science and religion at that time.

Of course, such blatant manipulation of reality is not the sole province of the ancients; in more modern times, Einstein’s cosmological constant was an equally blatant mathematical mirage designed to suit the ‘required populist truth’.  Luckily for Einstein, he got to make amends for his moment of weakness in his rush to comply with the wishes of the ill-informed majority.

As for the Ptolemaic system, the only tweak required to commit it to the garbage bin of magnificent human mirages was a slight adjustment to orbital physics.  The most basic mistake made in the first place by those who anticipated the heliocentric model, was to base their assumptions on perfect 360° ‘divine circles’.  In doing this, those heavenly bodies that wandered the night skies and should have had predictable orbits, were not where they were supposed to be at the appointed season!  In fact, if the orbits are based upon the true elliptical paths taken by the planets in our solar system, then we know with certainty, that those objects will unfailingly appear at the predicted times.

Refs:
Encyclopedia, W. T. F. (2011, March 1). Almagest. Retrieved April 4, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Almagest.
Encyclopedia, W. T. F. (2011). Aristarchus of samos. Retrieved April 5, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Aristarchus_of_Samos.
Encyclopedia, W. T. F. (2011, March 1). Ptolomy. Retrieved April 4, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Ptolemy.
Singh, S. (2005). Big bang. London: Harper Perennial.
Stamatellos, G. (1997). Philolaus of croton. Retrieved April 5, 2011, from philosophy.gr: http://www.philosophy.gr/presocratics/philolaus.htm.

Debatable – August 2011 – Davy Jones

First, get the facts, then you can distort them at your leisure – Mark Twain 1835-1910

The Great Debate, aka the Shapley-Curtis Debate, took place on the 26th of April, 1920.  It is described by some as ‘much more than a debate – rather the story of humanity’s discovery of the immensity of the universe, whose resolution amazed the world.’ Hosted by the National Academy of Sciences -Washington; the principal arguments centred on the nature of spiral nebulae and the size of the universe.  The rudimentary questions being debated were: are distant nebulae comparatively small, and do they lay within our galaxy - or are they huge, autonomous galaxies in their own right?  

Whilst the matters under debate took place in 1920 – scientific opinions relating to the topics had been around for many years – and would continue to cause dissention for many years hence.
Historically, the nature and background to the debate serves to demonstrate how far our knowledge in this field has progressed in a period of less than a hundred years.  Likewise, retrospectively we begin to appreciate the incredible advances in technology that have occurred. The protagonists, now long dead, were both well-respected astronomers in their own right, exemplifying the standard of those involved in the debate.  Typically, the disputants represented not only the views of their respective scientific factions – but also the divisions between established views and those who disputed the accepted entrenched interpretations.

As a young man, Harlow Shapley had ambitions to be a journalist, but the journalism course was cancelled.  A disappointed Shapley went back to the course list – at the top of the list was a-r-c-h-a-e-o-l-o-g-y which Harlow claimed he could not pronounce.  Over the page was a-s-t-r-o-n-o-m-y, which he could pronounce – and so began a distinguished career.  At the time of the debate, Shapley was about 34 years old; and certainly the less confident of the two men, holding Curtis in some awe.  At about 48 Heber Doust Curtis, was the older of the two, and a long-established, well-respected astronomer.  He is described as having an aura of superiority, and was well-known for speaking with authority and confidence in matters of astronomy.  It is recorded that both Shapley and Curtis actually shared a carriage on the 4000 km train journey from California to the debate venue in Washington.  The atmosphere between the two men remained extremely strained throughout their enforced time together.  By no stretch of the imagination could they have been considered ‘friends’. 

On the night of the debate, each man was given forty minutes to outline his case; a very short time for such a complex subject.  Shapley was the first to speak.  He kept his presentation broad, hoping to appeal to a scientific audience which lacked representation from astronomical fields.  It is worth noting here, at this time, Vesto Slipher (1875-1969), using spectroscopy, had already established the concept of red shift; and that the galaxies were moving rapidly away from each other.  Despite this, Shapley insisted the Milky Way was the whole universe.  Shapley estimated of the size of our galaxy to be ten-times larger than a previous estimate; made at the turn of the century by Jacobus Kapteyn (1851-1922).  Shapley predicted the diameter of the Milky Way to be some 300,000 light years, or 100 kilo-parsecs.  He also positioned the centre of our Galaxy approximately 20 kilo-parsecs from the Sun.  All of these estimates were reportedly made with the aid of Cepheid variables.  Having presented his *metagalaxy concept, Shapley suggested his model obviously precluded spiral galaxies being bodies in their own right.  A second element to Shapley’s argument concerned the 1885 nova in the Andromeda Nebula – however, this proved to be a major fault in his argument.  What Shapley failed to understand was the result of interstellar absorption on the apparent brightness of distant stars. (Terrestrial example: street lights on a foggy night).

Curtis elected to ignore the audience mix, and delivered an astronomically technical presentation.  As indicated, he spoke with great authority and self-confidence.  Heber Curtis firmly believed the Milky Way to be only a small part of a much larger universe.  Unlike Shapley, Curtis estimated the diameter of our galaxy to be 30,000 light years or 10 kilo-parsecs.  He also estimated the Sun to be very near the centre of the Milky Way.  In describing our galaxy, he suggested it might be shaped like a flat lens – like two dinner plates laid face to face.  In regard to spiral nebulae, he claimed them to be ‘island universes’ positioned outside our galaxy.  This idea had also been postulated by Immanuel Kant in the mid-18th century.  The key reason Curtis gave for disputing Shapley’s metagalaxy model was that Cepheid variables were not good distance indicators.  

Anyone with a basic knowledge of astronomy today would quickly realise the debate was not settled decisively by either man.  If anything, the ‘debate’ merely emphasized the lack of substantial evidence for either man’s argument.  Whilst the dispute focussed attention on a question that, at that time, was far from resolved, it also accentuated the dangers of professional arrogance.  Both men had publically presented rival theories concerning matters at the limits of science, each prepared only with the weakest of evidence.

Oddly, each man was accurate on at least one major point, and both were incorrect on a key point.  Shapley was correct, when he stated the Sun was well away from the centre of our Galaxy.  Shapley had also been correct in suggesting the Galaxy was much larger than previous estimates.  As we are now aware, Harlow Shapley was also right about the usefulness of Cepheid variables as distance indicators. 

Heber Curtis was of course right about spiral nebulae being outer galaxies, he had also been correct when discussing the inaccuracies of van Maanen’s measurements of these galaxies.  However – both men were wrong about some things they actually agreed upon – the most obvious being the importance of interstellar absorption of light.  Both men had stated this phenomenon was not important in determining the size of the universe.  Today, we understand this to be an extremely important issue.

Those who attended the May, MAS Forum, may remember the subject: "Slipher, and the discovery of galaxies and the expanding universe”.  Prof. John Peacock (Edinburgh Uni), explained in great detail how it is difficult, with the naked eye, to see anything that is not in our Milky Way.  Proverbially, one cannot see the wood for trees – or in this instance, cosmic dust etc.  This element was one aspect that caused confusion in the Shapley-Curtis Debate; and to some extent was still not fully resolved or understood in 1920.

Discussing the resolution of the Great Debate, Robert Nemiroff et al, specifies how in 1924, Edwin Hubble found Cepheid variables in the nearest major spiral nebula, M31.  This had followed a period where stars in this nebula were being determined.   When challenged with this evidence Shapley immediately acknowledged he was wrong on the spiral nebulae question.  Furthermore, during the 1920s and 1930s, evidence grew that interstellar (light) absorption was a significant issue.  During this period the importance of Cepheid variables for distance authentication was also verified.  

Whilst the Great Debate was neither ‘Great’ nor really ‘a debate’ – it was, nevertheless, an important intellectual event in the development of human understanding of the universe.  No individual person has all the answers.  Disagreement is as important as consensus, and mistakes are a vital part of our learning processes.  Both Shapley and Curtis lived to serve mankind as leaders in the fields of science – astronomy – physics and cosmology.  

Harlow Shapley’s ‘other love’ was Myrmecology – the study of ants – which was his lifetime hobby. He passed away two weeks before his 87th birthday, in 1972.  

After a long, illustrious career, Heber Doust Curtis, astronomer extraordinaire, died in 1942 aged 69.  Their story is yet another chapter in humanity’s on-going unravelling of the wonders of the universe.

Addendum: 
•	In 1920 America’s national debt was $24.3 million – (now $14.5 trillion), and the worlds’ population was two billion.
•	*Metagalaxy: the total system of galaxies and intergalactic space making up the universe
•	*Nebulae - German – nebelflecken
•	'Some piously record "In the beginning God", but I say "In the beginning hydrogen". – Harlow Shapley
Refs:
Gibbs, K. (2010). The Curtis-Shapley Debate - two different views of our universe. Retrieved June 25, 2011, from schoolphysics: http://www.schoolphysics.co.uk/age14-16/Astronomy/text/Curtis_shapley/index.html
Robert J Nemiroff et al. (n.d.). The Shapley - Curtis Debate in 1920 - The Scale of the Universe. Retrieved June 25, 2011, from http://apod.nasa.gov/diamond_jubilee/debate20.html
Singh, S. (2005). Big Bang. London: Harper Perennial.
Wikipedia. (2011, April 28). The Great Debate. Retrieved June 24, 2011, from http://en.wikipedia.org/wiki/The_Great_Debate

The Quest Continues - June 2011 – Davy Jones

Holy Writ was intended to teach men how to go to Heaven, not how the heavens go. Galileo (1564-1642) 

The historical events that guaranteed the demise of the Ptolemaic model are probably familiar to most readers.  Many famous historical names were coupled to that demise – Copernicus – Brahe – Kepler – Galileo Galilei – to mention a few.  Nevertheless, it should be remembered that many others, less well known, also contributed to the scientific progress that took place over this particular period of history.  Such is the nature of human advancement.

Even with the combined proofs provided by the aforementioned notables, culminating with the conclusive evidence offered by Galileo Galilei, the Catholic Church still refused to abandon its policy that the earth was set at the centre of the universe.  

In 1623, history seemed to swing in favour of sanity and science, when Cardinal Maffeo Barberini, was elected to the papal throne as Pope Urban VIII.  The new pope and Galileo were old associates, having attended the same university in Pisa.  This long-time friendship led to Galileo clarifying his theories in, what proved to be, one of the most divisive books ever penned in the history of science: ‘Dialogue Concerning the Two Chief World Systems’.  (Available on the Net in both eBook and PDF)

The Dialogue took ten years to reach the publishing stage, and whilst it had originally won papal endorsement - the intervening years had changed both the political and religious environment.  The consequences of these changes, coupled with mischief created by fellow astronomers aggrieved by his recognition, combined to ensure Galileo’s downfall.  Shortly after the Dialogues’ publication, the Inquisition ordered Galileo to appear before them on a charge of ‘vehement suspicion of heresy’.  This led to his trial in Rome, in April of 1633.   By the end of the trial, Galileo was forced to abandon and deny the truth of his argument; and so one of the darkest chapters in the history of science was brought to an ignominious end.  

Galileo was confined to house arrest – a relatively light sentence given the savage reputation of the Inquisition.  He eventually lost his sight in 1637, possibly as a result of observing the sun through his telescope.  Galileo died on January 8th 1642.  In a final act of bastardry, the Catholic Church refused to allow his burial in consecrated ground.  The Inquisition added the Dialogue to its Index Librorum Prohibitorum (List of banned books); where it stayed until Pope John Paul II issued an apology and finally lifted the proclamation in 1992. 

Humanity scarcely batted an eyelid at the passing of Galileo; however, with advances in technology over the following century, the world slowly came to accept the heliocentric model.  Another consequence of the passing of time is the passing of those with more conformist views; those who had opposed changes to the Ptolemaic system.  With their passing, a gradual realisation permeated the church hierarchy; it realised continued opposition to the new ‘reality’ made it look silly.  The church eased its position towards both astronomy and science; a new period of intellectual freedom was finally under way.

These periods in history – the Enlightenment, followed by the Industrial Revolution – gave rise to meteoric changes in our understanding of the world around us and the world beyond our earthly limits.  Supernatural myths that had held sway for centuries crumbled.  Philosophical mistakes and religious doctrine were replaced with precise, rational, demonstrable, natural explanations.  Science blossomed as discoveries opened our eyes to the true wonders of the natural world that surround us.

In spite of all this frenetic scientific activity, no one seemed keen to address the ultimate question: how had the universe been ‘created’?  The question itself seemed off-limits as scientists restricted themselves to explaining natural phenomena.  The ‘creation’ of the universe was the final bastion of the supernatural.  A bizarre mutual respect developed between science and religion which allowed this position to remain throughout the eighteenth century.

Indeed, such was the strength of this position that serious debate was entered into regarding the actual date ‘God’ might have created the universe.  Mankind, in spite of some amazing scientific advances, seems almost wedded to a need for the supernatural.  
That need for a spiritual element was never more evident than in the quest to confirm a ‘start date’ for the ‘creation’ of the universe.  Scholars sifted through endless lists of biblical quotes and references.  Royalty, church authorities and scientists alike contributed to a growing speculative inventory of possible dates.  Alfonso X of Castile and Leon suggested a very precise, 6904BC, whilst Johannes Kepler favored, 3992BC.  

James Ussher – later the Bishop of Armagh – after an enormous effort finally pronounced the exact date for the ‘creation’:  Saturday, 22nd October, 4004BC – at precisely 6:00pm.

Such was the authority of this pronouncement that in 1701, the Church of England officially recognised Ussher’s assertion.  Thereafter this date was published in the opening margin of the King James Bible all the way through until the twentieth century; even scientists and philosophers accepted Ussher’s dates well into the nineteenth century!  

Naturally, all this tomfoolery with dates couldn’t prevail in the face of mounting evidence to the contrary.  Ussher’s date, whilst happily accepted by religious authorities, only put the earth at some six-thousand years old.  With the publication of Charles Darwin’s - Origin of the Species – promoting an excruciatingly slow system of evolution, requiring millions or billions of years to occur, the inadequacy of Ussher’s date and time became very clear.  Once again, religion and science were heading for a clash – a clash still unresolved to this day in many minds!

By 1897, Lord William Kelvin had developed a technique, which produced a result showing the age of the earth to be at least 20 million years old.  Within a few years, John Joly (1857-1933) took a different idea again, when he suggested that the world’s oceans had started off as pure water.  From that point he attempted to estimate how long the oceans would have taken to reach their current salinity levels.  His results implied an age of approximately 100 million years.  

In the early twentieth century, physicists demonstrated how radioactivity could be employed to date the earth.  By 1907, refinements to this new technique increased the estimated age of the planet to over a billion years.  Clearly, each new development amplified the age of the earth dramatically.  With these rapid changes in the awareness of earth’s age came the obvious association relating to the age of the universe itself.  An ‘obvious conclusion’ began to form amongst scientists – if the earth was over a billion years old, then the universe must be infinitely older!   The general consensus in fact was that the universe might be ‘eternal’.  

The new modern age was dawning – the more questions that were answered produced ever more complex unanswered questions.  Cosmologists developed an array of tests and models which they hoped would provide some of the answers to the growing list of puzzles.  Amongst these questions were – what materials did the universe consist of and how did they behave?  What was gravity, and how did it effect interactions between the stars and planets?  What was ‘space and time’?  Most significantly, answering these elementary questions would only be possible once the speed of light itself had been determined!

Human arrogance is often highlighted by those quick to criticise the human race; some seeing it as a negative aspect of human nature.  On reflection, I suggest, without ‘human arrogance’ – one person would never offer an opinion that he or she thought was ‘better’ than the existing one.  It is arrogance combined with confidence and self-belief that has driven many individuals onward in the face of massive odds; even to the point of giving their lives to prove a point.  Of course, there is a negative aspect – the sort of arrogance which suggests ‘might is right’ - and the more powerful the ally the greater the chance of winning the argument.  What greater ally than a supernatural one that can neither be seen, nor argued with!

Refs:
Koestler, A. (1959). The sleepwalkers. New York: The Macmillan Company.
Singh, S. (2005). Big bang. London: Harper Perennial.
The Free Resource. (2011). Galileo: Fun facts, quotes, and resources. Retrieved May 3, 2011, from TFR Educational Resource Center: http://www.thefreeresource.com/galileo-fun-facts-quotes-biographical-timeline-resources.

Theoretically Speaking – Oct 2011 – Davy Jones

Spiritual prophets allow one to see the light.  Einstein allowed mankind to see beyond the light.

In today’s world, we are used to hearing the term modelling; the modelling indicates this – or the modelling shows that.   The general public feeds hungrily on such trite phrases and pseudo-information, thrown at them by a flood of people using jargon and big words.  Such people sought out by the media and politicians for their opinions, must be, by default, unquestionably regarded as experts. 

On hearing the word – modelling - we routinely think of computer modelling; however, modelling takes many forms.  One may construct a physical scale model, be it landscape or buildings – model the economy, based on spreadsheets and graphs – model fashion – or design an accurate computer simulation; conversely, an attempt can be made to construct a larger predictive model, based on known data and human conjecture.  Without wishing to enter a contentious terrestrial area of debate – the current, so-called, climate science debate, is a most obvious example.  The current computer predictive models being used are constantly updated as additional valid data becomes available; fine-tuning to reflect continually unfolding reality.  This does not render computer modelling useless, quite the contrary; using the latest technology gives modern scientists an edge never before experienced in history.  However, as with all science and things scientific, such modelling must always be open to challenge – rather than be treated as the absolute truth.

Throughout history, one of the more fascinating types of modelling has been, mental modelling, more popularly known as the thought experiment.  Adapted accordingly, thought experiments have served a number of disciplines, most frequently philosophy, science and physics.  Such experiments may be described as being a form of mental exercise, carried out to consider a hypothesis or opinion; the aim in science or physics, being to determine the probable consequences of the theory in question.  No matter how one describes the method there can be no denying its importance in bringing about conceptual change in science.  One of the earliest examples of a thought experiment dates back to Lucretius (99 BC-55 BC).  Attempts were made at that time to demonstrate that space is infinite:  If there was a supposed limit to the universe, a spear could be tossed at it.  If the spear flew through, no such limit existed; if the spear bounced back, there must be something beyond the hypothetical limit of space – a cosmic wall that stopped the spear – a wall that is space itself.  Either way there is no limit to space; thus space is infinite.  The logic is beautiful in its simplicity and, understandably, beyond practical testing.  Nevertheless, the example serves to demonstrate the deductive power that allows the thinker to step outside the ‘square of reality’.

Galileo is recognised as a key character in the progression of thought experimentation into its modern form.  He is responsible for the ‘mathematization’ required in creating an idealised illustration, and then linking that illustration back to the real world.  Whilst this might sound a bit vague – one must consider how all thought experiments – after undergoing the mental processes of the experimenter - are then described to the world at large in a narrative form.  The translation to story form makes the concept under discussion more acceptable and apparent, even to the uninitiated.  For example, consider how Galileo asked that two different sized objects made of the same material, be dropped from a height.  He then supposed the two objects be ‘tied together’ – with a thin, almost immaterial string (notice the intricate detail).  Galileo then indicates the two objects must fall both faster and slower, than as individual objects.  The two should fall faster, he stated, because the body has now become heavier: and should fall slower because the slower object should retard the motion of the faster (or heavier) object.   What Galileo elegantly exposed with his thought experiment were the discrepancies and uncertainties surrounding medieval thinking in regard to the differences in the speed of falling bodies, in relation to their weight.  Incidentally – on July 26th, 1971, astronauts on the Apollo 15 Moon mission carried out this same experiment using a hammer and a feather, on the surface of the Moon. http://www.youtube.com/watch?v=5C5_dOEyAfk
  
In September’s issue, I indicated two examples of thought experiments; these being Schrodinger’s cat and Maxwell’s demon.   These of course are two of the more well-known modern paradoxical examples of such experiments.   Considering these, I began to wonder exactly how such experiments featured in Einstein’s work, and how they so convincingly came together to present such an uncannily correct set of data.  
Allegedly, Einstein’s papers on Special Relativity grew from a thought experiment, performed when he was only sixteen years old.   Autobiographical notes recall how Einstein once daydreamed about chasing a beam of light as it sped through the universe.  He thought that if he were able to fly next to the beam of light, at the speed of light – he should be able to watch the light frozen in space as an ‘electro-magnetic field at rest though spatially oscillating.’  Sic

I find such vivid living detail in a daydream quite revealing in itself.  For Albert Einstein, at least, this thought experiment proved that for his imaginary observer - ‘everything would have to happen according to the same laws as for an observer who, relative to the Earth, was at rest.’

In yet another thought experiment, Einstein asks that we think about a magnet and a conductor in relative motion.  There are two possible methods by which a current might be produced.  First, the magnet is at rest and the conductor is moving; according to electromagnetic theory, the motion of the conductor through the magnetic field produces and electromotive force that creates a current in the conductor.  In the second case – the conductor is at rest and the magnet is moving.   Again, according to the theory, the motion of the magnet creates a changing magnetic field that induces an electric field, which in turn induces a current in the conductor.  However, with respect to the relative motions, it makes no difference whether it is the magnet or the conductor that is to be considered to be in motion.  Whilst it is beyond the scope of this article to go into the detail of such results – suffice to say the results did not correspond to earlier conclusions reached by one James Clerk Maxwell.  Certain elements of Maxwell’s Equations relied upon the concept of the aether and consequently, took the effects of the elusive aether into account on reaching conclusions and developing his famous equations.   In the course of his thought experiments, Einstein rejected the aether as needless and predicted the existence of a fixed speed of light, independent of the speed of the observer. 

History records that Maxwell’s equations were an essential component in the development of Einstein’s paper on Special Relativity.  However, in the opening paragraph of his paper Einstein refers to the thought experiment relating to the magnet and conductor in support of his own hypothesis - as opposed to Maxwell’s conclusions.

One thing seems certain; all thought experiments contain common features.  As noted above, by the time it is related to the community the thought experiment is in a narrative form – no matter how bizarre the situation might be in its presentation!  The assumption is that the experiment could be executed, and the chain of events would take place as in the real world.  Any thought experiment symbolises explicit suggestions concerning the hypothesis under investigation, and exposes contradictions or reveals paradoxes that arise under a variety of applied circumstances.  By the time it is presented to the world at large, the experiment always works and is often more convincing than most real world experiments.  Rarely do we get to see the failed thought experiments – which probably far outnumber successful ones.

 Being in a narrative form, abstractions from real world experiences are possible.  Certain features that would occur naturally can be removed including the colours of surroundings or the physical characteristics of an observer.  The scene is always pre-set according to the needs of the experiment.  There may be a need to include some quite intricate details to reinforce vital aspects of the experiment.  In one version of Einstein’s chest or elevator – experiment, Einstein even depicts the physicist as being drugged and then awakening in the container.  This point underpins the necessity for the observer being rendered unaware of the environment in which the experiment is taking place – thereby maintaining the integrity of the experiment.  
 
Human imaginative prowess has been central to the development of scientific thought.  Without human curiosity and the questions: “What if” or “Why” - we might still be at a very primitive scientific and technological level.  Certainly, in our own time, the formation of such deep abstractions as quantum mechanics would be most unlikely without the primary role played by the thought experiment.  Can computer modelling or simulation replace – the thought experiment?  My feeling is definitely: NO.  Computers are too restrictive, whereas, human imagination knows no bounds.  Nevertheless, I see no reason why one day, computing power will not widen our options in unravelling the mysteries of the universe and further augment the already fertile human imagination.  
Refs:
Brown, J. R. (1996, December 29). Thought Experiments. Retrieved September 4, 2011, from Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/entries/thought-experiment/#ComFeaThoExp
Fowler, M. (2009). Galileo and Einstein. Retrieved June 2, 2011, from Uva Dept of Physics: http://galileoandeinstein.physics.virginia.edu/
Jupiter Publishing. (1997). The Bible According to Einstein . New York: Jupiter Scientific Publishing Company.
Nersessian, N. Why Do Thought Experiments Work. Princetown New Jersey: Princetown University.
Norton, J. D. (2005, February 15). Chasing a beam of light: Einstein's most famous thought experiment. Retrieved September 4, 2011, from John D Norton: http://www.pitt.edu/~jdnorton/Goodies/Chasing_the_light/
Wikipedia. (2011, August 25). Maxwell's equations. Retrieved September 5, 2011, from Wikipedia the Free Encyclopedia: http://en.wikipedia.org/wiki/Maxwell's_equations#A_Dynamical_Theory_of_the_Electromagnetic_Field
Wikipedia. (2011). Thought Experiment. Retrieved September 3, 2011, from Wikipedia the Free Encyclopedia: http://en.wikipedia.org/wiki/Thought_experiment

To Infinity and Beyond – September 2011 – Davy Jones

Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.  
Albert Einstein (1879-1955) 

One could not venture far into the development of scientific thought in the early 20th century without mentioning, possibly one of the best known names in science, Albert Einstein.  In a career spanning over 50 years, he investigated many of the ambiguities of physics.  Above all else, his name will be forever synonymous with: The Theory of Relativity and the formula: E=mc2.   Many regard Einstein as a cerebral demigod; others, rate him high enough to be pasted onto a kitsch T-shirt.

Einstein was a theoretical physicist; an occupation stretching back to Pythagoras of Samos (570-495BC).  As the name implies, those who work in this area indulge more in - what should in theory happen – rather than what happens in reality.  Theorists create hypotheses with the use of mathematical models, formulae and thought experiments (German - gedankenexperiment:  Ancient Greek - deiknymi).  Such theories may not be proved conclusively for many years – if ever.  
*For famous thought experiments see: Schrodinger’s cat – or Maxwell’s demon.   

From our historical vantage point, it is only too easy to picture Mr A Einstein sitting in his patent office, pondering the finer points of relativity.  Then, like Archimedes, he has a light-bulb moment when everything falls into place.  “Heureka”, he shouts!  (German, for that other word)  He then dashes off to write his thesis before he forgets what he was thinking about.

I’m sure you’ll appreciate; it didn’t quite happen that way.  As we have proved convincingly throughout this year, such significant ideas do not ‘just occur’ in isolation.  To understand how the Theory of Relativity got going, it would be necessary to begin perhaps with Aristotle.  If one didn’t wish to delve that far back, then one would at least have to start around the time of Galileo (1564-1642) or Sir Isaac Newton (1642-1727).  
In more modern times, contemporaries of Einstein, Jules Henri Poincaré (1854-1912) and the Dutch physicist, Hendrik Lorentz (1853-1928), were both directly instrumental in the development of today’s Theory of Relativity.  

Whilst researching, I came across one document accusing Einstein of having stolen or plagiarized the idea of relativity from the abovementioned gentlemen.  The author of that document suggested Einstein would go down as the biggest fraud in history!  Nikola Tesla, an amazing character I have written about previously, went as far as to suggest the concept of relativity originated with a countryman of his, one Ruđer Bošković (1711-1787).  Incidentally, Tesla himself did not believe in General Relativity because it meant disposing of the idea of the ‘cosmic ether’.  

It is recorded that although Albert Einstein never directly acknowledged the contributions of either Poincaré or Lorentz, a few years before his death, he commented on Poincaré as being one of the pioneers of relativity, saying: “Lorentz had already recognised that the transformation named after him (Lorentz) is essential for the analysis of Maxwell’s equations, and Poincaré deepened this insight still further…”

The ‘logic’ behind the Theory of Relativity does not immediately fall into place in our terrestrial bound psyche, nor, as one reveals its essence, does it directly make much sense .  Trumpeted as one of the most significant advances of our time, Relativity is so named because time and length are shown not to be absolutes!  The clock on the wall and the tape measure on the desk seem like absolutes!  A minute and a centimetre for you, must be the same as they are for me and the same elsewhere in the universe; but they are not!  According to the theory of relativity, objects travelling (in space) near the speed of light will move slower and shorten in length, from the point of view of an observer on Earth.  For an excellent explanation of this phenomenon I recommend reading ‘the twins’ paradox’:  The Puzzle of the Twins pp. 59-65 – About Time – Davies (1995).  Time dilation, as an observable reality, is clarified by Davies in his usual inimitable style throughout this paperback.   The central point of time dilation, in this sense is: really high speed space travel is also time travel – the space traveller can travel into the future without physically aging at the same rate as an observer on Earth. 
Einstein’s third paper, ‘On the Electrodynamics of Moving bodies’ was published on the 3rd June1905.  It is this paper that deals with space, time and the speed of light.  Einstein’s final paper of 1905 established perhaps the most well-known formula in history: E=mc2.  This theory states that mass and energy is essentially the same thing.  From special relativity, (1905) he explained that as a body neared the speed of light, its mass increased.  As mass increases, the body becomes harder to push and accelerate; resulting in a universal speed limit, the speed of light itself.  Light, then, becomes the fastest speed at which it is possible to travel. 

It took Einstein several years to realise he had made a few oversights, hence the publication of an additional paper: The General Theory of Relativity.  This paper was published in 1916, and dealt with gravity and acceleration – thus completing his earlier propositions.

As expected, initial reactions to Einstein’s proposals were approached with great caution.  Some of the implications were quite astounding; if Einstein was correct then space itself was curved.  In addition, light could be bent by gravity (now known as gravitational lensing), black holes should exist, Cosmic Microwave Background Radiation (CMB) should be detectable and our cosmos would be expanding (as verified by Hubble in 1928).

Einstein’s theories of special and general relativity have, in recent times, been established with a high degree of accuracy.  Many of his calculations have been substantiated with the development of modern technology that allows measurements and experiments, undreamt of in Einstein’s time, to be carried out.  One of the earliest and most famous of these affirmations occurred during the total solar eclipse of 1919 – which proved beyond doubt that as starlight passed the Sun, on its way to Earth, it is deflected (bent) by the Sun’s gravitational pull.  Relativity also predicted the rate at which two neutron stars orbiting one another will move toward each other; when first documented, general relativity proved correct to better than a trillionth of a percent of accuracy.  Einstein no doubt felt some degree of relief at the extent of such accuracy; or perhaps he just whispered: ‘I told you so.’ 

Over the past one hundred years, many books have been written and many discussion papers have explored Einstein’s theories.  Successive experiments have continued to prove and support Einstein’s mathematical hypotheses.  Naturally – science being what it is – Einstein’s work is always open to criticism or challenge.  However, as time passes, proof piles upon proof, providing further support to the multitude of implications thrown up by his work.  The Science News – Nov 10, 2005 – reported how the University of Manchester (UK) discovered a new method to check aspects of the theory of relativity: see - http://www.sciencedaily.com/releases/2005/11/051110090022.htm

Yet again, in May, 2011, NASA Science released results of, what it described as, an Epic Space-Time Experiment: http://science.nasa.gov/science-news/science-at-nasa/2011/04may_epic/

The details outlined in the NASA press release confirmed that: Space-time around Earth appears to be distorted, just as general relativity predicts!  The extraordinary technology developed to gather the required data is mind-boggling.  Four gyroscopes were launched into space to record and measure the twist created by the Earth’s gravitational pull on the fabric of space itself.  The four gyroscopes are the most perfect spheres ever made by humans.  Each measures 3.81cm and never differs from a perfect sphere by more than 40 atomic layers.  The process of Atomic Layer Deposition (ALD) moves into the area of semi-conductors, and is worth reading about, should one feel so moved.  Einstein’s work continues its relevance in revealing the mysteries of the universe.  In so saying, we should never forget the contributions of those not fully acknowledged as we search to infinity and beyond. 

Refs:
All About Science. (2002). Teory of Relativity - A Brief History. Retrieved July 22, 2011, from All About Science: http://www.allaboutscience.org/theory-of-relativity.htm
Davies, P. (1995). About Time. In P. Davies, About Time - Einstein's Unfinished Revolution (pp. 59 - 65). London: Penguin Books.
Davies, P. (2003). The Origin of Life. London: Penguin Books.
fullspate. (unknown). The Theory of Relativity for Dummies. Retrieved August 12, 2011, from fullspate - English with attitude in search of a purpose: http://www.fullspate.net/
NASA. (2011, May 12). NASA Announces Results of Epic Space-Time Experiment. Retrieved August 13, 2011, from NASA Science - Science News: http://science.nasa.gov/science-news/science-at-nasa/2011/04may_epic/
Scanlon, P. (2011). Albert Einstein Facts 87. Retrieved August 13, 2011, from HubPages: http://hubpages.com/hub/Albert-Einstein-Facts
Science Daily. (2005, November 10). Einstein's Relativity Theory Proven with the Lead of a Pencil. Retrieved August 13, 2011, from Science News: http://www.sciencedaily.com/releases/2005/11/051110090022.htm
Singh, S. (2005). Big Bang. London: Harper Perennial.
Wikipedia. (2011, August 11). General Relativity. Retrieved August 13, 2011, from Wikipedia the Free Encyclopedias: http://en.wikipedia.org/wiki/General_relativity
Wikipedia. (2011, August). Henri Poincare. Retrieved August 12, 2011, from Wikipedia the Free Encyclopedia: http://en.wikipedia.org/wiki/Henri_Poincaré#Poincar.C3.A9_and_Einstein
Wikipedia. (2011, August 4). Special Relativity. Retrieved August 13, 2011, from Wikipedia the Free Encyclopedia: http://en.wikipedia.org/wiki/Special_relativity