Breaking the Universal Speed Limit?

Well, how do you measure the speed of light - and thus check that everything is observing this ‘universal speed limit’? Seven years ago, the closing months of 2011 saw much excitement in sciencey circles with the highly mediatized announcement that researchers at CERN, the world's most expensive physics laboratory, had detected sub-atomic particles apparently travelling faster than the speed of light. This, the papers assured us, was in defiance of Einstein and all the rules of relativity. Yet the plain ‘fact’ of the matter is that the speed of light is not magically ‘out there’ but merely a human convention. In a relativistic universe, how could it be otherwise?

Here the point is put nicely by Burt Jordaan in a blog posting of January 25, 2010. Burt writes:

‘In order to measure any one-way velocity, we essentially need two clocks: one at the start and one at the end. Obviously, the two clocks need to be synchronized and run at the same rate (and to be sure, they must not be moving relative to each other and also be at the same gravitational potential). Yet we reasonably assume that the two clocks run at the same rate, at least close enough for all practical purposes. Now we need to synchronize the two clocks to read the same at the same moment. How is this done?


In his 1905 paper on Special Relativity, Einstein says: “We have not defined a common ‘time’ for A and B, for the latter cannot be defined at all unless we establish by definition that the ‘time’ required by light to travel from A to B equals the ‘time’ it requires to travel from B to A”.

One can reasonably read Einstein's ‘by definition’ as ‘by convention’. 
Using Einstein’s convention to set the distant clock at a known distance, call it ‘D’, in empty space, we send a light signal at (say) time zero and when the distant clock detects the signal, it sets its time to D/c sec (the light travel time), where c is the standard speed of light in vacuum.

Now we can measure the speed of any object moving between the two clocks. We can also use the two clocks to measure the one-way speed of light, but we are obviously guaranteed to always get c. In this sense, we get the speed of any object only relative to c and not absolutely. 
In this way, the one-way speed of light is a convention, depending on the convention for clock synchronization."

Burt concludes by observing that there is a general belief system prevailing in physics that ‘whatever is known exists and rest is non-existent’. It is because of this belief system that scientists tend to fill  these existence-nonexistence gaps by cofficients. Yet there can be much more existent and important entities quite apart from the usual quantitites of space and time which physicist are led to ignore. This attitude is the reason that the existence of Dark Matter was unimaginable for four hundred years. As to the spped of light itslef, Burt says explicitly that he cannot understand why Einstein established a ‘religion of special abilities and qualities’ for light. Specifcally, he objects tha even though there are ways to measure the speed of light, there is no reason to believe that nothing can travel faster.

Our own correspondent, Muneeb Faiq, took up the issue for Pi too. Here he offers a thought experiment which again shows the arbitariness of the ‘speed of light’.

‘In fact, there is a lot of confusion about the harmony between the classical and quantum definitions of speed.If both quantum speed and classical speed mean the same then a very interesting difficulty comes to the front.

Suppose there exists only one body in the universe. Just a single point mass and space. Is it at rest or in motion? If, however, there come out two photons of light moving parallel to each other. What speed are they moving at? If an observor is stationed on the point mass, then both the photons are moving with the velocity of light. Suppose, all of a sudden, the point mass ceases to exist. Now there are two photons moving with same speed parallel to each other. Nothing else exists except space. Are these two photons moving now because they are at same position in relation to each other which will be defined as the state of rest.

It is interesting to note that before the point mass existed, the two photons were moving with the velocity of light. Now since the point mass has ceased to exist but nothing changed about the photons, they are not supposed to be moving now even if they are moving with the same previous speed.’

What Are ‘Facts’?

On the trail of the Higgs Boson

Posted by Keith Tidman

What are 'facts'? The ages-long history of deception and sleights of hand and mind — including propaganda and political and psychological legerdemain — demonstrates just one of the many applications of false facts. But similar presentations of falsities meant to deceive, sow discord, or distract have been even more rife today, via the handiness and global ubiquity of the Internet. An enabler is the too-frequent lack of judicious curation and vetting of facts. And, in the process of democratizing access to facts, self-serving individuals may take advantage of those consumers of information who are ill-equipped or disinclined (unmotivated) to discern whether or not content is true. Spurious facts dot the Internet landscape, steering beliefs, driving confirmation bias, and conjuring tangible outcomes such as voting decisions. Interpretations of facts become all the more confounding in political arenas, where interpretations (the understanding) of facts among differently minded politicians becomes muddled, and ‘what’s actually the case’ remains opaque.

And yet surely it is the total anthology of facts — meaning things (their properties), concepts, and their interrelationships — that composes reality. Facts have multiple dimensions, including what one knows (epistemological aspects), how one semantically describes what’s known (linguistic aspects), and what meaning and purpose one attributes to what’s known (metaphysical aspects).

Facts are known on a sliding scale of certainty. An example that seems compelling to me comes from just a few years ago, when scientists announced that they had confirmed the existence of the Higgs boson, whose field generates mass through its interaction with other particles. The Higgs’s existence had been postulated earlier in mathematical terms, but empirical evidence was tantalizingly sought over a few decades. The ultimate confirmation was given a certainty of ‘five sigma’: that there was less than 1 chance in 3.5 million that what was detected was instead a random fluctuation. Impressive enough from an empirical standpoint to conclude discovery (a fact), yet still short of absolute certainty. With resort to empiricism, there is no case where some measure of doubt (of a counterfactual), no matter how infinitesimally small, is excluded.

Mathematics, meantime, provides an even higher level of certainty (rigor of method and of results) in applying facts to describe reality: Newtonian, Einsteinian, quantum theoretical, and other models of scientific realism. Indeed, mathematics, in its precise syntax, universal vocabulary, and singular purpose, is sometimes referred to as the language of reality. Indeed, as opposed to the world’s many natural languages (whose known shortcomings limit understanding), mathematics is the best, and sometimes the only, language for describing select facts of science (mathematical Platonism) — whereby mathematics is less invented than it is discovered as a special case of realism.

Facts are also contingent. Consider another example from science: Immediately following the singularity of the Big Bang, an inflationary period occurred (lasting a tiny fraction of a second). During that inflationary period, the universe — that is, the edges of space-time (not the things within space-time) — expanded faster than the speed of light, resulting in the first step toward the cosmos’s eventual lumpiness, in the form of galaxies, stars, planets. The laws — that is, the facts — of physics were different during the inflation than what scientists are familiar with today — today’s laws of physics breaking down as one looks back closer and closer to the singularity. In this cosmological paradigm, facts are contingent on the peculiar circumstances of the inflationary epoch. This realization points broadly to something capable of being a fact even if we don’t fully understand it.

The sliding scale of certainty and facts’ contingency apply all the more acutely when venturing into other fields. Specifically, the recording of historical events, personages, and ideas, no matter the scholarly intent, often contain biases — judgments, symbols, interpretations — brought to the page by those historians whose contemporaneous accounts may be tailored to self-serving purposes, tilting facts and analyses. In natural course, follow-on historians inadvertently adopt those original biases while not uncommonly folding in their own. Add to this mix the dynamic, complex, and unpredictable (chaotic) nature of human affairs, and the result is all the more shambolic. The accretion of biases over the decades, centuries, and millennia doesn’t of course change reality as such— what happened historically has an underlying matter-of-factness, even if it lingers between hard and impossible to tease out. But the accretion does distort (and on occasion even falsify) what’s understood.

This latter point suggests that what’s a fact and what’s true might either intersect or diverge; nothing excludes either possibility. That is, facts may be true (describe reality) or false (don’t describe reality), depending on their content. (Fairies don’t exist in physical form — in that sense, are false — but do exist nonetheless, legendarily woven into elaborate cultural lore — and in that sense, are true.) What’s true or false will always necessitate the presence of facts, to aid determinations about truth-values. Whereas facts simply stand out there: entirely indifferent to what’s true or false, or what’s believed or known, or what’s formally proven, or what’s wanted and sought after, or what’s observable. That is, absent litmus tests of verifiability. In this sense, given that facts don’t necessarily have to be about something that exists, ‘facts’ and ‘statements’ serve interchangeably.

Facts’ contingency also hinges in some measured, relativistic way on culture. Not as a universally  normative standard for all facts or for all that’s true, of course, but in ways that matter and give shared purpose to citizens of a particular society. Acknowledged facts as to core values — good versus evil, spirituality, integrity, humanitarianism, honesty, trustworthiness, love, environmental stewardship, fairness, justice, and so forth — often become rooted in society. Accordingly, not everyone’s facts are everyone else’s: facts are shaped and shaded both by society and by the individual. The result is the culture-specific normalising of values — what one ‘ought’ to do, ideally. As such, there is no fact-value dilemma. In this vein, values don’t have to be objective to be factual — foundational beliefs, for example, suffice. Facts related to moral realism, unlike scientific and mathematical realism, have to be invented; they’re not discoverable as already-existing phenomena.

Facts are indispensable to describing reality, in both its idealistic (abstract) and realistic (physical) forms. There is no single, exclusive way to define facts; rationalism, empiricism, and idealism all pertain. Yet subsets of facts, and their multifaceted relationships that intricately bear on each other’s truth or falsity, enable knowledge and meaning (purpose) to emerge — an understanding, however imperfect, of slices of abstract and physical reality that our minds piece together as a mosaic. 

In short, the complete anthology of facts relates to all possible forms of reality, ranging the breadth of possibilities, from figments to suppositions to the verifiable phenomenal world.

Q&A On the Status of the Speed of Light

Pi’s New Year Q&A: Is the One-way Speed of Light a Convention?

Martin Cohen and former Pi contributor, Muneeb Faiq explore one of the claimed certainties of physics.

To introduce the issue, here's blogger Burt Jordaan wondering, way back in January 2010, about why the 'speed of light' suddenly became the one true measure of all things scientific.

Burt writes:

'In order to measure any one-way velocity, we essentially need two clocks: one at the start and one at the end. Obviously, the two clocks need to be synchronized and run at the same rate (and to be sure, they must not be moving relative to each other and also be at the same gravitational potential). Let we reasonably assume that the two clocks run at the same rate, at least close enough for all practical purposes. Now we need to synchronize the two clocks to read the same at the same moment. How is this done?'

Recall that Einstein himself clearly admits, in his 1905 paper on Special Relativity, that: "We have not defined a common 'time' for A and B, for the latter cannot be defined at all unless we establish by definition that the 'time' required by light to travel from A to B equals the 'time' it requires to travel from B to A."

Burt says from this that what Einstein terms as being 'by definition' is equally 'by convention'*. Consider: Is the radius of space's curvature related to the speed of light?

The Q&A


Martin: That's a four-guinea question, innit? I believe conventional accounts make space into 'space-time' and the speed of light is allowed to determine things like that, yes.

Muneeb: I don't understand why Einstein established a religion of special abilities and qualities of light. Though there are ways to measure the speed of light but there is no reason to believe that nothing can travel faster. I think a few thought experiments should be propounded to at least break the myth that light owns special physics and light makes nature asymmetric.

There is a lot of confusion about the harmony between the classical and quantum definitions of speed, for example. If both quantum speed and classical speed mean the same then a very interesting difficulty comes to the front. Suppose there exists only one body in the universe. Just a single 'point-mass' and space. Is it at rest or in motion? If, however, there come out two photons of light moving parallel to each other. Now what speed are they moving at? If an observer is stationed on the point-mass, then both the photons are moving with the velocity of light. Yet, suppose, all of a sudden, the point-mass ceases to exist. Now there are only two photons moving with same speed parallel to each other. After all, nothing else exists except space. Before, when the point-mass existed, the two photons were moving with the velocity of light. After, when it has ceased to exist, they seem to not be moving at all! And yet nothing has changed regarding the photons. I hope I have made my point!

Martin: Yes, I get your point... I've wondered about this sort of thing too!

Isn't the usual idea that the universe started with a single point, 'the singularity', and at this time indeed none of the usual laws applied. Then there seems to be a suggestion that the speed of light may not have become 'defined' in the key moments of the first 'explosions'.

Now what this caused me to puzzle a little about, is that if, in fact, the singularity was one particle - as you say, a photon - and if it travels, by definition, at the speed of light, then surely it can be everywhere at the same instant, because of those peculiar Einsteinian laws. In other words, could it be that the universe consists of just one photon, which is everywhere, creating both space and time?

Bear with me! Suppose this is the universe, then why would it matter what speed the photon travelled at, any more than where it was or when? Nothing would be meant by these comparative terms.
What do you think? Can we put our ramblings into a form that would make a suitable webpage? I'd like to try, PI is a good way to organise and explore ideas.

Muneeb: There is an interesting point to note: what are usual laws? Why are they usual? Are the laws of physics really laws in the first place - because if they would really be laws; then they should never fail to explain behaviour of everything that exists. This difficulty hovered around the intellect of many great physicists - including Einstein - and that is why he spent so many years in search of a unified theory that he hoped would explain everything.

Mathematics, theory and philosophy should go hand-in-hand in order to get a further insight into reality. Otherwise we all have to be convinced (like Stephen Hawkings) that there can never be a grand unified theory. But I am afraid in that case, then we have to be convinced that there are no governing laws at all. All physics will melt away.

Instead, let physicists, philosophers and mathematicians come together and work in harmony in an open-hearted, interdisciplinary manner to understand what none of these disciplines will ever be able to get grasp of independently.

Martin:   Well, y'know, this is certainly a good question, but I'm not sure it is quite as clear a distinction as you imply. For example, we might say it is a law of physics that energy can neither be created nor destroyed, no? Without being obliged to throw that principle away just because (eg) some neutrinos evidently don't want to be part of the present theory about cosmic speed limits?

Muneeb:   Yes. You are right. We, of course, can say it is a law of physics that energy can neither be created nor destroyed without being obliged to throw that principle away just because some neutrinos evidently don't want to be part of the present theory about cosmic speed limits. But what is the applicability percentage of these well established laws? If energy and matter can neither be created nor destroyed, then from where did it blast into existence? Shall we then opt for the principle of first cause where these laws fail altogether? No Newtonian law holds good when we discuss atoms and sub-atomic particles. Einstein himself said that quantum mechanics (which is again a set of laws)is not absolute. Furthermore- quantum and classical worlds are composed of same material and, therefore, some basic underlying principles must be obeyed which we have not yet been able to discover. It is not the question of neutrinos only because most of the universe is composed of dark matter and dark energy which was concealed from over imagination for hundreds of years because of the over emphasis paid by physicists on the laws that are collectively described as quantum and classical mechanics.

The portion of the universes that the currently available laws explain is negligible as compared to the great splendour of dark matter and dark energy that fill the universes (previously we concieved only one universe but now we say universes). There may be some "extra-bright matter" and "extra-bright energy" awaiting our discovery. For that, we again have to wait for the failure of currently known laws of physics and those great mathematical equations that terrify all those who are not physicists and mathematicians. Once we fortunately fail, we will be obliged to look for an explanation for the failure and may consequently theorize existence of very weird materials and phenomena faintly conceivable as of now within the delineated perimeters of quantum and classical conditioning. That is why I emphasize on first understanding what makes the universe (what material and quality of materials and types thereof constitute everything), then we need to classify all that material and non material on some sound basis.

We also have to classify on the basis of discovered and not-discovered. Then we have to understand their behaviour. On the basis of the theory generated; we then can develope mathematics which explains things and helps us to imagine what we cant with the help of mere theory. I hope I don't sound insane!

Martin:   Mmmm, absolutely, I do agree that physics is full of 'black holes' to pun little! But I just want us to avoid addressing ill-founded assertions in conventional science with our own ill-founded assertions. For example, the 'dark matter' mystery - is this not a theoretical construct itself, intended to plug an experimental hole in current theory? You speak of it as a discovered reality, but isn't that to fall into the same way of thinking as the people you are critiquing?

Thinking about the 'problem' of where the energy in the universe came from, isn't it perfectly logical to simply say that there is no 'before' to be dealt with or explained?

Over to you, or anyone reading?

Muneeb: Haha! I am caught in a loop.I am not smart enough for arguments. However, though my writing apparently reveals that dark matter is a reality but I don't mean that. That is why I have guessed the existence of extra-bright matter and energy. What I am doing is to use the discoveries of physics to prove the inconsistencies in physics itself.

I should put a caveat here that I am not anti-science or anti physics. Dark matter was discovered by science to plug the black holes (as you say)and may be some other matter and energy will sooner or later be discovered which disproves everything. Does it mean that we should try to adjust our current theories without revising our basic understanding of the universes. Science has made aeroplanes fly etc. but that does not mean science is correct everywhere. Regarding your question of Un-important "before", please allow me to disagree with you because "before" is of great importance.

First question is; what time-point in the evolution of universes is the beginning? Why is a particular scale of past not a "before" and why all of a sudden we think of something as "before"? Cant it be that this "before" may give us inkling into the evolution of the behaviour of everything that apparently exists. What happened before big bang seems to me as important as what happened afterwards. This is because if we come to know the state, status and behaviour of matter, energy, space, time, void etc.before big bang, we will surely get some idea about how matter, space and time evolves to a better extent than if we stop at big bang. Thanks!