There once was a girl named Bright/ Whose speed was much faster than light./ She set out one day/ In a relative way/And returned on the previous night.
Then I felt a wave of nausea that usually accompanies an intense feeling of cognitive dissonance. My sense of reality became up-ended. "The speed of light not a barrier?" I thought to my self. This cannot be. Certainly someone is mistaken.
The established ultimate boundary of cosmic speed was more than just a fact to me. From as early as I can remember, the exact speed of light (299,792,458 meters/second) was dear. I knew this number better than my girlf friend's telephone number (Yes, I had a girl friend, but she thought I was a geek, too.) Like many other physics students before me, I used to lay awake at night pondering the gedanken of Herr Einstein, wondering just what my experience would be were I to travel through the Minkowski space-time continuum at such breakneck speed. Collapsing light cones! Lorentz time dilation! Mass dilation! Dopplegangar paradoxes! Yes, I've invested emotion into this. As a former physics teacher, I've taught this...nay, I've preached this...with conviction from my pulpit. This was as solid as my grand mother's love or the ground beneath my feet. On June 5, 2000, as I reread the article, I think my universe changed, and dramatically so.
Understand what I'm saying. To say that nothing can go faster than itself is a truism. The proposition is internally self-consistent (like A=A) and requires no emperical evidence to be accepted as true. It is merely an extension of such a general statement to say that light cannot go faster than itself. We are still in the realm of statements that can be accepted without question. While incontrovertible, though, they are not particularly interesting. But to say that nothing can exceed the speed of light is an altogether different kind of statement. We do not say this because we have tested every particle in the universe to see which ones can or cannot exceed the speed of light. Although we have accumulated some body of experimental data and mathematical constructs that strongly imply that to say, "Nothing can exceed the speed of light" is acceptably true, there really is no definite empirical evidence that it is true. But although the evidence is strong, to believe it without a moment's reflection requires either a type of faith or omniscience, of which none of us possess the latter. (For another interesting article on the subject of the speed of light and the possibility that it might not represent the ultimate speed, visit here.)
I'm choosing my words carefully at this point. I did say "faith." Don't fall into the popular misconception that faith is the belief in something without any evidence, a type of prejudice or presupposition. Quite the contrary. For centuries, theologians have used the term "faith" to mean the belief in something that cannot be seen based on the evidence of things that have been experienced, particularly in this context, through past interations with God. But to ease things up a bit, I'll paraphrase the venerable Reverend Bayes, a man of faith (and a Calvinist, too, for those of you "determined" not to listen): knowledge about the state of our environment is subject to uncertainty and ambiguity. Absolute certainty can only be obtained through omniscience.
Please, do not misunderstand what I'm saying. I would not go so far as to say that there is nothing that can be known or that we cannot know anything other than our own existence (a sort of Cartesian naked singularity). I fear such an unresolvable solipsism as much as the next guy. Something about our experience is rooted in some objective reality. Even if we cannot truly see IT, something about IT is being transduced through our senses to our consciousnesses. What I am saying, though, is that knowledge and information, from the raw, pure data we collect by Popperian methods to the natural common sense we regress with our experiences and senses, should be regarded as possessing a degree of ambiguity, uncertainty, and bias (both cognitive and motivational); and we should always (dare I now use such an absolute adverb?) regard it as such. I think not only humility dictates it, but as of June 5, 2000, the Sunday Times seems to dictate it.
This discussion could lead down numerous pathways, and I would love to discuss them all with each of you. The conclusion I want to emphasize is the need to include a healthy understanding of the uncertainty and our biases involved in any major decision situation at hand. In all seriousness, I do not think that the speed of light should be regarded as an uncertainty. In fact, although I may be quite wrong, I feel reasonably sure that the questions regarding the speed of light apply to "special" cases, the effects of which do not dominate in most daily situations. But if something as resolutely established as the inexcessible speed of light can be brought under serious cross examination, imagine the myriad "facts" we think we know by which we guide our decision-making that have never been confirmed by so much as a sigh from Mt. Sinai or even one controlled experiment.