Wednesday, April 06, 2005

Misunderstanding relativity

The folks who are bringing us Intelligent Design seem also to be targetting Einstein. It is interesting to speculate why. First, let us list the mistakes in Jay Richards' Did Einstein really show that time is an illusion? here:

1. The title is of the nature - Have you stopped beating your wife?

Einstein did not set out to show that time is an illusion nor did he end up doing so. Time remains very real in the theories of Special and General Relativity.

2. The quote from Jim Holt's New Yorker article is badly mangled.

Jim Holt's article is actually not bad for a popular account. What Jay Richards omits between "A century ago, in 1905, Einstein proved that time, as it had been understood by scientist and layman alike, was a fiction." and "If the events in question are at some distance from one another, judgments of simultaneity can be made only by sending light signals back and forth." is a long explanation of why Einstein made the postulate that the speed of the light is the same for all observers, regardless of their motion relative to each other, and the consequences to the clocks, rulers of observers in motion relative each other and to the notion of simultaneity of events that are separated in space. Apparently Jay Richards did not understand the significance of all that, and expostulates "Maybe there is more to Einstein's argument than that".

The one bit of confusion in Holt's presentation is the statement "If the events in question are at some distance from one another, judgments of simultaneity can be made only by sending light signals back and forth." More correct, in my opinion, is to say that any method of judging simultaneity must agree with that made by sending light signals back and forth. If it did not, then we would inevitably find that different observers would find a different speed of light, violating the postulate that Einstein started with.

3. "Right now, my wife is doing something at home. She's doing it right now even though I don't know what it is she's doing."

Yes. No one disputes that, not even Einstein. But an observer moving at a high speed (and high speed means a significant fraction of 186,000 miles per second, i.e., of the speed of light) relative Jay and his wife, will not see as simultaneous events that Jay and his wife consider to be simultaneous. If Jay and his wife are on the phone with each other and hang up simultaneously, such an observer, depending on the specifics of his state of motion, would see one hang up before the other.

4. " It is said that Einstein did away with a Newtonian concept of universal time in his special theory of relativity. (Actually, he purportedly did away with change, but that nuance isn't usually preserved.)"

Einstein did not do away with change, the content of physical theories is typically to describe how things change. As described in point 3., different observers typically disagree on the time order of events that are separated by some distance, and so there is no universal time in that sense.

5. "But Newton quickly reappeared with Einstein's General Theory of Relativity, which is integral to Big Bang cosmology. If Big Bang cosmology is broadly true, then right now, everywhere in the universe, it's the same time since the big bang."

Newton did not reappear in General Relativity. In Big Bang cosmology is turns out that there is a preferred set of reference frames in which the description of the universe is simple and which enables us to define a version of time for which the universe appears to be of the same age in each reference frame. Any observer moving with respect to these reference frames, for instance, someone travelling with a high energy cosmic ray, will have all the paradoxical effects of special relativity that so confounded Jay Richards.


Now the speculation - Intelligent Design (D) is an attempt to make a Designer (of life, or even of the whole universe) scientifically respectable. Though IDers refuse to identify candidates for the Designer, it is obviously intended to be God. Science and religion, specifically Christianity, have been at odds since at least Galileo. It turns out persecuting Galileo was a mistake - the laws of physics are not obviously incompatible with the Will of God and the Plan He has for the Universe. God could be conceived as the clockmaker, who set the whole universe in motion, and lets it continue as per the laws of physics. But Darwinism is incompatible with any humanly comprehensible purpose. The existence of life and of humans, supposedly made in the image of God, are reduced to chance, where is the place for purpose and meaning? So getting rid of Darwinism is an essential to restoring religion. But why go after Einstein's General Relativity?

The reason I can think of is that it is Einstein's General Relativity that makes a science of cosmology possible. It also, but to a lesser extent than Darwinism, makes God redundant to a description of nature. So it too must be taken down.