Relativity and Biological Clocks

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If speed alters the actual flow of time (SR), then is reasonable to expect a traveling twin to really be younger on return than the stay-at-home twin. And it is reasonable to expect the age difference to correspond ‘exactly’ to the difference in (atomic) clock readings.

But if speed only causes electrons to orbit nuclei more slowly (LR), we should expect the traveling twin to be just as old, biologically, as the stay-at-home.

I see no way for variations in the orbital speed of electrons or other internal atomic processes (photon absorption/emission, radioactivity, etc.) to have an impact on the “ticking” of a biological clock. A sugar molecule with slow electrons in its atoms is still a sugar molecule. It will still “burn” when it contacts an oxygen molecule with slow electrons. AFAIK we have no reason to suspect that such a reaction is a function of the number of times an electron orbits the nucleus. If it were, would the cell ‘notice’ that the reaction took ten nano-seconds instead of one? (I’m guessing about the times, here.)

There are no (known) intra-cellular or inter-cellular processes that depend on the propagation of electromagnetic energy. But if there were, could it matter as far as aging is concerned? Note - it takes milli-seconds for nerve impulses (electro-chemical in nature) to move around our bodies. Most of this time comes from waiting for ions to physically move across gaps. Most of the things that happen in our bodies happen at rates that are limited by molecular diffusion rather than by electromagnetic propagation.

There might be some as yet unknown aspects of biology that do depend on electromagnetism in some way and these could be altered by speed. If there are, it seems unlikely that the overall impact of these changes would mimic what we think of as aging. But they ought to correlate with the change in (atomic) clock reading.

Have you (or any of the readers) heard of any such mechanisms?

Regards,
LB

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>There might be some as yet unknown aspects of biology that do depend on electromagnetism in some way and these could be altered by speed. If there are, it seems unlikely that the overall impact of these changes would mimic what we think of as aging. But they ought to correlate with the change in (atomic) clock reading. Have you (or any of the readers) heard of any such mechanisms?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

You are correct that the equivalence of biological clocks and atomic clocks is assumed rather than demonstrated, and may not be correct. The reasoning goes something like this.

If all motions at the atomic level inside a body ceased, then nothing could change, and the body would remain frozen in stasis. If atomic motions were have their present rates, then biological processes, which are just a complex ensemble of atomic processes, should likewise occur at half their present rates.

One factor this does not take into account is the influence of external entities -- photons, cosmic rays, etc. In fact, the possibility of travel near or above the speed of light has been challenged on the grounds that it would turn every photon into a deadly gamma or cosmic ray and every atom into an A-bomb.

Another loophole is that the speeds of electrodynamic (Coulomb) and gravitational forces are not affected by motion. It is not obvious how important these may be in biological aging.

So when it comes to discussing the physical implications of a switch from SR to LR, you are right that we may not have the biological clock parts right. But at this stage, we are still struggling with getting the physics concepts straight. As a "politics of science" strategy, I feel it may be necessary to minimize the apparent differences between SE and LR until a critical mass of scientists has swallowed this bitter pill. The more "side effects" known in advance, the greater the reluctance to go there at all. As Kuhn pointed out, scientists are invested in maintaining the illusion that all progress is forward. -|Tom|-

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
One factor this does not take into account is the influence of external entities -- photons, cosmic rays, etc. In fact, the possibility of travel near or above the speed of light has been challenged on the grounds that it would turn every photon into a deadly gamma or cosmic ray and every atom into an A-bomb.
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That's a very important issue. We see the full spectrum of cosmic background radiation as essentially isotropic, with a distinctive minimum in the microwave band where the infamous CMB resides. If an observer travels at a considerable speed, then the spectrum appears directionally non-isotropic at all parts of the spectrum except the quantum background limit which is Lorentz-invariant.
Thus, in some very profound sense, the rectilinear motion in this universe is absolute rather than relative.