Natural Science Forum / Physics / Relativity / May 2006

Also the planes were flying *around* the earth, which required dramatic
"changes" from a linear direction (earth's circumference). Changes from
linear direction while flying at Mach speeds = acceleration &
deceleration which also must have kept affecting the clock's
measurements?

People are weak and fragile.

No.

Since that will not be good enough, I ask a question in response: If
your theory is correct, what happens if I spin a clock in a centrifuge?

Do you feel abnormal pressures while sitting in your chair?

You are zipping around the earth at a rather high speed right now, about 800
mph(depending on your latitude), which is above mach1. The earth is zipping
around the sun at about 24 km/s or 5400 mph.

Does that answer your question?

Sure. Every clock comes with a specification of the environmental
factors for which it remains an accurate clock. Most clocks have
environmental limits on: temperature, pressure, humidity, vibration, and
acceleration. If you attempt to run a clock outside its specified limits
it will no longer be a clock, it will be broken. Whether or not it will
work again when back within specifications depends on the type of damage
it sustained.

The clocks used by Haefle and Keating, and by Alley et al, were able to
sustain the g forces of the airplanes while remaining within their
specifications. The experimenters are not stupid.

The GPS satellite clocks are designed to sustain launch forces without
damage, but I'm pretty sure they do not run during launch. The GPS
designers are not stupid.

A pendulum clock depends on the strength of gravity for its timekeeping
mechanism, and cannot sustain any acceleration without ceasing to be a
clock.

A muon is an elementary particle that decays with a well known decay
constant; their "internal clock" has been measured to be unaffected by
accelerations up to at least 10^18 g (see the reference to Bailey et al
in the FAQ).

Have you never been in a commercial jet? They fly about Mach 0.8, and
passengers and crew can move freely inside once cruising altitude is
reached; during acceleration it is much more difficult (and dangerous).
The jet fighters that can achieve Mach 2 or so are too small for the
pilot to leave her seat, but the same principle would apply. Of course
this only works for an _enclosed_ plane....

Tom Roberts

It simply doesn't matter to obsess about how to measure time in an
airplane. Time dilation can be far more easily deterected and verified
using a paricle accelerator. The lifetimes of particles are very well
known for many different particles. It is "relatively" trivial to
measure their lifetimes at high velocity. Boom - verification of time
dialtion in accordance with SR.

It is telling that all the anti-SR posters avoid explaing two things -
agreement with experiment of time dilation in particle accelerators,
and how the non-constant velocity of light would sabotage causality.

Instead we have allegations that experiment shave undermined SR, and
then we see that these experiments were never published in significant
journals.

All you have to do, with using profanity, is to post the reference for
any peer-reviewed article in a significant journal (Science or Nature)
that describes failure of time dilation or any other prediction of SR.
Should be quite easy.