🚀 go-pugleaf

So, from inside a small room can one tell the difference between the
room being in a gravity field and being linearly accelerated, or what?

No.  And the "look for tides" or "look for mossbauer effect" or whatever
won't help you, since you don't know the mass distribution around your
room in either scenario.  With a suitable surrounding mass distribution,
tides (and other spherical gravity field effects) can be reduced to
arbitrarily small effects in the gravity case.  And even then, "finding
a tidal effect proves you aren't accelerating" is incorrect, since the
"tides" might be provided by cleverly placed auxiliary masses for the
acceleration case.

Further, you can't wait and try to observe special relativistic effects
either as suggested here:

> zdenek@heathcliff.columbia.edu (Zdenek Radouch)
> But I think you'd find out anyway. The human body starts to act really
> funny when it moves at the speed of light. The strongest effects are on
> the digestive tract.

because there are no such "funny effects" on the body.  Physics (and
chemistry, and digestion) are supposedly invariant across reference
frames.  (Zdenek's suggestion is incongruous, especially the reference
to the digestive tract, and may therefore be a joke.  If so, obviously I
didn't get it.)

And, for the same reason, these suggestions won't work either:

> pmk@prometheus.UUCP (Paul M Koloc)
> I think in one case as time went on time dilation would begin
> setting in as well as increasing contraction (spatial) along the
> line of acceleration.

Perhaps so.  But how would one measure it from inside the room?
(Hint: one could not.)

Certainly this attempt fails:

> By
> checking the "frequency" spectroscopy of sharp line emmissions 
> in the "horizontal" plane of the elevator using a grating spectro-
> meter and comparing it with the standard (reference on a known 
> platform), perhaps the time dilation due to increasing velocity 
> would become apparent although the spacing of the grating rulings 
> should not be effected, unless rotated.

because all measuring instruments will be similarly time-and-space
"distorted", so that they will insist that all is as it was at rest.
Even the slight cheat of "looking outside" (by refering to measurements
taken on a "known platform") doesn't help, since (from inside the room)
the room should have all the characteristics of the "known platform" (if
it too was at rest relative to the measuring devices).

The only (ah say ONLY!) way to tell is:

> [...] we could open the door and look out!

--
"Pwease, mistew ewevatow opewatow, I've twied EVEWYTHING...
 I'll give you aww this vawuabwe scientific equipment if you wouwd just
 teww me what's WEAWWY going on!"

"Why SOIT'NY m'boy!  It's REALLY another puzzle in sci.physics!"

"AAAAAAAAUUUUUUUUGGGGGGGGHHHHHHHHH!!!!!!!!"
-- 
Wayne Throop      <the-known-world>!mcnc!rti-sel!dg_rtp!throopw