Radiation of an accelerated elektron

**Clinton C Zimmerman** · #11 September 10th 03 posted to sci.physics.relativity

Igor wrote in message . ..
On 5 Sep 2003 19:36:47 -0700, (Bastian) wrote:

My Professor used to ask this question in oral exams: What happens if
an elektron falls off from a table? Usual answer: The elektron is an
accelerated charge and so it radiates elektromagnetic waves.
I argued that an elektron would not radiate when accelerated by an
gravitational field. The picture that guides me is the following: An
elektron usually radiates because some elektromagnetic force from
outside couples to the charge of an elektron but not to the
elektromagnetic field generated by that elektron. The field tries to
follow the charge and in order to do that it radiates. An infinite
homogeneous gravitational field would accelerate the free falling
elektron in the same way as it would accelerate the elektromagnetic
field of the charge because gravitation does not couple to charge but
energy (field- and massenergy), so an free falling elektron in an
infinite homogenous gravitational field would not radiate.

Another argument is, if an elektron which is accelerated by such a
field would radiate for an observer on earth (let the grav. field of
the earth be an infinite homogenous field in good approximation) then
it would loose some Energy and the observed acceleration would be
less. For a free falling observer the electron would not radiate
(Imagine the observer and the elektron are locked in some dark box -
then there is now way to detect the gravitational field). Then we
arrive at the following paradox. The elektron would radiate in a way
that the free falling observer could not see the radiation, but the
observer on earth would see it (difficult to imagine if the two
observers have the same time and space coordinates) and for the
observer on earth the elektron falls slower then the free falling
observer on the other hand for the free falling observer the position
realtiv to the elektron would not change.
So I am quite sure, that an accelerated elektron in a field discribed
above would not radiate.
Whats your opinion about this

No, it would not radiate. Since it's a point particle falling in a
gravitational field, it is travelling on a geodesic in GR. This puts
its situation on par with the same electron traveling at a constant
speed in a straight line, and it certainly would not radiate in that
case.

By the way, how is the uncertainty principle handled when trying to
determine if an individual electron radiates to an observer at rest,
since there would be no way to determine that the electron is at rest
with respect to an observer without measuring it and the measurement
would seem to disturb the state of
rest it was already in.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Radiation reaction for a uniformly accelerated charge	spardr@netscape.net	Current Physics Research (Moderated)	2	February 24th 06 01:35 AM
Radiation reaction for a uniformly accelerated charge	Ken S. Tucker	Physics - General Discussion	0	February 21st 06 10:51 PM
Accelerated Cosmic Expansion	Steve McGrew	Current Physics Research (Moderated)	1	October 29th 03 07:58 PM
Myth or Science? (Accelerated SR)	greywolf42	Physics - General Discussion	1	August 24th 03 11:11 PM
Cherenkov radiation inside an atom Synchrotron Radiation intrinsic	Archimedes Plutonium	Physics - General Discussion	8	July 28th 03 07:16 AM