[Enthalpy]

Hello dear friends!

Whether a charged particle radiates when falling in a gravity field has been debated
http://www.scienceforums.net/topic/80770-do-electrons-radiate-from-electostatic-acceleration/page-4#entry861035
https://www.scribd.com/doc/100745033/Dewitt-1964
Whatever the prediction by plain Relativity is, a disagreeing observation would be a precious hint towards a more general theory, possibly a unification of gravitation and electromagnetism.

Here I propose elements for an experiment to check it. "Elements", because the figures I have right now aren't a complete solution - but this can only improve

The radiation, if any, is badly small. A chunk of lead attracting an electron would bring no chance to observe something. My proposal instead is to (try to) observe at an accelerator the synchrotron radiation of ultrarelativistic particles falling in Earth's gravity field.

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Synchrotron radiation provides more light to an observer facing the quick particle's path, because it makes a shorter but much taller pulse that totals more energy. The observer sees first the part of the pulse emitted as the particle's deflection begins, but because the particle nears almost as quickly as the electromagnetic field, the part of the pulse emitted as the particle's deflection ends is seen very shortly after. This near compensation of the travel times occurs only in a narrow cone around the particle's instantaneous direction, narrower or broader than the particle's deflection depending on the conditions.

At least when a magnetic field deflects the particle, a known and verified formula (appendix) gives the emitted power, thanks.

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A particule rushing horizontally through Earth's gravity falls at 1g for the Earth-bound observer. Reasons:

• Its kinetic energy increases the inertia, hence increases the gravity force the particle creates and experiences.
• Our Sun, Galaxy, other stars and galaxies create gravity fields where the Earth, the observer and the particle fall freely. If the particle's behaviour differed from the Earth's and observer's one, we would know from local observations if we're in the gravity field of some astronomical object.

This is precious to make the particle less sensitive to influences other than gravity, for instance the residual geomagnetic field.

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My figures show three big difficulties up to now - hopefully no worse one will appear:

• Radiation by the falling particle is faint, even with the synchrotron amplification.
• Radiation by the particle in magnetic fields is strong. Accelerators' storage rings need dipole magnets, even linear accelerators need quadrupoles.
• The residual magnetic field at the free fall zone must be tiny, since its radiation contribution occurs at the bad location.

The existing accelerators were not designed for this experiment, that's a strong constraint.

I'll expose my answers - or elements as I said, because the initial figures look discouraging  . But that's usual life at accelerators, isn't it?

Marc Schaefer, aka Enthalpy

[Borek]

Sorry, we lack the expertise to discuss these things. Please stick to chemistry.