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Q & A: gravitons

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Most recent answer: 12/18/2009
Q:
Is anything known about the wavelength and energy ranges of gravitons?
- Matt Schur
New York, NY
A:
We think that gravitons can have any wavelength and any energy, just like the particles of light, called photons. Gravitons (gravity waves) would be emitted by accelerating masses, just as photons (electromagnetic waves) are emitted by accelerating electrical charges. The particular wavelengths of electromagnetic waves depend on the source- radio transmitters, lasers, etc. The same would hold for gravity waves- the wavelength depends on how the mass in the source is accelerating around.

Actually, my first statement may not be quite right. There is reason to suspect that gravitons with wavelengths less than about
1/100,000,000,000,000,000,000,000,000,000,000 centimeters might not exist. Since no gravitons have yet been observed, that may not be worth worrying about yet.

Mike W

(published on 10/22/2007)

Follow-Up #1: Does gravity cause light?

Q:
you said gravitons are emmitted by accelerating masses(masses can be electrical charged masses ,i.e. photon too).that means that gravity is a cause of light.so in dark there should be no gravity, but such is not felt. and then where do black holes get gravity from since it is dark. please explain the relationbetween graviton and photon. thanx
- apurva (age 17)
A:
No.   Gravitational and electromagnetic radiation are two different things.  They are not necessarily coupled together.  For example you can have a completely electrical neutral object, for example a rotating dumbbell, that will emit gravity waves but not EM waves. Similarly you can have accelerated charge configurations that will emit EM waves but not gravity waves. Certain configurations of charge and mass can emit both simultaneously, for example, if the ends of the rotating dumbbell were electrically charged.

LeeH

(published on 12/18/2009)

Follow-up on this answer.