Presumed mass content of photon as gravitational source

AI Thread Summary
The discussion centers on the relationship between a photon's frequency and its gravitational influence, questioning whether a photon can be associated with a "mass content" despite the inapplicability of rest mass. It is noted that the effects of a photon near a mass differ from those of a massive object, as the fast motion complicates the application of Newton's laws. However, in a gravitational field like Earth's, photons are suggested to behave similarly to other objects, falling with the same acceleration. An example from Paul Hewitt is referenced, comparing the behavior of a falling ball and a beam of laser light in a reflective environment. The conversation highlights the complexities of integrating photon behavior within gravitational contexts.
DaTario
Messages
1,092
Reaction score
46
Hello,

I have read some of the posts which discuss the meaning and mistakes involving the equation:
## m_0 = \frac{h f }{c^2}.##

My question has to do with gravitation. I would like to know if it is correct to associate to a photon with frequency f, crossing a region near a mass M, a gravitational influence based on the "photon's mass content" above described (even if the concept of rest mass is not applicable).

Best wishes,

DaTario
 
Science news on Phys.org
That doesn't work. The effect is more similar to an object with twice the mass, but you still have non-negligible effects from the fast motion that doesn't allow to apply Newton's formula for example.
 
But near the surface of the earth, for example, being a region where we can approximate de gravitational force on a mass m to mg, and which implies that all bodies will fall with the same acceleration g, the photon will also behave like this, isn´t it?
I recall an interesting exercise proposed by Paul Hewitt in Physics Teacher magazine, in which he asks for a comparison between the fall of a ball and a beam of laser light, both bouncing back and forth in perfectly reflecive walls.
ball and light drop hewitt.jpg
 
Just for the sake of good references, in the previous post (#3) I attached an illustration by Paul Hewitt, relative to the very problem I cited.
 
Thread 'A quartet of epi-illumination methods'
Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So...
I am currently undertaking a research internship where I am modelling the heating of silicon wafers with a 515 nm femtosecond laser. In order to increase the absorption of the laser into the oxide layer on top of the wafer it was suggested we use gold nanoparticles. I was tasked with modelling the optical properties of a 5nm gold nanoparticle, in particular the absorption cross section, using COMSOL Multiphysics. My model seems to be getting correct values for the absorption coefficient and...
Back
Top