How Does Gravity Affect Light with Zero Mass?

[squareroot]

So, an object can move with c if and only if it has 0 mass.So howcome that light is bended by gravity? How can smth with 0 mass be bend by gravity?


Ty

 

[Banjy]

So, an object can move with c if and only if it has 0 mass.So howcome that light is bended by gravity? How can smth with 0 mass be bend by gravity?


Ty

Well,I think when the 0 mass moves,it's mass is no longer 0 according to the formula E=m*c^2

 

[Bill_K]

Because gravity couples to energy (and momentum, and stress), not mass. A photon has zero mass but nonzero energy.

 

[squareroot]

ty for your answers .I haven't studied relativity in school yet but from what i know gravity is mass times gravitational acc.,but.if u apply that here m is zero so G is zero

Are the formulas from classic mechanics applicable in any relativistic situation?

 

[Mark M]

So, an object can move with c if and only if it has 0 mass.So howcome that light is bended by gravity? How can smth with 0 mass be bend by gravity?Ty

The bending of light around objects with mass, gravitational lensing, occurs because the spacetime around a massive object (such as the sun, a galaxy, etc.), is curved, and distorts the path of the light traveling near that object.

See this image for an example:

http://scienceblogs.com/startswithabang/upload/2010/07/see_a_quasar_gravitationally_l/gravitational-lens-01.jpeg

As Bill K said, it is the momentum of the photons that determines how dramatically they are curved away from their original path.

 

[jtbell]

FAQ: If photons don't have mass, why do their paths "bend" in a gravitational field?

 

[HallsofIvy]

ty for your answers .I haven't studied relativity in school yet but from what i know gravity is mass times gravitational acc.,but.if u apply that here m is zero so G is zero

Are the formulas from classic mechanics applicable in any relativistic situation?

Only as approximations in the "v much less than c" case.