If photons are massless, how is light affected by the gravitational force of a black hole?

Question

I may just be reading some out-of-date articles, but I'm 15 and I find physics (especially astrophysics and cosmology) the most interesting subject, ever. But I have a few questions... If light can't escape a black hole, surely photons must have mass? Even if it's a tiny tiny tiny tiny mass? Black holes must have an incredibly high escape velocity (if I understand the term correctly). If there is thought to be a black hole in the center of most galaxies, why is there a big light in the middle? Surely there would be a black dot or something? I find the term infinite in physics to be really annoying, I mean nothing can be infinite right? I've read you can't go faster than the speed of light because eventually you would need an infinite amount of energy to do so... but wouldn't you be going at infinite speed? A singularity might be incredibly small (or near infinite, another term which doesn't make sense) but it can't have infinite mass right? If it did, it would suck up the whole universe surely? I'm sorry this is a really unclear question but I have a chemistry teacher at school at the moment (and my physics teacher is a bit rubbish) and I would really love to have a talk with someone who knows all this stuff. But yeah, does light have mass or not? I think this is all about what quantum mechanics states right?

Answer 1

the force of gravity is so strong in a black hole, remember it was a blue giant star(a big star).also photons might have a mass but the odds are its very low but nothing escapes a black hole not even a planet.(if you have any questions ask me on youtube my user name is reychew)



also a black hole is not a time related substance it is a "dead" star.

Answer 2

Photons are not really defined as mass. Basically Photons are mathematical wave construct that indicated how much luminous power falls on a discreet surface.

Masses are subject to a gravity power field. And it is the pressure of gravity that glues masses together.

A black hole by definition is really a conservative system where no mass can escape its event Horizon. Hence light being a micro mass structure is no exception.



One unit of light miro mass moving at the speeed of light would have a discreet energy. in accordance the Henri Poincare Equation = Ed=Md x C^2

Where Md is the discreet mass of light ,C is the average speed of light in local space,and Ed is the discreet Energy of the moving micro mass light particle.



Basically in the Universe there is nothing at rest ;every thing is in continuous motion. Hence there ain't no such thing as a Rest Mass.

So light is also in continuous motion =it never stops.

Einstein use the term rest mass only relativistically in terms of the Principle of Relativity. He did not mean that a mass at rest relatively does not move.



The difficulty with the Einstein interpretation of the Equation E= MC^2 where he equates mass and energy equivalency, is really in defining mass. Basically the fallacy occured about defining how mass increases or decreases. Mass consistst of atomic structure with particular architecture.

Thus Einstein left out Temperature out of the Energy Equation.



The Einstein famous Energy Equation that Einstein used should have been changed as follows;

;

E(t) = M(t) x C^2



Where E(t) is Energy Change as a function of temperature ,and M(t) is mass change as a function of temperature ,And C^2 is the average speed of light square in local space.



The Present Status Quo of Physics no longer uses the term Relativistic Mass increase in the Einstein mass equation of a particle moving at relativistic speeds. The reason is that Physists where not able to reconcile how mass can increase with increased velocity when the laws of thermodynamics indicated the opposite.



About Singularity= The micro mass particle of light was the first singularity created ,as per the Biblical record of Creation.

And as a singularity being the smallest in size , is the densest mass structure in the Physical Universe.

Answer 3

Photons have no mass. Mass warps space-time. Photons follow the curvature of space-time.



Light has mass?

Light particles (Photons) are pure energy and exist only when in motion. We can debate if photons have mass. Because of Einstein's E = Mc^2 matter and energy are 2 forms of the same thing. Since photons have energy it can be argued that they have Relativistic Mass. On the other hand, Einstein was uncomfortable with the concept of Relativistic Mass because:



Many contemporary authors such as Taylor and Wheeler avoid using the concept of relativistic mass altogether:



"The concept of "relativistic mass" is subject to misunderstanding. That's why we don't use it. First, it applies the name mass - belonging to the magnitude of a 4-vector - to a very different concept, the time component of a 4-vector. Second, it makes increase of energy of an object with velocity or momentum appear to be connected with some change in internal structure of the object. In reality, the increase of energy with velocity originates not in the object but in the geometric properties of spacetime itself.



http://en.wikipedia.org/wiki/Mass_in_spe…



http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

Scroll Down to “Relativistic Mass”

In any case, photons have zero Rest Mass.

When we get into Relativity, “mass” has 2 different meanings. There is “Rest Mass” and “Relativistic Mass” and they are NOT the same thing.

Answer 4

All particles in the universe either contain mass or are of negative mass, some refer to it as being "massless". Think of the particles on an integer scale from negative mass to positive mass. Gravity affects all particles,at least, within three dimensional space. Gravity even affect particles, like photons, with negative mass. If enough particles with negative mass combine they accumulate mass.



The light in the middle of galaxies is either the incredibly dense population of stars, just beyond the strong influence of the event horizon of the black hole or it is from the quasar produced by the event horizon when too much energy is forced toward the mouth of the black hole.



Few things are infinite, like energy and time, but the universe is not one of them. The universe is finite though incredibly vast to us puny humans.



Physical things, that is matter, cannot go as fast as light.



There is no such thing as infinite mass. Possibly incalculable mass but not infinite.



I can only share the truth about these things but not everything you are going to be taught in science class is truth. Some of it is dogma and unproven theory. It may be best, in order for you to pass the class, to understand it as it is taught to you in class from the text books and your teacher. You can also, like you are attempting to do here, communicate with someone who can explain it as you are taught in class, except more clearly than your teacher.

Answer 5

Who says light doesn't have mass.



E = mc^2 so if they have energy they have mass

P = hc/lambda

No mass = no momentum so this would contradict this formula too.



In physics we use models to describe the behaviour of things.

Whether you treat the acceleration of a particle via the classical mechanics model ( light has mass and is attracted by gravity) or via the general relativity model ( space time is warped) you get exactly the same result.



So which is right? They both are ( sort of)



Now the question "does light have mass?"

It acts as if it has mass in many situations hence the duality of light. The mass can be calculated and the gravitational effects on light are similar to the effects on a particle of that mass at that speed.



But light isn't a particle like any other you know either. It has no REST MASS. the mass is only the result of its energy ( and momentum)