How is light beng ( space time/ gravity) when light is made of protons and protons dont have mass?

Question

i ve recently heard on the radio about bending gravity and light and stuff about space time, but yet it is not quiet clear to me..
can someone explain
in simple terms
and maybe give me ideas on a book i can buy about this
thank you

Answer 1

You're talking about photons, not protons. Imagine space like the earth's surface: we walk on the earth's surface, photons "walk" on space. Well when we come to a crater, lets say, it affects our path. If we continue putting one foot in front of another (i.e., going "straight") we may end up walking down the side of the crater, and our path would curve because the surface itself is curved. Gravity is like that in space; it bends space, and the light is just following it's normal, straight path, but gravity is a "curved surface," and it follows that.

Answer 2

The maxim that photons have no rest mass is a mathematical ASSUMPTION, that may not be true. Physicists OFTEN make mathematical assumptions to simplify mathematical problems. Most of the time this works. I was taught to do open and closed system physics problems in a 2-dimensional universe, yet that assumption for mathematical simplification does not accurately represent the 3 and 4 dimensions of the reality of space-time. There is a danger in 2-D mathematical models, as I discovered when I was analyzing the flooding of New Orleans from the storm surges of Katrina. Adding the third dimension to my mental models actually simplified my analysis of the physics of the flooding.



"...An upper limit to the photon mass can be inferred through satellite measurements of planetary magnetic fields. The Charge Composition Explorer spacecraft was used to derive an upper limit of 6 × 10-16 eV with high certainty. This was slightly improved in 1998 by Roderic Lakes in a laboratory experiment that looked for anomalous forces on a Cavendish balance. The new limit is 7 × 10-17 eV. Studies of galactic magnetic fields suggest a much better limit of less than 3 × 10-27 eV, but there is some doubt about the validity of this method...."



http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html

Answer 3

Photons are the light particle. It may have no mass, but it physically exists as a ball. Einstein stipulated that objects make an indentation in the space time fabric, the greater the mass, the greater the indentation.

If we lose a dimension, its like standing on a trampoline. If you roll a ball along it, whilst you are standing there, the ball will roll around you like in orbit. Given the enormous speed at which light travels, it doesn't go into orbit, it just gets bent around it.

The larger the object, the greater this indentation, hence more curvature. It is difficult to visualise because we cannot "see" another dimension for indentation.

Answer 4

It's not easy to explain in simple form unless you just accept the outcomes of Einstein's work. He found out the light was "special", being able to travel both as a wave whilst sometimes acting like a proton. He concluded that light is made of "photons" which travel like waves.



These photons (not protons) have no mass. There have been experiments to prove that these photons do exist and that they do work in this way.

Answer 5

It's gravity that bends light, rather than gravity being bent. Light consists of photons (not protons), which have zero rest mass (although they do carry momentum).

These concepts are part of Einstein's Theory of General Relativity, which is not easy to understand without a good background in physics. I've found a book at amazon.com, though, that might be good for the layman:

http://www.amazon.com/General-Relativity-B-Robert-Geroch/dp/0226288641/ref=sr_1_9?ie=UTF8&s=books&qid=1247821634&sr=1-9



Also, the Wikipedia article on General Relativity contains good information that does not require a physics major to understand (some of it, at least!).

http://en.wikipedia.org/wiki/General_relativity

Answer 6

Protons do have mass, as evidenced by the fact that black holes can entrap light, the mass of a proton is just incredibly minute and under normal circumstances, they move at such a speed and are so small that we do not notice how they are affected by other forces.



Light bends on earth due to it slowing down, such as when it passes through water, it is made up of a number of different colours that have slightly different wavelengths, known as "The Spectrum" without going into too much detail on this, the different wavelengths means that when light is slowed, some of them take more time to reach us than others.



So to conclude with your question, it's the fact that protons have a minute, rather than no, mass that they are affected by gravity.

Answer 7

light is made of photons, not protons. protons have mass, photons don't. well, actually, they do, but it's infinitely small. the bending part was already explained. if you still can't get it, go to wikipedia and search for Light. Go to the most relevant hit and enjoy.

Answer 8

What gravity does is bend space itself (relativity thinks of it as bending space, quantum mechanics thinks of it as particles. If you found out how to reconcile those two, you'd win the nobel prize). Light follows this bend.

Answer 9

A black hole has a very very strong gravity force, causing so big curvature in space time that causes the light to bend. Or actually light doesn't bend in relationship to the curves in space time, its space time that curves in relationship to the light.

Answer 10

The mass will increase as the energy of the machine which is 14 TeV. Very high but not infinity.

Answer 11

This is why Brian May decided to join Queen

Answer 12

A few having.For c is maximum.