Is the concept of space(-time) warping correct?

Question

You must excuse my ignorance as I have not the faintest idea of what I am talking about.

I dont want a link to a site that is well over my head either.

If energy and mass are interchangeable in E=MC², and Electromagnetic waves (light) by description have magnetic fields, then isnt gravity another form of electro magnetic field?

OK for example the bending if light around lage structures such as galaxies.

If the galaxy is seen as a macro scale generator, then it will have a huge magnetic field and this may explain the deflection of light.

Sorry if I have fundementally missed the point here, and I understand Einstein and other geeks have probably answered this a million times.

But please put me out of my misery.

Braxton
Thanks I understand what was said, but am confused with the disclaimer.

My question again is why can a large object such as galaxy not act like a generator and produce such high magnetic fields to produce gravitational lensing.


Now the disclaimers back on your original question: If your magnetic field is strong enough over a large enough distance, you can have enough energy stored in it to do gravitational lensing, and then refer to the above answer on gravitational lensing. This however is a very difficult way of getting a strong gravitational field. It is much easier just to collect a galaxy’s worth of matter than to collect the equivalent energy in a magnetic field (neither is particularly easy, I admit!)

Answer 1

Great question!

The path light takes is NOT affected by the presence of a magnetic field. Light itself is composed of an oscillating electric and magnetic field, and one very important property of electric and magnetic fields is what's called "linearity." That is, if you have two sources of electric and/or magnetic fields, you can predict what the combined field is just by adding the two source fields together. The two fields don’t change each other at all. So if you add the field of a light ray to any other field we can imagine, the light ray will continue as before and the extra field will just stay the same, adding to it in places where the extra field is strong, but having no effect beyond the reach of the extra field. So there is no way that a magnetic field can bend light.

Answer 2

Yes, i think i understand your point, and you see: gravity is not an electromagnetic field, it's a property of bodies whose reason of being is still being defined. Here's Hawking speaking. Listen:

"Gravity is by far the weakest of the four forces. However, it makes up for its low strength by having two important properties. The first is that it is universal. That is, it affects every particle in the universe in the same way. All bodies are attracted to each other. None are unaffected or repelled by gravity. The second important property of the gravitational force is that it can operate over long distances. Together, these two properties mean that the gravitational forces between the particles in a large body all add up and can dominate over all other forces.
The second of the four categories into which the forces were divided is the electromagnetic force, which is carried by a particle called the photon. Electromagnetism is a million billion billion billion billion times more powerful than the gravitational force, and like gravity, it can act over great distances. However, unlike gravity, it does not act on all particles in the same way. Some particles are attracted, some are unaffected and some are repelled."

As you see, they're different. Gravity is proportional to the mass of a body, Electromagnetism is proportional to the charge.

Wikipedia says:
"Einstein proposed that spacetime is curved by the presence of matter, and that free-falling objects are following the geodesics of the spacetime. More specifically, Einstein discovered the field equations of general relativity, which relate the presence of matter and the curvature of spacetime."

Answer 3

How long have you got for this one?

Galaxies certainly do have large magnetic fields, but magnetism does not affect light in the way you suggest. The light is bent by the gravity, or more accurately the presence of the mass of the galaxy.

A large mass such as a galaxy has a relativistic effect - what we nominally call it's gravitational field. As you get closer to a large mass, distances get shorter and time slows down.

Now light travels at a constant 300,000,000 metres per second, but as the light gets closer to the galaxy the metre gets shorter and the second gets longer, so effectively the light slows down. When light is slowed down it gets refracted, just like light passing from air into glass it gets bent. Consequently light passing a large mass such as a galaxy is bent towards it.

The 'warp mesh' or 'rubber mat' explanation is a way for us to visualise it, but it should not be taken too literally.

If you are doubtful that mass causes time to slow down, bear in mind that the clocks on satellites have to be set to run slightly slow, as otherwise, being further from the Earth than we are on its surface, they will run fast.

Answer 4

Imagine a net. The net consists of straight strands that cross each other at right angles. A spider crawls along one of the strands in a straight line.

Now place a heavy ball in the net in front but to one side of the spider, not impeding its path. The net sags and you observe the spider crawl down a dip and up a slope along the same strand. As far as the spider is concerned, however, it has just carried on straight along in the same direction.

Space-time is a geodesic net. Light follows the strands in straight lines. If you place a large mass (with large gravity) into the geodesic, the lines warp but the light follows the same strand, appearing to an observer to bend, but actually it's still going straight as far as it's concerned and thus obeying the rule about travelling in a straight line.

Answer 5

No idea
S Hawkings

Answer 6

Relativity is incorrect. The universe is well behaved.

Answer 7

sure why not!