Bending space and time?

Question

Einstein was brilliant, but common sense really says that you can't bend what doesn't exist, meaning that space is empty. Empty includes the lack of gases. Go into space, take a hydraulic press, and try to bend space. Pretty hard, eh?. One point I do follow though, an object with incredible mass can bend light. I am still slightly confused on many of these concepts, and please be conciderate, but I would like some help understanding these theories. Thanks!

Answer 1

Another way to think about how supermassive objects are able to "bend" the path of light is to consider the equation: E = MC^2. I'm sure you have seen this before. What this translates to is 'Energy equals Mass (or "M") times the speed of light ("C" which is also 300000 KM per second) squared. The main point in this is that Energy and mass are directly related, which explains why gravity, an attraction between an object with mass and any other massive objects, can have an effect on a "massless" object such as light.

Simply stated, the energy in light has an equivalent mass, per se, that allows for this attraction to take place and effectively bend the light.

As for your other questions, I would recommend reading a few books that explain this manner in not so complicating terms. It can be overwhelming to open a graduate level Astrophysics book and see nothing except strange symbols and greek letters. So look around in your local bookstore, they will have them. Try to find a book that explains more of the concepts if you cannot follow the math.

Good Luck!

Answer 2

Hi iracoon - I think that your analogy to the application of electricity is interesting but not necessarily accurate. It is certainly true that anyone from the Middle Ages would consider large portions of modern life to be indistinguishable from magic. However, to impose the restriction that the discovery that we will make in the field of interstellar travel will involve the bending of space is speculative and based on your desire for what we should find - not on what we will find. Folks from those times did not understand the limits of physics and work to get around them; they didn't understand that there were any limits in the first place. We do understand that today. There are some pretty tough challenges in terms of the way the universe works that tend to prevent things like interstellar travel, except in extreme cases (like spending a lifetime imprisoned in a starship with no hope for a return home and no promise of anyplace to land when you get there). Bending space and time (or spacetime, which probably makes more sense) is not even on the radar, much less a technical goal that is within reach. Even if we could do it, I'm not sure that we would want to. Consider what it could do to the solar system... Your questions are good ones, but are perhaps based more on your hopes than on your grasp of the difficulties involved. Keep working and prove me wrong! Please!

Answer 3

Space and time are dimensions according to Einstein. Mass creates a distortion in space-time (which we call gravity) which bends light. Actually, the light moves in a straight line, but due to the mass (gravitational) distortion, a straight line through this space isn't "straight".These theories are really too complex to completely understand without a great deal of study. They do not conform to common sense. Very few people completely understand general relativity.

Answer 4

Just because space is empty doesn't mean it doesn't exist. In this case, empty is relative. (Pardon the pun.) While very thin, there is matter in space. Dust particles, gas molecules, the occasional stray astronomical body, etc. But that doesn't matter, (not another pun!) space would exist even if it were truly empty. There would still be length, width and depth.

Answer 5

Space is not empty nothingness. "Space" is actually a substance rather like plasma, subject to certain fluid dynamics. Hence, space can exhibit "wave" characteristics. Observe the effects of space-plasma on a galaxy or solar system or a comet moving through space...the front edge is rounded, and the back part forms a "tail", indicating space presents a certain resistance. So, space is a substance, not emptiness.

Answer 6

though space is absent of molecules there is something underneath. If not, how can the gravity of the earth travel to the moon?

even though it influences atoms, it does not travel through them, so it probably travels through another dimension

to completely understand this we must first discover the gravity wave and thus discover the medium it travels through.

to bend space we need something that exists both in our dimension and gravity's and that is going to be extremely difficult, and certainly wont even be understood until the new particle accelerator is up and running.

Answer 7

It's pretty obvious you're confused. Go take a course in general relativity to straighten things out - but you'll need about 6 years of college physics first. Good luck with that.

Common sense doesn't get you too far in physics - math does.

Answer 8

Go read a physics book and forget common sense...
just because YOU can't perceive something -either because you lack the physical senses or the wit, does Not mean they dont exist...