Arjun Artro

I've been thinking about gravity and its curving effect on spacetime. It seems very strange to me that a massive object can warp space and time around it. I have a few questions: 1. Would a magnetic field as strong as the gravity around a black hole bend the spacetime around it? If so, it's the bending effect same as that of gravity? 2. If gravity is a curvature in spacetime, and not a force, why doesn't the centre of an object experience the same curvature? (for eg, Fg=0 at the centre of the earth)as I thought it is because the forces cancel out each other at the centre.

Thank you for the information.

We know that light slows down inside a dense medium like glass, water, etc. But the moment the light beam gets out of the dense medium to vacuum, it regains the original speed c instantaneously. I know that waves doesn't require acceleration to travel in a particular speed but as light also behaves in particle nature ,shouldn't it obey the laws of particles too ?

That's all what I am saying here. It exists only in math. And objects like tesseract or 4d hypercube can only be modelled with certain assumptions and I don't we cannot visualize it because we live in a 3d world but because such objects only exist in math.

Okay that's for locating an object. And I agree that dimensions are needed for that just like the latitude and longitude of the earth. But we never use the terms like "a latitude object" , a "longitude object" like we call 2d object, 3d object etc. I might be wrong, but imagine this- suppose there is another world which is 2 dimensional. And the projection of a 2d surface is a "line" right? Suppose there are two lines - red and blue. How would you know that one is red and the other is blue if those lines only have length and no width (even if it is negligible, width cannot be equal to zero) . Am I right?

I wanted to learn about 4d space and got curious why I cannot visualize it so I searched in the internet for some answers. I am not satisfied by how it is explained, especially the flatlander's theory. First of all, how can a 1d or 2d object exist? Lets take 1d for an example. Its called 1d because it only has length and no width. How can you see a line that has no width, even the slightest width and the slightest height? Okay, 3 dimensions might be needed to do the math but in reality , are dimensions real? And our theory about 4d, 9d and 25d might be just helping quantum physics and string theories but I dont think it's actually there.

Okay let's assume that space is expanding when gravity is not strong enough to pull objects together. But why does gravity lose its grip with time? It's been billions of years since big bang and there's no other force that push objects away . So there must be some sort of energy that overpowers gravity.

Google it.. This is a discussion forum. Or this may help- http://en.wikipedia.org/wiki/Black_hole

still no scientific base? How does things align so quickly to perfect these dreams ? If dreams are stories made up by mind from bits of what we've seen at some point of life, how do we remember those dreams the next morning or so?

Lucid dreaming is a technique by which we can control our dreams with practise and certain sound waves. I've tried it and have once succeeded in doing it. I've read that dreams just last for about 2 seconds and that it is made up by our sub conscious. If so, how can these people or even myself control these scenes and stuff that show up just for a couple of seconds? What is the science behind this? And does dreams have solid scientific base? Does anyone have a clear idea about this?

"Nothing" in his statement means absolute nothing. Not even space. Space and time makes something. And we can't find anything that hasn't been recorded in space or time or both.

does that mean when the speed of bullet is .9c+v, speed of the light emitted from flashlight is c+c=c?

Why is it still c?

Imagine a spaceship traveling at 99% speed of light. Inside the capsule there is a gun. when it fires, space time will be warped so that the time around the bullet is reduced to such an extent that it doesn't break the speed limit. But what if instead of a gun, a flashlight was lit? Would it emit light like usual?