Time warp in black holes

How do black holes distort space-time?

From the coining of its term by John Wheeler, the term black hole has come of great significance to physicists, cosmologists and sci-fi geeks. Of course, it's only natural if it didn't make scientists go nuts. Sure, we all know what the term black hole includes: sucking in of matter, huge bursts of cosmic radiation, time warping and as a consequence, human spaghettification and a lot more!! But the real theories behind these bizarre phenomena is actually not that complicated. It's all just a little bit of Einstein and a whole lot of imagination with examples from our surroundings. In this context, the cause and effect of time warping in space, specifically black holes will be discussed.

Role of gravity in a time warp and space distortion

We all consider gravity as a force just like electromagnetic force or nuclear force. But what we're missing is that gravity isn't merely a force, it causes space-time curvature. Now, to make this point more clear, consider a fabric cloth stretched out and fixed, just like a trampoline. Imagine a heavy stone placed on the surface of the stretched fabric. It's logical that the weight of the stone on the sheet will literally create a curve (or hole) and will make the stretched plane sheet uneven. The more massive the stone is, the deeper will be the hole and thus, the lack of uniformity across the sheet increases.

 

This is the exact same phenomenon that occurs in black holes. The stretched fabric sheet representing space-time and the stone on its surface being any heavenly body like a planet or a star or a black hole. Since the objects are massive, their mass tends to distort or curve the space-time (being the sheet). 

Now again imagine that there's a weightless ball placed near to the stone on the curved sheet. We observe that as the ball approaches the stone, due to curved sheet, it starts to move in a circular motion (orbit) and the closer it gets to the stone, the faster it moves in the circular path, and will eventually fall towards the massive stone (centre).

In the case of black holes, the curve or distortion made by them is awfully large due to their infinite mass. A black hole is actually a region where all of the matter of a supergiant star, is clamped or squeezed up into a single-dimensional point called a singularity. This point is astonishingly small, so small that its diameter is about 10^-3 cm, which is a hundred hundred billion times smaller than the size of an atom. We can only imagine the density of this point and the infinite amount of space-time curvature it creates. The distortion turns out to be a funnel-shaped curvature, which looks like a hole filled with void.

As we go further into a black hole, space-time will occur to be more and more distorted, whose consequence is known as time-dilation, where time is completely curved or distorted that time itself slows down. 

So, if an object falls into a black hole, the object will simply appear as slow-motion or completely frozen for a viewer far away.

Both of the above occurrences were actually predictions of Einstein's General Theory of Relativity in 1915. 

This spectacle occurs for our very own sun, whose mass creates a distorted space-time curvature and causes the planets to orbit in elliptical paths, to avoid collapsing (falling) themselves into the sun. The moon orbits the earth due to the space-time curvature created by the earth's mass.

In the great physicist, Kip Thorne's words, " Matter directs gravity on how to behave, gravity directs matter on how to move ".