# Einstein's gravitational waves.

Hi everyone!

As many of you may have heard, It was recently proved that Einstein was right about Gravitational waves. What are these waves?

Well, for starters, it was 100 years ago that Einstein predicted the presence of gravitational waves, as a part of his theory of relativity.

The idea was that the waves are like ripples in space, caused by some of the violent and energetic processes in the Universe. For example, two black holes crashing into each other.

Imagine throwing a rock into a pond. When the rock hits the flat surface of the water, it creates ripples or waves. Spacetime is like the surface of the water. So that means gravitational waves are like the ripples moving out from where the rock hits the water.

For years, scientists were closely watching the movement of two black holes in a galaxy far off. When they finally crashed into each other, after spiraling due to loss in energy due to gravitational waves , it was with such power and force, that gravitational waves rang throughout the universe, like a giant bell. A power lager than 50 times the power of all Stars in the universe combined

Travelling at the speed of light, The gravitational waves reached Earth after 1.3 BILLION years later. (Imagine that for a distance.)

As quoted by scientist Abhay Ashtekar "Our understanding of the heavens changed dramatically "

Gravitational waves are certainly a breakthrough discovery in Spacetime.

Note by Mehul Arora
4 years, 9 months ago

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You might enjoy this wiki: gravitational waves.

Also see: spacetime and black holes.

Staff - 4 years, 9 months ago

Thanks! @Eli Ross. The wikis are brilliant!

I'm so sorry I just saw your comment :(

- 4 years, 9 months ago

Yeah I checked it,but as they say the gravitational waves stretches one arm and shrinks(space ripple) other will there be a similar effect in time(time ripples)?

- 4 years, 9 months ago

Actually this fabric stuff is just the visualization of spacetime ripples. It's originally 4 dimensional!

- 4 years, 9 months ago

What exactly spacetime rippeles cause and how it is detected?

- 4 years, 9 months ago

Spacetime ripples can practically be imagined as a high amount of energy.

Imagine spacetime as a pond. When you throw a stone, Ripples are created, right? So, same with Spacetime. When A powerful activity like the intermixing of two black holes takes place, Ripples are caused.

As far as their detection is concerned, they were detected using a machine called LIGO, you can search it up. It was specifically created for the detection of these waves.

- 4 years, 9 months ago

Its basically a wave like solution of Einstein Field Equations where the solution, the metric tensor $g_{\mu\nu}$, has a wave like structure.

- 4 years, 9 months ago

Nice note @Mehul Arora. If you're interested, you should also check out the actual apparatus that they had used to detect the presence of G-waves! It was kinda cool!!! :P

- 4 years, 9 months ago

Well yes I did! The LIGO right? It was pretty cool!

- 4 years, 9 months ago

Does these ripples will easy to find in space?

- 4 years, 9 months ago

It took more than 50 years to detect these ripples. They are not easy to detect. But they are present everywhere, in fact we are living in a sea of Gravitational waves but the effect is negligibly small. Detecting them is just telling us that we have obtained such a good technology. And this is not the end in fact it just opens a new kind of window for us to look into the universe in a completely different way.

- 4 years, 9 months ago

We can say space as a rubber ball which when applied force gets deformed

- 4 years, 9 months ago

Umm yes, that is one way of perceiving it.

Although, we can't really imagine everything related to spacetime on a ball, because it is not for certain that the "shape" of spacetime is that.

Although, when we think of the ripples created, i think a rubber ball is an apt example.

- 4 years, 9 months ago

Okok one doubt if we travell faster thn speed of light thn will we be in future

- 4 years, 9 months ago

Wait.. U are saying the waves reached 1.3 billion yrs later?? U also said that scientists were watching this when this happened?? U mean scientists were watching this activity 1.3B yrs before even when human kind didn't exist?? No offence, but i think ur calculation is wrong somewhere..

- 4 years, 9 months ago

@Arun Krishna: Actually, yes. You see, although light travels at great speeds, but still, the universe is expanding, and as long as our speed of expansion is less than that of the speed of light, that light WILL reach us. I know, it is a bit difficult to grasp that we are seeing something that is not currently happening now, but to make it clearer...take the example of our Sun.

We all know that the light from our Sun takes about 8 minutes to reach us. This means that the light i receive right now, is the one that left 8 minutes ago. So, technically, I'm looking at our Sun, the way it was 8 minutes ago, and not right now. No matter how fast light is, it has to traverse some distance which causes a time lag. If you wnna read about more complex examples, google Cosmic Microwave Background up, and you'd be surprised! :)

- 4 years, 9 months ago

Look, 1) I did not calculate this :P

Also, it was 1.3 billion years earlier that the two black holes combined.

Only 50 years earlier was that scientists started looking for these waves.

There wee some activities as such, ,which helped the scientists to trace the black holes back to 1.3 billion years ago.

- 4 years, 9 months ago