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À procura das Ondas Gravitacionais, por Helvi Witek

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Hello, everyone. My name is Helvi Witek and I was a PhD student here at the Center for Astrophysics in Lisbon. Part of my work was related to so-called gravitational waves. What are gravitational waves? So, imagine the fabric of spacetime and objects moving in the spacetime. When they move, they distort the fabric of spacetime, and send out ripples, and these ripples are what we call gravitational waves. And if you imagine to have an inspiral merger of black holes, this gravitational waves' signal is very strong. To give you an idea, for a very, very short moment, the strength is larger than the light that you can see from all over our visible universe. So it's something quite hard to imagine. And, nevertheless, the signal that reaches Earth is very, very small. So imagine you have a tunnel which is 1 kilometer long. If you try to measure the difference in length which is smaller than a proton or an electron... so something that is smaller than the elementary particles that make up our matter, and still we try to measure these objects. And there are gravitational waves detectors here on Earth, so if we could hear what they measure, it would only sound like white noise. Imagine you have an old radio and you can't quite find the channel, what you would hear would only be white noise. And in that white noise, we try to find this physical signal that comes from this very violent process. To do that, we try to model these signals theoretically. So we look at Einstein's equations, the equations that describe gravity in our universe, and try to model the motion of black holes. To do that, we need to use supercomputers and do very, very long calculations and then we find the signal. And then, people take these theoretical signals, and compare that to the white noise that they find in the detector. And that's how we try to learn something about our universe.

Video Details

Duration: 2 minutes and 37 seconds
Year: 2013
Country: Portugal
Language: English
Genre: None
Producer: Gravitão
Views: 158
Posted by: gravitao on Feb 23, 2013

Helvi Witek explica o fenómeno das Ondas Gravitacionais

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