Three scientists, Barry Barish, Kip Thorne, and Rainer Weiss were just awarded the 2017 Nobel Prize for Physic. Physics is the study of things like energy and matter.
What did they win this for? For detecting gravitational waves.
What are gravitational waves? To explain this, I am going to have to tell you about gravity and black holes. Gravity is the force that attracts you to the earth and keeps you here instead of floating about in the air. It is the same force that brings a ball crashing to the earth when you throw it up.
OK so now what is a black hole? You know how there are tons of stars in the sky? Well as a star burns out and dies, it forms a Black Hole. This black hole has gravity so strong that it sucks up everything into it and nothing can escape. Not even light. This black hole then bounces around the universe. When it bumps into another black hole, the collision causes waves of gravity to be sent out in different directions. Kind of like when 2 stones hit the water near each other and the water ripples out. These are gravitational waves. The energy from this collision is extremely intense, but it lessens over distance. Measuring the intensity of the waves can tell us how far away the collision took place and can tell us about the size of the black holes that collided as well.
The three Nobel prize winners from this year built a machine that could ‘hear’ these waves. They came up with the concept about 42 years ago, and it was only recently that it was finally powerful enough to detect these collisions.
When were black hole collisions and gravitational waves first thought about? Albert Einstein had a theory about their existence about 100 years ago, but it remained unproven until very recently.
When were the first black hole collisions ‘heard’? Black hole collisions were first detected in February 2016! But these were from collisions that occurred over 1 billion light years away.
What is a light year? The distance light would travel in space in a year.
How do we know that what was heard were black hole collisions? The machines that have been built at LIGO laboratories (Laser Interferometer Gravitational-Wave Observatory) in America and in Italy, measure and detect light traveling through very long tubes, and bouncing off mirrors in the tubes. So the scientists will shine laser light in the tubes, and if there are no gravitational waves, the light will bounce off mirrors in the tubes and be detected at a certain time. In the presence of gravitational waves, there will be a slight difference in the time that it takes for the light to be recorded. If you were to put a sound to that, it might sound like this:
So why does this matter anyway? Scientists believe that detecting these collisions will give us a timeline on other events occurring in the universe and that we may be able to trace various things like the formation of planets for instance. Perhaps one day we can fully understand how our universe was formed!