Tải về "What Are Gamma Ray Bursts?"

The life of the Universe is characterized by the presence of many extraordinary events, some of them involving huge amounts of energy. But have you ever wondered what is the most powerful type of event in the Universe? And did you know that it is something so powerful that could potentially even cause life extinction on Earth? Curious to know what is it? Stick with me and I will tell you in a few moments ------------------------------------------------------------------------------------------- Subscribe for more videos:https://www.youtube.com/c/InsaneCuriosity?sub_confirmation=1? Business Enquiries: [email protected] ------------------------------------------------------------------------------------------- In the Universe, extremely powerful events happen all the time. Think, for example, to a supernova. A supernova is an immense exp*osion that occurs when a massive star “runs out of fuel”: the star collapses on itself, producing a huge ex*losion. These events are so energetic that a supernova occurring in our galaxy would be visible during daylight in our sky! The amount of energy produced by a supernova in a few seconds is more than the energy emitted by the Sun during its whole life: that’s impressive! However, supernovas are not even the most powerful events in the Universe: in this special ranking, the honour belongs to another type of event, called “gamma ray burst” (or GRB for friends). But, what are they? GRB are brief bursts of gamma rays. Gamma rays are the most energetic form of electromagnetic radiation. What does it mean? There are different types of electromagnetic waves. In fact, they are classified into seven categories, depending on their frequency: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. You should be familiar with some of them: microwaves, for example, are used to cook food, radio waves are used for telecommunications, while X-rays are used for medical imaging. These seven types of radiation are ranked from lowest to highest frequency: lower frequency means lower energy, while higher frequency means higher energy. This also means that radio waves are the electromagnetic waves with lowest energy, while gamma rays are the most energetic ones. In fact, gamma rays are very dangerous to humans. They are, for instance, emitted by some radioactive sources, and they can penetrate through the human body, causing damage to tissues and organs; they can even cause DNA mutations with long-term effects, such as increasing the risk of cancer. So, gamma ray bursts are intense, short-lived bursts of extremely energetic gamma rays. But how are they produced? It depends. In fact, they are classified into two types, depending on their duration: short GRBs and long GRBs. Short gamma ray bursts have a duration of less than 2 seconds, and they can even last a few milliseconds only. Although scientists are not exactly sure about their origin, they think that short gamma ray bursts are produced during events known as “neutron star merger”, in which two neutron stars collide producing a more massive one or a black hole. When these huge cosmic collisions occur, a lot of energy (in the form of gamma rays) is released, producing a gamma ray burst. It is believed that short gamma ray bursts are also produced when a neutron star merges with a black hole. On the other hand, long gamma ray bursts are those lasting more than 2 seconds. Some can even last a few minutes. These represent the majority of GRB events, and they are usually produced during a supernova explos*on: in the collapse of the star, a lot of energy is released, producing a GRB. But how were they first discovered? Well, this is interesting: in fact, they were discovered… by accident! In the 1960s, during the Cold War, the United States sent a group of satellites, the Vela satellites, into space. These satellites were equipped with gamma-ray detectors, and their main purpose was to detect possible nuclear explosi*ns (on Earth or in space), which would have been a sign of military activity on behalf of the Soviet Union. ------------------------------------------------------------------------------------------- "If You happen to see any content that is yours, and we didn't give credit in the right manner please let us know at: [email protected] and we will correct it immediately" "Some of our visual content is under a Attribution-ShareAlike license. (https://creativecommons.org/licenses/) in it’s different versions such as 1.0, 2.0, 3,0 and 4.0 – permitting comercial sharing with attribution given in each picture accordingly in the video." Credits: Ron Miller Credits: Nasa/Shutterstock/Storyblocks/Elon Musk/SpaceX/Esa Credits: Flickr