Edo Berger: Gamma-Ray Bursts: The Biggest Explosions Since the Big Bang
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- Опубликовано: 12 сен 2024
- Representing nature's biggest explosions since the Big Bang itself, gamma-ray bursts were first accidentally spotted in the 1960s by Department of Defense satellites hunting for terrestrial nuclear blasts. In this talk Prof. Berger describes the ensuing decades-long quest to decipher the origin and energy source of these mysterious explosions. He explains how gamma-ray bursts are now used to probe the first generation of stars and galaxies formed less than a billion years after the Big Bang.
Excellent lecture! I've watched it a few times. GRBs still fascinate me. I appreciate his dry humor. He's a great speaker and teacher.
I just want to thank Harvard and Prof. Berger for making this video available.
Lecture begins at 2:00
Why can't every introduction be that concise?
Excellent presentation!
Fantastic lecture. thank you very much for sharing.
Outstanding!
Pretty dead crowd!!
I think this guy is great.
So, it is probably a trivial question, just curious as I want to learn, in order to see Universe origins through light that arrives to us, it necesarily means after the Big Bang the universe expanded faster than velocity of light, right?
... Google "harvard big bang" and it asks if you meant "Howard big bang" ... >.
From 57:20 to 57:50, Berger mentions that we see about 1% of all gamma ray bursts due to how narrowly focused the beams are. That translates to most of the energy being focused into 3.6 degrees(1.8 degrees on one end and 1.8 degrees on the opposite), right? Is there any more detail on how precisely those beams are focused or how laser-like those beams are? Did that figure come from computer simulations or what?
He showed the simulations at 32:45.
@@schmetterling4477 thanks. Are those simulations how they determined that most of the gamma radiation is focused on 1% of possible directions?
@@IARRCSim The details most likely yes. If I remember correctly there is a relativistic back of the envelope argument for the beam width that should get you pretty close. It rests on the assumption of relativistic matter beams going trough gas surrounding the star, but I am not familiar with the physics of relativistic shock waves, so I can't tell you what it boils down to mathematically.
I think the time span of the dark ages is declared wrong in the lecture.
As my calculations say, the Quasars create dark matter until the galaxy they help to create stabilized and that stops the AGN, soon I will show my calculations.
don't understand
would be really grateful if you have a technical society with no price tag for hobbyists unaffliated to any organisation and bearing the Legal citizenship of a countries which meet your policies.
I am an Indian,And await such a society.
I've never been pulled out of a lecture more than when he called hypotheses theories. He is literally educating people, yet he uses the wrong word to explain something to people who most likely haven't heard of the distinction before. Why not be more clear? It makes no sense. If there were hundreds, how could they be theories? They were hypotheses, not theories. They were not proved by anything then.
ga..ga..ga...gggggg.ama rrrrrrrayyyss...
Excellent presentation!