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  • the death of a giant star.

  • It's more than just an epic explosion.

  • It unleashes a storm of elements that form the universe around us.

  • There's a wonderful cycle of death and life in the universe.

  • Individual stars are born, they live their lives and they die when they die.

  • They enriched in the universe with new atoms and new chemicals.

  • Those go on to form new stars and new planets.

  • Dust blows out from the explosion, forming spectacular interstellar clouds.

  • Nebulous nursery of stars, including our solar system.

  • We were just ah cloud of gas and dust and nebula, minding its own business but big cloud of gas at the brink of gravitational instability.

  • And you just need to give it a push to get it going.

  • That push could well have been given by a supernova, say, five billion years ago.

  • Here's the theory.

  • A star nearby went supernova.

  • It's Shockwave push the cloud of gas and dust together, forming our son and the remaining guys formed all the planets in our solar system.

  • So what's the proof when the biggest pieces of evidence we have is that supernova themselves produce some very rare radioactive elements, Radioactive elements that we can still see embedded in the solar system.

  • Today, it's sprinkled like radioactive salt.

  • Thes radioactive elements found right across our planet are only produced in supernovas, proof that Earth and the solar system were created from exploding stars 4.6 billion years ago.

  • But supernovas may have affected Earth much more recently.

  • No, we do have some evidence that there was a particular supernova explosion that rained down on the earth about two and 1/2 1,000,000 years ago on deposit a specific kind of iron.

  • Iron 60 is a radioactive element.

  • May during supernova, it's found in fossils from around this way.

  • See it embedded in the crust of the earth itself.

  • We see pieces of evidence.

  • Two and 1/2 1,000,000 years ago, life on Earth changed dramatically.

  • Africa lost much of its forests to grasslands, various plants and animals when extinct and many new species appear.

  • But how could a supernova changed life on Earth so dramatically without destroying it completely?

  • When a supernova explodes, it produces a tremendous amount of gamma rays, and if that supernova is close enough to the earth, you could imagine it really doing damage to our atmosphere some of the incredible amounts of energy found in a supernova.

  • Leave the star in gamma ray beans.

  • If that beam were to be pointing at Earth, then the ozone layer could be harmed.

  • It affects our ozone layer, which affects the amount of UV radiation that can hit the surface, which can trigger mutations, which can trigger different forms of vegetation, which can kill off algae in the oceans.

  • There's a lot of potential effects.

  • Mutations drive evolution in all forms of life, from the simplest to the most complex.

  • So it's conceivable that as a result of a relatively nearby supernova, the mutations lead to early hominids and then Homo SAPIENs that actually affected the evolution of life on Earth and humans in particular eyes.

  • It just coincidence that ancient humans started to appear at around this time or was our humanity sparked by a supernova?

  • Supernovas seemed to be an example of violent death, but there were so many steps in the formation of our solar system information of you that are intimately related to supernova.

  • They created the chemical elements, maybe even drove our evolution.

  • We very likely would not exist if it were not for exploding stars from the elements in our DNA to the solar system and the world we live in.

  • Supernovas have made us reason we study astronomy at all is to actually answer the question as to who we are, where we came from and where we're going.

  • And with supernovas, that's all wrapped up into this amazing story.

  • Literally, you are the death of a star.

  • These epic explosions are unlocking the biggest mysteries of our existence.

  • The story of supernova have become more interesting and more complex with every discovery.

  • So as we learn more, we discover what it is that we don't understand.

  • Yet the cosmos is something that can seem so distant and so unreachable.

  • But stars are the things that brilliant light to the cosmos with which we have the most strong connection.

the death of a giant star.

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人類の進化は超新星の放射線によるものだった?| 宇宙のしくみ (Was Human Evolution Driven By Radiation From A Supernova? | How The Universe Works)

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    林宜悉 に公開 2021 年 01 月 14 日
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