Spaaaaace

Can you explain how that isn’t fission? Isn’t that what decay is?

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Radioactive decay: discovered 1896 by Marie Skłodowska-Curie and Henri Becquerel. Occurs naturally in 28 chemical elements on Earth that are radioactive. No, I’m not going to go into alpha, beta and gamma decay, or nucleon emission, or electron capture, or internal conversion, and whatnot.

Nuclear fission: discovered/explained 1938/1939 by Otto Hahn, Fritz Strassmann, Lise Meitner and Otto Robert Frisch. Needs extra neutrons to start. Provides its own neutrons when it gets going.

Spontaneous fission: first observed around 1940. A type of radioactive decay that can occur without neutron bombardment. It is a purely probabilistic process, a result of competition between the attractive properties of the strong nuclear force and the mutual coulombic repulsion of the constituent protons. And very slow.

What I’m trying to say is: yes, in a way everything can be seen as decay because the original material changes into something else and isn’t there anymore.
However, “fission” is usually understood as the thing with the neutron bombardment, and “decay” as the thing without the neutron bombardment.

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Season 1 Episode 3 GIF by The Simpsons

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Former European Space Agency astronaut Tim Peake has joined Axiom Space’s astronaut team as a strategic advisor supporting a potential all-UK human spaceflight mission.

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[NASA Astronauts to Deliver Free Astrophotography Lesson From Space | PetaPixel]

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Swindon, we have a problem.

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[…]

An FAA spokesperson told The Register: "After a comprehensive review, the FAA determined no public safety issues were involved in the anomaly that occurred during the SpaceX Starlink Group 9-3 launch on July 11.

“This public safety determination means the Falcon 9 vehicle may return to flight operations while the overall investigation remains open, provided all other license requirements are met.”

[…]

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Opinion:

Interesting read with interesting links.

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Hearing NASA’s Mars rover has found signs of life

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[…]

Walker also confirmed that SpaceX would be switching Dragon recovery operations to the dUS West Coast after parts of the spacecraft’s trunk repeatedly survive reentry and hit the ground.

The change will require that Dragon’s deorbit burn is performed before the trunk is jettisoned, and whatever survives of the trunk will then splash down uprange of the spacecraft off the coast of California.

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Finally a definitive answer to the question the Black Eyed Peas first asked nearly 19 years ago.

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