111–120 of 153 posts
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He has also written a few books. https://www.amazon.com/Roger-Penrose/e/B000AQ045A%3Fref=dbs_...
Has anyone read his writings on consciousness? When I was young and still believed in free will I imagined that consciousness used quantum mechanics as a way to generate free will. I later learned that Penrose had theories that sounded similar. But have not read about it.
Earlier quoted context omitted.
He has also written a few books. https://www.amazon.com/Roger-Penrose/e/B000AQ045A%3Fref=dbs_...
Has anyone read his writings on consciousness? When I was young and still believed in free will I imagined that consciousness used quantum mechanics as a way to generate free will. I later learned that Penrose had theories that sounded similar. But have not read about it.
I'm elated that Andrea Ghez won!! She came to talk at my high school in 2007, and sparked a lot of my interest in astrophysics. Highly deserved. Here's something closely related to her research that always blows my mind: A video of stars orbiting Sag A*: https://www.youtube.com/watch?v=B0QRpid5_QU
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An illustration in the press release contains this phrase: "When a massive star collapses under its own gravity, it forms a black hole that is so heavy that it captures everything that passes its event horizon. Not even light can escape. At the event horizon, time replaces space and points only forward. The flow of time carries everything towards a singularity furthest inside the black hole, where density is infinite…
Worth noting that the "BH so massive even light can't escape" meme, a staple of popular science, wouldn't make sense since photons don't have mass. What's happening is that space is skewed (according to Schwarzschild if I got it right). It can be better groked with a modern depiction of a BH such as in eg "Interstellar" where the far end of the accretion disk is observed as a second disk.
Even worse, it is frequently explained with an analogy to escape velocity. You have a certain escape velocity at the surface of the Moon, the analogy starts, and your rocket needs to exceed that to get out. Gravity is stronger at the surface of Earth, so escape velocity there is higher, and rockets need to go even faster.
At the event horizon, gravity is strong enough that escape velocity is the speed of light, and so nothing can get out because you can't go faster than light.
Great--except the escape velocity thing only applies to trying to get out ballistically. (Current rockets are essentially ballistic because they expend most of their fuel while still deep in Earth's gravity well).
Escape velocity explains why someone inside the event horizon can't throw things out of the black hole using a catapult, or using a rocket that expends all its fuel before reaching the event horizon.
It doesn't explain why something with continuous thrust could not get out. It doesn't explain why someone inside couldn't build a ladder that extends past the event horizon and simply climb out. It doesn't explain why someone outside could not lower a tether in and pull someone out.
Earlier quoted context omitted.
An illustration in the press release contains this phrase: "When a massive star collapses under its own gravity, it forms a black hole that is so heavy that it captures everything that passes its event horizon. Not even light can escape. At the event horizon, time replaces space and points only forward. The flow of time carries everything towards a singularity furthest inside the black hole, where density is infinite…
Non poetic but hopefully bit more understandable explanation of what it tries to say: After crossing the event horizon the radial direction becomes like time. And what used to be time becomes like space. What this means that you will inevitably travel to the center, just in the same way as you travel into the future in normal life. Inside the event horizon the center is not at any place that you can see, instead it i…
Congrats! Am so happy that Penrose lived long enough to be able to see an actual movie of a black hole ;) Monitoring the Morphology of M87* in 2009-2017 with the Event Horizon Telescope https://arxiv.org/abs/2009.11842 And when all is said and done I believe his insights into the Quantum Correlates of Human Consciousness may end up being the most fruitful Consciousness in the Universe: Neuroscience, Quantum Space-Tim…
Or lived long enough to receive the prize at all - 1965 was 55 years ago!
Earlier quoted context omitted.
Non poetic but hopefully bit more understandable explanation of what it tries to say: After crossing the event horizon the radial direction becomes like time. And what used to be time becomes like space. What this means that you will inevitably travel to the center, just in the same way as you travel into the future in normal life. Inside the event horizon the center is not at any place that you can see, instead it i…
I have heard of space becoming timelike, but have never heard of time becoming spacelike in a black hole. Do you have more information on that?
Genuine question: Do they ever not give a nobel prize? Have there been years where no significant progress was made?
Physics: 1916, 1931, 1934, 1940, 1941, 1942
Chemistry: 1916, 1917, 1919, 1924, 1933, 1940, 1941, 1942
Medicine: 1915, 1916, 1917, 1918, 1921, 1925, 1940, 1941, 1942
Literature: 1914, 1918, 1935, 1940, 1941, 1942, 1943
Peace: 1914, 1915, 1916, 1918, 1923, 1924, 1928, 1932, 1939, 1940, 1941, 1942, 1943, 1948, 1955, 1956, 1966, 1967, 1972
https://www.nobelprize.org/prizes/facts/nobel-prize-facts/#:....
Genuine question: Do they ever not give a nobel prize? Have there been years where no significant progress was made?