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Joined 2 years ago
Joined 2 years ago
One cool thought expressed by Penrose is the possibility that all matter will eventually decay or annihilate and all that's left will be massless radiation such as photons. If this happens then the concept of space and time itself will cease since from within the reference frame of a photon space and time are undefined.
In this scenario the distinction between an infinitely expanded, cold, and dilute universe and an extremely small, hot, and dense universe becomes undifferentiable. Without any physical scale by which to distinguish the two, the far distant future of our universe where all matter has disappeared can be equivalently viewed as the big bang of a new universe.
This is what Penrose calls conformal cyclic cosmology [1]. There was a time when physicists debated whether the universe would continue expanding forever or whether gravity would eventually halt its expansion and cause it to collapse back in on itself in a Big Crunch, potentially giving rise to another Big Bang. Conformal cyclic cosmology allows for an endless repeating cycle of universes even in the case where the universe expands forever, by identifying the infinitely distant future of one universe with the Big Bang of the next.
This is highly speculative and almost certainly false, but it's at least grounded in actual physics and is kind of poetic.
[1] https://en.wikipedia.org/wiki/Conformal_cyclic_cosmology
Light absolutely interacts with gravity in Newtonian mechanics. One of the neat features of Newtonian gravity is that gravitational charge (which is mass) equals inertia so the two cancel each other out exactly in the equation of motion. No other force has this property.
This means gravitational acceleration is independent of inertia, even in the case where inertia/mass approaches zero.
In relativity the event horizon really is a point of no return, whereas in Newtonian physics it's the point at which escape velocity is equal to the speed of light. The escape velocity on the surface of the Earth is 11 km/s, but that doesn't mean that I as a human can't escape the surface of the Earth momentarily just by jumping and I certainly don't jump 11 km/s or even 1 km/s for that matter.
Similarly in Newtonian gravity it would be possible for an object to enter the event horizon of a black hole, and then "jump" back out at a much lower speed than the speed of light and then get sucked back beyond the event horizon, and you can in principle do this over and over again so long as you had some sufficiently powerful source of thrust.
In general relativity this is in principle not possible.
Like most things in life, it's not a matter of difficulty, as if I am so incapable of going to a grocery store to buy groceries and the undue hardship it will cause me. It's simply a matter of how I like to budget my time. I judge that the 30 minutes it can take to do groceries is better spent doing other things with my life.
The hypothetical god who punishes believers of a Christian God is a legitimate objection to Pascal's wager, but it doesn't establish the original assertion I objected to. You're confusing demonstrating that the asymmetry isn't guaranteed with demonstrating that it requires Christianity to be the only possibility. Those are two entirely different claims.
https://www.youtube.com/watch?v=KAWA1DuvCnQ
Slides are here:
https://www.aristeia.com/TalkNotes/TheLastThingDNeeds2-ups.p...
The conclusion is "The last thing D needs is someone like me." meaning D should avoid designing a language where you basically need a niche of lawyers crawling through the language standard to decipher the meaning of various features and then write about how to safely use those features. It's not that languages shouldn't have experts who give good advice, but that the nature of advice in C++ has come down to explaining arbitrary rules, inconsistencies, and obscure corner cases rather than how to use the language effectively to solve actual problems.
He says at some points (taken from the transcript):
"There are some arbitrary, wacky decisions, in my opinion ... There's a lot of, in my opinion, simple arbitrary choices that did not have to be made that make explaining things more complicated and also make working with the tool more complicated."
"Much too much of what I've written about has been tool use, talking about language idiosyncrasies, arbitrary decisions, things you need to be able to remember."
"There is epicycle on epicycle on epicycle inside this language."
And then he followed it up a few years later with a blog post explaining that he won't be updating his book with language related fixes because he no longer trusts himself to know what's right from what's wrong:
"C++ is a large, intricate language with features that interact in complex and subtle ways, and I no longer trust myself to keep all the relevant facts in mind."
https://scottmeyers.blogspot.com/2018/09/the-errata-evaluati...
Anthropic needs to earn 52B a year in annual revenue to honor those specific commitments plus obviously its own operating expenses... and yeah that will require Anthropic to grow as a company, but their S-1 indicates 67.2B a year in revenue and sure maybe they stop growing and this is their peak... or maybe they do manage to grow further to 80B a year, 90B a year...
I'm not going to predict whether Anthropic succeeds or fails, just that it's very misleading to claim that Anthropic needs to grow to $500b in revenue without making it clear that it's $500B in revenue per decade rather than $500B in revenue per year which is what most people reading such a number would assume.
Applying that equation to the observable mass of the universe violates basically every single requirement needed to apply the equation.