"Pressure" as a concept doesn't apply to black holes. They are the size they are because of their mass. The bigger the mass, the larger area where their gravity is so great light can't escape. Scientists model black holes as only have a mass and a spin on the inside because that's all the external universe cares about. Information being inscribed on the exterior is an artifact of tike dilating as an object approaches a black hole, iirc.
The Schrödinger wave-function is expressed in a unit which is the square root of an inverse cubic meter. This fact alone makes clear that the wave-function is an abstraction, forever hidden from our view. Nobody will ever measure directly the square root of an inverse cubic meter.
Freeman Dyson, Why is Maxwell’s Theory so hard to understand?
Sorry, my mistake, I was distracted when I wrote that reply. Yes, I did write that, but it's not actually essential to the point I was trying to make, which was: what could the result of measuring anything to an infinite precision possibly look like?
> what could the result of measuring anything to an infinite precision possibly look like?
Depends on what you're measuring. To illustrate why that isn't a facetious response, consider the difference between 'measuring' pi, 'measuring' a meter and 'measuring' the mass of a proton. (Or, for that matter, the relative mass of three of something to one of it.)
By repeatedly throwing a needle on a striped pattern: [1]. Obviously, you will need an infinite number of throws for an infinitely precise measurement of pi.
That would affect only a few borderline trials and would average out with subsequent throws. It would be much more worrisome that the length of a needle or the width of a stripe is not infinitely precise, that would consistently affect all the trials.
Considering that we don't know the value of pi (not that we could write it out nor read it), I'm not sure your definition of "measure" is the same as mine or most people's.
Hmm, I should say "the numerical value of pi in base 10" (or really any rational base), even if we were to weaken that with the qualifier "a to arbitrary degree of precision".
We know pi in the sense of "a unique real number satisfying many useful properties".
Isn't "3.14" pi to an arbitrary degree of precision? Or am I misreading that.
> We know pi in the sense of "a unique real number satisfying many useful properties".
We know it a lot better than that. We have efficient programs that output the numerical value of pi for as many digits as you want.
There's a bunch of real numbers we can identify that are far harder to make use of or approximate, and don't have easy exact description of their value.
You can calculate or 'measure' an arbitrary approximation of that ratio by various methods, but calculating all of it takes infinite time, which I don't have and thus can't do it.
Because the basic understanding of physics is that all particles move at constant speed c in spacetime; the proportion of their speed that is happening in the three spatial dimensions is determined by their mass. So, any particle's speed through space is a fraction of the "speed of light" c; the higher its mass, the lower the fraction.
The other items I mentioned are then caused by the speed of these particles. The speed of sound in a medium is determined by how fast particles collide into other particles in the medium. The speed of the earth around its axis (the length of a day) is determined by the speed of the particles making it up in the warped spacetime of the earth's gravitational field. The speed of chemical reactions is also limited by how fast atoms and electrons move and can interact with each other.
The length of a day, at least, is unrelated. There was a big splash in the news not long ago because it was determined that the length of Earth's day was changing and we might need to change it by a second.
Venus has a much, much slower rotation on its axis, but Mars is almost the same.
I doubt it was a big splash of news given that leap seconds have been a fairly routine thing for quite a while. Lately there’s been talk about a possible negative leap second, as Earth’s rotation speed has been increasing for a few years now. Many things can have a measurable on Earth’s rotation, including dynamics of the molten outer core, earthquakes, ocean currents, and melting of polar ice caused by the climate change.
Even before we invented precise enough clocks that there was any need for leap seconds, we knew that Earth’s rotation is slowing down due to tidal drag – the moon is literally robbing angular momentum from Earth, and getting farther from Earth in the process. Back in the Cambrian, day length was around 21 hours. Shortly after the formation of the moon, 4.5Ga ago, it would have been only around five hours, assuming the giant impact hypothesis is correct.
Leap seconds are just an imperfection in how we measure days. The recent splash was largely because it was being blamed on changes due to global warming.
In any case, it all goes to my point- the Earth's mass has no bearing on its rotational speed.
The Friedman Doctrine ( what you are espousing, that business are only set up to make money) is a relatively recent social construct, having been first articulated in 1970. Questioning whether or not it should be the basis of how we organize an economy is perfectly valid. Simply saying "this is the responsibility of Google" is missing the point. Cases like this should make us ask if this should be the way we assign responsibility to businesses or if we should assign them different responsibilities.
The argument made here includes not just that the company should not spend it's resources on things other than profit for the sake of shareholders, but also worries about employees and customers. At least in this article Friedman was advocating for something much more positive than the situation we found ourselves in today
>The Friedman Doctrine ( what you are espousing, that business are only set up to make money) is a relatively recent social construct, having been first articulated in 1970.
What were the robber barons of the 19th century doing then? Or do you think that companies like standard oil were not "only set up to make money"?
The robber barons are specifically examples of people considered not to be fulfilling their social responsibilities. The idea that business are only responsible to make money is the new concept, not that people were acting only to make money previously. It was seen as a bad thing, now its a deflection for bad behavior.
It's purposeful. It's green washing money - they are able to get good press by doing something pretty minor, like holding a conference. But that money ultimately came from causing far greater environmental harm.
I don't think the purpose of this sort of research is to be immediately applicable, it more shows a direction that could be useful in the future. Shor's algorithm has not been used practically, but it's hard to imagine modern cryptography without "post quantum" being an important topic.
It’s similar to tipping, once one guy starts doing it all the others look like assholes unless they start doing it too. A similar phenomenon happens sometimes in drive-through coffee shops: someone will pre-pay for the coffee of the person behind them in line, then that person is informed that a stranger paid for their coffee. There is then a social expectation to do the same thing for the next person in line to keep the chain of anonymous “charity” going. Nobody wants to be the asshole that breaks the chain. It’s certainly an odd phenomenon, but many people love it.
The stated reasons is patriotism. The real reason is that the military buys a lot of airline tickets and the military member gets to choose from a list of flights from a variety of airlines.
