Search found 3221 matches

by Eebster the Great
Fri Mar 15, 2019 11:46 am UTC
Forum: Mathematics
Topic: The frog riddle
Replies: 23
Views: 2796

Re: The frog riddle

SuicideJunkie wrote:The difference between knowing after the flips, or before the flips. :)

You missed the super obvious context that I knew I wouldn't flip two tails because of information I got from a time traveler from the future.
by Eebster the Great
Thu Mar 14, 2019 10:00 am UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

It sounds as though you could get a nice SF story about intelligent races struggling to extract enough energy to keep going at the end of the universe, seeking out the boundaries and resources, and scavenging each other. Not a million miles, I suppose, from the end of the cities in flight stories. ...
by Eebster the Great
Thu Mar 14, 2019 9:43 am UTC
Forum: Mathematics
Topic: The frog riddle
Replies: 23
Views: 2796

Re: The frog riddle

Similarly, if I flip a coin twice, I know that I am twice as likely to get a heads and a tails as I am to get two heads. And if I know for a fact that I will not flip two tails, I now have a 2/3 chance of flipping a heads and a tails and a 1/3 chance of flipping two heads. If flipping the same coin...
by Eebster the Great
Tue Mar 12, 2019 2:56 am UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

Nickel-62 has the most binding energy per nucleon, so if your future species can somehow get all the nuclei to fuse or fission into those, they could probably extract a little more energy than the expected process of iron star formation I think. (Assuming protons do not decay.)
by Eebster the Great
Mon Mar 11, 2019 9:42 am UTC
Forum: Science
Topic: Extracting energy from a black hole via gravitational blueshift
Replies: 19
Views: 649

Re: Extracting energy from a black hole via gravitational blueshift

I'm not sure I understand the Ferris wheel analogy. Whether or not a satellite's mass is constant, if the only force acting on it is gravitational, its acceleration should not depend on its mass. That's not the problem with OP's proposal. You definitely have to consider relativistic effects, since t...
by Eebster the Great
Sun Mar 10, 2019 11:38 am UTC
Forum: Science
Topic: Extracting energy from a black hole via gravitational blueshift
Replies: 19
Views: 649

Re: Extracting energy from a black hole via gravitational blueshift

You can extract energy out of a rotating black hole by slowing down the rotation though. This is fun. https://en.wikipedia.org/wiki/Penrose_process This is far too efficient. I prefer to wait until the universe has cooled down to a lower temperature than the black hole and collect its Hawking radia...
by Eebster the Great
Wed Mar 06, 2019 8:29 pm UTC
Forum: Science
Topic: Circadian Clock
Replies: 15
Views: 697

Re: Circadian Clock

You can of course adapt to 24.65 hour days, because you can quite easily adapt to 28 hour days. It's probably true that schedules on Mars would be based on the length of the Martian sol, which is fine, because that's almost identical to the length of an Earth day. People's circadian cycles already v...
by Eebster the Great
Wed Mar 06, 2019 3:22 am UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

On the other hand, you say that because of the UV catastrophe, classical thermodynamics is useless. I have not mentioned the UV catastrophe, or EM radiation. I said the classical and statistical thermodynamics aren't perfectly consistent, but I didn't say either was useless. You said that they prov...
by Eebster the Great
Tue Mar 05, 2019 7:06 pm UTC
Forum: Science
Topic: Circadian Clock
Replies: 15
Views: 697

Re: Circadian Clock

People on Mars would be living under and around artificial light 24/7 anyway like we do on Earth, but to a greater extent and with a weaker sun. If there were a long-term evolutionary effect on circadian rhythm on Mars, because people with certain rhythms had more successful children than others, I ...
by Eebster the Great
Tue Mar 05, 2019 7:01 pm UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

since the variables that we use simply would not be macroscopic variables While scientists have a tendency to define the the macro-states in terms of the micro-states, knowledge ultimately goes the other way: We know the macro system first, and we learn the micro system through careful analysis/ ex...
by Eebster the Great
Mon Mar 04, 2019 7:33 pm UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

First) The second law under classical thermodynamics definitions is (in principle) separable from the statistical mechanics definitions. For Pfhorrest's original question, I would consider any situation regularly breaking the classical law as valid example of the experiment he is seeking. I agree w...
by Eebster the Great
Sun Mar 03, 2019 6:18 am UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

The second law is easily laid bare. It's not like we discovered statistical mechanics first. We worked backwards from what we observed to determine a mathematical truth, which is very nice. Regardless of your ontology, it is a historical fact that the understanding of information theory came from th...
by Eebster the Great
Sat Mar 02, 2019 5:26 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2117: "Differentiation and Integration"
Replies: 45
Views: 3102

Re: 2117: "Differentiation and Integration"

As I understand it, metal oxide semiconductor FETs use metal oxide semiconductor material. So for a silicon wafer, you will have a layer of SiO or SiO2 on top of the silicon, which then gets etched to make a working chip.
by Eebster the Great
Sat Mar 02, 2019 5:47 am UTC
Forum: Science
Topic: Lorentz force
Replies: 16
Views: 820

Re: Lorentz force

@prosilo Dont take it personally, this is the internet. There are people around on the web that will argue to the death that 1*1 cannot equal 1 (Im serious. This is a real thing that some people believe) and that modern mathematics is a conspiracy. Oh my God I just looked this up, and now I wish I ...
by Eebster the Great
Sat Mar 02, 2019 5:25 am UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

That is incorrect. The second law is an empirical law that states "these statistical rules apply". There isn't (and cannot be) anything a priori that says the statistics must apply to the world. Sort of. As I already pointed out, there is nothing making it impossible in principle for the ...
by Eebster the Great
Fri Mar 01, 2019 6:44 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2117: "Differentiation and Integration"
Replies: 45
Views: 3102

Re: 2117: "Differentiation and Integration"

Pfhorrest wrote:Silicon dioxide has no "ish" about it, that's straight up what most of most stones are made of.

I am not so educated in the ways of minereroalogy as to know stone from metal or clay or whatnot. But it's a thingy and it does homework.
by Eebster the Great
Fri Mar 01, 2019 4:45 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2117: "Differentiation and Integration"
Replies: 45
Views: 3102

Re: 2117: "Differentiation and Integration"

That is why my calc teacher preferred the conditional, I could teach a stone to get a 5 on the ap if the stone did its homework. Well, I could teach a stone to get a Nobel Prize if the stone did its homework. Silicon is kinda stone-ish, and I could program some to do homework, but I doubt you could...
by Eebster the Great
Thu Feb 28, 2019 11:25 pm UTC
Forum: Science
Topic: Lorentz force
Replies: 16
Views: 820

Re: Lorentz force

I assume you started this thread to discuss an idea, but the problem is that it isn't clear what your idea is yet and you won't accept the answers you've gotten based on what it appears to be. Maybe you could help fill in some details. 1. What are the required elements in your design, and how are th...
by Eebster the Great
Thu Feb 28, 2019 5:53 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2117: "Differentiation and Integration"
Replies: 45
Views: 3102

Re: 2117: "Differentiation and Integration"

Integration: Risch algorithm. Nothing could be simpler. If I understand correctly, every implementation of this algorithm must fail for certain integrals because it is undecidable whether parts of the integrand ever equal zero. (This isn't specific to the Risch algorithm; it is a problem with any C...
by Eebster the Great
Wed Feb 27, 2019 8:35 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2117: "Differentiation and Integration"
Replies: 45
Views: 3102

Re: 2117: "Differentiation and Integration"

As my calculus teacher in high school told us, multiple times: “you can teach a monkey to differentiate, but integration is a skill”. I’ve always been kinda interested in how asymmetrical differentiation/antidifferentiation seems — it’s really neat. I mean, even for very, very complex functions lik...
by Eebster the Great
Wed Feb 27, 2019 4:50 pm UTC
Forum: Science
Topic: Lorentz force
Replies: 16
Views: 820

Re: Lorentz force

What is pushing against what here? Is the cable attached to anything? As I understand it, you have a cart moving along a straight, level, two-rail train track. On the cart, you have magnets set up in some way such that the magnetic force on a wire running left-to-right pushes the wire forward. This ...
by Eebster the Great
Wed Feb 27, 2019 1:40 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2115: "Plutonium"
Replies: 34
Views: 3509

Re: 2115: "Plutonium"

English speakers who pronounce "karaoke" the English way aren't consciously aware of the fact that the pronunciation is heavily distorted, nor are they actively making a decision to pronounce that way for a specific reason; it's just the way they say the word because that's how they've al...
by Eebster the Great
Sat Feb 23, 2019 2:42 pm UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

A constant source of new free energy would violate the first law but not the second law, because as you said, entropy would still continue to increase. A constant source of free energy and a sink for energy should do the trick though, since you could just hook one end up to your refrigerator's power...
by Eebster the Great
Fri Feb 22, 2019 5:59 pm UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

I disagree that the observable universe is a universe any more than an acting president is a president. It may be all we can I observe of the universe, and he may be acting as the president, but it's not the universe, and he's just a pretender.
by Eebster the Great
Fri Feb 22, 2019 2:22 pm UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

A system that is not closed doesn't deserve to be called a universe.
by Eebster the Great
Fri Feb 22, 2019 1:09 pm UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

Well, it's not like that, because we in fact live in a universe where energy is not conserved yet entropy is nondecreasing. Energy is conserved locally, and entropy increases globally, always. It is possible to violate the second law of thermodynamics in principle (though not in practice), but it is...
by Eebster the Great
Fri Feb 22, 2019 9:15 am UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

Yeah, you can set up a system of particles to evolve into a lower entropy state. So if all possible initial conditions are real, then in some of them, entropy decreases. Like I said, it's a statistical law. But it is difficult to overstate just how unlikely this is, requiring the double exponential ...
by Eebster the Great
Fri Feb 22, 2019 7:01 am UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

I suppose in a strict sense, superdeterminism can violate the second law. And like, if we live in a teleological universe where God has already set things up in order to play out in a specific way, then there is no law of physics saying it could not have been set up to play out in a very surprising ...
by Eebster the Great
Thu Feb 21, 2019 8:33 pm UTC
Forum: Science
Topic: What if the second law was breakable?
Replies: 71
Views: 2795

Re: What if the second law was breakable?

The reason Eddington (and doogly) say this is that the second law is, at its most fundamental, a purely statistical law. It is not just true because we observe it to be true but because literally just counting proves that it must be true. So in this hypothetical universe, counting doesn't work either.
by Eebster the Great
Thu Feb 21, 2019 8:26 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 2113: "Physics Suppression"
Replies: 23
Views: 2423

Re: 2113: "Physics Suppression"

Incidentally, there is a scenario of increasing cosmological "constant" in which all particles really do get ripped away from each other into their own isolated observable universes. It's called the Big Rip. It's not a super plausible end to the universe at this point, but it's difficult t...
by Eebster the Great
Thu Feb 21, 2019 8:16 pm UTC
Forum: Language/Linguistics
Topic: Regional Dialect and Idiolect Oddities (pronunciation)
Replies: 944
Views: 264049

Re: Regional Dialect and Idiolect Oddities (pronunciation)

flicky1991 wrote:Definitely "pat-a-cake" in UK. I associate "patty-cake" with US.

Wikipedia gives "pat a cake" from 1698 and "patty cake" from 1765. As an American, I'm also familiar with the latter.
by Eebster the Great
Wed Feb 20, 2019 2:15 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2113: "Physics Suppression"
Replies: 23
Views: 2423

Re: 2113: "Physics Suppression"

It's a nice fact to be true if you believe in eternal recurrence, I guess, though you can always find other ways for that hypothesis to be true if you really want.
by Eebster the Great
Tue Feb 19, 2019 12:15 am UTC
Forum: Individual XKCD Comic Threads
Topic: 2113: "Physics Suppression"
Replies: 23
Views: 2423

2113: "Physics Suppression"

https://imgs.xkcd.com/comics/physics_suppression_2x.png Title text: "If physics had a mafia, I'm pretty sure the BICEP2 mess would have ended in bloodshed." I see this attitude all over the place, that physics is monolithic and the only reason whatever crackpot theory isn't mainstream is ...
by Eebster the Great
Sun Feb 17, 2019 3:51 pm UTC
Forum: Mathematics
Topic: The frog riddle
Replies: 23
Views: 2796

Re: The frog riddle

Similarly, if I flip a coin twice, I know that I am twice as likely to get a heads and a tails as I am to get two heads. And if I know for a fact that I will not flip two tails, I now have a 2/3 chance of flipping a heads and a tails and a 1/3 chance of flipping two heads.
by Eebster the Great
Sat Feb 16, 2019 7:35 pm UTC
Forum: Science
Topic: Favorite home experiments
Replies: 590
Views: 463048

Re: Favorite home experiments

An on-topic bump, how about that!
by Eebster the Great
Fri Feb 15, 2019 12:37 am UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 191
Views: 34677

Re: Science fleeting thoughts

The scale factor increases exponentially, which is what it means for the cosmological constant to be constant.
by Eebster the Great
Thu Feb 14, 2019 7:36 pm UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 191
Views: 34677

Re: Science fleeting thoughts

Yeah, ΛCDM is by far the best model we have so far.
by Eebster the Great
Thu Feb 14, 2019 2:20 am UTC
Forum: Science
Topic: Science fleeting thoughts
Replies: 191
Views: 34677

Re: Science fleeting thoughts

Dying in negative absolute pressure (that is, in tension) isn't so much "decompression" as being actively torn apart.
by Eebster the Great
Wed Feb 13, 2019 7:44 am UTC
Forum: Language/Linguistics
Topic: Is this logical statement true or false?
Replies: 15
Views: 5996

Re: Is this logical statement true or false?

Pfhorrest wrote:("What is?" they ask. "This", I say. "That's not an answer" they insist, but I retort "That wasn't a question").

Hoisted by their own pet aardvark
by Eebster the Great
Tue Feb 12, 2019 6:32 pm UTC
Forum: Mathematics
Topic: Help please
Replies: 4
Views: 804

Re: Help please

His answer does suggest a practical method for getting an exact answer to this problem by adjusting the individual charges until they are equal. It's not the algebraic method that the teacher probably wants and that extends to future problems, but it is a better method for solving the problem mental...

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