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Modeling a White Hole With Your Kitchen Sink
jamie passes along this excerpt from Wired:
"That ring of water in your kitchen sink is actually a model white hole. For the first time, scientists have shown experimentally that liquid flowing from a tap embodies the same physics as the time-reversed equivalent of black holes. When a stream of tap water hits the flat surface of the sink, it spreads out into a thin disc bounded by a raised lip, called the hydraulic jump. Physicists’ puzzlement with this jump dates back to Lord Rayleigh in 1914. More recently, physicists have suggested that, if the water waves inside the disc move faster than the waves outside, the jump could serve as an analogue event horizon. Water can approach the ring from outside, but it can’t get in."
What if my sink is black? Looks more like a black hole to me. In fact, the whole analogy reminds me of a black hole. Water pours out and spins around meeting at the center before exiting into another dimension which in this analogy, we'll call the "U-Joint".
... that our universe is some kid's kitchen science experiment.
If you check the second link in the slashdot summary you'll see that this is a serious paper, and cannot be dismissed merely by the flippant comment of a random slashdotter. Although arxiv is a preprint repository, virtually all papers you find there have ended up published in peer-reviewed publications. Anyway, an analogy can be made between any two things, and it's just a matter of degree how suitable an analogy is; it's not a black and white choice.
"Politicians and diapers must be changed often, and for the same reason."
It's a sink ... and some water coming out of the faucet. There is no mystery here and it isn't related to a black hole.
Why would you say this? If they had said that the movement of large amounts of water in a dam or lake shares the same physical properties as a black hole, would you so flippantly dismiss the study? Similarly, if they had compared it to a stream of atoms, would you have said "that's interesting" or would you have claimed that there can be no relation between atoms and black holes?
I suspect that it is the mundane familiarity of the common sink that makes you dismiss this without having studied the concepts at all.
...stellar flares can be modeled via intestinal gas and Jupiter's Great Red Spot can be modeled via severe acne.
Table-ized A.I.
The peril of an abstraction.
The manifestation of the experiment wasn't the most interesting part. It was the fact that the math behind it matched so closely to the existing models. It is all to common that small scale events mimc larger ones.
I find this comforting.
(obligatory Douglas Adams reference)
"You get this bath, see? Imagine you've got this bath. And it's ebony. And it's conical."
"Conical?" said Arthur. "What sort of ..."
"Shhh!" said Ford. "It's conical. So what you do is, you see, you fill it with fine white sand, all right? Or sugar. Fine white sand, and/or sugar. Anything. Doesn't matter. Sugar's fine. And when it's full, you pull the plug out ... are you listening?"
"I'm listening."
"You pull the plug out, and it all just twirls away, twirls away you see, out of the plughole."
"I see."
"You don't see. You don't see at all. I haven't got to the clever bit yet. You want to hear the clever bit?"
"Tell me the clever bit."
"I'll tell you the clever bit."
Ford thought for a moment, trying to remember what the clever bit was.
"The clever bit," he said, "is this. You film it happening."
"Clever," agreed Arthur.
"You get a movie camera, and you film it happening."
"Clever."
"That's not the clever bit. This is the clever bit, I remember now that this is the clever bit. The clever bit is that you then thread the film in the projector ... backward!"
"Backward?"
"Yes. Threading it backward is definitely the clever bit. So then, you just sit and watch it, and everything just appears to spiral upward out of the plughole and fill the bath. See?"
"And that's how the Universe began, is it?" said Arthur.
"No," said Ford, "but it's a marvelous way to relax."
We are agents of the free
Read it again. The article is not talking about black holes. It's talking about white holes.
Learning about brewing beer, by brewing beer.
Black holes and atoms?!? That's the most ridiculous thing I've heard all night!
GENERATION O98346: The first time you see this, copy it into your sig and remove a random number from the generation. T
It seems like these days almost all slashdot posts are flippant comments, or something even less relevant.
Don't you miss the days when slashdot posts were by people with I.Q.s that were larger than their shoe sizes?
CAT: So, what is it?
KRYTEN: I've never seen one before -- no one has -- but I'm guessing it's
a white hole.
RIMMER: A _white_ hole?
KRYTEN: Every action has an equal and opposite reaction. A black hole
sucks time and matter out of the universe: a white hole returns it.
LISTER: So, that thing's spewing time back into the universe? (He dons
his fur-lined hat.)
KRYTEN: Precisely. That's why we're experiencing these curious time
phenomena on board.
CAT: So, what is it?
KRYTEN: I've never seen one before -- no one has -- but I'm guessing it's
a white hole.
RIMMER: A _white_ hole?
KRYTEN: Every action has an equal and opposite reaction. A black hole
sucks time and matter out of the universe: a white hole returns it.
LISTER: (Minus the hat.) So, that thing's spewing time back into the
universe? (He dons his fur-lined hat, again.)
KRYTEN: Precisely. That's why we're experiencing these curious time
phenomena on board.
LISTER: What time phenomena?
KRYTEN: Like just then, when time repeated itself.
CAT: So, what is it?
They all stare at him.
CAT: Only joking.
LISTER: (Suddenly upright, and minus his hat, again) Okay, so it's
decided then. We consult Holly.
CAT: Hey, wait a minute -- I missed the discussion!
RIMMER: (Suddenly on the bench, where the CAT used to be sitting) We all
did.
KRYTEN: (Suddenly on the table previously occupied by LISTER) Time is
occurring in random pockets. The laws of causality no longer apply.
An action no longer leads to a consequence.
CAT: (Back on the bench) So, what is it?
KRYTEN: I think we've experienced this period of time before, Sir.
CAT: Only joking.
KRYTEN: And that one. Since we're no longer affected by the laws of
causality, we can override these time jumps if we concentrate.
RIMMER: Look, the only way out of this is to consult Holly.
CAT: (Snaps fingers) I'll go with that.
KRYTEN: Gets my vote.
LISTER: Okay, so it's decided then. We consult Holly.
KRYTEN: Ah, I think we've just encountered the middle of this
conversation!
CAT: So, what is it?
LISTER: Ooh, someone punch him out. Bring Holly up.
KRYTEN: She only has two minutes left. Perhaps I should talk to her.
RIMMER: Leave this to me, Kryten. (To terminal) On.
HOLLY fades into being on the viewscreen.
RIMMER: (All in one breath) White hole. Spewing time. Engines dead.
Air supply low. Advise please.
HOLLY: Excuse me?
RIMMER: (Again, as though attempting a world record on the most words
spoken in one breath) White hole. Spewing time. Engines dead.--
HOLLY: I can't understand a word you're saying.
RIMMER: White.
HOLLY: Yes.
RIMMER: Hole.
HOLLY: Right.
RIMMER: Spewing.
HOLLY: Yes.
RIMMER: Time.
HOLLY: With you.
RIMMER: Engines dead.
HOLLY: Oh.
RIMMER: Air supply low.
HOLLY: Ah.
RIMMER: Advise please.
HOLLY: Right.
I think this just illustrates the elegance of the universe. For many different scales, the same mathematics get reused, whether it's a theoretical white hole or a hydraulic jump in a kitchen sink. Another example which may be similar is the edge of our solar system, the heliopause. In a very similar way, high-speed solar wind particles prevent a lot of particles from outside from entering the inner solar system. Like the hydraulic jump in a kitchen sink, the heliopause is where the speed of the outgoing particles reaches the speed of sound of the medium in which it is traveling.
One minor correction. Rather than
"virtually all papers you find there have ended up published in peer-reviewed publications"
it should read
"virtually all papers that have ended up published in peer-reviewed publications started there"
i don't have feet, you insensitive clod.
what if goatse really is the secret to the universe?
Table-ized A.I.
Everytime I flush I'm creating a new universe, and it's gonna be a crappy one...
I've got better things to do tonight than die.
And what gives you the knowledge to make those assertions? We could as well be further than many wanting-to-look-smart-people might assume.
(obviously we're not talking simply about "GIS, but for the Universe" thing)
One that hath name thou can not otter
The tap phenomenon has been known for some time as a useful analogue to a termination shock at the edge of our solar system.
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
That's not true either. After hitting the paywall for may, many interesting papers, I wish they were all available on Arxiv.
A white hole?
Aide-toi, le Ciel t'aidera - Jeanne D'Arc.
It's a sink ... and some water coming out of the faucet. There is no mystery here and it isn't related to a black hole. Let's keep things in perspective. Analogies are great, especially car analogies, but a small wave of water in my sink is not analogous to the event horizon of a black hole any more than my garbage disposal is analogous to the rest of the black hole.
What are you talking about? This idea was completely brilliant. If physics has shown us anything, it is that the mysterious and the commonplace are often inexorably linked. I read what you just said like this:
It's an piece of turf... and an apple falling from a tree. There is no mystery here and it isn't related to our planet going round the sun. Let's keep things in perspective. Analogies are great, especially car analogies, but a small piece of fruit on a tree is not analogous to a planet circling round a sun any more than my garbage disposal is analogous to the rest of the solar system.
Except...it is.
Big apple, new Yorik, undig it, something's unrotting in Edenmark.
As usual, Red Dwarf has it covered: White Hole, from Meltdown.
If all you have is a grenade, pretty soon every problem looks like a foxhole -- MightyYar
The ability to discover simple to control systems that operate as analogues to more advanced physics is wonderful and not some fake trick as some comment posters suggest.
Check out this page where the kitchen sink phenomenon is shown as well as another analogue for an event horizon, the "fish in the stream" analogue. (Where water flow is faster than a fish's top speed, a fish will hit a point of no return.) Found by googling for: physics analogue kitchen.
This page has some interesting explanations and also mentions there are other analogues that for example suggest answers to the still open question of what happens at planck lengths where space is expected to become grainy or net-like.
There is another page that describes another use of the same circular hydraulic jump in the kitchen sink, saying that it is a three-way analogue: "The connection between ocean bores, stellar gases, and the swirl of water in the kitchen sink is a splendid example of a three-way physical model." So with white holes brought in maybe this is a four-way analogue now. This page is quite a fun read and describes in detail why the hydraulic jump appears. It also describes how this is like the shock wave caused by the upwelling of gas from a star's surface meeting gas that is falling back onto the sun.
In nature there is a similar phenomena called a Microburst.
My ism, it's full of beliefs.
FTA:
"Then they stuck a needle in the oil to make the Mach cone. Just outside the spot where the jet of oil hit the plate, the water parted around the needle at an angle of about 18 degrees. As the physicists move the needle outward, the angle smoothly increased to about 45 degrees, then rapidly opened up to reach 90 degrees near the ridge of the jump.
That implies that the speed of the waves inside the ring is equal to the speed of the waves outside the ring, "and hence constitutes a clear proof that the jump indeed represents a white hole horizon for surface waves," the team wrote. "The fact that the circular jump represents a white hole horizon illustrates that the concept of horizons is not limited to relativity.""
First of all, in the first paragraph it says "...the water parted...". No, as the article said earlier on, they used silicone oil, not water.
Secondly, the fact that the angle of the mach cone was less than 90 degrees inside the hydraulic jump implies that the speed of the waves inside the ring is GREATER than the speed of the waves outside the ring.
The fact that it goes to 90 degrees indicates, as the article also said earlier, that the speed of the interior waves is equal to the speed of the exterior waves AT THE HYDRAULIC JUMP.
The whole point of the experiment was to show that the waves are traveling faster inside the jump than outside.
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
I wonder if they're going to add this to the next version of Nethack?
I do.
Blogging because I can...
There is evidence of White Holes in our Universe? That would explain why our universe is expanding. Fundamentally, our universe is then a "Cosmic Land Fill" by other surrounding Universes.
Modpoints for ACs, that'll be the day...
Truth arises more readily from error than from confusion. -Francis Bacon
Well, in this case it is precisely black or white ;)
WTF am I doing replying to an AC at 5 A.M on a Friday night?
Doesn't it come down to the lack of an equal opposite force, or basic physical dynamics? The water hitting the bottom of the sink is coming with a certain force, then it hits an immovable object--the bottom of the sink, and spreads out. As the water continues downward from the tap, the force is a constant. The water trying to get inside the circle is not coming with any where near as much force. Please allow me to illustrate with my toilet bowl. When I can't get everything to go down by flushing alone, I have to use a bucket of water, adding force due to the weight of the water in the bucket as well as the distance the water is coming, picking up speed due to gravity. If I were to flush it at the same time, the water from the bucket still pushes all the other water up and out before coming back down and going down the hole first. Then, the flushing water goes down. Ultimately, I think it has more to do with fluid dynamics and the nature of the water, which perhaps the physicists aren't taking into account.
Best Regards, David Geer
Their follow-up article: How to Model a Brown Hole Using Your Toilet.
Want to improve your Karma? Instead of "Post Anonymously", try the "Post Humously" option.
Given the news, I've been reading a little more about Mandelbrot than I should, but that blew my mind!
Spork.
P.S. Spork.
Although arxiv is a preprint repository, virtually all papers you find there have ended up published in peer-reviewed publications.
I'm sorry, but this is just wrong. I've plenty of crappy non-peer reviewed papers on ArXiv.
"I've plenty of crappy non-peer reviewed papers" I'm sure yours are.
"Politicians and diapers must be changed often, and for the same reason."
Now you know why an Australian toe nail can be described as 'horny'
PS: Here's a 'whoosh' in advance for me and my dumb cohorts
The new right fascists are bilingual. They speak English and Bullshit.
It's like the air in that balloon when something bad happens
The new right fascists are bilingual. They speak English and Bullshit.
I thought that in space no one can hear you scream?
The new right fascists are bilingual. They speak English and Bullshit.
Yeah, because one typing error on an uneditable web forum is an indicator eh? Makes total sense.
My point still stands. Much of what's on ArXiv is crap. I've seen too many jackoffs claim that they've proven/disproven the Riemann hypothesis, and they go to ArXiv because it's the only place that doesn't tear their paper apart.
I have no feet and yet I must trample!
Actually, thinking about it, when you stomp in a mud puddle, and the water goes flying out from beneath your shoe sole (presuming you had feet and shoe soles) ... doesn't that also resemble the effect of a water stream striking a flat surface? Yet you don't disappear through an event horizon when you stomp through a mud puddle.
Bah humbug, I say!
Ok, if a white hole were really the opposite of a black hole, wouldn't stuff come popping out of the white hole and then start orbiting, with the orbit getting gradually larger?
I learned of Feynman's Sprinkler from this post:
http://www.natscience.com/Uwe/Forum.aspx/physics/33265/Possible-to-win-the-Powerball-Lotto-using-antimatter
Prolly applies to white-holes/black-holes too.
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