Modeling a White Hole With Your Kitchen Sink 104
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."
Re:Um, No (Score:5, Insightful)
Re:Um, No (Score:5, Insightful)
Don't you miss the days when slashdot posts were by people with I.Q.s that were larger than their shoe sizes?
Re:Um, No (Score:4, Funny)
i don't have feet, you insensitive clod.
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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!
Yes (Score:2)
I do.
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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
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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"
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Well, in this case it is precisely black or white ;)
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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.
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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.
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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
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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.
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Read it again. The article is not talking about black holes. It's talking about white holes [wikipedia.org].
Red Dwarf (Score:2)
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It's the opposite of a black hole. Whereas light and matter can enter a black hole, but cannot escape, light and matter cannot enter a white hole, but can escape. The entire concept is specific to certain physical theories.
Re:Opposite as a Black Hole? (Score:2)
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 [natscience.com]
Prolly applies to white-holes/black-holes too.
Re:Um, No (Score:5, Interesting)
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.
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Um, Yes (Score:4, Insightful)
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.
Black Sink (Score:4, Funny)
Comment removed (Score:4, Funny)
Re:Black Sink (Score:5, Funny)
Re:Black Sink (Score:4, Funny)
Close, but a P-trap is what I call my toilet when it's clogged. The thingie under your sink is a pipe.
Re:Black Sink (Score:4, Funny)
Re:Black Sink (Score:4, Funny)
Close, but a series of tubes is the internet. The thingie under your sink is a thirsty unemployed dwarf named Henry.
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Ceci n'est pas une pipe.
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A black hole isn't pushing out so much energy and matter that matter can't get any closer than it's event horizon. If anything it welcomes new matter with open arms so to speak.
This is about a white hole, not a black hole.
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Good point. I also keep thinking that this means the laws of physics must different in Australia since the water would be spinning the other direction. It does go along way to explaining Australia....
Re:Black Sink (Score:5, Funny)
What if my sink is black?
Hire a maid?
Yet more evidence... (Score:5, Funny)
Re:Yet more evidence... (Score:5, Funny)
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Hey, when I was a kid, I had all kinds of "white holes". On my face. Each also ended with a cataclysmic explosion if I pinched it just right.
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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. [tufts.edu]
(obviously we're not talking simply about "GIS, but for the Universe" thing)
In related news (Score:2, Funny)
...stellar flares can be modeled via intestinal gas and Jupiter's Great Red Spot can be modeled via severe acne.
Not classic physics (Score:2)
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And pizza and be used to model pi.
No, but it's a marvelous way to relax (Score:5, Funny)
(obligatory Douglas Adams reference [naderlibrary.com])
"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."
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HE-MAN! [tv.com]
(though I was trying to quickly find an episode of some other animated series from around that time; in which neglected geeks were tricked by the villain into creating a black hole - which in turn starts to consume, in a "fluid" way, the planet of protagonists; which ultimately can be only stopped by "something as destructive as itself" (some death ray, apparently); turning it into white hole spewing all the structures back; oh well...)
White hole. (Score:5, Funny)
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.
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you left out the funny bit.
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you left out the funny bit.
So what is it?
(Dons furry hat)
Close, but a 'U-joint' is a universal joint, part of your car's drive train.
The thingie under your sink is an S-trap.
Close, but an S-trap is more likely at the base of your toilet. The thingie under your sink is a P-trap.
Close, but a P-trap is what I call my toilet when it's clogged. The thingie under your sink is a pipe.
Only joking.
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He's probably pished.
Scary thought (Score:1)
what if goatse really is the secret to the universe?
What about the toilet? (Score:5, Funny)
Everytime I flush I'm creating a new universe, and it's gonna be a crappy one...
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Termination shock (Score:2)
The tap phenomenon has been known for some time as a useful analogue to a termination shock [wikipedia.org] at the edge of our solar system.
So what is it? (Score:4, Funny)
As usual, Red Dwarf has it covered: White Hole, from Meltdown [youtube.com].
Real physicists use analogues commonly. (Score:2)
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 [st-andrews.ac.uk] 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 m
Re:Real physicists use analogues commonly. (Score:4, Informative)
It has practical uses as well... if you are running a combustion based rocket motor with a continuous flow of liquid fuel, you really don't want the ignition to travel back through the fuel lines. At the same time, you don't want so much fuel going out that it is unburnt. One way to solve this is to have a narrowed constriction along the fuel line which forces the pressure and velocity up, thus preventing any backflow.
Microburst (Score:2)
2 serious errors in the article. (Score:2)
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 jum
Kitchen Sink? (Score:1, Funny)
I wonder if they're going to add this to the next version of Nethack?
White Holes are the Opposite of Black Holes? (Score:2)
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> There is evidence of White Holes in our Universe?
No. A white hole is a sort of an inside-out black hole, so you can learn a lot about the latter by modeling the former.
Eureka, I have it! (Score:1)
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Why do those morons even bother getting PhDs when they could just read Slashdot instead..
Next Article (Score:3, Funny)
Their follow-up article: How to Model a Brown Hole Using Your Toilet.
OK, I'll admit it... (Score:1)