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Modeling a White Hole With Your Kitchen Sink

Soulskill posted more than 3 years ago | from the fancy-equipment-is-for-wimps dept.

Science 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."

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gay hole (-1, Flamebait)

Anonymous Coward | more than 3 years ago | (#33921608)

fuck my ass hard please.

Re:gay hole (0, Offtopic)

zhong-guo (1872764) | more than 3 years ago | (#33921622)

some day your will learn to respect our people in the daily life. But after seeing the hole where your butt is more like the grand canyon with donkeys walking down into a cave.

Re:gay hole (-1, Troll)

Anonymous Coward | more than 3 years ago | (#33921894)

What do you mean by "our people"? Gay linux users?

Re:gay hole (0)

Anonymous Coward | more than 3 years ago | (#33921970)

is there any other kind?

Re:gay hole (0)

Anonymous Coward | more than 3 years ago | (#33921992)

Not at all: there's also gay Apple users.

Re:gay hole (0)

Anonymous Coward | more than 3 years ago | (#33922032)

I think that is a bit redundant.

Re:gay hole (0, Interesting)

Anonymous Coward | more than 3 years ago | (#33922702)

What's redundant is insecure Windows users constantly trolling.

Re:gay hole (0)

Anonymous Coward | more than 3 years ago | (#33925552)

lol. Right on for that +1 Interesting, but after so many years of senseless and at times irrational bashing of Windows and its users, this community pretty much asked for those (counter-)trolls..

Um, No (-1, Flamebait)

WrongSizeGlass (838941) | more than 3 years ago | (#33921620)

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.

Re:Um, No (5, Insightful)

Prune (557140) | more than 3 years ago | (#33921686)

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.

Re:Um, No (4, Insightful)

meerling (1487879) | more than 3 years ago | (#33921974)

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?

Re:Um, No (4, Funny)

Anonymous Coward | more than 3 years ago | (#33922420)

i don't have feet, you insensitive clod.

Re:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33925266)

The previous statement still holds true....

Re:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33924344)

Heeeeeeerrrrrrppaa Duuuuuuurrrrrrrrp!

Yes (1)

PotatoHead (12771) | more than 3 years ago | (#33925102)

I do.

Re:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33925806)

I have huge feet.

Re:Um, No (1)

uninformedLuddite (1334899) | more than 3 years ago | (#33929162)

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

Re:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33922076)

And with many things in hydraulics, analogies are very suitable. Most slashdotters have surely seen circuit diagrams replaced with figures of pipes and valves. I've also read that the groundwater flow equation was "solved" by noting that it has the same form as the heat diffusion equation and stealing the solution. And then there's the MONIAC computer which was designed to model the UK economy by transferring water between various tanks. What matters in all these cases is that the forms of the equations are the same, or at least close enough for the analogies to be useful in conceptual and even quantitative modelling. And now it seems that there's one more analogy to add to the list: circular hydraulic jumps as models for the event horizons of white holes.

Re:Um, No (1)

uninformedLuddite (1334899) | more than 3 years ago | (#33929170)

It's like the air in that balloon when something bad happens

Re:Um, No (1)

dookiesan (600840) | more than 3 years ago | (#33922316)

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"

Re:Um, No (1)

EdZ (755139) | more than 3 years ago | (#33922866)

That's not true either. After hitting the paywall for may, many interesting papers, I wish they were all available on Arxiv.

Re:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33922938)

Got no mod points (I don't understand why Slashdot doesn't give mod points to its most prominent contributor?) to mod you up, but you stole the words from my mouth. While technically still incorrect, your statement represents the actual situation much better. The GP's statement is awfully incorrect.

Re:Um, No (1)

neumayr (819083) | more than 3 years ago | (#33925608)

Modpoints for ACs, that'll be the day...

Re:Um, No (1)

GNUALMAFUERTE (697061) | more than 3 years ago | (#33925848)

Well, in this case it is precisely black or white ;)

Re:Um, No (1)

Entropy2016 (751922) | more than 3 years ago | (#33926666)

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.

Re:Um, No (1)

Prune (557140) | more than 3 years ago | (#33928738)

"I've plenty of crappy non-peer reviewed papers" I'm sure yours are.

Re:Um, No (1)

Entropy2016 (751922) | more than 3 years ago | (#33931898)

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.

Re:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33921698)

next up, how to model a Hispanic hole with a flashlight and some rubber cement

Re:Um, No (2, Insightful)

Gadget_Guy (627405) | more than 3 years ago | (#33921736)

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.

Re:Um, No (1)

DJRumpy (1345787) | more than 3 years ago | (#33921806)

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.

Re:Um, No (1)

longhairedgnome (610579) | more than 3 years ago | (#33921900)

Black holes and atoms?!? That's the most ridiculous thing I've heard all night!

Re:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33922090)

Would you prefer that your black holes come with revelations?

Re:Um, No (1)

VanGarrett (1269030) | more than 3 years ago | (#33921844)

Read it again. The article is not talking about black holes. It's talking about white holes [wikipedia.org] .

Red Dwarf (1)

h4rm0ny (722443) | more than 3 years ago | (#33923022)

A white hole?

Re:Red Dwarf (1)

VanGarrett (1269030) | more than 3 years ago | (#33925352)

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:Um, No (0)

Anonymous Coward | more than 3 years ago | (#33921952)

Awwhhhh! Look at tha wittle genius debunking allll the sciency research stuff with his one wittle witty comment, the cutie pie didn't even need to read da article!

Re:Um, No (4, Interesting)

phlegmofdiscontent (459470) | more than 3 years ago | (#33922296)

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.

Re:Um, No (-1)

Anonymous Coward | more than 3 years ago | (#33923016)

It rather illustrates the problem with assuming that math and physics go hand in hand.

White holes is a construct that came from modelling the black holes as singularities and someones idea that things have to be symmetric.

Re:Um, No (1)

uninformedLuddite (1334899) | more than 3 years ago | (#33929214)

I thought that in space no one can hear you scream?

Um, Yes (3, Insightful)

neoshroom (324937) | more than 3 years ago | (#33923042)

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.

Ok....so what about my toilet? (-1, Offtopic)

Anonymous Coward | more than 3 years ago | (#33921632)

Is that the equivalent of a blackhole?

Ironic...captcha is physics

Re:Ok....so what about my toilet? (-1, Offtopic)

Anonymous Coward | more than 3 years ago | (#33925412)

Ironic...captcha is physics

That word. I do not think it means what you think it means.

Black Sink (4, Funny)

p0p0 (1841106) | more than 3 years ago | (#33921648)

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".

Re:Black Sink (3, Funny)

reboot246 (623534) | more than 3 years ago | (#33921678)

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.

Re:Black Sink (4, Funny)

runningduck (810975) | more than 3 years ago | (#33921752)

Close, but an S-trap is more likely at the base of your toilet. The thingie under your sink is a P-trap.

Re:Black Sink (4, Funny)

Anonymous Coward | more than 3 years ago | (#33921810)

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 (4, Funny)

TwoScoopsOfPig (900069) | more than 3 years ago | (#33921904)

Close, but a pipe is what I was just smoking. The thingie under your sink is a series of tubes (not a big truck).

Re:Black Sink (4, Funny)

Anonymous Coward | more than 3 years ago | (#33922790)

Close, but a series of tubes is the internet. The thingie under your sink is a thirsty unemployed dwarf named Henry.

Re:Black Sink (1)

hoggoth (414195) | more than 3 years ago | (#33923874)

Ceci n'est pas une pipe.

Re:Black Sink (0)

Anonymous Coward | more than 3 years ago | (#33925500)

Au contraire, mon Capitan! http://www.youtube.com/watch?v=M405eU4niYw [youtube.com]
Ceci n'est pas un chapeau!

Re:Black Sink (0)

Anonymous Coward | more than 3 years ago | (#33921820)

The thingie under your sink is an S-trap.

Not anymore in new construction. They've been replaced with U or even P versions.

Still not Joints, but -traps, or occasionally -bends depending on who's talking.

Plumbing codes, they exist for your protection!

And captcha is...excrete.

Re:Black Sink (1)

p0p0 (1841106) | more than 3 years ago | (#33923246)

Dammit Jim! I'm a nerd, not a plumber!!

Re:Black Sink (1)

DJRumpy (1345787) | more than 3 years ago | (#33921888)

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.

Re:Black Sink (0)

Anonymous Coward | more than 3 years ago | (#33925478)

Shame it didn't swallow your wanky apostrophe, you donkey knob.

Re:Black Sink (1)

EdIII (1114411) | more than 3 years ago | (#33922100)

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 (0)

Anonymous Coward | more than 3 years ago | (#33924124)

Fail! No, it wont. Google is your friend.

Re:Black Sink (4, Funny)

sjames (1099) | more than 3 years ago | (#33922112)

What if my sink is black?

Hire a maid?

Re:Black Sink (0)

Anonymous Coward | more than 3 years ago | (#33922836)

What if my sink is black? Looks more like a black hole to me.

That's an African-American hole, you insensitive clod!

Durr (0)

Anonymous Coward | more than 3 years ago | (#33921652)

They were comparing it to a white hole, not a black hole. I guess you have to be smarter than the kitchen sink to understand what the article is talking about. Good luck.

Yet more evidence... (4, Funny)

cjfs (1253208) | more than 3 years ago | (#33921664)

... that our universe is some kid's kitchen science experiment.

Re:Yet more evidence... (5, Funny)

martin-boundary (547041) | more than 3 years ago | (#33921762)

It gets worse. It turns out the kid's name is "Calvin".

Re:Yet more evidence... (0)

Anonymous Coward | more than 3 years ago | (#33922326)

maybe his name is god?

Re:Yet more evidence... (0)

Anonymous Coward | more than 3 years ago | (#33922728)

Maybe it's Flying Spaghetti Monster... both of these seem just as relevant anymore.

Re:Yet more evidence... (0)

Anonymous Coward | more than 3 years ago | (#33922538)

It turns out the kid's name is "Calvin".

He used to go by the name YHWH.

Re:Yet more evidence... (2, Funny)

MarkRose (820682) | more than 3 years ago | (#33921836)

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.

Imagine, we have only discovered 0.0000001% (0)

Anonymous Coward | more than 3 years ago | (#33921764)

Imagine, as advanced as we feel, as much as we think we know, our collective knowledge to date is likely less than 0.0000001% of the total knowledge of the universe.

We are so ignorant, we can't even figure out for sure why shower curtains blow inward during a shower! [ http://bit.ly/4jeiVL ]

Major advances can still be made in every single area of human endeavour, without exception. If important steps forward in our ability to understand OUR universe can be made in our washrooms, think about what we could find if left the house, metaphorically, from time to time.

Kinda Random: It's interesting how the concept of human locality has evolved so quickly. We started in our cave and progressed, as a species, to viewing ourselves as "locals" of our world. Most people refer to the planet Earth, as "our" planet. What's interesting is the concept that we are locals in our own solar system; it's our solar system, our galaxy, and even our universe.

In related news (2, Funny)

Tablizer (95088) | more than 3 years ago | (#33921778)

...stellar flares can be modeled via intestinal gas and Jupiter's Great Red Spot can be modeled via severe acne.

Not classic physics (1)

NicknamesAreStupid (1040118) | more than 3 years ago | (#33921780)

The peril of an abstraction.

Re:Not classic physics (1)

Sulphur (1548251) | more than 3 years ago | (#33921880)

And pizza and be used to model pi.

No, but it's a marvelous way to relax (4, Funny)

Logos (80812) | more than 3 years ago | (#33921826)

(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."

Re:No, but it's a marvelous way to relax (1)

sznupi (719324) | more than 3 years ago | (#33922860)

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...)

Yuo FAil It (-1, Troll)

Anonymous Coward | more than 3 years ago | (#33921838)

Percent of the *BSD pro-homosexual continues in a keed to be Kreskin 'You see, 3ven continues in a cans can become

White hole. (4, Funny)

Merls the Sneaky (1031058) | more than 3 years ago | (#33922038)

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.

Re:White hole. (1)

JustOK (667959) | more than 3 years ago | (#33922512)

you left out the funny bit.

Re:White hole. (1)

DarthBender (1071972) | more than 3 years ago | (#33922554)

So what is it?

Re:White hole. (3, Funny)

mcneely.mike (927221) | more than 3 years ago | (#33922962)

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.

Re:White hole. (1)

internewt (640704) | more than 3 years ago | (#33923686)

He's probably pished.

Shock Wave (0)

Anonymous Coward | more than 3 years ago | (#33922042)

Another name for the so-called hydraulic jump.

Scary thought (1)

Tablizer (95088) | more than 3 years ago | (#33922472)

what if goatse really is the secret to the universe?

What about the toilet? (4, Funny)

Hamsterdan (815291) | more than 3 years ago | (#33922502)

Everytime I flush I'm creating a new universe, and it's gonna be a crappy one...

Re:What about the toilet? (0)

Anonymous Coward | more than 3 years ago | (#33925120)

This gets +5 Funny?

Re:What about the toilet? (3, Informative)

TangoMargarine (1617195) | more than 3 years ago | (#33925764)

This is a tautology.

ep?!! (-1, Flamebait)

Anonymous Coward | more than 3 years ago | (#33922786)

most people into 4

Just as Richard Feynman would have explained it... (0)

Anonymous Coward | more than 3 years ago | (#33922812)

Just as Richard Feynman would have explained it, as he tended to use examples which people could try out right away on their own to pique their curiosity. Amazing.

Termination shock (1)

Trogre (513942) | more than 3 years ago | (#33922842)

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? (3, Funny)

BertieBaggio (944287) | more than 3 years ago | (#33923084)

As usual, Red Dwarf has it covered: White Hole, from Meltdown [youtube.com] .

Real physicists use analogues commonly. (1)

mattr (78516) | more than 3 years ago | (#33923110)

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 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 [discovermagazine.com] 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.

Re:Real physicists use analogues commonly. (3, Informative)

mikael (484) | more than 3 years ago | (#33924876)

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 (1)

MrKaos (858439) | more than 3 years ago | (#33923506)

In nature there is a similar phenomena called a Microburst [wikipedia.org] .

2 serious errors in the article. (1)

maillemaker (924053) | more than 3 years ago | (#33923792)

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.

Kitchen Sink? (1, Funny)

Anonymous Coward | more than 3 years ago | (#33924288)

I wonder if they're going to add this to the next version of Nethack?

Other Kitchen Sink Models (0)

Anonymous Coward | more than 3 years ago | (#33924584)

> That ring of water in your kitchen sink is actually a model white hole.

If you stick your hand in far enough down the drain and throw the switch it's also a model shark attack.

White Holes are the Opposite of Black Holes? (1)

LifesABeach (234436) | more than 3 years ago | (#33925178)

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.

Re:White Holes are the Opposite of Black Holes? (1)

John Hasler (414242) | more than 3 years ago | (#33925634)

> 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! (1)

geercom (1921694) | more than 3 years ago | (#33926352)

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.

Re:Eureka, I have it! (1)

j00r0m4nc3r (959816) | more than 3 years ago | (#33930204)

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.

Why do those morons even bother getting PhDs when they could just read Slashdot instead..

Next Article (2, Funny)

nacturation (646836) | more than 3 years ago | (#33926526)

Their follow-up article: How to Model a Brown Hole Using Your Toilet.

OK, I'll admit it... (1)

zish (174783) | more than 3 years ago | (#33926586)

Given the news, I've been reading a little more about Mandelbrot than I should, but that blew my mind!

Is it just me .. (0)

Anonymous Coward | more than 3 years ago | (#33931824)

or did anybody else read it the first time as 'Modeling White House With Your Kitchen Sink'?

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