typodupeerror

## Modeling a White Hole With Your Kitchen Sink104

Posted by Soulskill
from the fancy-equipment-is-for-wimps dept.
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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## Modeling a White Hole With Your Kitchen Sink

• #### Black Sink (Score:4, Funny)

on Saturday October 16, 2010 @10:20PM (#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 (Score:4, Funny)

on Saturday October 16, 2010 @10:30PM (#33921678) Homepage
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 (Score:5, Funny)

on Saturday October 16, 2010 @10:55PM (#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 (Score:4, Funny)

by Anonymous Coward on Saturday October 16, 2010 @11:10PM (#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 (Score:4, Funny)

<twoscoopsofpig@g ... m minus math_god> on Saturday October 16, 2010 @11:40PM (#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 (Score:4, Funny)

by Anonymous Coward on Sunday October 17, 2010 @04:35AM (#33922790)

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

• #### Re: (Score:2)

Close, but a dwarf is a star that was not massive enough to create a black hole when it burned up all of its fuel. What's under your sink is the event horizon of a black hole that won't let go [slashdot.org].
• #### Re: (Score:2)

Ceci n'est pas une pipe.

• #### Re: (Score:1)

Dammit Jim! I'm a nerd, not a plumber!!
• #### Re: (Score:2)

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: (Score:2)

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)

on Sunday October 17, 2010 @12:49AM (#33922112) Homepage

What if my sink is black?

Hire a maid?

• #### Yet more evidence... (Score:5, Funny)

on Saturday October 16, 2010 @10:23PM (#33921664) Homepage Journal
... that our universe is some kid's kitchen science experiment.
• #### Re:Yet more evidence... (Score:5, Funny)

on Saturday October 16, 2010 @10:57PM (#33921762)
It gets worse. It turns out the kid's name is "Calvin".
• #### Re: (Score:3, Funny)

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.

• #### 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)

The peril of an abstraction.
• #### Re: (Score:1)

And pizza and be used to model pi.

• #### No, but it's a marvelous way to relax (Score:5, Funny)

on Saturday October 16, 2010 @11:15PM (#33921826)

"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: (Score:2)

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)

on Sunday October 17, 2010 @12:19AM (#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.
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.
HOLLY: Oh.
RIMMER: Air supply low.
HOLLY: Ah.
HOLLY: Right.

• #### Re: (Score:2)

you left out the funny bit.

• #### Re: (Score:1)

So what is it?
• #### Re: (Score:3, Funny)

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: (Score:2)

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)

on Sunday October 17, 2010 @03:00AM (#33922502)

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

• #### 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)

<bob@m[ ]cs.eu ['ani' in gap]> on Sunday October 17, 2010 @06:24AM (#33923084) Homepage

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.

• #### Re:Real physicists use analogues commonly. (Score:4, Informative)

on Sunday October 17, 2010 @12:33PM (#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 (Score:2)

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

by Anonymous Coward

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)

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: (Score:2)

> 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)

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 h
• #### Re: (Score:2)

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 (Score:3, Funny)

<`moc.liamg' `ta' `noitarutcan'> on Sunday October 17, 2010 @04:51PM (#33926526) Journal

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

• #### OK, I'll admit it... (Score:1)

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

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