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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."
(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
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.
i don't have feet, you insensitive clod.
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.