h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Ah yes... it's a semantical argument, but I think a valid one. If there were a universe without intelligent beings to call this waveform 'sound' or receptors to catch the waveform and interpret it as 'sound' then 'sound' would not exist. The waveform would definitely exist.

Why is it not possible for these anomilies to exist? There is always an equal amount of energy in the universe and if black holes are constantly pulling energy from this universe then surely black holes in other universes must be depositing the energy back into our own universe through white holes.

You're asking, huh? There's no real evidence, just a lot of theory, so it's a great topic to discuss in the back room with a bunch of science types.

I think that we know very little about the universe and as we travel and observe, we'll get more information on how black holes work. Perhaps once we figure out what's at the center of a black hole, we'll know whether white holes exist. I like the idea, personally. I think that the possibilities are endless for just about anything to happen in this universe; and if not this one, the one next door.

I think the author you're searching for is John Gribbin. He's a great astronomy/theoretical physics writer.

That name sounds familiar - thanks! I'd like to actually own the book, instead of looking for it in weird libraries.

to trees and apples. I don't know mush about apples but I do know a little about trees and I've often wondered... if a tree falls in the forest and there isn't a forester around to identify it can we really be sure if it was a tree in the first place?

May I just say that you lot have missed one important point. 1, if black holes exist on a very small, perhaps molecular levl, then what is keeping the galaxy from just drifting apart? Answer: A super ultra-mega-massive black hole. That's what's holding the galaxy, and all other galaxies together. 2 (Contradicting myself for argument's sake), there is no proof whatsoever that black holes, white holes, wormholes, hyperspace, or anything like that existing except mathematically. 3, Sully, you've got that wrong. If a tree falls in the wood, and there's nobody for miles around,how can we be sure that the tree made a sound in the first place? Hmmm. Just walk of and contemplate that.



*Walks off and contemplates*

You see, for this, you have to look at the law of conservation of mass-energy. This says that anything up to the speed of light has mass, and past the s.o.l, is energy. It also says that neither can be created nor destroyed, they only change form, so theoretically, when the light reaches the black hole, it changes back into some form of mass, most likely a photon, and is now part of the Super-Ball

That's what I've always thought - that when light enters a black hole, it's accelerated to the speed of light and beyond, and becomes mass, which is spewed out... where? Potentially in a white hole somewhere else.

Holyman - look at my post on trees, one LED before this one. Silly? Yes.

Agreed, I was also looking at your energy to mass theory, and you've got it somewhat backwards. E (energy)= M (mass) C (speed of light) squared meants that the mass has to be multiplied by the speed of light, and then squared, to become pure energy. So, on approach to a black hole, it is possible that mass could become energy, but since a black "hole" is actually something that has mass, it would strike the surface, and once again become mass (because it slowed down). In certain theories, anything that gets pulled into a black hole actually becomes part of its mass. Though this has yet to be proven.

There is some good evidence for black holes. There is something really really dense at the core of our galaxy, some stars orbiting nothing, and some weird x-ray sources with hhigh gravity. All of these fit well into the black hole model, but not well into any other explanation.

If a white hole is the opposite of a black hole that would mean it would not be able to contain anything. This therefore should mean that it has a zero mass and zero gravity(because it has no mass). But here's the question, how can anything have zero mass? Also If all the matter that went into a black hole came out of an opposing white hole, then they would be "vomiting" insane amounts of matter all the time, and this would be very noticible. How is it then that no white holes have been observed, when black holes have? Also If everything that went into a black hole came out it would have no mass, no gravity and therefore would not be able to pull matter into itself. I think the whole white hole theory is really just a bit far fetched.

"If a white hole is the opposite of a black hole that would mean it would not be able to contain anything. This therefore should mean that it has a zero mass and zero gravity(because it has no mass)."

No, it would have negative mass and gravity (if that means anything).

I agree with 241371. A black "hole" isn't actually a hole. It is actually just a super condensed ball of matter. The only reason it was given the name hole, is because nothing escapes from it. Thus giving it the appearence of a hole. You also have to think in 3d. A black hole is pulling in matter from ALL directions therefor there really is no point for it to "spew" anything out of.

Yes, a singularity is an infinitely dense point that pulls matter in in three diumentions. However, relativity is based on the idea that gravity is actually a four-dimentinoal curving of spacetime. In this fourth dimention, the black hole could be linked up to another point in the universe, or in another universe!

yes I will hve to agree that until you can provide substantial proof about whiyte holes you should
just ignore this subject

There are a few things that need clarifying in this thread. e=mc^2 basically suggests that the mass and energy of an object (anything from a photon to the Universe itself) are to some degree interchangable. Both energy and mass are aspects of objects, not substances in their own right.

Light has mass to begin with, and is actually in the form of photons anyway (if your experiment parameters need it to!) The quantum world is so bizarre that scientists just claim that all subatomic particles have a "wave-particle duality;" All SAPs can be considered a wave (like the conventional model of light) or a particle (like a photon). Waves and particles, like so much in science, are just models designed to help the poor human brain cope with something it otherwise couldn't imagine clearly enough. In "reality," whatever that may be, they are neither, and they are both. Like I said, bizarre...

One final point: There is no "past the speed of light." It's the ultimate speed limit; nothing, with the possible exception of tachyons (and that's debatable), can travel faster than c. Interestingly, it was this very question that prompted Einstein's discovery of his now-legendary equation: "What *would* happen if you tried to push an object past it?" He realised that all the kinetic energy being poured into the object must be going somewhere, and could only be converted to mass. Try to push something past c, and it just gets heavier.

And as for white holes themselves? Well, the Universe seems to love binary states (matter vs anti-matter; "up" vs "down" spin on electrons et al; pairs of virtual particles; the surprising propensity for binary star systems) so who knows? White holes existing to complement black holes makes sense, and makes for a classic Red Dwarf episode! Anyway enough of my blether; anyone fancy a game of planetary pool?

Oh, and speaking of tachyons, I just remembered a limerick I once read:

There was a young lady named Bright,
Whose speed was far faster than light.
She went out one day,
In a relative way,
And returned the previous night!

-Reginald Buller

Theres and easy answer
This has been since the bennining of time
For everything that exist theres and opposite form
(i.e. negative electron and positive electrons)
Also Newtons law: For every action theres and opposite and equal reaction. that means if a black hole sucks in mass which is also a form of energy, than it must realese the same energy (matter) it obsorbed before which can now be called a white hole.

Yes thats true but then why don't we see "White holes" i suppose they could be in some other universe or dimension and if thats the case then this conversation is just speculation as there is no way we can find out if its true as i am fairly sure we will not be able to create a probe that would survive going through a black hole in the fore-seeable future. Also i imagine at the other end of black hole the mass would soon increase so that light cannot escape again unless if its in another universe where the laws of physics are very different. So basically if white holes exist then they will quickley become balckholes as there mass increases. Maybe we will be able to accurately predict more if we find out what goes on in the centre of a black hole which will be very hard as all current methods that could be used need light to come back. Also we do not know what a black hole is really. It might not send whatever it sucks up accross the galaxy as then it would decrease in mass. I see nothing wrong with a black hole being just a huge ball of mass like a sun that the light it emits cannot break free of its gravitational pull in the same way if you throw a tennisbal into the air it cannot break free of earths pull.