I was wondering if matter has an opposite black holes should be able to have a opposite too.

http://www.matter-antimatter.com/white_hole.htm

are white holes its opposite? If they are does this justify wormholes and possibly another universe?

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perfect is an opinion word-3dknight

it doesn't matter if I get 3 hours of sleep or 6, I still wake up just as tired!-Neverfly

These are the questions that boggle my mind-3dknight

One problem in the linked article:

As far as we know, (as has been discussed here before) antimatter has positive mass.

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

I can guess but I want to be sure what is positive mass?

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perfect is an opinion word-3dknight

it doesn't matter if I get 3 hours of sleep or 6, I still wake up just as tired!-Neverfly

These are the questions that boggle my mind-3dknight

Positive mass is mass that is attracted by other mass, your regular over-the-counter piece of mass, that you can buy in the grocery store.

Negative mass would, if you look at Newton's law, experience a repulsive force from a positive mass.

Antimatter is matter that have all properties (charge, spin, etc.) EXCEPT for mass opposite to normal matter. This means that antimatter is positive mass.

It has been posited that "white holes" could exist, which would be the opposite of "black holes". Maybe they could be the "exit" of a black hole somewhere in our universe (or in a parallel universe) connected through a worm hole. There have even been ideas that e.g. quasars are actually white holes. Up to now, there have been no discoveries of white holes, I think we can safely say that they do not exist.

For the rest, there is so much nonsense on that antimatterdotcom page, that I would refrain from reading more, your brain and IQ may suffer serious damage.

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************************************************** *************************
Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
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Martin ( http://www.geocities.com/DrMartinV )

Thanks for the warning.

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Everyone is entitled to his own opinion, but not his own facts.

I agree; in fact, the hypotheses about parallels universe or so, connected through wormholes are a bit fantastic. Nonetheless, this possibility is very puzzling and intriguing me.
So, as you sayd that there have been no discoveries of white holes up to now, I suppose that you refer to some specific research project aimed to detect their hypothetical presence in our universe.
If so, could you point out some link to papers, or (better, for me at least) give some hints about how a white hole could be detected?

Many thanks and regards.

[b]Bancor]/b]

I am so not up to date with that stuff, but here you can find a list at ADS with papers on white holes (note that not every paper deals with white holes, because white dwarf and black hole come up often in the titles).

Have fun browsing.

__________________
************************************************** *************************
Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
************************************************** *************************
Martin ( http://www.geocities.com/DrMartinV )

I reject wormholes (outside the many aspects of agricultural production) and white holes as nonsense. If black holes could pass mass to white holes through wormholes black holes would not grow as large as those we seem to have "detected". If white holes exist and are capable of transferring mass within the universe or from domains outside our observable universe, the eruptions of mass from point sources within our observable universe would be difficult to ignore. This leaves an assymetrical condition such that wormholes and white holes only drain mass from our domain to some others which seem to be a level of improbability not worth any serious attention from us. Postulations about the generating of isolated domains (aka multiverses) via quantum fluctuations is held to be equally absurd by me.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Many thanks; indeed, I hoped to be given something less vast, however I'll try to seek for my question in that mare magnum.

In the meantime, I take note of your admission to have stated a thing that you didn't know if it were true: article of faith or whatever else?

Bye.

I have said that I was not up to date with all this stuff.
AFAIK all that I said was true about the black hole - white hole - worm hole stuff, and the fact that quasars were once posited to be white holes.

I have no idea what you mean by: article of faith or whatever else?


This from the earlier message that you wrote in answer/question to one of my messages.

I was not pointing to any project looking specifically for white holes. I just stated the general fact here that up until now there is no evidence that white holes exist.

But maybe I am missing something here with respect to your answer.

__________________
************************************************** *************************
Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
************************************************** *************************
Martin ( http://www.geocities.com/DrMartinV )

Dear tusenfem,
no hidden goal in my question; I asked to learn only.

As you said (my bold) my question aimed to know on what basis (research project, theoretical studies and/or assumptions, etc.) the existence of white holes may be "safely" excluded, since the simple lack of discoveries is obviously untenable, because one may exclude the existence of something only when he previously searched for it, at least.

You answered that you were "not up to date with that stuff" (i.e. you didn't know of any research or other results about the question), so I wondered if, when you stated that white holes don't exixst, you based your certainty on something: an article of faith (e.g.: according to my (scientific) creed they cannot exist, so they don't exixst), or whatever else (to your choice).

In other words, when we affirm that a thing doesn't exist, are we bound to explain on what basis we exclude its existence, or can we pass over?
I seemed that here, in this forum, the former is due, not the latter.

Regards.

Lack of evidence to the contrary, whether inferential or direct.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

And that's the very question: lack of evidence on what basis?

Because we never saw a white hole? Do we know how to detect a white hole? Did we ever searched for them?

Because we inferred that they don't exist? What was the basis for this deduction?

Those were my questions, which stand unanswered.

So long.

I base my meaning on the fact that, although I am not up to date with the theoretical work etc. on white holes, there would have been a tremendous scientific uproar when one of these objects would have been found. Up to now, there has been no such thing, and a white hole would be a rather peculiar highly intense object, which would be much easier to find then a black hole.

Naturally we cannot 100% exclude its existence, but the probability is low.

__________________
************************************************** *************************
Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
************************************************** *************************
Martin ( http://www.geocities.com/DrMartinV )

If there is value in establishing priorties for expending time and effort on investigating or wondering about various aspects of the universe, I suggest that white holes and cosmological wormholes be moved to the lowest priority. However, wormholes made by apple maggots and coddling moths are quite another thing. No fair postulating comological apple maggots nor an apple shaped universe.

__________________
For those inclined to oppose human meddling with the structure of the universe or the composition and configuration of objects and groups of objects within the universe, consider:
Whether there is a limit to the magnitude of a modulation of chaos below which order remains invariant? Or, is order but a fiction invented by perspectives applied over finite, however large, time intervals?

Ok, I agree and I get more and more in accordance with you, on these logical bases.

However, my question aimed not so much to know if white holes were discovered (you're right, it would be easy to be aware of this, for me too), as to know if, and by what methods, they were searched out.

As you say that they would be much easier to found than black holes (by now discovered each day of the week, including holidays...), it would be easy and non-expensive to verify their presence or absence in the sky, but I didn't find, AFAIK, any paper on this issue.

Regards.

Useless answer, but maybe it was my question to be useless; sorry for this.

Regards.

It's true that absence of evidence does not equate to evidence of absence. So we can't say white holes don't exist because we haven't seen one.

NEVERTHELESS, I agree with Gourdhead. The question is, where did this concept even come from? I'm not up on this area of "inquiry" either, but I believe the idea came from someone thinking "What if..." followed by some very, very unlikely premises. Thinking "What if..." can sometimes lead to promising areas of research, but in this case, I think it has only led to science fiction.

As mentioned in Kip Thorne's book, Black Holes and Time Warps, there has been research into wormholes, and I believe the probability for a functional wormhole has been constrained practically to zero.

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Everyone is entitled to his own opinion, but not his own facts.