Re Black Holes (My Dumb Question)

[JohnB]

Reading the Parallel Worlds thread.

 

I have to wonder and ask. If black holes are indeed losing mass to create other universes then isn't the total energy/mass of our universe decreasing over time? Given that we don't know how many black holes there are or how fast each is leaking mass the rate of change of mass becomes inherently unknowable.

 

Wouldn't this mess up the maths?

 

For example, we look at a distant Galaxy now and can calculate it's mass but if it contains black holes leaking mass then the mass it has now is less than the mass it had when it formed. Ergo, calculations of the Galaxy's formation based on the mass now must be incorrect.

 

Obviously calculations based on the Galaxy's mass at the time of observation would be correct but wouldn't there be an increasing "uncertainty" as we look backwards or forwards in time?

 

Is this a problem?

[Jean Maxwell]

I do not think it has been settled, this question of total mass.

 

Estimates abound. If we had a decisive understanding of the mass, then we would also have very strong evidence to either the validity or the rejection of inflation as a standard model.

 

Most scientists agree on a close range which seems to suggest that mass leaking from black holes into "other universe" is not occuring, but again we have not settled other questions completeley quit yet.

[Martin]

Excellent reply by Jean Maxwell!

I agree with what Jean says, but I will talk some more about the issues anyway.

 

Reading the Parallel Worlds thread.

 

I have to wonder and ask. If black holes are indeed losing mass to create other universes then isn't the total energy/mass of our universe decreasing over time?

no, definitely not

 

your question assumes there is a welldefined "total" so assumes the universe is spatially finite, which is fine (quite a lot of current observation tends in that direction )

 

lets suppose it is spatially finite. as far as is known it DOES NOT LOSE MASS by black hole formation.

the current model called LCDM (lambda cold dark matter) which fits the observational data remarkably well says that the universe is GAINING MASS or energy exponentially due to expansion

 

dark energy is a constant uniform density----0.6 joules per cubic km---so every time you create an additional cubic km you get an additional 0.6 that nobody had to pay for

 

this may seem strange but it does not violate any laws---THERE IS NO GLOBAL ENERGY CONSERVATION LAW, general relativity does not allow one to be proved.

 

it is just one of the puzzles of science. maybe quantum gravity, as the theory matures, will resolve some of these puzzles

 

In any case, in the models we have so far of black holes, which aren't all that bad, THERE IS NO LEAKAGE

 

you don't have to worry----our universe, or region of the larger assemblage, is not losing but on the contrary as far as we can tell is gaining

 

 

 

 

Is this a problem?

 

No. There are lots of problems in cosmology, but this is not one of them.

 

BTW in Smolin's reproductive cosmology scenario a stellar-mass black hole collapse can sometimes create a universe like our own.

this may seem funny----like, "who pays for it?"

But it does not contradict any known laws.

 

The trick is inflation. It's roughly estimated that over 99 percent of our own universe's energy came from nowhere, by inflation.

Alan Guth has a handwaving argument about this, but it is inconclusive. He says maybe it was paid for by gravitational potential energy, but nobody can point to the actual gravitational potential well that we are down inside. Theoretical physicists are wonderful people but they still have a lot left to figure out and explain.

 

Anyway, inflation is based on a uniform density "scalar" field rather like the "dark energy" we talk about. It causes exponentially accelerating expansion in the early universe and (just as with "dark energy") this causes a huge increase in the amount of energy in the universe----so and so much joules for every cubic km you create.

 

eventually that scalar field energy decays into ordinary matter and becomes stars and you and me. Nobody paid. Or at least Alan Guth doesnt know who paid.

 

So if we can have inflation scenarios become standard mental furniture ever since 1980s-----then certainly Smolin can think that a small, star-size, black hole can cause the beginning of a whole universe. All he has to say is "inflation".

 

Actually things are getting better. A new field called Quantum Cosmology is emerging and will be making testable predictions that you can check against the temperature map of the CMB (microwave background) and the distribution of clusters of galaxies. QC is beginning to make more substantive explanations. I've been watching the field since 2003 and it has made remarkable progress. So I expect that they will make more sense out of black holes and the beginnings of expansion and all that stuff before very long.

[JohnB]

Thank you gentlemen. It's a bit clearer now.

 

I now have to wonder though and I hope no "free energy" types jump on this. How can there be no Global Conservation Law? How does the Universe get energy for nothing on a staggering scale yet it doesn't work on a small scale?

 

Also. Is the Universe expanding because of the increasing energy or is the energy increasing because the Universe is expanding? It seems like both at the same time.

[fredrik]

dark energy is a constant uniform density----0.6 joules per cubic km---so every time you create an additional cubic km you get an additional 0.6 that nobody had to pay for

 

this may seem strange but it does not violate any laws---THERE IS NO GLOBAL ENERGY CONSERVATION LAW, general relativity does not allow one to be proved.

 

it is just one of the puzzles of science. maybe quantum gravity, as the theory matures, will resolve some of these puzzles

 

This is really interesting stuff. What I find interesting is that these questions have relevance even outside cosmology specifically. I am personally not that much focusing on the cosmology in particular, but I still share the same questions. And I think that many deep questions from different fields will receive a common resolution.

 

I'm currently circling around these topics, but I keep getting bounced back and forth different topics as if they are unseparable, or different sides of the same coin.

 

Yesterday I tried to toy with a picture what the concept of temperature, and equilbirium would mean, in a world composed of questions and answers. What would the generalization of "information temperature" be? If you elaborate the

 

[math]1/T = \frac{\partial S}{\partial E}[/math]

 

S ~ Missing answers to considered question

E ~ Significance/Relevance of given questions

 

The questions and the possible expected set of answers are formulated in terms of a) probability spaces and corresponding b) probability distributions.

 

Each probability distribution is assigned a probabilistic relevance, that is associated with energy or mass. This I picture by means as origination from a compilation of the history of interactions. Thus if we evolve a new probability space, at first the probability distributions has no significance, or mass. This means that for this "empty" field (think vacuum) to be in equilibrium with other fields at a given information temperature, the entropy of the zero-mass "question" must be zero. In other words, take to it's extreme: we do not lack answers to irrelevent questions. Ie. there is no driving force behind asking irrelevant questions. The only possible drive if there is a small increase of significance of the question, then the entropy of the distribution will grow.

 

Now it seems if the temperature is constant, and the relevance of a given question increases, the amount of missing answers must also increase.

 

So, if we add "energy" one way of maintaining the equilibrium is to make sure the uncertainty increases correspondingly so that somehow the probability of each possibility is constant.

 

But wether this is favourable or not, must bring the change itself in as a question, and to eventually explain how the originally (and statically) improbable, can be shown to have a definite probability to grow more probably to the point where it's no longer improbable.

 

The hardest parts seems to find the appropriate formalism, which is what I am trying to wrap my head around. Standard probability theory axioms fails because the probability spaces themselves need to be dynamical. And my conclusion is that an evolutionary model seem to be the only possibility I can see, and the only hope would be to identify the magic consistent induction step, or "learning rule". But even this is probably evolutionary which means I'm not sure it can be entirely consistent, except to a certain estimate level of accuracy, so I'm struggling for an acceptable starting point. I have alot of missing answers here... so you might consider it fuzzy, but my experience still assigns massive significance to these basic questions, which I can't ignore even though the head hurts.

 

I've tried to elaborate a few of the unsolved issues to try and get an overview, which is not easy either because my memory is too small

 

Vaccum is interesting because while it's supposedly empty, something doesn't smell right with the notion of a certain amount of nothing. There must be something "supporting" this void, that is related to the observer who claims it to be void from his point of view.

 

Sorry about the ramblings.

 

/Fredrik