LHC Black Holes

Man, I hope nobody is stupid enough to do that. A miscalculation could literally destroy the planet.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

See, that's the problem. We have invented something we call Hawking radiation and without ever making an observation to confirm the idea, we are convinced it must happen.

Of course it's the same problem. The reason we looked for the Higgs boson is because its existence has to do with theory that we are still developing.

That's not the point.

None of the above is relevant. The point is that it had to be verified and has been many, many times. Hawking radiation, not so much.

Not sure who you are responding to here. It would appear to be yourself.

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Rick C

How is that?

BTW, I think you overvalue the planet. We are headed for a planet that won't sustain life in not so many centuries anyway. I'd like to see some cool stuff before then.

--

Rick C

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relatively small black holes in the process of merging to make a slightly b igger small black hole, so we do know that they exist. Their properties can be deduced from regular physics.

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at otherwise seem impossible to explain. Electrons are equally hypothetical .

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- and we can see them close enough to the black hole to know that the total mass in the volume available implies a black hole. That's as visible as a black hole is ever going to get.

and an event horizon.

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vent horizon, which is all you need for Hawking radiation.

If there wasn't any Hawking radiation, we'd have to reconstruct quite a lot of physics. We can be pretty confident that it exists. It took Hawking to realise that it had to exist, but it did turn out to be a rather useful ins ight.

t the counter-intuitive bits as part of the package. Reject them and you ar e back to flint axes.

exactly how heavy it was going to be.

The bit of theory that said that there had to be a Higgs boson wasn't all t hat specific about how heavy it had to be.

comes up trumps once again. We've got to the point where anything that rep laces the theory of relativity has got to make the same predictions with re markably high precision.

That's exactly the point. Science doesn't accept any theory as proven - it' s merely not yet falsified, if you take Popper seriously.

, and it was recognised as problem before Einstein came up with his explana tion..

, but that's a different class of problem.

For some value of "verified", which means "proved to be true". "Not yet fal sified" is what science offers - verification is strictly for theologians a nd mathematicians, whose propositions exist only within their minds.

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to black hole. No human eye could survive there, but the effect would be v isible at a greater distance, for a sufficiently small black hole that was emitting Hawking radiation sufficiently rapidly.

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could move it off to safe distance before it came apart.

it doesn't feel that way to you.

If you expect every posted line to be an immediate response to the line abo ve it. In fact your problem - as spelled out at length in a series of respo nses that I'm unwilling to snip because they do make a more or coherent exp osition of a somewhat incoherent objection - is that you find Hawking radia tion counter-intuitive and get shirty when we point out that this isn't a u seful observation.

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Bill Sloman, Sydney

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Having a black hole eat the entire planet would be a bad outcome,

We aren't. You've been listening to John Larkin again.

Anthropogenic global warming may take the planet into a state that's incomp atible with modern industrial society, creating a human population crash, b ut - as even John Larkin points out - individual humans would do fine on a warmer world, though they have to change where they got their food and what they ate (which is a point that John Larkin tends to skate over).

Try to learn enough to let you appreciate what's actually cool - like Hawki ng radiation.

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Bill Sloman, Sydney

Sure, having a black hole eat the planet would be bad. But how would that relate to creating black hole in the lab? The idea that even a tiny black hole would be catastrophic is great for science fiction, but /very/ far from reality.

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That's interesting. I'd never actually noticed the point that small - low m ass - black holes would have to be very dense. The Chandrasekhar limit is 1 .3 solar masses, and the Tolman?Oppenheimer?Volkoff limit i s between 1.5 and 3 solar masses.

Anything heavier can collapse into a black hole under the influence of grav ity alone. Black hole candidates in X-ray binaries seem to lie in the mass range from 3 to 20 solar masses.

The black hole fusion observed by LIGO in 2015 was of two black holes of 36 times and 29 times the mass of the Sun respectively, and the post-merger b lack hole had a mass of about 62 times the Sun's mass.

Black holes at the centre of galaxies are much more massive, and can be bui lt up of much less dense matter.

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Bill Sloman, Sydney

Okay, you sound very sure about that. Which of course you ought to be, cons idering that the wager you propose is the lives of billions of people plus all of human civilization forever (plus a few dogs and cats and wild animal s) versus some asshole's curiosity.

I wonder what odds Jimmy the Greek would offer on that one.

Cheers

Phil Hobbs

There is the issue that 3 solar masses were apparently radiated away, some of it *after* the merger. Quite a feat for an object that was supposed to be 'black'.

Jeroen Belleman

Theoreticians are horrible at naming things.

Cheers

Phil Hobbs

With respect to neart term capabilities, the argument I have seen is that the collisions involved have happened billions of times on Earth already. Due to atmospheric collisions by the higher energy cosmic rays.

It reminds me of the early nuclear weapon tests. They did a calculation to check if the device would ignite the atmosphere...

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John Devereux

/All/ black holes are very dense. Even ignoring considerations of different sizes of black holes having different densities, a small mass black hole is going to be extremely small. It is also going to have extremely low mass. This means its gravitational pull is going to be extremely small, and it is extremely unlikely to capture any other matter within its pull.

So if we assume there is no Hawking radiation and black holes can grow but not "evaporate", if we made a black hole in the lab it would move under the influence of gravity just like a point mass. It would not interact with other matter in any significant way, as it would simply pass through any atoms (just like neutrinos). Depending on its mass and initial speed, it is likely to end up in orbit around the earth's centre of gravity. Based on the values given in the links above (which I have no reason to doubt), it would perhaps swallow a proton every hundred years or so. It is not exactly a disaster.

Note also that while CERN have managed to make collisions with impressively high energies, we are regularly hit by cosmic rays with /much/ higher energies. If we had the remotest chance of making a black hole in the lab, and if that black hole posed the remotest danger, then we would already have been gobbled up by a black hole from a cosmic ray collision.

Yes, I /am/ very sure about it.

And I can't lose. Or at least, if I lose, the other side can't collect!

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Grizzly H.

Nope. The bigger the mass, the lower the density. In fact not so long ago there was significant doubt whether or not the whole universe was a black hole (i.e. closed).

(Of course you can't really talk about volume in the neighbourhood of a singularity, so it's usually computed as 4/3 pi r**3, where r is the Swarzschild radius.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

The signal was observed some 12 billion years later, and a very long way away.

Creating gravitational waves does use up energy - presumably three solar masses worth in this case - so the two object presumably stopped being entirely black while they were merging.

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Bill Sloman, Sydney

Regarding black hole density, the universe and all that: You better start believing in black holes. You're in one!

If the universe is closed, that is. Yes, I know that view

Jeroen (savvy?) Belleman

We all die. What's the difference of when? Death by the sort of black hole you are talking about, it it could happen, would be pretty quick. Once the black hole reached some size I expect it would contain the entire earth rather quickly.

We are only on this planet temporarily anyway. In a few billions years the sun dies and takes us with it. Mankind is doomed anyway.

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Rick C

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considering that the wager you propose is the lives of billions of people p lus all of human civilization forever (plus a few dogs and cats and wild an imals) versus some asshole's curiosity.

If you'd paid any attention to the subsequent discussion, you'd have realis ed that anything we could have created would have been small enough to radi ate itself away faster than it could collect new mass. Cosmic rays must be generating more very small black holes than CERN ever could - if CERN were capable of generating them, which does seem unlikely (though perhaps not en tirely impossible if you accept the current estimate for the size of the sm allest possible black hole)

The sun doesn't die - it blows up into a red giant whose surface would incl ude the earth's orbit, before collapsing into a white dwarf (to skip over a lot of fascinating detail).

It would take some fancy geo-engineering to save the planet - though whatev er is living here by then would probably have started moving it away from t he sun rather earlier to cancel the increase in solar output.

If we were silly enough to be stuck to the planet, and dumb enough not to a ble to move it, we'd deserve to die.

The chance that the human species would still be around by then are pretty remote. As a successful species we can be expected to evolve different sub- species to exploit different environments, and generate a bunch of new spec ies, each adapted to a different environment.

The average survival time of a mammalian species is apparently about 10 mil lion years - after that something different shows up that that is better ad apted to the particular ecological niche than the species that used to occu py it.

Human being show a remarkable ability to exploit different ecological niche s, so this isn't going to be quite the way it works for us. At present ther e are people who think that we could exploit the asteroid belt, and it does n't take much extrapolation to see the next generation exploiting the Oort Cloud - the sky doesn't seem to be the limit. Olaf Staptleton was a piker.

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Bill Sloman, Sydney