Hmmm.......

[Xymox]

This is a interesting new paper

http://arxiv.org/PS_cache/arxiv/pdf/091 ... 1884v1.pdf

"The existence of extra spatial dimensions [1, 2] and a
sufficiently small fundamental scale of gravity opens up
the possibility that microscopic black holes can be produced
and detected [3, 4, 5] at the Large Hadron Collider
(LHC). Since the existence of large extra dimensions permits
the formation of microscopic black holes, these large
extra dimensions and black holes will be searched for at
the LHC. Therefore it is important to study all of the implications
of the Randall-Sundrum (RS) model for black
hole production and decay at the LHC."

[c.h.man]

They lost me at "ds2 = e−|y|/` gμ dxμ dx + dy2".

I found the conclusions part of the paper you linked to also interesting (especially for those who are worried about the project destroying the world)

"Tables IV and V then show that, for black holes trapped inside the Earth, after a time comparable with the age of the present Universe, the mass is on the order of 10−14 kg, which is still negligibly small."

The article explains (before the quote above) why the earth would never capture a black hole in the first place.

[Texanguy]

"Significant amounts of missing energy"..nothing catastrophic, right? hmm.. i'll keep my faith in the numbers. people that know what they're doing suggest its all safe, so yeah..i'll believe its safe.

[Texanguy]

i'll believe it's safe also because of similar experiments carried out at RHIC and Tevatron..as well as particle colliders before them (as there have been more)..and those had no catastrophic consequences..so the process of such collisions must be safe ._.

[Xymox]

Yep !

Safe it will be, no doubt.

The only thing I have EVER had -ANY- concern about is in 10-20 years when we might be able to exceed the energies of cosmic rays. EeV or PeV will alarm me and I know physicists will take those kinds of energies seriously. So I am still not too worried.

But what I found interesting in that story is that a black hole was kinda more like a particle and could pass through matter. That was kinda interesting. I am NOT a physicist and I had not considered a black hole as being as tiny as a particle. It was interesting.

Do we know if this occurs now in nature ? Have we detected this ? I would think this could be common ? If the GeV collisions that will occur in the LHC can generate these micro black holes then I would think that cosmic rays could too ?

If cosmic rays don't generate micro black holes then i would think that the LHC will not either ?

BUT im a novice and know nothing really.. But it did cause me to go Hmmmmmm....

[Xymox]

http://arxiv.org/ is NOT peer reviewed. Thats important to keep in mind. That means that other scientists have not independently reviewed the papers for errors and only a very basic check is done.

So its important to keep that in mind.

[c.h.man]

But what I found interesting in that story is that a black hole was kinda more like a particle and could pass through matter. That was kinda interesting. I am NOT a physicist and I had not considered a black hole as being as tiny as a particle. It was interesting.

From what I understand (I'm not a physicist either), the black hole will be smaller than the protons it's made of. Since atoms are mostly space, I don't have a hard time believing the black hole could pass through most of them without incident like neutrinos will. I'll go hunting for more information, see if I can find something more substantial than "From what I understand", and return with what I learn tomorrow.

[Xymox]

Interesting !

Yes I was thinking neutrinos...

But, they wouldn't react with stuff they hit ? This is interesting.

Also would a spray of them from constant collisions produce a harmless form of radiation ?

Wow.. Black radiation... Kinda catchy phrase...

Now nobody start freaking out. Its HARMLESS... I think...

Well you know.. the whole paper is not peer reviewed so it might not even be possible AND one escaping the detector is only under weird conditions and it living long enough to go anywhere would be difficult..

I dont think its dangerous at all, but very interesting...

At the least Black Radiation is a great science Fiction idea. It could have really freaky effects that alter time and space. Good stuff for scifi movies.

I think its pure scifi tho. Fun thought...

[Texanguy]

Hmm..well the general consensus of actual (non-alarmist) physicists is that micro black holes, if created at the LHC, will not have a macroscopic effect, if any effect whatsoever. according to the laws of hawking radiation, the smaller the black hole, the faster and hotter it radiates, so the quicker it is gone..meaning the less time it has to accrete any matter. i read somewhere that even a black hole the size of an automobile would only take a matter of nanoseconds to evaporate.. seemed pretty interesting to me. i don't think the energies of the LHC are strong enough to create a black hole,though..and even if it does, when you really put it into perspective, it's hard to imagine a black hole smaller than two ..protons.. gobbling up the earth. it just sounds silly at that point.

[Xymox]

But wait... we need good scifi !. Good end of the world stuff !.. Dont spoil it with reality !

These is a point where a black hole goes from evaporation to expansion. Again im not a expert AT ALL. But I think I read that its a pretty small size ? This paper talks about that. In insanely technical math. But I am not sure about this.

I still am interested in if cosmic rays produce micro black holes ? They should right ? We should be able to detect them ? If we can detect them, and we dont see them, does that imply that LHC will never be able to produce them ?

[c.h.man]

My search wasn't very productive.

I still am interested in if cosmic rays produce micro black holes ? They should right ? We should be able to detect them ? If we can detect them, and we dont see them, does that imply that LHC will never be able to produce them ?

Kinda hard to detect something that lives for only an instant, especially when it isn't in a controlled environment, miles above the Earth. If there are more dimensions, like in string theory, then cosmic rays can produce micro black holes.

[Xymox]

But cosmic rays do make it to the ground. The LHC detectors have been doing "Cosmics" and watching the stuff from space go thru the detector. Not many of them of course.

Once a BH is created by a cosmic ray it might have terrific momentum right ? So they could travel a terrific distance in a very short time and might then continue to the ground. Maybe we could detect them when they strike some other particle ? Rare as that would be ?

I would think we should have seen this already with other cosmic ray monitoring ?

[Xymox]

Man that quote color is ugly huh ? I will have to look at that and see if I can fix it.

[c.h.man]

It reminds me of orange cream soda

Yeah, you could be right. Maybe a large vacuum filled container, with something that could detect the radiation given off by the black hole as it passes through. It would be a quantum needle in a haystack.

[Xymox]

There we go. Quote color all fixed... Man that was ugly.....

Well we have some pretty intense experiments deep underground looking of rare particles. You would think they might have already detected some of these things..