Black Holes From the LHC Could Last For Minutes

KentuckyFC writes "There is absolutely, positively, definitely no chance of the LHC destroying the planet (or this way either) when it eventually switches on some time later this year. And yet a few niggling doubts are persuading some scientists to run through their figures again. One potential method of destruction is that the LHC will create tiny black holes that could swallow everything in their path, including the planet. Various scientists have said this will not happen because the black holes would decay before they could do any damage. But physicists who have re-run the calculations now say that the mini black holes produced by the LHC could last for seconds, possibly minutes. Of course, the real question is whether they decay faster than they can grow. The new calculations suggest that the decay mechanism should win over and that the catastrophic growth of a black hole from the LHC 'does not seem possible' (abstract). But shouldn't we require better assurance than that?"

Comments

Its all okay. Nothing to see here.

[tnk1]

There is absolutely, positively, definitely no chance of the LHC destroying the planet (or this way either) when it eventually switches on some time later this year. ...

But physicists who have re-run the calculations now say that the mini black holes produced by the LHC could last for seconds, possibly minutes. Of course, the real question is whether they decay faster than they can grow.

Well its good to know that despite their uncertainty about the the data, they are absolutely certain of their conclusions.

Well...

[AltGrendel]

...there's one sure way to find out.

Fire it up, boys!

cosmic rays

[cats-paw]

I thought that this entire line of doomerism had been dispensed with thanks to cosmic rays.

Since cosmic rays are striking the earth all the time, and a decent percentage of them have a much higher energy level than anything the LHC can produce, we should have already seen such a phenomena.

?

Re:cosmic rays

[Goldsmith]

There is no need for comments on this article other than the parent. In fact, this article should just be put into idle.

As a physicist, this whole thing has been an embarrassing reminder of just how bad physicists are at public relations and the failure of many people to think logically. I'm not the biggest fan of LHC, but I'd like to see some intelligent criticism out there (Is this really where we should be putting our smartest scientists? Are particle accelerators the best way to do this measurement?), not this junk.

Re:cosmic rays

[Thiez]

> Is this really where we should be putting our smartest scientists?

What gives us the right to decide where to 'put' 'our' smartest scientists? They belong to themselves, right? It is their choice what to do with their brains (cure cancer or get drunk or work at the LHC).

If you insist on asking a question I guess you could ask 'Do we really want to fund the LHC?'.

Storm in a very, very tiny teacup

[Mindwarp]

The Sun in conjunction with the Earth's atmosphere has been colliding particles with WAY higher energies that the LHC could ever manage for billions of years now. As far as I know we've not been consumed by a mini black hole yet.

Re:Assurances

[jespley]

To put some numbers on this, the LHC will produce protons with 10^14 eV of energy. At that energy, we expect more than 1 per m^2 per year. I haven't seen any black holes recently in the square meters of the Earth's surface I routinely interact with. You? I wish the numerical illiterate would stop scare-mongering.

Gravity still applies

[dazedNconfuzed]

A black hole is just the gravity well of a given mass compressed into a sufficiently small space. In this case, the given mass is miniscule, so very little (practically nothing, hence the "evaporation" issue) will be drawn to it.

You have more to worry about from the gravitational pull of your shoes.

Re:Please Mod Parent Up To The Maximum!

[chunkyq]

The parent post is also a fine example of making grand claims about advanced science without providing a single reference.

Re:Bogus

[LeDopore]

First things first: I'm not an alarmist, and I don't think the LHC will blow up the Earth.

That said, I'd like to point out that not nearly all of that 10^20 eV is available to make new particles/black holes in the center of mass frame of the collision. Since all the collision products will have to have a ton of momentum in the direction that the cosmic ray was originally traveling, the available energy for creating new, potentially dangerous particles scales with the square root of the product of the energies (see http://www-bd.fnal.gov/public/relativity.html for a pretty good explanation of where this square root dependency comes from).

In contrast, the LHC will collide two particles in the TeV range head-on, which means the collisions have more of a chance of creating an "exotic" than even a 10^20 eV particle hitting stationary atmosphere.

However, I bet two high-energy cosmic rays each with energy > 10^14eV sometimes collide with *each other*, and that collision would have more available energy than the LHC collisions. The big question is how often does this happen? If collisions like these happen at a slow enough rate, I could imagine that the LHC might put Earth into unexplored territory in terms of numbers of collisions with ~10^14eV of available (i.e. not constrained to producing products with high momentum) energy.

I trust that the physicists have worked out the rates of these head-on, two-cosmic-ray collisions. Otherwise they would have no right saying that cosmic ray history shows that the LHC will be safe. Still, the only defense based on cosmic rays I've heard has been talking about cosmic rays hitting atmosphere, which isn't valid. Does anyone have a good link to a website analyzing the frequency of head-on two-cosmic-ray collisions?