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End of World One Step Closer. Or Not. Answered

A vast physics experiment - the Large Hadron Collider (LHC) - reaches a key milestone this weekend ahead of an official start-up on 10 September.

Engineers had previously brought a beam of protons - tiny, sub-atomic particles - to the "doorstep" of the LHC.

On 9 August, protons will be piped through LHC magnets for the first time.

The most powerful physics experiment ever built, the LHC will re-create the conditions present in the Universe just after the Big Bang.

  • This last sentence is the one that's caused a little panic amongst certain groups of the population - they are convinced that the experiment will create miniature black holes which will fall through the LHC towards the centre of the Earth, where they will orbit around, gradually consuing the planet from beneath our feet.

When the collider is commissioned, the beams will cross paths at allotted points along the tunnel, smashing into one another with cataclysmic force.

  • My God, have these people never seen Ghostbusters??

Scientists hope to see new particles in the debris of these collisions, revealing fundamental new insights into the nature of the cosmos and how it came into being.

Now that is seriously cool (well, hot, actually) - to be able to recreate what the whole of reality looked like mere femtoseconds after it started...

BBC story

Critics have previously raised concerns that the production of weird hypothetical particles called strangelets in the LHC could trigger the mass conversion of nuclei in ordinary atoms into more strange matter - transforming the Earth into a hot, dead lump.

Earlier BBC story

Amusingly paranoid story

Analog Magazine article



10 years ago

I assume the definition of event horizon is that point where the escape velocity becomes greater than speed of light. Now if we fire in a bullet towards a black hole, but a bit offcenter such that the projectile goes in like a comet which is not aiming the sun. If the projectile goes beyond the event horizon, why would it not come back out? It did gain the energy to come out while on the way in. Amusingly, I think I have a way to exceed the speed of light. If the laws of physics work symmetrically, if a particle at event horizon needs greater than light speed to escape the black hole, then a particle falling into the black hole faster than say, a particle starting at rest from infinity, will be accelerated to higher than light speed when it hits the event horizon :-) Or have we changed the definition of event horizon? On the same lines, I guess any particle which is not aimed at the dead centre of the black hole should be able to simply loop out...

Anything entering at or below the event horizon will spiral into the singularity.

Just crossing the horizon does not mean they exceed c. To escape, they have to exceed c, and since they cannot even reachc, that is impossible.

Look at my reply to Adrian Monk... What I was wondering was that according to symmetry, if I expend x amount of energy/velocity coming far from a heavenly body like the earth/sun etc, I should gain the same amount while falling in. Since no amount of energy/velocity is enough to escape a black hole, a particle falling into the black hole should gain precisely that amount of energy and velocity - which are infinite energy and "more than speed of light"... Ofcourse this sounds absurd... what I was wondering is how they understand/resolve it.

A) Do you mean supersymmetry? If so, the answer is no. The theory of super-symmetry doesn't have to do with that.

B) Energy and velocity are two very different things.

C) Well, no-there's no relationship there. It might happen, depending on your velocity while you're heading there, but not necessarily.

D) What?

E) It is impossible to gain have infinite energy.

Aww... lets just agree that we wont reach the answer between us. I cant explain the question any more :-)

Actually, I just noticed this, but the definition of even horizon is as follows: The point at which an object can never escape the black hole. There is no way to locally tell if you have passed the event horizon, it's not marked in any way.

But they can't exceed the speed of light. According to Einstein, you can't even attain it. You can come very, very close, but you can never reach, or exceed the speed of light.

I know... we cant attain speed of light. But what I have is a question of symmetry. Imagine the following situation... Escape velocity from earth is 11km/sec. If atmospheric friction and other heavenly bodies are ignored, then an object fired up from the earth surface at 11 km/sec will get away from earth and become slower and slower such that asymtotically, it will come to rest at infinity. Reversing this, we see that any object sufficiently far from earth at rest will start to accelerate towards the earth and will reach a velocity of 11 km/sec when it hits the surface. How does the same scenario play out in the case if the earth surface is replaced with the black hole's event horizon. Gravity is so strong that maximum velocity possible is not good enough to escape... reversing this situation, what velocity will a particle attain if sent in from far away? Same question to kiteman as well.

> it will come to rest at infinity. That comment shows a lack of understanding of the concept of infinity. Nothing can come to rest at infinity. First of all, infinity is a mathematical concept, not a place. Secondly, by definition, this object would never come to rest. >any object sufficiently far from earth at rest will start to accelerate towards the earth and will reach a velocity of 11 km/sec when it hits the surface. No it won't. Newton showed this. Objects at rest stay at rest unless acted on by an outside force. You mentioned no force. >what velocity will a particle attain if sent in from far away? Do you mean, how fast will a particle go if it crosses a Schwarzschild black hole's event horizon? Distance should make no difference, assuming the particle is, as Kiteman said, at or below the event horizon. If that is your question, the answer is impossible to define-scientists believe the answer to such a question would require a knowledge of quantum physics which we do not possess.

I apologize for my last comment which I deleted ... I was a bit rude. for point 1 - The word asymtotically means just that. As the particle goes farther and farther, it becomes slower and slower, so that when you draw a graph, it will "seem" to come to zero velocity but after travelling a huge distance. for point 2 - earth's gravity will pull the object. point 3 - I think this is an interesting question which physicists must have thought about... just need to find one who can shed some light. :-)

I didn't see the comment, but whatever it said, I forgive you. :-)

Again, unless acted upon by another force, it will keep on going forever-Newton's first law of motion.

All I'm saying is that a particle at rest, beyond the event horizon, will stay at rest, unless acted upon by an outside force.

It's definitely an interesting question-unfortunately, it's also impossible to answer at this point in time. Maybe in a few years, after scientists have analyzed the data from the LHC...


10 years ago

It will create Black Holes, but they will be destroyed in less than 1 second. Natural reactions with much more energy occurs naturally in the atmosphere. There is no damage.

It might create black holes.

But other than that, yes, that is correct.

Good that you missed it.. I take back my apology :-)

*Brow furrows in confusion* Then I take back my forgiveness... :D

Bring it on.


10 years ago

Check out the Large Hadron Rap:


There are so many reasons that should suck, but none of them are true.

Thats one mad beat son!

Can someone explain to me why a black hole with the mass of a couple protons is going to have more gravity than a couple of protons? The fact of being a black hole doesn't automatically cause everything to get sucked into it. The gravitational force is going to be overpowered by all the other forces in such a case anyway - why all the fright? Do people just like being scared?

It's the gravity gradient - anything that gets close enough goes in, and doesn't come out.

Potentially, if an electrically-neutral black hole was created, it would drop out through the bottom of the accelerator and through the earth. It would then "see-saw" back and forth through the planet, devouring the occasional subatomic particle on the way.

Gradually, slowly, it would build in mass and size, until it started to eat whole atoms, then larger and and larger masses until, at some point, the whole planet starts to collapse and the whole thing folds into the hole.

The bizarre thing is that all the orbiting objects - satellites, the Moon, would remain in their orbits (although a little fried by X and Gamma radiation emitted by the collapse.

Fun thing: if you find a small black hole - say a few hundred thousand tonnes - you can feed it charged particles until it gains a net electrical charge. It can then be moved and restrained by electrostatic generators or electromagnetic fields. It can then be used as a power supply, dropping stuff in (anything, including nuclear waste) and using the energy flashes to drive a conventional steam-driven power station.

anything that gets close enough goes in...

Considering the Pauli Exclusion Principle, wouldn't particles that small have no chance of collision (at least, in relatively docile states)? And wouldn't a black hole that small evaporate at a ridiculously fast pace? (To quote W-Pedia, "a 1-second-lived black hole has a mass of 2.28 × 105 kg...")

I didn't say it would happen...

That is what I was waiting for. I have no need to freak out until Kiteman says it is time to freak out.

. Has anyone guesstimated how long it would take to devour the Earth? . Hadn't thought about the orbiting objects staying put, but since there is no gain in mass, it makes sense. I'm guessing, that during the final collapse, enough energy would be emitted to actually push most objects out of orbit (or vaporize them). . I haven't seen anything on "charged" black holes. Sounds very interesting. Wow! Google turns up 1,980,000 hits for "charged black hole"

Is this from the that documentary "The Big Bang Machine?"

This thing scares the crap outta me. People on /b/ keep ranting that this thing's gonna create black hoes, and it seems scarily real... Oh well, they built it, so whatever happens...happens.

"...hardon colliders."

Of course they are experts on hard-on colliders...


Hahahahahahaha. This is /b/ we're talking about! hardon collider. *snicker*


..create black hoes..

</lack of maturity>

Might want to read your comments before you post them..


Oh wow, didn't see that lol!!!

My 'l' key has been sticking lately...

I'm not sure you even realize the irony of that typo though. =P

Haha, Its okay, It happens to the best of us.. *snicker

I saw that I just didn't want to bring it up XD

Ahh that's awesome... Now to get myself enough money to buy one of mine own...

What! You want one of those and make black holes and have the black holes to eat you!!!

Haha, joshf kind beat you to it...

LOL, I didn't look at the dates-why wasn't this one featured instead of making a redundant post, I wonder? Oh wells, no big I guess...

He just didn't check before he posted. He's added a backlink now, though.

That's good. (ROFLOL at the ninny who thinks that the LHC will cause a "time travel" and its firing up will cause it to never fire up.)

particle physicist colleagues raise your hand :-)

People need to ignore any countdown that exists. CERN has stated that they don't know when they're going to actually start doing the experiments, so no countdown can be correct.
And oddly enough, the most popular counter out there, whose url I can't remember, is actually run by a /b/-tard.

We're safe until sometime september, at least. And I seriously don't think that the world will end.