Astronomy Without A Telescope – Why The LHC Won’t Destroy The Earth

by Steve Nerlich on August 27, 2011

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Concerns about a 'big science machine' destroying the Earth have been around since the steam engine. The LHC is the latest target for such conspiracy theories. Credit: CERN.

Surprisingly, rumors still persist in some corners of the Internet that the Large Hadron Collider (LHC) is going to destroy the Earth – even though nearly three years have passed since it was first turned on. This may be because it is yet to be ramped up to full power in 2014 – although it seems more likely that this is just a case of moving the goal posts, since the same doomsayers were initially adamant that the Earth would be destroyed the moment the LHC was switched on, in September 2008.

The story goes that the very high energy collisions engineered by the LHC could jam colliding particles together with such force that their mass would be compressed into a volume less than the Schwarzschild radius required for that mass. In other words, a microscopic black hole would form and then grow in size as it sucked in more matter, until it eventually consumed the Earth.

Here’s a brief run-through of why this can’t happen.

1. Microscopic black holes are implausible.
While a teaspoon of neutron star material might weigh several million tons, if you extract a teaspoon of neutron star material from a neutron star it will immediately blow out into the volume you might expect several million tons of mass to usually occupy.

Notwithstanding you can’t physically extract a teaspoon of black hole material from a black hole – if you could, it is reasonable to expect that it would also instantly expand. You can’t maintain these extreme matter densities outside of a region of extreme gravitational compression that is created by the proper mass of a stellar-scale object.

The hypothetical physics that might allow for the creation of microscopic black holes (large extra dimensions) proposes that gravity gains more force in near-Planck scale dimensions. There is no hard evidence to support this theory – indeed there is a growing level of disconfirming evidence arising from various sources, including the LHC.

High energy particle collisions involve converting momentum energy into heat energy, as well as overcoming the electromagnetic repulsion that normally prevents charged particles from colliding. But the heat energy produced quickly dissipates and the collided particles fragment into sub-atomic shrapnel, rather than fusing together. Particle colliders attempt to mimic conditions similar to the Big Bang, not the insides of massive stars.

2. A hypothetical microscopic black hole couldn’t devour the Earth anyway.
Although whatever goes on inside the event horizon of a black hole is a bit mysterious and unknowable – physics still operates in a conventional fashion outside. The gravitational influence exerted by the mass of a black hole falls away by the inverse square of the distance from it, just like it does for any other celestial body.

The gravitational influence exerted by a microscopic black hole composed of, let’s say 1000 hyper-compressed protons, would be laughably small from a distance of more than its Schwarzschild radius (maybe 10-18 metres). And it would be unable to consume more matter unless it could overcome the forces that hold other matter together – remembering that in quantum physics, gravity is the weakest force.

It’s been calculated that if the Earth had the density of solid iron, a hypothetical microscopic black hole in linear motion would be unlikely to encounter an atomic nucleus more than once every 200 kilometres – and if it did, it would encounter a nucleus that would be at least 1,000 times larger in diameter.

So the black hole couldn’t hope to swallow the whole nucleus in one go and, at best, it might chomp a bit off the nucleus in passing – somehow overcoming the strong nuclear force in so doing. The microscopic black hole might have 100 such encounters before its momentum carried it all the way through the Earth and out the other side, at which point it would probably still be a good order of magnitude smaller in size than an uncompressed proton.

And that still leaves the key issue of charge out of the picture. If you could jam multiple positively-charged protons together into such a tiny volume, the resultant object should explode, since the electromagnetic force far outweighs the gravitational force at this scale. You might get around this if an exactly equivalent number of electrons were also added in, but this requires appealing to an implausible level of fine-tuning.

You maniacs! You blew it up! We may not be walking on the Moon again any time soon - but we won't be destroying the Earth with an ill-conceived physics experiment any time soon either. Credit: Dean Reeves.

3. What the doomsayers say
When challenged with the standard argument that higher-than-LHC energy collisions occur naturally and frequently as cosmic ray particles collide with Earth’s upper atmosphere, LHC conspiracy theorists refer to the high school physics lesson that two cars colliding head-on is a more energetic event than one car colliding with a brick wall. This is true, to the extent that the two car collision has twice the kinetic energy as the one car collision. However, cosmic ray collisions with the atmosphere have been measured as having 50 times the energy that will ever be generated by LHC collisions.

In response to the argument that a microscopic black hole would pass through the Earth before it could achieve any appreciable mass gain, LHC conspiracy theorists propose that an LHC collision would bring the combined particles to a dead stop and they would then fall passively towards the centre of the Earth with insufficient momentum to carry them out the other side.

This is also implausible. The slightest degree of transverse momentum imparted to LHC collision fragments after a head-on collision of two particles travelling at nearly 300,000 kilometres a second will easily give those fragments an escape velocity from the Earth (which is only 11.2 kilometres a second, at sea-level).

Further reading: CERN The safety of the LHC.

k.skynr August 30, 2011 at 7:20 PM

What I think this whole theory hinges on, and was touched on in passing by the Author. Is that the hypothetical microscopic black hole even though weak and rare in its ability to collide with normal mass, is not normal and even though having left the gravity of the Earth, might have caused a wormhole depression at the point at which it originated and even further as it collides with other particles in Earths interior. Kind of like a virus infecting the organs of the body, which would then have a cumulitive effect and numerous points at which black hole collapse might begin.

WaxyMary August 30, 2011 at 8:07 PM

@k.skynr,

Your statements:

What I think this whole theory hinges on, and was touched on in passing by the Author. Is that the hypothetical microscopic black hole even though weak and rare in its ability to collide with normal mass, is not normal and even though having left the gravity of the Earth, might have caused a wormhole depression at the point at which it originated and even further as it collides with other particles in Earths interior.

The actual article you claim to have read is more clear than your review of it here. The Author (Steve Nerlich) actually stated contrary views to what you claim, and not just in passing and he never affirmatively touched on any issue you have brought forward.

Nowhere did Steve claim a wormhole depression at the point of origination or the continued impact on particles within the Earth other than to state, plainly and in no uncertain terms, that any Microscopic Black Hole would –

Here, I’ll just pull the QUOTE from the article… this hypothetical is the only place where Steve brings up any possibility for encounters with Earthly matter. The keyword here is LINEAR, you know, straight line motion. I do not know about your particle accelerators, but here and now we build them as flat to the geode as is possible –never in a perpendicular to the geode.

“It has been calculated that if the Earth had the density of solid iron, a hypothetical microscopic black hole in linear motion would be unlikely to encounter an atomic nucleus more than once every 200 kilometres – and if it did, it would encounter a nucleus that would be at least 1,000 times larger in diameter.”

Additionally he stated –
So the black hole couldn’t hope to swallow the whole nucleus in one go and, at best, it might chomp a bit off the nucleus in passing – somehow overcoming the strong nuclear force in so doing. The microscopic black hole might have 100 such encounters before its momentum carried it all the way through the Earth and out the other side, at which point it would probably still be a good order of magnitude smaller in size than an uncompressed proton.

Where do you get anything remotely resembling your statements, even in passing, from what I show quoted from the article.

Kind of like a virus infecting the organs of the body, which would then have a cumulitive effect and numerous points at which black hole collapse might begin.

Nowhere in the article did Steve state anything which could be construed by any rational and reasonable person to remotely equate, even in passing, this statement you have made.

If one were to fill out the premise make here, inflate the correlations and assumptions into something testable one would find this statement unable to support the tissue of fantasy used in its composition.

Mary -contagion is all too common in the lunatic fringe-

Anonymous August 31, 2011 at 12:11 AM

At 1-10 TeV the radius of a black hole is about 10^{-49}cm, which is much smaller than the quantum unit length for a black hole 10^{-33}cm. The “black hole” produced is called a soft black hole, or a shadow state of a black hole. It is not at all a black hole that can grow by consuming matter. The quantum amplitudes for a black hole at the scale of 10^{-33} has a renormalization “flow” to different scales, which means a quark-gluon plasma can assume black hole quantum properties. This is not something which can consume the Earth.

LC

Robert September 10, 2011 at 4:15 AM

That “we are still here” proves nothing. The LHC has been operating less than two years (not “three”) at half-power, and the shortest estimate for a mini black hole consuming the Earth is “50 months to 50 years” (Prof. Otto Rossler). Unlike cosmic rays hitting Earth, the symmetrical collisions in the LHC can result in a slow down of the products, some to below escape velocity (not “a dead-stop”). Thus, regarding neutral microscopic black holes, CERN’s safety report admits: “Those produced by cosmic rays would pass harmlessly through the Earth into space, whereas those produced by the LHC could remain on Earth.”

Higher energy cosmic rays would merely cause a faster exit of such products. In 2008 CERN relocated the cosmic ray argument to dense neutron stars and white dwarfs but, as its analysts conceded, these are shielded by powerful magnetic fields, which may deflect or weaken cosmic rays so they can’t form black holes.

Steve Nerlich claims: “Microscopic black holes are implausible.” But according to CERN physicists, “the 14 TeV centre-of-mass energy of the LHC could allow it to become a black-hole factory with a production rate as high as about one per second” (A. Barrau and J. Grain, CERN Courier, Nov 12, 2004).

Mr. Nerlich also claims that a “microscopic black hole couldn’t devour the Earth anyway.” Yet even three physicists affiliated with CERN found that if “the LHC produces a…black hole which gets stuck” in the earth, then “with one extra dimension, the earth would be accreted into the black hole in 27 years” (B. Koch et al. at ArXiv.org, 7/22/2008, v.1). LHC critics never claimed there’d be instant doom, only an eventual risk, nor that CERN leaders are conspiratorial – only that they’re reckless.

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