No this is not a line from a new novel by Douglas Adams, but our regular doomsayers. Yessir, not only have we become powerful enough to destroy the Universe, we are foolish enough to do it too! So after several failed warnings, finally the end of the world is in sight and you do not have to pay your EMI any more. Only this time it has not do with the turn of the millennium or a celestial body bringing the wrath of the Gods or the second coming of Christ, but something we humans are going to unleash upon ourselves. And it goes by the inane name of LHC. No it is not a mass hypnosis drug - far from it - LHC stands for the Large Hydron Collider, the largest particle accelerator in the world.
What are particle accelerators, you ask and how can one end the world? Well particle accelerators are instruments built by physicists (the Einstein variety of scientists - classification by subject matter, not gray) to study the behavior of very tiny particles at high energies. To get these tiny particles at the high energy levels, they make them go round and round in a long circular tube, accelerated by magnetic fields, till they start approaching the fastest speed possible - that of light in vacuum (a staggering 300,000 km / second). Then these particles are smashed into one another producing fireworks which the physicists watch with anticipation and glee. The glee is mostly because of being able to spend billions of dollars to smash things into one another at high speeds, but occasionally is also caused by observation of phenomena that reveal truths about the fundamental nature of our world - how the Universe got created and why things work the way they do.
At a length of 27 km and a budget of 6 Billion dollars, the LHC is just the largest and the most expensive of these toys yet. And apparently this toy can create particles that can destroy our world, or so say some scientists. Nay, say the toy makers- CERN - the same lot who built the world wide web. Nay, also say the 7000 odd kids who are going to play with the toys - some of the most eminent physicists of the world. The situation has the beautifully tragic potential of a foolish young civilization ending itself by probing too deep into the mind of God. It also has an element of ironical comedy which would have fitted straight into a sub-plot of the Hitchhiker's Guide to the Galaxy. But we are dealing with an important question here - whether to pay the EMI or not - and must find out which camp to believe.
Now popular media cannot be believed, since it is caught up between two forces - the commercial force of getting more eyeballs which leads to sensationalism and the commercial force of credibility so that they can continue to get eyeballs which leads to more responsible reporting. Of course when it comes to such a juicy story, the immediate grabbing of eyeballs is more important, credibility can be built by other stories. Which is why you see "News" channels these days warning people against the wrath of the solar-eclipse and the evil eye of Saturn in the vocal styles of C-grade horror movie protagonists - it is all about immediate cash flow. However, this blog is not constrained by commercial interests - partly because my employers take good care of me (not for long, says my manager, if I continue writing such pieces), but mostly because Microsoft is late to bring out an ad-module for Live Spaces. So lets examine the arguments on both sides.
Of the several particles that would be produced at the LHC, the following four are the ones under the spotlight:
1) Micro Black Holes:
What is a Black Hole?
All masses attract each other thru the force of gravity. However the force is very weak - if you place two balls apart, they do not automatically collide since the force of attraction is unable to overcome the force of friction. This force of gravity increases as the mass of an object increases and the distance between the objects decreases. For objects as large as the planet Earth, the force is quite strong - actually it is this force that holds you and me to Earth. Since matter is made up of smaller particles, all particles also attract thru the force of gravity, a single piece of matter can get compressed. However, the internal repulsive forces prevent this from happening. Which is why we do not collapse to a single point. However, when the mass is as high as a Star, the internal pressures can be overcome and the mass can collapse on itself undergoing a compression. The reason Stars do not collapse is because the tight compression fuses nuclei and generates energy which pushes particles apart, preventing further compression. However, very large stars, after exhausting their nuclear fusion can go on compressing infinitely producing what is called a Black Hole. Nothing is able to escape the gravitational pull of a Black Hole, not even light with its fast speed. That is why the name Black Hole - it cannot be seen because light is not able to escape it. So a black hole swallows matter around it and grows stronger. However, Black Holes are not a one way tunnel. Stephen Hawking proved that Black Holes evaporate energy, diminishing their mass gradually unless they completely disappear. This is called Hawking Radiation. Hawking Radiation is stronger for smaller black holes than larger black holes. This means that a small black hole radiates energy faster. Since the pull of a small black hole is smaller, it also grows slowly as compared to a larger black hole. Hence, a small black hole dissipates faster than a big one.
What is a Micro-Black Hole?
Theorists have long held that lighter black holes are also possible. As light as a millionth of a gram! However, the energy that it would take to produce such a small black hole is quite high. Now remember that in the LHC, particles would collide at very high energies, so maybe, just maybe a micro black hole can get formed. According to one theoretical model however, the energy required would actually be just sufficient and micro black holes can get formed at a rate of as much as one black hole per second in the LHC.
What is the Danger?
Since black holes grow and swallow other mass, there is a chance that a micro black hole will be formed that can swallow the entire Earth. There are several factors required to lead to this situation:
a) Micro black holes should be formed in the first place. The currently accepted models of micro black holes put the energy levels required at a thousand times the capability of the LHC. The doomsday scenario people claim that an alternative model makes it possible
b) The Micro black hole must not evaporate. This would happen only if Hawking Radiation is not a true phenomenon - that is, only a theoretical curiosity, not an actual fact.
c) The Micro black hole would be produced at low velocity so that it does not cross the Earth very quickly. At a high speed (remember the particles are colliding in the LHC at speed approaching that of light), the particle can leave the Earth very quickly without causing any harm
2) Strangelets:
All matter consists ultimately of a set of fundamental particles called Quarks and Leptons. I will not explain Quarks and Leptons here, you can read more on them on my other blog. There are 6 kinds of Quarks and one of them is called the Strange Quark. Don't go on the name - the scientists named the quarks in creative ways and all quarks are equally strange. Typically matter is made of neutrons and protons which are made of Quarks called Up and Down quarks. However, there can also be matter made of Up, Down and Strange Quarks and such matter is called Strange Matter. Strange matter can occur in the core of very dense stars called neutron stars (these stars fall somewhat short of being a black hole) or in isolated droplets called Strangelets or a neutron star may get converted to a Strange Star if the mass is very high, but just short of being a black hole.
What is the Danger?
Typically we do not observe Strange matter because it is unstable. However, it is possible that if there is more of Strange Matter, it may be stable. The LHC may produce strangelets in enough quantity that they become stable. It is also possible that when a strangelet comes in contact with another nucleus it may convert that to a strangelet as well, thus setting off a chain reaction which may convert all of matter on Earth into Strange Matter.
3) Vacuum Bubbles:
There are theoretical models that predict that the vacuum in space is not the lowest-energy vacuum, but that there is a lower state vacuum called True Vacuum. This means that the Universe has False Vacuum. Thus at some point, our Universe may transition into the True Vacuum. However, this has not happened in 13 billion years so far. At LHC, since very high energy conditions would be there, it is possible that a region of True Vacuum - called a Vacuum Bubble may appear.
What is the Danger?
If a Vacuum Bubble is created, space surrounding it would also collapse into a lower energy state and it would expand. Such a bubble can grow at the speed of light and convert the entire Universe in a state of True Vacuum. This can destroy the Universe as we know it.
4) Magnetic monopoles:
If you have seen a magnet, you know it has two poles - North and South. Ever seen a magnet without two poles? What do you think would happen if you cut a magnet in half? People have tried this, and it leads to two magnets - each with two poles. No one has a seen a magnet with a single pole - a magnetic monopole. However, current theories predict magnetic monopoles, in fact they require that magnetic monopoles exist in order to be self-consistent. Just that they have not been observed anywhere, simply because they are obviously very rare and hence not likely to be encountered by a particle detector. Also, because they are very heavy, they are not created by particle accelerators. However, the LHC is a bigger and more powerful accelerator than any. And hence the possibility of a magnetic monopole getting formed.
What is the Danger?
In some models, it is predicted that a magnetic monopole can catalyze nucleon decay - this means that if a magnetic monopole strikes a large number of nuclei, causing them to decay and to release massive amounts of energy creating a gigantic nuclear explosion.
What Does CERN say?
Having understood the various threats in a little bit of detail, let's now try and see why CERN and a majority of Earth's physicists are not worried about this. The basic argument has to do with the LHC experiment being common in nature. To understand that we need to understand a phenomenon called Cosmic Rays.
Earth is constantly bombarded by high energy protons coming from deep space. These particles zipping all around us - called Cosmic Rays - originate in the Sun, in Supernova explosions in the outer Galaxy, in the Super-Heavy nuclei of various Galaxies, in Gamma Ray bursts, and in phenomena we do not know / understand yet. These particles can travel at very high energies. The highest energy comic ray possible is defined by the GZK limit and is held at 6 x 1019 eV - around that of a tennis ball thrown at 90 km/hr. However, cosmic rays with higher energies have also been observed and these are called Ultra High Energy Cosmic Rays. The magnetic field of the Earth and the Sun is able to divert most Cosmic Rays towards the poles - this is what leads to the beautiful Northern Lights phenomenon, and that is one reason why life was able to originate on Earth - the magnetic field allowed creation of more complex molecules which would not have been possible under an open exposure to the Cosmic Ray shower. But the point is this - Cosmic Rays are common.
What does this have to do with the LHC? Just this - the particles produced in the LHC would have energies around 1017 eV - three orders of magnitudes less than the highest energy cosmic rays! What? I hear you ask! Then why spend 6 billion dollars of tax payers money to produce stuff that nature already produces??? Well, one reason is that big boys like playing with big toys. The other reason is that the particle accelerator provide controlled environments to reproduce and study such phenomena which is not possible in the open Cosmic Ray environment. Nevertheless, the collision energy produced in the LHC is far less than what occurs in nature and hence it would not produce anything which is not otherwise found in nature. It would just provide an environment to study the phenomenon. According to CERN:
"Over the past billions of years, Nature has already generated on Earth as many collisions as about a million LHC experiments – and the planet still exists. Astronomers observe an enormous number of larger astronomical bodies throughout the Universe, all of which are also struck by cosmic rays. The Universe as a whole conducts more than 10 million million LHC-like experiments per second. The possibility of any dangerous consequences contradicts what astronomers see - stars and galaxies still exist."
While CERN also goes on to publish rebuttals to each type of threat individually, to me the argument above sounds like a good one. If you are interested in a more detailed discussion, read http://cern.ch/lsag/LSAG-Report.pdf.
So my recommendation is to plan your life on the assumption that the world is not ending. Not tomorrow when they inject the first set of particles, not after a couple of months when the LHC is fully functional, and not after a few years when enough meta-stable micro-black holes, magnetic monopoles, strangelets and vacuum bubbles have accumulated to destroy everything we know and love. And yes, do pay your EMI. I am continuing to pay, and so are the doomsayers!
