Illustration from Wikipedia
I recently published two articles discussing Europe's Large Hadron Collider (LHC). In both those articles, I reported concerns that the Collider may pose serious safety threats. Included in the second article entitle "Will Black Holes swallow Switzerland" was a definition of a black hole and the potential consequences should a "mini black hole" be created in under the Swiss countryside.
In this article I will address another of the several concerns raised by plaintiffs in a lawsuit aimed to delay the start of the LHC based on claims that the Collider was a disaster waiting to happen. This other concern involves theoretically lumps of matter commonly know by the peculiar name "Strangelets".
What is a Strangelet?
The simple definition is that a Strangelet is the term given to a hypothetical microscopic lump of "strange matter" containing almost equal numbers of particles called up, down, and strange quarks.
Ordinary matter, including the protons and neutrons that form the nucleus of atoms, is made up of even smaller particles known as quarks. The standard model of particle physics predicts that the universe contains 6 different quarks. Physicists refer to these 6 types of quarks as "flavors". The 6 quark flavors, listed in the order of their respective masses, are referred to as:
1. Up
2. Down
3. Strange
4. Charmed
5. Bottom
6. Top
According to quantum theory and as illustrated below, the proton is composed of two up-quarks and one down-quark. That same theory holds that the neutron is made up of two down-quarks and one up-quark. In addition to the difference in mass, the up-quark and down-quark also differ in electrical charge.
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In addition to ordinary atomic matter which is composed of up and down quarks, experiments have also revealed that the universe has other more exotic particle species. It's through prior collider events that experimenters have identified the four other quarks, including the strange-quark, which is 30 times more massive than the lightest quark, the up-quark. The evidence of these extra exotic quarks may have been plentiful just after the big bang, but today they are produced only as the ephemeral debris from high-energy collisions between the more familiar ordinary particle species.
The incredible energies (approaching conditions present at the big bang) that will be produced at the LHC is where the fear of the Strangelet comes into play.
This hypothetical Strangelet consists of a bound state of roughly equal numbers of up, down, and strange quarks. Assuming that a stable Strangelet can really exist, its size would be a minimum of a few femtometers (10 (-15) m) across with a mass equal to a light atomic nucleus. However, according to the strange matter hypothesis, if the tiny stable strangelet comes into contact with a lump of ordinary matter, such as the atoms within the Large Hadron Collider, it could convert that ordinary matter into "strange matter". The disaster scenario being touted by those trying to stop the collider experiments is as follows: One strangelet hits a nucleus, causing its immediate conversion to strange matter. This reaction liberates energy, producing a larger, more stable strangelet, which in turn hits another nucleus, catalyzing its conversion to strange matter. In the end, all the nuclei of all the atoms of Earth are converted, and Earth is reduced to a hot, large dead lump of strange matter.
So should we be concerned that when the LHC creates a swarm of free-flying quarks, some of those up and down quarks might recombine creating a stable, negatively charged "strangelets" that could transform everything they touch into more strangelets resulting in another end of times scenario? Is it possible that the LHC could create strange quarks that would coalesce with ordinary matter and convert that ordinary matter into strange matter?
According the the experts, the answer is NO. The possibility of a "strangelet" calamity was first raised prior to the start up of the Relativistic Heavy Ion Collider (RHIC) in New York. In 2000, a study of the potential dangers of strangelets showed that there was no cause for concern. Since that time, the RHIC has run for nine years searching for strangelets without detecting any. But won't the LHC produce more energy than the less powerful RHIC? The answer is yes and that is why there is no chance of a run away strangelet at LHC. The fact that the LHC's proton beams will generate more energy and produce "hotter" events than RHIC makes it even less likely that stranglets could form at the more powerful European LHC. And here's why:
The higher the temperature the less likely that a strangelet could form. It is difficult for strange matter to stick together in the higher temperatures produced by large colliders for the same reason that ice does not form in hot water. Models indicate that strangelets are only stable or long-lived at low temperatures. Strangelets are bound at low energies in the range of 1 to 10 MeV, whilst the collisions in the LHC release energies in the range of 14 TeV (1 Megaelectron Volt = 1.0 x 10(-6) Teraelectron Volts). Moreover, the quarks that are produced at LHC will be more diluted than at RHIC, making it more difficult to assemble strange matter. Therefore, strangelets production at the LHC is far less likely than at RHIC which has be operating for the past nine years. The experience at RHIC has validated the notion that strangelets cannot and will not be produced at the LHC.
Comments
Experts say not to worry. They have a conflict of interest. Their expertise is in analyzing these experiments, which they can’t do unless they are safe. They have given many safety assurances that have proved wrong. First, colliders were safe because black hole production required energy beyond reach of any collider. Then string theorists began predicting black hole production at colliders. Then black holes were supposed to dissipate via Hawking radiation. Then two papers questioned the theory behind Hawking radiation. A collection of strangelets was supposed to be electrically positive on its surface and not attract normal matter. Then a new paper found that strangelets could be electrically negative. An analogy between colliders and cosmic rays was supposed to demonstrate safety. However, that analogy was flawed, and had to be modified in a recent safety paper. This history suggests that physics in this area is not mature enough to produce definitive safety factors.
It is to be noted that, thus far, the RHIC Au-Au collisions are of sufficiently low energy that they do not produce enough strange quarks that a quark-rearrangement can occur to create a strangelet.
The intended higher-energy LHC collisions of Lead-Lead will create far more strangelets than the RHIC does, which is the worry. It only takes a fleeting instant for the re-arranged quarks, if enough strange quarks are present, to form a stabilized strangelet. There have been several theorized processes by which this could occur, and which have not been experimentally ruled out by the RHIC, which does NOT produce enough strangelets to do the job.
The intended Pb-Pb collisions are not mimiced in nature, as the cosmic rays do not have high-energy high-Z atoms at the LHC COM energies, and are instead composed of low-Z atoms at those energies, which would not create enough strange quarks even if they were to strike a Pb atom lying on the moon.
The risk is too high.
Say you were to be proved wrong, ie., after billions of collisions in the LHC no potential for an earth-destroying black-hole appears. Will you then admit to your readers you were mistaken?
I say, Let's fire it up and see what happens :)
How naive are you? CERN produces lies that an undergraduate physicist would laugh at. Because the LHC has more energy, and E=Mc2, and viceversa, M=E/c2, the more energy the bigger the mass of the strangelet formed will be. The events with lead at the end of 2010, as the Shangai Institute of Nuclear Physics has proved, will create over 10.000 strange quarks, enough to start up an ice-9 reaction,. The temperature 'alibi' is irrelevant here. Because the collision will take place at ultracold temperature and 'temperature' is a property of electroweak atoms NOT of quarks. What matters is the conversion of energy into mass. Quarks by definition DONT have energy. At RHIC a proto-strangelet that lived billion times more an accrete 10.000 times more was formed. It had all the properties of an ultracold superfluid fermion condensate. At Haifa last month a dumb hole was formed with an atomic condensate and not evaporation was found. The homologous will be a quark hole, a fermion condensate
There has been a couple of accidents at CERN, worst case
a collision takes place and creates strangelets, and at
the same time a failure occurs(happened) with liquid
hydrogen containment.Extreme cold, plenty of matter,
and poof, quark soup.
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