Apologies to our vast international readership who do not have the privilege of paying the BBC licence fee, but tonight there will be a programme on BBC2 at 9pm, called, ahem, Horizon: The Six-Billion Dollar Experiment.
Yes, it is about the LHC.
Since there is absolutely nothing else on the telly tonight, I am sure the whole nation will be captivated by this programme.
Among the questions to be answered tonight:
- Will the BBC get the physics right?
- Might the LHC create a black hole which will gobble up the planet (a question that I was asked at passport control last month!)
- Will anyone tell them that "the God Particle" is a really really useless name for the Higgs? (with all due respect)
- Will any of our colleagues at Imperial HEP appear?
- How will Peter Crouch do against John Terry and Michael Essien?
11 comments:
It seems like a big part of the programme will be on if the public is willing to take the risk that LHC will destroy the planet when turned on. See the voting (and the associated video) at http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/universe/vote/
Where they have got the number that there is a 1 in 50 million chance that the LHC will cause the destruction of the Earth I don't know - presumably from some part of an interview completely taken out of context.
It should be made clear that the energy of the reactions in the LHC are no different from reactions taken every day when ultra high energy cosmic rays hit nuclei in the upper atmosphere. This has taken place for billions of years.
Ulrik
Thanks Ulrik, just checked the voting page out -- the way they ask the question: "Given these odds, do you think the LHC should be turned on" clearly directs you towards answering "No!".
When multiplied with what would be at stake, ie., the destruction of the Earth, 1 in 50 million (wherever that came from!) would not be a number close to zero at all, so of course you wouldn't want to risk it.
They should have another question asking "Given that much higher energy particle collisions are occurring around us all the time, do you believe that the LHC has any chance of causing the destruction of the Earth?".
By the way I told the passport officer who asked me the same question that it is shown by natural cosmic rays that the LHC will not cause the planet to be sucked into a black hole.
Though I did tell the officer about the possible creation of mini black holes at the LHC (which are too small to do anything nasty!). Now I see that that might not have clarified the matter particularly....
I reckon Crouchy will start, but not finish. Chelsea to win, and Yoshi to listen on five Live.
I don't understand why they make such a fuss about black holes in the teaser. The actual show was very nice, starting by explaining how science has been able to look back in time, almost down to the big bang. Then it connects to mass and the Higgs. Well done. Great images!
There's just two minutes on extra dimensions and multi-dimensional black holes. And all their experts say it won't happen. There's just Jim: why did you say we're almost sure it won't swallow Geneva?
So for Yoshi's questions, I say: Well done for the physics, no big deal about back holes, no mention of God, and of course Jim as one of the guides through the film.
Ah, yes, and nobody scored during the film.
Yes, I smiled when Jim Virdee used the word "almost", it was probably a routine qualifier in the sense that nothing is strictly speaking absolutely impossible, and I don't think I would have even noticed it if we hadn't been anticipating a long exposition based on this on LHC black holes gobbling up the Earth.
The one minute they spent on black holes coincided with the last minute of injury time after 90 minutes, so the whole nation probably missed it anyway, and after that I am sure everyone switched back to Horizon to learn about the Higgs.
The unwritten question on everyone's mind "will Mourinho be gracious in defeat?" had the least surprising answer, it goes without saying....
PS. There is a video podcast available for the next 7 days, at http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/podcast.shtml.
Frank Close has shed some light on how the BBC messed up so badly with the promotion surrounding the Horizon programme, in an article in Physics World.
When I asked the producers of Horizon where they had obtained the 1-in-50-million statistic, I was told it had been taken from a "reliable source": Our Final Century by Cambridge University cosmologist Martin Rees. But when I read his book, it became clear that the programme's research had sadly been incomplete.
It turns out the number came from a theory that wasn't about black holes, and was based on a possible projection for the RHIC accelerator, which has now been running for 7 years (although that may not be so clear from Prof Close's article). Even before RHIC started running, a full study was performed, putting the figure at 1/10000000000000000000, not 1/50000000000.
These numbers are obtained by looking at the fact that objects in space have been bombarded for billions of years by particles with much higher energies than those at our accelerators, without causing Armageddon. So they are empirically observed quantities which don't depend on the details of the theories.
The article ends by mentioning the use of similar dubious science "factoids" in the media in general, some of which have affected government policy.
My advice is that if you see an error in the media, speak out, write to the editors and try to get corrections made. It is an opportunity to get good science in the news.
I suppose it could be said that in the instance of the Horizon programme, we were able to put this partly into practise on this blog!
The Large Hadron Collider [LHC]at CERN might create numerous different particles that heretofore have only been theorized. Numerous peer-reviewed science articles have been published on each of these, and if you google on the term "LHC" and then the particular particle, you will find hundreds of such articles, including:
1) Higgs boson
2) Magnetic Monopole
3) Strangelet
4) Miniature Black Hole [aka nano black hole]
In 1987 I first theorized that colliders might create miniature black holes, and expressed those concerns to a few individuals. However, Hawking's formula showed that such a miniature black hole, with a mass of under 10,000,000 a.m.u., would "evaporate" in about 1 E-23 seconds, and thus would not move from its point of creation to the walls of the vacuum chamber [taking about 1 E-11 seconds travelling at 0.9999c] in time to cannibalize matter and grow larger.
In 1999, I was uncertain whether Hawking radiation would work as he proposed. If not, and if a mini black hole were created, it could potentially be disastrous. I wrote a Letter to the Editor to Scientific American [July, 1999] about that issue, and they had Frank Wilczek, who later received a Nobel Prize for his work on quarks, write a response. In the response, Frank wrote that it was not a credible scenario to believe that minature black holes could be created.
Well, since then, numerous theorists have asserted to the contrary. Google on "LHC Black Hole" for a plethora of articles on how the LHC might create miniature black holes, which those theorists believe will be harmless because of their faith in Hawking's theory of evaporation via quantum tunneling.
The idea that rare ultra-high-energy cosmic rays striking the moon [or other astronomical body] create natural miniature black holes -- and therefore it is safe to do so in the laboratory -- ignores one very fundamental difference.
In nature, if they are created, they are travelling at about 0.9999c relative to the planet that was struck, and would for example zip through the moon in about 0.1 seconds, very neutrino-like because of their ultra-tiny Schwartzschild radius, and high speed. They would likely not interact at all, or if they did, glom on to perhaps a quark or two, barely decreasing their transit momentum.
At the LHC, however, any such novel particle created would be relatively 'at rest', and be captured by Earth's gravitational field, and would repeatedly orbit through Earth, if stable and not prone to decay. If such miniature black holes don't rapidly evaporate and are produced in copious abundance [1/second by some theories], there is a much greater probability that they will interact and grow larger, compared to what occurs in nature.
There are a host of other problems with the "cosmic ray argument" posited by those who believe it is safe to create miniature black holes. This continuous oversight of obvious flaws in reasoning certaily should give one pause to consider what other oversights might be present in the theories they seek to test.
I am not without some experience in science.
In 1975 I discovered the tracks of a novel particle on a balloon-borne cosmic ray detector. "Evidence for Detection of a Moving Magnetic Monopole", Price et al., Physical Review Letters, August 25, 1975, Volume 35, Number 8. A magnetic monopole was first theorized in 1931 by Paul A.M. Dirac, Proceedings of the Royal Society (London), Series A 133, 60 (1931), and again in Physics Review 74, 817 (1948). While some pundits claimed that the tracks represented a doubly-fragmenting normal nucleus, the data was so far removed from that possibility that it would have been only a one-in-one-billion chance, compared to a novel particle of unknown type. The data fit perfectly with a Dirac monopole.
While I would very much love to see whether we can create a magnetic monopole in a collider, ethically I cannot support such because of the risks involved.
For more information, go to: www.LHCdefense.org
Regards,
Walter L. Wagner (Dr.)
Hi Walter, a quick word or two on your concerns about subnuclear black holes being captured by the Earth's gravitational field:
Here I'll set aside the fact that we don't know how a subnuclear black hole could survive for any length of time without evaporating, but just talk specifically about how likely it is for a heavy object produced at the LHC can be captured by the Earth's gravitational field.
You point out the fact that high energy cosmic ray collisions in nature, which represent one of the reference points for discussions on safety, often happen in a "fixed-target" set-up, in other words, a particle slams into an effectively stationary particle in a planet or a star. In that case, to an observer on that planet, the products of the collision would move away at close to the speed of light.
At the LHC, on the other hand, the particles in the beams will be moving towards each other with about the same energies, which allows us to see the resulting particles spreading out in the rest frame, where the detectors sit.
So therefore, you are concerned that miniature black holes will be produced "at rest", and be trapped by the Earth's gravitational field and possibly wreak havoc (to put it mildly!) in the unlikely event that they don't disappear.
To be captured by the Earth's gravitational field, an object would have to be produced at less than the escape velocity, which is 11.2 km/s. That might feel quite fast in everyday terms, but for elementary particles, where speeds approaching that of light -- 300,000 km/s -- is the norm, 11.2 km/s is decidedly piddling.
In collisions at the LHC, a 1 or 2 TeV object of the sort we are talking about would be produced with speeds on average of one or two hundred thousand km/s, about half the speed of light. The likelihood of one emerging at as slow as hundreds of km/s, let alone 11km/s, is utterly minuscule!
This is because the actual interactions are not occurring in the centre-of-mass frame, but are between the quarks and gluons inside the beam particles, which are (sort of) whizzing about inside them.
This isn't based on conjecture, we have seen this experimentally. The beam particles also often emit other particles as they interact, which also moves their centre-of-mass outside the stationary frame.
A simple example of centre-of-mass hadron collisions producing non-stationary heavy objects can be seen in the transverse momentum distribution of Z bosons being produced at the Tevatron, which shows that the bosons are given a large sideways kick, even though there is no sideways component in the beams that are colliding. And this is just the transverse component!
I hope this helps puts your mind at ease....
No one I know thinks it is worth risking the existence of the planet to understand the universe better, honestly.
Welcome to the Imperial HEP blog!
Hello Yoshi:
Thank you for addressing the comments I posted.
I am aware that there will be a full spectrum of velocities (energies) from "central" collisions that may or may not produce miniature
black holes[or other theoretical particles like strangelets].
I've had physicist friends of mine look into this for me, and they report to me that there should be, for the central [direct head-on]
collisions about 14% that would have velocities below 40,000 km/hr [escape velocity].
While thelight-weight small particles [muons, electrons, protons, etc.] that typically emerge from such collisions[when exotics like
MBHs are not produced] have relatively large energies, if we have a situation of creation of a relatively massive particle [on the order
of 10,000,000,000 amu for a MBH] in which all of the kinetic-energy mass is converted into the new exotic-particle mass, it seems to me
that the figure of 14% is plausible.
I would be willing to entertain reviewing your calculations, but nevertheless, it seems certain that there would be some residual
relatively massive novel-particles [MBH] that could be created at less than escape velocity.
One of the suggestions being made is that the collider should have slightly different beam energies [e.g. 1% should do the trick], to
insure that any new particle created would have large velocity and escape both the earth and the Sun.
However, there is still the [slight] problem that theultra-high-E cosmic ray showers have not been 'proven' to be from ultra high-E
cosmic rays, rather than from the break-up of the rest-mass of high E/c^2 "exotic" particles not currently known. This hurdle will
likely be solved in the next few years via the Pierre Auger [if not already].
Check at www.lhcdefense.org for more information.
Regards,
Walter
The Daily Show yesterday carried an interesting report on this matter....
Possibly one of the finest and most effective pieces of outreach work that's been produced for us Yoshi, in my opinion. Particularly about the black hole debate. Maybe we should start to use a little bit of satire in our own outreach activities...
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