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Scientists working on the Atlas experiment at the Large Hadron Collider ( Photo: REX FEATURES & The Telegraph)

No, this is not an in-depth critique of string theory along the lines of Lee Smolin’s The Trouble With Physics: The Rise of String Theory, The Fall of a Science, and What Comes Next or Peter Woit’s Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law. It’s more along the lines of how do you know when a physicist is joking?

I think part of the attraction of modern physical theories and speculations are their non-intuitive nature. I buy that – and don’t find myself rejecting ideas just because they violate “common sense.” But I have often through that this non-intuitive nature does leave the field wide open to bullshit.

OK – I am aware that pseudo-science uses this to it’s own advantage to sell products and ideologies. But here’s a more practical problem I face – who do you believe when you read stories about physical discoveries on or around April 1 every year?

For example – I am pretty sure that the CERN Newsletter editors were pulling my leg when they reported – CERN scientists report sidereal influence on the behaviour of antimatter:

CERN scientists today reported an unexpected effect in the behaviour of antiprotons in the ALPHA experiment’s particle trap. ALPHA traps antiprotons from the laboratory’s Antiproton Decelerator and mixes them with positrons to form antihydrogen.

The experiment’s ultimate goal is to perform spectroscopic measurements on antihydrogen atoms in order to investigate nature’s preference for matter over antimatter. ALPHA reported an important step forward last month with the announcement that they had succeeded in changing the internal state of antihydrogen atoms using microwaves.

One of the key stages in CERN’s antimatter programme is slowing the antiprotons down as much as possible, a process known as cooling. In all measurements to date, the ALPHA experiment has cooled the antiprotons to a temperature of just 0.5 Kelvin. However, when the experiment ran on Monday 26 March, they observed antiprotons cooled to 0.4 Kelvin: in other words, they were moving more slowly than usual. Another curious phenomenon was that the temperatures of the antiprotons followed a Poisson distribution instead of the usual Gaussian. The following day, the antiprotons were back to their normal temperature of 0.5 Kelvin.

“We took a long time to figure this one out,” explained collaboration spokesperson, Jeffrey Hangst. “On Monday, the antiprotons were particularly cold, but they responded well to microwave warming, allowing us to conclude the run. On Tuesday, our antiprotons were back to normal.”

The solution came from an unexpected direction.

“There was something else strange about Monday’s run,” said Hangst. “Our run coordinator Niels Madsen arrived an hour late, which is very uncharacteristic behaviour for him.”

This provided the clue the ALPHA collaboration needed.

“I’d forgotten that the time changed over the weekend,” said Madsen. “And of course no one had told the antiprotons that the clocks went forward either, so they were just a little more slow than usual. By the time we got to Tuesday, they’d adjusted to Central European Summer Time.’

But what about this from Jon Butterworth – a physics professor at University College London and a member of the High Energy Physics group on the Atlas experiment at Cern’s Large Hadron Collider. He’s normally a serious guy but reported in his Guardian Blog Life and Physics recently (April 1 actually) that “a bug in the software used to model the detectors at the Large Hadron Collider could have been covering up evidence for extra space time dimensions” (see  First evidence for string theory at the Large Hadron Collider):

Complex software models are used to understand the results from the Large Hadron Collider. These include simulations of the particle physics in the proton-proton collisions, as well as of the material and geometry of the detectors and the strength of the various magnetic fields. As more data are accumulated, the required precision of this software increases.

A recent review recommended that the number of decimal places used to represent numbers in the software should be increased. This means all mathematical constants such as e and pi, as well as physical constants and the measured dimensions of the detectors. So far, so routine. But when adding more precision to pi, a strange effect was noticed. The alignment of charged particle tracks across detector boundaries actually got worse when a more precise value was used. In addition, the agreement between simulation and data also got slightly worse.

This really should not happen – more precision should mean better alignment and better agreement.

Boring scientists say this is probably evidence that some physicists don’t know how to write proper code. However, string theorists have pointed out that a firm prediction of string theory is the existence of extra space-time dimensions. In a space which is curved into a higher dimension, the apparent value of pi can deviate from that seen in real life. And thus the LHC may have proved that they were right all along. More data are needed before we can be sure.

Well, I don’t know. Sounds as credible as most of the stories coming from the LHC and the scientists working there.

Perhaps a hint that the story is an April Fool’s joke comes from the last sentence:

Less welcome news for CERN is that since they have been near to the beams for two years, the values of pi used in those parts of the ATLAS which were built in the UK are now hot, and therefore as of today will attract VAT.

Or perhaps it’s only the last sentence which is the joke?

That’s the trouble with modern physics. When should we take it seriously.

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