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Comment by jwuphysics | Hacker News Reader

I study astrophysics, so I won't be able to say much about SUSY or string theories or conformal field theories. I do agree that we're living in a golden age of physics! But your second and third points, inflation and SUSY-- those are definitely not confirmed. In fact, the primordial gravitational waves from BICEP2 are almost certainly dust contamination signal (e.g., http://arxiv.org/abs/1405.5857). The discovery of supersymmetric particles would also be extremely shocking to me, since my institution is heavily involved in CERN LHC experiments, and I haven't heard any hints of a discovery yet. Perhaps you know something that I don't!

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Not confirmed in the sense that many in the community are denying the result, which is as it should be. Even considering many models including dust a robust result remains. I think PRL and others are being unreasonably pessimistic but the only way to settle this is for there to be more experiments at different frequencies. Then they can move from the shock and denial phase onto the grieving process. BICEP scooped Planck, big time. It doesn't matter to me but it matters a whole lot to some people and the degree of sour grapes and poor sportsmanship is really stunning. Yes, I am saying a good deal of this is motivated by the tiny team beating the much bigger team though I absolutely disagree with their hypercompetitive interpretation of the whole enterprise of experimental physics. History will tell us that BICEP got lucky, very lucky and they got there first. The dust up is happening on Earth not in space and the latter is certainly much easier to explain away and still have at least a six sigma result. I've read the dust papers with an open mind and none of them add up.

Regarding SUSY, strictly speaking no particles have been directly detected but anomalous currents abound and just about everything seen works perfectly with light SUSY and much better than with the standard model. The dilepton events alone are very compelling. http://www.science20.com/a_quantum_diaries_survivor/a_susy_e... SUSY is in plain view much the way the Higgs was in plain view for about a year before the official announcement. I have no special insider information, just a humble internet connection to download the important papers and a decent knowledge of particle physics. In hind sight, everyone will say 'of course' which always happens. From a theory point of view, SUSY is simply not an option unless there is some spectacularly new theory out there with novel concepts to replace QFT. The Coleman-Mandula theorem is extremely compelling. It basically tells us accept SUSY or find something to replace QFT. Since QFT works and there's no good reason to move on to something else (especially when something else doesn't exist presently and possibly never will), it's a safe bet SUSY must exist somewhere. It just so happens to be light SUSY and we're seeing it at the LHC right now. I think we're presently seeing the equivalent of a COBE picture of SUSY and next year it will sharpen up into a WMAP picture.

> The discovery of supersymmetric particles would also be extremely shocking to me, since my institution is heavily involved in CERN LHC experiments, and I haven't heard any hints of a discovery yet.

Why does an absence of evidence imply that the arrival of evidence would be shocking? They're doing the experiment because they already believe things are this way and they're trying to get evidence to confirm it. If they disconfirmed it, that'd be surprising.

>They're doing the experiment because they already believe things are this way and they're trying to get evidence to confirm it.

Hypothesizing is one thing, but to believe without evidence is just blind faith.

Isn't faith blind by definition?

No. One of the most commonly used definitions of faith is trust or confidence in a person or thing. Whether or not that trust or confidence is based on evidence or not is a separate matter that is not conveyed by the word.

Even in the case under discussion, that someone might have faith that something is a particular way, and are doing an experiment to confirm it (more likely disprove an alternative), that doesn't mean it's 'blind' as in without reason. People can have a lot of good reasons for believing something is a particular way without having measured it directly yet.

If you don't have a higher Bayesian prior on the hypothesis than others, how did you select it out of hypothesis-space as something to test? (http://wiki.lesswrong.com/wiki/Locate_the_hypothesis)

> They're doing the experiment because they already believe things are this way and they're trying to get evidence to confirm it.

That's not science, that's confirmation bias. In science, one would want to look for evidence that one's theory is false with as much vigor as a search for evidence that it's true. Science isn't law, and it's not religion.

> If they disconfirmed it, that'd be surprising.

If they falsified their theory while only seeking confirming evidence, yes, that would be surprising. This is why open-minded scientists try to avoid assuming what they should be proving (the real meaning of the expression "beg the question").

I'm not trying to start an argument here, but wouldn't "assuming what they should be proving" be the same as "hypothesizing?" That's a critical point of the scientific method. You don't really design experiments that can both confirm and refute a theory. When an "open-minded" scientist attempts to perform an experiment to test theory, they aren't personally responsible for subsequent theories and experiments that could disprove their results.

> wouldn't "assuming what they should be proving" be the same as "hypothesizing?"

No, the expression "assuming what you should be proving" has a special semantic meaning -- it refers to a thought process that uses its conclusion to support its investigation, or takes the preferred outcome as a given from the start, without seriously considering alternative explanations.

Hypothesizing means taking existing theory and extrapolating new untested properties, then presumably investigating whether there is any evidence for the hypothesis.

> You don't really design experiments that can both confirm and refute a theory.

On the contrary, the best experiments have the chance to either confirm or refute a hypothesis. The Michelson & Morley ether experiment is a classic of its kind -- its outcome would either confirm or refute the ether as it was imagined to be.

http://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experi...

> When an "open-minded" scientist attempts to perform an experiment to test theory, they aren't personally responsible for subsequent theories and experiments that could disprove their results.

Not so. An open-minded scientist wouldn't pass up the chance to uncover any positive or negative evidence for or against his theory -- both kinds of evidence contribute to our understanding of nature. Remember the story about Bell Labs engineers Penzias and Wilson cleaning bird droppings from their microwave dish? They did that so someone else wouldn't scoop them by discovering that they had been fooling themselves about the source of the noise in their antenna (which ultimately was identified as the cosmic background radiation, now standing as evidence for the Big Bang).

http://www.aps.org/programs/outreach/history/historicsites/p...

The bottom line? Science isn't law, it's not adversarial, there aren't two competing sides, and a responsible scientist maintains an open mind with respect to evidence both for and against his theories.

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