Are You a Good Witch or a Bad Witch?

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Star dust casts doubt on recent big bang wave result

[O]ther things apart from gravitational waves, such as dust, can emit polarised photons.

To minimise the chances of this effect causing a false signal, the BICEP 2 team pointed their telescope at a patch of sky far away from the Milky Way’s dusty disc. Then they used models of the dust in that part of the sky to estimate its effect on the polarisation. They found that this could account for no more than about 20 per cent of the signal that they attributed to gravitational waves last month.

But Mertsch says the models they used didn’t account for dust shells produced as the expanding remnants of supernovae slam into surrounding gas and dust.

So the results may not hold up. This is bad, right? We get all worked up about a result, and it turns out it might not be correct.

Except it’s not. Procedurally, this is good. This is exactly the way science is supposed to work. You do your best attempt at the research and looking for confounding effects that might be giving you a false signal. You have it peer reviewed, and you publish. As I’ve talked about before, that’s just the first hurdle. After that comes feedback from other scientists, including attempts at replication. And that’s where we are now — some attempts at replication are already ongoing, and here we have someone who has new information that might affect the conclusion. This is how science moves to get things right.

The bad part is that the first results get hyped, because they’re new, and there’s no restraint for waiting for the weight of evidence to pile up. Sometimes the first results won’t stand up to scrutiny. I recognize that this might weaken the confidence some have in science, but in reality it should strengthen it: other scientists are willing (enthusiastic, even) to stand up and say, “Wait a minute!” when all the ducks don’t line up. There’s no conspiracy to conform. Scientists questioning loudly trumpeted results like this gives me confidence that all of science is subject to the same kind of feedback.

At the Tone, it Will be 'Now' O'Clock

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The Problem of Now

I don’t spend much effort thinking about this sort of issue, since I’m much more interested in the experimental aspects of measuring time than the philosophical aspects of it, but I’ve run across some folks who think this problem of “Now” is so perplexing they can’t get past it. (again, because my interests lie elsewhere, this seems more of a dorm-room discussion, or possibly one involving a professor who looks like Donald Sutherland discussing whether atoms can be universes). My view of the utility of this is that while “It’s always now” may or may not be deep thinking, it doesn’t help GPS tell you where you are. (unless “You are here” is an acceptable answer)

[R]egardless of whether you use an external definition of time (some coordinate system) or an internal definition (such as the length of the curve), every single instant on that curve is just some point in space-time. Which one, then, is “now”?

Later on there’s also an interesting point about memory not needing consciousness.

There's More to Physics Than The LHC

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Particle Fever is aptly named

[T]his equating of “physics” with “particle physics” not only plays along with the media myth that the only thing worth noting in physics is what is going on at CERN, but also explains outbursts like this one I received from a (non-particle) physicist recently: “Perhaps the poster child for overselling science should be high-energy physics. They oversold the most expensive toys that physicists have ever produced: high-energy particle accelerators… their arrogance when they talk about ‘the god particle’ and ‘the most important problems’ is disappointing.”

Plenty of Science Yet to Do

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Science Is Running Out Of Things To Discover?

[H]aven’t we learned anything from the history of science? The last time someone thought that we knew all there was to know about an area of physics, and all that we could do was simply to make incremental understanding of the area, it was pre-1985 before Mother Nature smacked us right in the face with the discovery of high-Tc superconductors.

I have some serious doubts about the original article as well. When I say the claim the the time was getting longer for nobel awards I thought it was a typo, because in my atomic physics corner of the world, that trend does not seem to be in place at all. AMO physics has reflected a short gap between discovery and Nobel. And looking at that trend makes me doubt the physics graph presented in that paper.

The 1989 Nobel went, in part, to Norman Ramsey for his separated oscillatory fields method used in atomic clocks, developed in 1949. I don’t see a 40-year data point anywhere on the graph.

The 1997 Nobel was awarded for contributions to laser cooling and trapping, with the experimental start in the early/mid-1980’s. I don’t see any ~15-year data point for 1997.

The first Bose-Einstein condensate was observed in 1995. The Nobel was awarded for that in 2001 – a scant six years. No such data point exists.

The optical frequency comb was demonstrated in 1999, and the Nobel was awarded (again) six years later. That data point is missing as well.

I don’t know what’s going on, but this doesn’t smell right.