Gravity's Oldest Puzzles
medium.com
medium.com
These errors are surprises in the data itself: since the position of the object can be measured by multiple systems, it's considerably less likely that they would all make the same mistake. Of course it's possible that there's a 'single point of failure', like the data published back from the probe, that causes all the calculations to be off by the same amount.
On the other hand, the fact that these same probes/instruments can report everything else with extraordinary accuracy discounts that theory somewhat. It's still possible (perhaps the bug / cosmic-ray-induced bit flip only affects one particular data collection code path..) but it's less likely.
Altogether, my intuition for the neutrino result was "this is probably a broken experiment", but my intuition for this is "there's an effect that's not being accounted for". That effect could easily be forgetting to account for thermal radiation reflection or something else that's relatively uninteresting, but, I still think there's something going on.
Now, after they said that plenty of people ran with it way to far. However, I feel the team did the right thing.
https://en.wikipedia.org/wiki/Faster-than-light_neutrino_ano...
http://www.lescienze.it/news/2012/03/30/news/opera_ereditato...
What happened before is described in the Nautilus article:
"In March of 2012, as the dust settled, the OPERA collaboration held another vote, this time to determine whether the collaborators had confidence in the leaders of the experiment. Each member institution got one vote. The tally ended at 16 to 13 favoring no confidence with several abstentions, well short of the two-thirds majority required to impeach the leadership, but enough to send a strong message. Both the OPERA leader, Ereditato, and the experimental coordinator, Dario Autiero, resigned."
He's, as far as I understand, now the director of the Laboratory for High Energy Physics at Bern University:
> The pioneer probes were nuclear powered through a radioisotope thermoelectric generator (RTG). These RTGs usually give off heat uniformly, but the design of Pioneer meant that some of the radiant heat was reflecting off the probe resulting in a thermal recoil.
You could make it loads more efficient by putting the RTG at the focus of a parabolic reflector. Now all the photons are being emitted in a single direction, which means you get much more thrust.
According to this article:
https://en.wikipedia.org/wiki/Nuclear_photonic_rocket
...a perfectly collimated photonic rocket runs at about 300MW/N. Assuming you're New Horizons, you have a mass of about 500kg and a 4kW RTG, so you'll get a thrust of 0.1mN, which means an acceleration of 5x10^-8 m/s^2. Assuming my arithmetic is correct (a totally unwarranted assumption!), then over a year this adds up to a velocity change of 1.5 m/s.
I know a lot of physics, and have strong opinions on physics writing, but I still think this was a pretty interesting and entertaining article. If we have problems with it can we say what they are instead of just assuming everyone agrees that it's bad?
There are completely mundane explanations (upper atmosphere models slightly wrong, unaccounted-for EM effects) so while there may be a fundamental cause (gravity is doing something exciting) the odds are that it's a boring effect, just like the superluminal neutrino observations.
I didn't find the writing misleading at all. It didn't overstate the likelihood that there is actually new physics to be found in these anomalies and gave a specific example where an anomaly was explained by known physics that was merely unaccounted for.
Discovering that the Pioneer probes were off due to the moment of their thermal radiation was not 'new physics', but it was still interesting, in that it was missed in the initial attempt at modeling. And that's fine. It's still interesting and made for good reading.
Anyway, I liked it. I don't think it was mediocre at all.
http://slashdot.org/~StartsWithABang
It's B-grade science writing, written to be interesting and informative to a mass audience. It probably does fairly well on its own terms. However, I'm not personally interested in a remedial physics education, I'm interested in physics news. For me, that's where SwaB consistently falls short. Or, to be more concise, the blog is generally lowest-common-denominator physics writing. I am unpleasantly surprised to be met with contradiction and derision based on your reading of one article.