This just in: many living (and formerly living) things contain carbon and hydrogen. Details at The Naked Scientists
Archive for July, 2011
You have to do this with a rotating system because of space considerations and I think the globe is really neat, but …
I have to pick nits here. I really wish the video makers/interviewer had drawn a better distinction between the granite globe and the earth. The globe in the video was certainly not created spinning as it is, and we know there is friction, so asking why it’s spinning (or not stopping, at about the 1:00 mark) is really the wrong question if you are going to discount answers that say it’s because there’s a force (or torque) on it. I’m not sure if I wouldn’t interpret “it’s not stopping” as meaning that it’s simply not coming to a stop while I’m watching it, rather than it will not come to a stop over a much longer period of time. A key in all this is the identification of friction as a force and not some inherent property — that sometimes requires some mental untangling. You have to be sure you’ve done that for a successful misconceptionectomy.
Plus, we know that the earth is slowing down as it trades angular momentum with the moon.
In Fringe’s third season finale, for instance, Whitman and Chiappetta contacted physicist (and Exchange consultant) Sean M. Carroll for a particularly puzzling wormhole/radiation conundrum. “In the finale, which is set in 2026, a wormhole is opened in the middle of Central Park,” explains Whitman. “What we wanted the characters to realize, in a couple of lines of dialogue, is that the wormhole leads to a specific point in time, 250 million years ago. So the question was, what could they detect coming out of the wormhole that would allow for that conclusion?”
Boiling it down to a few lines of dialogue was not an easy task, but with Carroll’s help, the two story editors found a conceivable explanation. “We needed something that could make people go ‘Aha! That’s connected to another period of time!’” says Carroll. “We threw around a couple of ideas and [Whitman and Chiappetta] settled on an unknown form of radiation.” Since the season finale is set in the future, it is possible that scientists could discover a new form of radiation. So, Whitman and Chiappetta “discovered” kappa radiation, which became the series’ tell-tale sign that a wormhole goes through time, not space. “It’s not something that exists in known physics,” says Carroll, “but it is a plausible way that future scientists could tell something fishy was going on.”
Having been in a vaguely similar position, I have to say I think I like the solution. It’s plausible and doesn’t overtly contradict the laws of physics, so it’s within the realm of science fiction’s poetic license. They key is using it consistently and not going to that well too often, as I think Star Trek eventually did, which is precisely why I didn’t want to come up with a specific name and new kind of particle when I had the chance.
The name is two miles across — with letters a kilometre high. It is so huge that the “H”, the first “A” and part of the “M” have been made into waterways.
By “break a law,” of course, they mean “find where the law doesn’t apply”. Can’t break a law when you’re in a jurisdiction that doesn’t have that law.
In 1996, American physicists C. L. Kane and Matthew Fisher made a theoretical prediction that if you confine electrons to individual atomic chains, the Wiedemann-Franz law could be strongly violated. In this one-dimensional world, the electrons split into two distinct components or excitations, one carrying spin but not charge (the spinon), the other carrying charge but not spin (the holon). When the holon encounters an impurity in the chain of atoms it has no choice but for its motion to be reflected. The spinon, on the other hand, has the ability to tunnel through the impurity and then continue along the chain. This means that heat is conducted easily along the chain but charge is not. This gives rise to a violation of the Wiedemann-Franz law that grows with decreasing temperature.
… because you have found conditions where the law does not apply. So: neat science. Predictable behavior from the title editor.
Swans on Tea is a blog written Tom Swanson, an atomic physicist at the US Naval Observatory who posts under the nickname swansont – hence the name of his blog.
Three posts a day is not uncommon, although many of these entries are quite short, consisting only of links to news stories, online videos, or photos, plus some brief comments from Swanson. Longer posts involving the author’s own work or non-work activities are much rarer, dwarfed by the sheer quantity of interesting stuff he manages to find elsewhere on the Internet.
Nothing you didn’t already know. Just in case you were wondering, though, I was not interviewed (meaning they actually read the blog). I heard about it when someone gave me an attaboy, and have been waiting for the online version to appear.
Turyshev and co say there appears to be an exponential drop in the size of the anomalous deceleration over time. It’s not easy to see in the data for sure, but there are certainly signs it is there.
That’s an important clue. Pioneer 10 and 11 are powered by the radioactive decay of plutonium-238, which of course decays exponentially.
Final images from well-known movies. I think it’s easier when you clearly see faces, especially if it’s multiple actors — easier to narrow down the movie, even if you don’t recognize it as the final scene.
Detailed breakdown of the tricked-out Aston Martin DB (imagining Q saying “Pay attention, 007!” optional) and a timeline of the cars.
Scientific American claims Nuclear Fission Confirmed as Source of More than Half of Earth’s Heat
Nuclear fission powers the movement of Earth’s continents and crust, a consortium of physicists and other scientists is now reporting, confirming long-standing thinking on this topic.
But … there’s a problem. The paper’s abstract says nothing of the sort.
[U]ranium-238 and thorium-232 together contribute 20 (±error) TW to Earth’s heat flux. The neutrinos emitted from the decay of potassium-40 are below the limits of detection in our experiments, but are known to contribute 4 TW. Taken together, our observations indicate that heat from radioactive decay contributes about half of Earth’s total heat flux.
That’s radioactive decay, not fission. While they are both nuclear interactions, they are very different, and any science journalist writing on the topic should know the difference. David Biello and Scientific American screwed the pooch on this, and need to issue a mea culpa.
edit: maybe the body of the paper says something different, but it would be strange to not include it in the abstract
They have like a gazillion gorillapods.