Plastics unite to make unexpected ‘metal’
Both TTF and TCNQ are electrical insulators. But Morpurgo’s team found that a 2-nanometre-thick strip along the interface between the two crystals conducts electricity as well as a metal.
So it’s “metal” in the sense that it’s plastic, but conducts very well along the interface. Apparently using “conductor” in the title would have broken some journalistic creed. Why go for accuracy when you can have imagery?
Neat result, though.
A splash of astronomy news. Astronomers create first four-continent telescope
Astronomers have long combined observations from individual telescopes. The process, called interferometry, produces the same resolution as a single dish as wide as the distance between the antennas.
Recently, the Arecibo Observatory in Puerto Rico joined a project called Electronic Very Long Baseline Interferometry (e-VLBI), which can make temporary radio telescopes that rival the size of the Earth.
Timekeeping measurements always rely on the comparison of two oscillators; when you check to see if your clock or watch is running fast or slow, you do this by comparing it to another clock. Finding disagreement between two clocks won’t tell you a priori which one is the culprit, just as in the adage that a man with two clocks is never sure what time it is. But comparing three clocks allow pair-wise comparisons, and begin to allow one to assign a stability to the individual clocks.
Comparisons are what the scientists did in the second paper in my review, “Time, Analysis of records made on the Loomis chronograph by three Shortt clocks and a crystal oscillator.” The quartz crystal oscillator gave the input to the Loomis chronograph, and the three Shortt clocks were compared to crystal, and could then be compared with each other by differencing the data, which removes the crystal from the measurement.
The interesting (to me) part of the paper begins a few pages in, where they begin discussing the influence of the moon. The moon should give rise to a change in amplitude that would occur over an interval of 24h 50m, and should be distinguishable from diurnal terms present in the pendulum clocks. Two different time series were analyzed, one having a duration of 54 days, and the other having a duration of 146 days. This was long enough to average out noise terms, since the preliminary estimate of the effect was 153 microseconds per half-period of oscillation (i.e. one second)
The theory of the effect of direct attraction is presented in terms of tidal potentials, and it, of course, ends up depending on the angular position of the moon and the latitude of the observer. There are secondary effects as well. The tidal effect of the moon is not only on the water, but on the solid earth as well, though because it is not particularly elastic, the earth’s deflection is smaller, and this changes the radius by a small amount. There is a redistribution of mass when this occurs. Further, there are the local effects of the depression of the ocean bed and coast at high tide (as this was fairly near new York City), and the change in mass that occurs because of the water. It turns out that these indirect effects very nearly cancel, and the results should be close to the 153 microseconds predicted by direct attraction.
Continue reading
Via Built on Facts, it turns out that the cellphone-popping-the-popcorn movie was A FAKE! Gasp, thud. Making popcorn with a cellphone happens only in the movies.
(or should that be “only happens in the movies?”)
More than 6 million people have watched our little videos since May 28, 2008. We are very happy to have made this contribution to an important international public debate.
Important international public debate? Jane, you ignorant slut.
A lie gets halfway around the world before the truth has a chance to get its pants on. Churchill, inspired by Twain, pre-internet.
Genepax Unveils a Car That Runs on Water and Air
Try again, you sensationalizing hacks. Versions of this story have spread across the web like a bad rash.
Their new “Water Energy System (WES),” generates power by supplying water and air to the fuel and air electrodes using a proprietary technology called the Membrane Electrode Assembly (MEA). The secret behind MEA is a special material that is capable of breaking down water into hydrogen and oxygen through a chemical reaction.
If there’s a chemical reaction taking place, then it’s not running on water and air!
As said in the press release
The main feature of the new system is that it uses a membrane electrode assembly (MEA), which contains a material that breaks down the water to hydrogen and oxygen.
Got that? It contains a material that breaks down the water to hydrogen and oxygen. There’s a chemical reaction going on, for Odin’s sake! There are materials that like Oxygen even more than Hydrogen does. Introduce them, let them get acquainted, and they’ll get busy producing Hydrogen. But — and this is very important — the other material will eventually run out, and you’ll have to “refuel.”
To give an example, you can generate Hydrogen with water, Aluminum and Gadolinium (the latter is a catalyst which keeps the Al from forming an oxide layer, which would shut the reaction down, and the reaction is not exactly a “new process”). I don’t know if this is what’s going on here, but something sure is, because in this house we obey the laws of thermodynamics.
Update: good takedown over at Good Math, Bad Math
Volunteers asked to help find dead spacecraft on Mars
HiRISE software developer Guy McArthur, also at the University of Arizona, has invited the public to scan these images for signs of the Mars Polar Lander. It’s a huge challenge because although there are only 18 images, each of them is enormous – typically 1.6 billion pixels.
“If your computer screen is 1000 by 1000, that means you need 1600 screenshots to view one image,” says McEwen. “On the HiRISE team, we haven’t put much effort into looking for this – we’re too busy with other things.”
h/t to CD
I told the Captain that after the G-awareness maneuver, we would do a quick inverted check to verify cockpit security. Looking back, I should have recognized his anxiety when he mocked me and said, “Just a quick inverted check?” then laughed. I didn’t realize hanging upside down with nothing but glass and 11,000 feet of air separating you from the desert floor might not be the most comfortable situation in the world for a surface-warfare officer.
[. . .]
After we completed the checks, I asked him, “Are you ready for the inverted check? Do you have everything stowed?”“All set” was the last thing I heard him say.
I wonder if “Can we do that again?” came up in later conversation.
Jargon help:
Black shoe – “Terrestrial” Navy
Brown shoe – Naval Air
NVG – Night Vision Goggles
h/t to RTS
Oh, and another ejection story
The teaser for the evening news just showed a clip of cellphones purportedly popping popcorn, and asking the question of whether it’s a hoax. My money’s on yes. Wired has a story on it, and there’s more than one video.
Assume a kernel has 0.1 g of water in it. You need to heat it from ~20 ºC to 100 ºC and then boil it, which is what happens when you pop popcorn. The heat capacity is 4.18 J/g, and the heat of vaporization is 2260 J/g. So this requires 80*4.18*0.1 +2260 * 0.1 = 260 Joules. This happens in a few seconds, so the absorbed power is somewhere around 50-100 Watts, per kernel. The transmitted power of the phones would have to be much, much larger, since it’s not focused on the popcorn.
Not.
Google also tells me that Zapperz beat me to the punch here.
Update: It looks like I overestimated the water content by a factor of about 5 (see link in comment 2; I assume medium-large kernels, though, not small. Orville has standards). Doesn’t change the overall answer. It takes my microwave oven ~3.5 minutes to pop my popcorn. A few hundred Watts for a (few) hundred kernels so let’s call it 1 Watt per kernel for 270-330 seconds (onset of popping is at about 2.5 minutes). That matches up pretty well with the numbers above, which we now know are overestimated. I see no reason to hypothesize that only infinitesimal boiling is happening.
The home of the future, from the perspective of 1939
Microwave ovens, electrical appliances, VCRs/DVRs, heat pumps . . .
The Precipitron, however, eliminates more than ninety-five per cent of such air-borne particles by charging them with electricity and then drawing them off to oppositely charged collector plates. Housewives will appreciate what this means in keeping rugs and curtains clean.”
And good old-fashioned sexism. Honey, make me a sandwich.
However,
Alas, they didn’t get everything right:
“In 1928 the average residential power user consumed 460 kilowatt-hours of current a year and paid an average of six and six-tenths cents per kilowatt-hour. In 1938 he used 850 kilowatt-hours and paid only four and two-tenths cents per kilowatt-hour. This saving has been made possible by increased efficiency in the production and distribution of electric power…..Against the reality of such figures and achievements, one dares not place any limits on the possibilities of electricity in the future.”
I think maybe the Great Depression might have had an effect on the costs, too. According to the westegg inflation calculator, in the US, a product costing 7 cents in 1939 (or 9 cents in 1928) would cost a dollar today. So what’s the problem? Residential electricity today is about ten cents per kWh. The cost has generally gone down over time. There’s a graph here from 1960 onward (figure 3, in year 2000 dollars). I’m not seeing the wrongness of the claim, except for using kWh for current.
Physics of GPS relativistic time delay over at Unused Cycles, yet another appears-to-be-new math-y/physics-y blog. Goes through the calculation of the gravitational and kinematic effects on GPS satellites.