Earth and Wind only.
Category Archives: Physics
It's Color Film, but it's not a Talkie
This video shows the thinning of a vertical soap film. Normally, this is a linear process, with gravity pulling the fluid downward and progressively thinning the film from top to bottom at a constant rate. At 0:20 a cold rod slowly contacts the film, adding a thermal driver for the film’s thinning.
The colors are a result of interference between the light reflected off of the front and rear surfaces of the film. If the film is very thin, there is almost complete cancellation of the reflected light.
The Best Moon
License to Killjoy
Did James Bond Want His Martinis ‘Shaken, Not Stirred’ Because Of An Alcohol-Induced Tremor?
James Bond’s famous catchphrase “shaken, not stirred” may have stemmed from his inability to stir his drinks due to an alcohol-induced tremor affecting his hands, researchers reveal in a new, tongue-in-cheek medical report.
Such a tremor would be likely in a spy who drank more than four times the recommended limit of alcohol throughout his missions, they said, writing in a special Christmas issue of the BMJ — a lighthearted edition of the medical journal that includes real research.
As the HuffPo notes, this is not serious (though this has gotten a lot of play and not all articles make this observation), but I’m going to be a killjoy anyway and apply Betteridge’s Law: the answer is no.
It’s not because of the silliness of applying medical analysis to a frikkin’ fictional character, or that the fictional data is anecdotal in nature, or even that the fictional empirical evidence says no, because Bond was a crack shot with his pistol. It’s because Bond was ordering the drinks, not mixing them himself. A tremor is moot.
But there’s more to this. One version I read (and unfortunately I can’t find the link to the specific article, but several versions are out there) included a description that a properly mixed martini would be stirred, and with a thin wooden spoon, rather than a metal one which would raise the temperature of the drink. This is baloney, but probably a case of right answer, wrong reason. The reasoning is wrong, because the drink is mixed with ice, so the final temperature is going to be the same — probably the temperature of the ice cubes.
I say probably because this is most likely not the case like where you have a pure water/ice mixture, which stays at 0 ºC because of the phase change going on. In the drink you will have a mixture or alcohol and water, and the freezing point will be lower. For a 50/50 mix, the freezing point will be -32 ºC, and the ice is probably warmer than that — freezers don’t generally get that cold. (dissolving things in water lowers the freezing point, and this is a colligative property, meaning it depends on how much stuff you have dissolved. It’s why putting salt on ice tends to melt it if you’re near 0 ºC: there’s always a little water, and when the salt dissolves the solution freezes at a lower temperature, which allows the ice to melt)
If the final temperature is independent of the spoon type, then what’s right about this? The metal spoon will absorb more energy from the solution, so while the final temperature is unaffected, this will tend to melt more of the ice, and that will water down the drink. From a thermodynamic standpoint that is more likely why you want to use a wooden spoon. Some years ago there was an episode of the West Wing where the president was complaining about “shaken, not stirred” in the context that shaking makes the ice chip, and small chips won’t get strained out when you pour the drink, which also has the effect of watering the drink down.
All of this reminds me that my parents used to complain about “shaken, not stirred” when we’d see these movies on TV. My dad was a bartender at one point, and the complaint (from both) was that shaking would bruise the alcohol. I knew enough science to know that this could not be literally true, but I never got an explanation of what “bruising” really was; I assumed that it was a euphemism for something undesirable and left it at that. Now that the internet exists, I can find something calling itself the martini FAQ and see that this is a matter of aeration.
Another addendum to this is that the link I can’t find had in it a link to some martini information, in which it was claimed that a dry martini had a lot of dry vermouth in it, but claimed that recently this had changed to mean very little (or no) vermouth. Well, that doesn’t jibe with the bartender joke I know where someone asks for a dry martini and the bartender asks how dry they want it. To which the customer responds, “Just whisper ‘vermouth’ over the glass.” That joke is probably older than I am, so no vermouth = dry is not a recent trend.
Phase Change Comes from Within
Engineer Designs Mug to Keep Coffee Temperature Just Right
A material (possibly paraffin) that melts/solidifies at the right temperature, so the liquid stays warm for an extended period of time. Reminiscent of Coffee Joulies. Which don’t seem to work as well as advertised, especially in an open ceramic mug. A test with lids in place shows better performance. This mug has a vacuum insulation layer and a lid, but caveat emptor. Though the physics behind the concept is sound.
The concept of a “phase-change” coffee mug to keep beverages warm was patented in the 1960s, but never made it to the marketplace due to manufacturing difficulties. But Maxwell happened to meet an engineer named Dean Verhoeven who had already solved the manufacturing problem. Dean and Maxwell teamed up and Joeveo was born
Their kickstarter closes on Jan 1, with delivery slated for next summer, so not a last-minute gift idea for this year, but perhaps an early shopping idea for next, even if delivery gets delayed a little.
You Usually Don't Get Condensation When it's This Warm
Bose-Einstein Condensate Made at Room Temperature for First Time
[R]esearchers at IBM’s Binnig and Rohrer Nano Center have been able to achieve the BEC at room temperature using a specially developed polymer, a laser, and some mirrors.
Sounds vaguely McGuyver-ish. I’m sure duct tape was involved somewhere. Duct tape is always involved.
Anyway, I’m not sure how this is useful yet, given that the BEC only lasts for a few picoseconds. Atom laser and optical switch sound like boiler-plate responses. (Similar to how other atomic physics efforts are hyped to be great for making new types of atomic clocks, but that rarely ends up happening) I would be interested in knowing how they determined that they had a BEC in the first place.
What's the Matter, Bill?
A Hot Mess
Chernobyl’s Hot Mess, “the Elephant’s Foot,” Is Still Lethal
By the fall of 1986, the emergency crews fighting to contain the nuclear disaster at Chernobyl made it into a steam corridor beneath failed reactor Number 4. Inside this chamber they found black lava that had oozed straight from the core. The most famous formation was a solid flow that their radiation sensors firmly told them not to approach. With cameras pushed in from around a corner, the workers dubbed the dimly lit mass “the Elephant’s Foot.” According to readings taken at the time, the still hot portion of molten core put out enough radiation to give a lethal dose in 300 seconds.
The Elephant’s Foot could be the most dangerous piece of waste in the world.
via fine structure
Lead, Rather than a Duck.
Since we are not asking “What else floats in water?”
Use of ancient lead in modern physics experiments ignites debate
Unfortunately the story really doesn’t lay out the case for why ancient lead ballast falls into the category of “cultural heritage artifact” or why more than a small fraction of it would need to be preserved for study. Newly mined lead is contaminated with Pb-210, which has a half-life of about 22 years and is present because it’s in the decay chain of U-238. So Pb that’s been around for several hundred years (especially under water where it would better shielded against any kind of activation reaction) has been separated from the source of the unstable isotope that produces it (ultimately U-238, but realistically Ra-226, which is the “most recent” previous step along the decay chain with a half-life longer than a year) is more useful for shielding detectors, as it has essentially no sources of radiation that might cause spurious readings.
ASCII and You Shall Receive