The Lab Lemming tells us we shouldn’t be afraid of laser isotope separation of Uranium, and then tells us what we should really be scared of.
[T]he critics of this planned laser separation technique don’t even explain how they expect proliferation to happen. It is just a vague sentiment that if this particular nuclear technology works, it will somehow spread to the hands of the bad guys.
I Do Not Think “Adiabatic” Means What You Think It Means
The definition of “adiabatic” given above, namely a process that occurs very quickly, is amusing to me because it’s almost exactly the opposite of the definition I usually encounter. In my corner of cold-atom physics and quantum optics, when we talk about something being “adiabatic,” we almost always means that it’s a process that takes place slowly.
You should read the post that induced this, Letting Air Out of Tires, and its followup, Letting Air Out of Tires II (The Wrath of Lance Armstrong)
Why wood bats ‘crack’ and metal bats ‘ping’ and much more. Physics and Acoustics of Baseball and Softball Bats
There is a tremendous amount of physics and engineering that goes into the design of a baseball or softball bat, especially the new high-tech aluminum and composite bats which are currently dominating the market. There is also an amazing amount of physics involved in the bat-ball collision, and in the performance and behavior of the bat itself. My interest in the physics of baseball bats began in 1998 when I was setting up a laboratory experiment for my students and decided to have them look at the vibrational behavior of a youth baseball bat. Now, several years later, vibrational and acoustic analysis of softball and baseball bats has become my primary area of research. I have been able to correlate the vibrational frequencies of bat barrels to measured performance, and have signicantly contributed to an understanding of the trampoline effect in a hollow bat. In addition, my vibrational analysis of the bending modes of a bat has added to the understanding of perception and feel, including why some bats sting more or less than others.
tip o’ the baseball cap to Skye
[T]he infamously Machiavellian coach told his draft picks that there was no potable surface water for “hundreds of miles”; that it would be in their best interests not to attempt to contact any locals who crossed their path; that only the fruit at the very center of the thornbushes would be edible; that most of the indigenous wildlife, especially the arachnids, was very, very poisonous; and that one of the things he had just told them was a lie.
“Show me what you got, boys,” Belichick said to the group from the backseat of a spotless black Range Rover. “If you want to be on this team, I’ll see you in four days. And if you’ve been paying attention at all, you’ll know exactly what to do. Oh, you can take your blindfolds off now. “
Faster than light, smaller than an atom
What do you do when you get an unphysical answer on an exam, and is there any way to mitigate this?
Some combination of carrot and stick is the usual way; of course; when I had control over grading policy it was in the navy and we mainly used the big stick: grossly unphysical answers were conceptual errors and it meant a big loss of points on the question — there was no amount of correct information that would let you have a passing score on that particular problem. To drive this home, it was reinforced with feedback from homework and quiz results — I tried to not let an opportunity pass where I could point out how wrong such an answer was and how much it would cost come test-time. But it was also buttressed by having other divisions using similar grading policy, which is a knob not really available (or at least less accessible) in an academic setting.
xkcd blag: Color Survey Results
Indigo was totally just added to the rainbow so it would have 7 colors and make that “ROY G. BIV” acronym work, just like you always suspected. It should really be ROY GBP, with maybe a C or T thrown in there between G and B depending on how the spectrum was converted to RGB.
The Most Amazing Laser Application of All Time Is…
The people have spoken, and it doesn’t get any more amazing than laser cooling, which is hereby awarded bragging rights over all other fields of laser-related physics.
Those of us who do laser cooling already knew this, but it’s nice that we have this stamp of approval. The post has links to explanations of all 12 of the contestants, done with the usual Uncertain Principles style and quality.