credit: Danielle
Or you can just be a theoretical chemist and wear sandals too.
credit: Danielle
Or you can just be a theoretical chemist and wear sandals too.
My lockdown: here’s what it was like living in Boston this week
Two wanted men kept a major American city — and my family — on high alert
I’ve lived in Boston (or one of its neighboring towns) for almost 14 years, and I can’t remember a time that the entire MBTA, our public transportation system, shut down. No trains, no buses, no commuter rail. Maybe on 9/11, and parts of the system have been out of service during particularly brutal winter storms (or the occasional hurricane), but I can’t recall a day like today. Thanks to a wild manhunt for two young men who detonated explosives during the Boston Marathon, the entire region was held hostage for nearly a day until law enforcement was eventually able to tighten the noose.
Isocyanides could be identified from 3 things:
1: their strong, unpleasant odor
2: their high fluorescense under UV light
3: the headache what they cause when you accidentally contact them
But at all, this looks fairly nice(:
Electronic chips self-heal after laser blast
It might sound like the stuff of science fiction, but a team of engineers at the California Institute of Technology (Caltech), for the first time ever, has developed just such self-healing integrated chips.
The team demonstrated this self-healing capability in tiny power amplifiers. The amplifiers are so small that 76 of the chips—including everything they need to self-heal—could fit on a single penny.
In perhaps the most dramatic of their experiments, the team destroyed various parts of their chips by zapping them multiple times with a high-power laser, and then observed as the chips automatically developed a work-around in less than a second.“It was incredible the first time the system kicked in and healed itself. It felt like we were witnessing the next step in the evolution of integrated circuits,” says Ali Hajimiri, professor of electrical engineering. “We had literally just blasted half the amplifier and vaporized many of its components, such as transistors, and it was able to recover to nearly its ideal performance.
The team’s results appear in the March issue of IEEE Transactions on Microwave Theory and Techniques.
Read more
A complex system can, in principle, be observable – that is, the system’s complete internal state can be reconstructed from its outputs, which would ostensibly involve describing in complete quantitative detail all of its internal state variables at once. In an actual experiment, however, such measurement is typically beyond our reach, and so is limited to a smaller number of those variables. Referred to as sensors (or sensor nodes), these key variables can be used to make the complete system observable. Recently, scientists at Northeastern University and MIT devised a graphical approach that first derives the mathematical equations describing a complex system’s dynamics, and then determines the key sensors for that system. Moreover, when applying their approach to biochemical reaction systems, the researchers discovered that the derived sensors were both necessary and sufficient to describe the complete system. The scientists conclude that their findings allow a systematic exploration of many diverse natural, technological and socioeconomic systems. (via Through a sensor, clearly: Complex systems made observable)
Google’s bombshell last night that it would be shutting down the Google Reader RSS client hit the web, well, like a bomb. Just as with any major tech event, it spurred a raft of reactions on what is currently our best real-time conversation broadcasting network, Twitter. Reactions ranged from outrage to sadness to smugness — the latter epitomized by the camp who say that RSS was already a confusing mess that needed to be shot down completely and besides, it had been replaced by Twitter itself anyway.
Well, no. RSS matters.
Pi’s parametric coordinate functions
This is the second of three animations I’ll be posting today (here’s the first). Be sure to check them out later if you miss them!
The polygonal trigonometric functions I described earlier were based on the interior angle, instead of the length along the polygon’s border.
This simplified things a lot, and created some interesting uses for the functions. However, since I could only have one value of radius for each angle (they were based on polar equations), I could not draw arbitrary shapes with a continuous line based on the [0,2π] interval.
The solution is to extend the idea to general closed curves, by using the position along the curve to define the sine and cosine analogues. In other words, we want “path trigonometric functions” for which the input parameter is the position along the path, and whose periods are the curve’s total arc-length.
But the concept of “sine” and “cosine”, as well as “trigonometric”, completely lose their meaning at this point. It has nothing to do with triangles or angles.
We’re now dealing with the functions x(s) and y(s) that together describe the curve, by being used in the parametric equation r(s) = ( x(s) , y(s) ), where r(s) is a vector function and s is the arc-length. This is very standard stuff, so it isn’t incredibly exciting anymore.
But we do get to see what these functions look like and what they are doing. So here’s the coordinate functions for the arc-length parametrization of a pi curve!
Happy Pi day!
Extremely sore. I can’t bowl 6 games in a night, it seems, at least not after going the night before. Disappointing, but it cuts back on the costs.
I’m glad that I finally got a chance after about 7 years to join a league again, this time with some grad school friends; in a cruel twist of fate, they’re all organic chemists.
Just bought a new ball for the first time since 2008. I was tired of the non-antics of my Brunswick Twisted Fury; it just wouldn’t hook for me, since I don’t throw with a lot of revs, meaning I would have to slow down quite a bit, which I wouldn’t want to do. Even though I never used it in league, I’d say my average went up ~30 pins over the time I had it and used it as my only ball. I could expect to average 180-190 with it, but half my games were in the low 200s and the other half were 160, 170s. If I couldn’t find the pocket, it wasn’t a particularly forgiving ball, not like my old polished Danger Zone HPC. That thing would hook forever; it’s a particle ball, and the Fury isn’t. I always felt like I was trying to make the Fury do something that it didn’t want to. When I went to the local pro shop this past week, I found out that part of it was the way the ball was drilled.
Drove out 45 minutes to the middle of “nowhere” on the recommendation of some random guy at the alley with a picture perfect swing and ball reaction to match it. He watched me bowl, talked a bit about symmetric vs. asymmetric cores, helped me figure out where my PAP is (4 3/4” out, 7/8” up), and drilled a layout that flares about 6-6.5” instead of 2”. A 267 out of the box means fun times are ahead. My car and all my equipment smells like a fruit basket now, because Storm bowling balls all have a fragrance, and the Lucid is (I kid you not) “vanilla citrus”. Personally, I think it smells amazing…my old Power Bolt still smelled like green apples after 300 games.
Hard to believe I’ve gone from this
to this
to this
and now to this.
I can’t find the pocket yet, which is frustrating, but I can already tell my spare percentage is gonna go up; I made 75% tonight, when normally I’d be closer to 50%. I always had trouble shooting spares with the Fury. Average 195 over 6 games the second time out with it? Yes please.
When the Catholic Church and Science get along