… or maybe he’s up this telephone pole!
Or maybe at the top of this ladder.
We had a pretty bad p-chem seminar yesterday. The opening slide had about a million slightly related topics that he was going to discuss. He must have sensed something from the audience, because he said:
“Many things, you might be confused. But my brain is clear!”
That got a good laugh.
Unfortunately, he failed to transfer that clarity to the audience…
I’ve got a question to all the chemists out there: Why can’t I put anything on the bottom of the sonicator bath? It says not to right here:
But we often put stuff directly on the bottom of the bath while the sonicator is on:
I mean, what’s the big deal? Does anyone have a good reason? Could it damage the sample or the sonicator?
The latter would explain why we’ve gone through a baker’s dozen of sonicators in the last six months.
OK, more comics. I saw this on my RSS feeds, which really says it all.
Powers of Ten is a 1977 short documentary film written and directed by Charles Eames and his wife, Ray. The film depicts the relative scale of the Universe in factors of ten (see also logarithmic scale and order of magnitude). The idea for the film appears to have come from the 1957 book Cosmic View by Kees Boeke.
I was perusing Wikipedia the other day, when I read the article on fluorescein. The article claims that the molecule is often used as a dye for rivers. I had heard this, too. It makes sense, because fluorescein is generally considered nontoxic and it’s very fluorescent, so it would be a good marker.
But something puzzled me: why is the Chicago river green in the image? When I think fluorescein, I think “Absorbs at 487 nm and emits in the green (510 nm).” Fluorescein in water should look yellow. In fact, there is an image in the Wikipedia article of an eyedropper with a yellow fluorescein solution. And here’s a pic of my vial of fluorescein in water:
Sure looks yellow to me.
I mentioned my confusion to a friend. We concluded that they must dump a shit-load of fluorescein into the river to make it look green. He decided to test this by putting some fluorescein in water (I’m sure he’s not pouring that stuff down the drain!):
As you can clearly see, water looks green. And he didn’t even use very much dye (probably ~1 mg).
Here’s the point: when you look through the solution in a vial, it looks yellow because you’re seeing the transmission. When you look at the solution in a river (or a ice bucket) from above, you only see the fluorescence excited by sunlight. You can even see that it looks more yellow as he pours it out of the ice bucket (because then you can see some transmission as well as fluorescence).
Well, duh! Now, I feel silly for being confused: that was so obvious. I forgot that the quantum yield of fluorescein is nearly unity. Thanks, Wikipedia.
Last weekend I had the pleasure of judging middle school science fair projects. It’s always refreshing to see the kids interested (or at least pretending to be interested) in science. There were a lot of great projects. It was also nice to have a coordinator that wanted us to find a winner, instead of the “everyone’s a winner” approach I’ve encountered judging at some other schools. In honour of their efforts, I’ve put together my own science fair project.
How do glasses relax? This is important because glasses are important for people with bad site to see good.
I think glasses will relax. I think this because if glasses didn’t relax, then we wouldn’t be able to see through them. But I’ve seen through a glass before, so it must have relaxed.
3) Regeneratively amplified femtosecond Ti:Sapphire oscillator
6) Something to make things cold
1) I ask 5 friends, David, Melissa, Lindsay, Billy, and Rainbow if they thought glasses relax.
2) I wrote down what they said, and averaged the results.
3) Make a liquid supercold.
4) Shine a lazer through it, and see what comes out.
5) Analyze your results.
My independent variable was the number of people I asked. My dependent variable was if the glass relaxed.
These were my results.
As your can see, David, Melissa, and Rainbow all said that glasses relax, while Billy and Lindsay said glasses cannot relax. This confirms my hypothesis that glasses can relax, because more people think glasses can relax than glasses cannot relax.
My hypothesis was correct. If I could do this experiment again, I would see if playing different types of music would make the glasses relax faster. This experiment was important because it shows science works.
Science Fair Thesis Projects
The Top Ten Lies Told by Graduate Students
(taken from the Harvard Crimson)
10. It doesn’t bother me at all that my college roommate is making
$80,000 a year on Wall Street.
9. I’d be delighted to proofread your book/chapter/article.
8. My work has a lot of practical importance.
7. I would never date an undergraduate.
6. Your latest article was so inspiring.
5. I turned down a lot of great job offers to come here.
4. I just have one more book to read and then I’ll start writing.
3. The department is giving me so much support.
2. My job prospects look really good.
1. No really, I’ll be out of here in only two more years.
We were discussing some grammar at Chemical Physics Journal Club this week: which is the (more) correct sentence?
1. It is important to deconvolute the fluorescence lifetime from the instrument-response function.
2. It is important to deconvolve the fluorescence lifetime from the instrument-response function.
I think sentence 2 is better. To me, “convolve” is to (usu. mathematically) roll together multiple things, while “convolute” means to make complex: you can convolve two mathematical functions or signals, and you can convolute a sentence. (Unfortunately, the noun form of each is “convolution.”)
I don’t think the official Webster or Wikipedia definitions agree with me, or clear up the mess (it’s so convoluted!), but my argument makes so much sense in my head that I can’t give it up. I get annoyed when scientific papers state they “deconvoluted” something, unless they mean that they made something less complicated.
I suppose convolving is a type of convoluting.
Other thoughts, here?
It’s not the worst figure, but I did laugh a little that only 2 out of 10 points fit comfortably within their respective error bars.
There has been a wave of thefts in the physics buildings on campus—losers stealing lab equipment—so we decided to have someone watch over our labs all night and day:
He startles us often. But he’s the hardest working grad student!