Isn’t there something where a feather and a brick are actually pulled at the same speed towards the earth when dropped but in reality they fall at different speeds because of their different surface areas and the friction they cause with the air? or something like that? like if you made a brick out of feather and dropped it with a normal brick they’d fall at the same speed? Read the rest of this entry »
Sunburns are real burns. Your skin is actually damaged by the solar radiation, i.e. light, that comes from the sun. In particular, light, or electromagnetic radiation, in the UV spectrum are responsible. Why UV? Because, being a shorter wavelength and higher frequency than visible light, it carries more energy per photon. Therefore, each photon can penetrate into your skin farther and carries enough energy to wreak some havoc with your skin cells. On the farther extreme, think of x-rays. They’re so powerful they penetrate all the way through your soft tissue and out the other side. Only hard tissues top them. Read the rest of this entry »
I was just reading in Science Times that Dr. Watson, of the famed duo Watson and Crick, had his genome sequenced and made public. And all for under $1 million! Of course, it wasn’t a perosnal endevour; it was done by the Human Genome Sequencing Center and the company 454 Life Sciences in a showing of their newest sequencing machine. It was done for science, and they chose him because of the critical role Watson and Crick played in deducing the double helical structure of DNA. But I’m sure, if you have $1 million to spare, you too could get your genome sequenced and put on 2 DVDs. That’s right, 2 DVDs, that’s all it takes to completely define one of us as an organism distinct from, say, a jellyfish.
I could chat about the ethical or moral issues raised by making your personal genome available to the public, but right now, I’ll discuss what all this really means. What is a genome? What are chromsomes, genes, DNA, double helices, sequencing, and what are they all good for? Read the rest of this entry »
In the same issue of Physics Today, there was another letter in response to Leo Kadanoff’s commentary. Robert Levine, from Sierra Vista Arizona, makes some excellent points concerning a core change that impacting science: “The nation has shifted in philosophy from the search for truth to the postmodern denial that objective truth exists.” I’m not entirely convinced that the whole nation has jumped on this bandwagon, considering the scores of conservative religious people who would not let most-modern philosophy get between them and the holy truths. But, even in those cases, the general philosophy of a mutable truth, dependent upon opinion and point of view, helps throw doubt over the worth of science and legitimizes the choice in faith over acceptance of observed fact. Read the rest of this entry »
Arthur Smith, from Selden, NY wrote this letter in response to a column by Leo Kadanoff proposing changes in physics education. The letter appeared in the May 2007 Physics Today, and I’m rewriting parts of it without permission, because I agree with every word of it. It mirrors some things I’ve been thinking about for quite some time, and I feel Mr. Smith has put it quite eloquently.
…But it seems to me there’s a more fundamental problem than just the improvement of the way we teach: How do we make physics a subject that more people want to learn about? Read the rest of this entry »
I was in the car the other day, and my friend asked, out of the blue, “What’s a Fourier Transformation?” At work, her company had been receiving sales data from a client. The data had shown periodic spikes and declines in sales, and the client wanted to understand how to spot spikes and declines that were irregular. In other words, there seemed to be some sort of natural periodic behavior in the sales data, and they wanted to be able to spot funny spots, when things were different. Her boss, an ex-physicist, suggested a Fourier Transform. Read the rest of this entry »
I was just reading about bridge strategy (I know, like an old woman, playing bridge) and I came across this claim: “There are more bridge deals possible than there are grains of sand on a beach.” Of course, I just had to figure out if that’s true, because man, that’s a lot of possible deal! Read the rest of this entry »
-by Seila
We physicists are doomed. When we are at a party and meet somebody new, the conversation inevitably heads towards our occupation. After admitting to being a smarty-pants physics PhD student, we get one of two comments: either “Huh, I don’t understand anything about physics” or “Wow, you must be so smart!” The first one usually marks the beginning of the end of the conversation, because the other person has already decided that they’re not really interested in what we do. The second comment we pretend to reject vehemently (even though we secretly like it). In either case, either disinterest or envy, the idea of physics brings to mind a crazy laboratory of science fiction and very long completely incomprehensible mathy stuff on a chalkboard. Read the rest of this entry »
It’s often quoted that humans use, in one year, the amount of energy that arives on Earth from the sun in one hour. What an untapped resource! At first glance, that seems to say that if we were only more effective at harnessing solar energy, we could solve our energy problems. Another way to look at this fact is to average over the Earth and one year. Meaning, to satisfy our energy hunger, we need to capture the energy from 1/10,000 of the Earth’s surface. Let’s perform some further estimates using this data, and see what they can tell us about our energy use, and the possible future of solar energy utilization. Read the rest of this entry »
This is a really good question, and one that had been debated for some time. Originally, after their theoretical prediction and their eventual experimental discovery, they were thought to be massless, in the same way that photons are massless. However, they were later shown to undergo “flavor oscillations” that indicate they have mass. Various experimental (mostly from astronomical measurements with and cosmological calculations) data put a very strong upper limit on the mass, however. For more information, check out:
http://en.wikipedia.org/wiki/Neutrino and here for a more detailed review of current research in the field.
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