Wednesday, August 31, 2011
Tuesday, August 30, 2011
Human History and Science
Truly terrific set of videos showing a representation of science and human history. By Uppruni Tegundanna.
Wednesday, August 24, 2011
Tuesday, August 23, 2011
Evolution as Fact and Theory
Here's a neat article on discussing the fact and theory of evolution. Everyone should read it.
Monday, August 22, 2011
Risk Benefit of Science
Theo Gray has a good lecture on risks and benefits of learning science here.
Sunday, August 21, 2011
A Case Study of Science in Science Fiction, Part 1
About mumbly-seven, Congdon and Weed published my first novel, Caliban Landing. It's still for sale as a used book and I'd like to bring it out as an e-book. Just as soon as I get up the nerve to cut up and scan the hard cover. Until then, you can get a copy here. Go ahead. I can wait.
I've been talking a lot about how science, evolution and fiction go together. So I'm going to talk about specifics by using Caliban as an example. Heck, maybe it will generate enough interest that somebody might want to read a mumbly years old book.
Caliban had a lot of science fiction elements in it: faster than light travel, several alien species, human/AI interconnection, cyborgs-- all sorts of things. I'm going to limit my discussion to the biology in the book.
Caliban was a first contact novel. Humans come to the planet Caliban to survey it for human exploitation and maybe stake a claim or two. The planet has ostensibly been cleared of sentient habitation. This turns out to be incorrect and the team accidentally kills one of the sentients. The legal situation being what it is, they decide to try and make first contact and in effect get absolution and stay out of a higher, and less forgiving, court. Things don't go as planned.
Given this was a first contact novel, what drove the book was the nature of the aliens. Since I was a biologist, the aliens had to be biologically derived. What drove the aliens were the plants.
Photosynthesis on earth uses only a small portion of the available spectrum of light. This derives from the heritage and limitations of chlorophyll, the primary pigment used to capture the energy of photons. Chlorophyll a has its absorption peaks in magenta and orange. Chlorophyll b has its absorption peaks more in the blue and yellow. The lighter blues and greens and the UV and IR regions are essentially areas of no absorption. One would expect that chlorophyll must be very efficient and conserved to remain so common across essentially all photosynthetic organisms.
Hm. I thought. Chlorophyll only responds in a fairly narrow set of ranges. Opsins, the pigment in the eye, have multiple absorption spectra. In humans, blue cones peak at 437 nm (blue), rods (night vision) peak about 498 nm (sort of blue to green), green cones 533 nm (green), red cones 564 nm (yellow). Rhodopsin, a common opsin in rods, is somewhat broader in absorption than the color opsins. In addition, there are variations in rhodopsins that have differing peaks. (A good description of how seeing works is here.) Rhodopsin is quite sensitive to light but fragile. It's why we have good night vision but also why that night vision can be easily destroyed. (See here.)
What if (an SF writer's favorite phrase) we had a pigment (or pigment system) that was tuneable. That is, its peak absorption spectra could be changed according to available light spectra. Possibly, it wouldn't be as efficient as chlorophyll but it might be adaptable to multiple conditions. An interesting side effect is how it would look to us. The close uniformity of green in the plant world is an effect of the narrow ranges of the pigments involved. There's variation in the other pigments but chlorophyll is pretty constant. A tuneable pigment would have different reflective properties depending on how it was tuned. The top of a forest canopy would be a different color than the interior. Shaded plants of the same species would change depending on light level. And most plants would change considerably with the seasons.
I took the idea and filed it away.
Later, I was reading an article on the biochemistry of photosynthesis. After all, the photon must be absorbed before its energy can be captured. That's got to be pretty interesting.
Photosynthesis is dependent on fluorescence. (See here and here.) Fluorescence is the process by which something that has absorbed energy by either light or other electromagnetic radiation emits it. Commonly, a photon strikes an electron of a substance and imparts energy. The electron emits a photon as the energy is released. Photosynthesis is a fluorescent reaction in that the energy is received from the photon by captured by biological systems rather than be re-emitted.
Hm. I thought again. I remembered my tuneable pigment. Let's say our pigment can absorb terrifically in its narrow tuned range but it can't retain the photon as easily such that the photon is re-emitted. That's what happens in fluorescent paints. Of course, if the photon comes in as blue and emits as green that's not much of an energy gain. To make this worth it as many of the photons would have to be absorbed as possible and then re-emitted at as low an energy as possible.
Visible light is just what we see. It's not magic. It's the visible part of the electromagnetic spectrum. The spectrum goes up into gamma rays and down into microwaves. So I thought, let's make them re-emit radio waves.
Cool, I thought. And put it away again.
Time passed and I was reading Hubel's work on visual systems. The eye captures photonic data but it's the brain that makes sense of it. I wondered what it would be like to have a visual system that didn't operate on the rules of optics. Radio waves, for example.
Ping!
I dusted off the plants I'd thought up and then derived an alien biology that would take advantage of it. There are drawings of these guys in my notes, skulls that were laced with radio detecting proteins (likely with metallic cores). Opsins chemically resemble chlorophyll.
All opsins have a common heritage (see here) that is different from the evolution of chlorophyll. (See here.) But both chemical families harvest available light. I made the presumption that if radio waves were as present and as ubiquitous as light then biochemical systems would evolve to take advantage of them. I also made the presumption that animals who could detect their environment using radio waves would be selected for over animals who could merely detect visible light. Neither of these assumptions were provable but they made great aliens.
Okay. I had an alien biology and an alien ecology. Now I needed intelligence. Culture. Communication.
I was reading a lot about dolphins in those days and one article I read (which I cannot find, unfortunately) noted that dolphin sonar (like the sonar of bats) created the medium of perception rather than used one that was available. The article suggested that if dolphins were intelligent, they could communicate by actually producing an "image" of an object to show a receiver.
Oh, this was too cool to leave on the floor. I modified my Caliban aliens to be able to manipulate the radio waves they were receiving and seeing by-- sort of like modern metamaterials, though I certainly didn't think of them.
I now had an alien biology. But I still had to create an alien culture.
Stay tuned for Part 2.
Saturday, August 20, 2011
Google's Ad Sense
I signed up for ad sense on this blog. It's an experiment. Maybe I'll make some money. We'll see.
However, what's incredibly interesting is what has been chosen to present for the ads. Of course, these ads are local to the computer being used to view the blog.
So: why would a set of ads involving Summer's Eve Douche show up on my computer?
Well, I was viewing articles involving facing off on evolution, the selfish gene becomes a musical, metropolitan undergrounds, smart elephants, risk in science education and an article on vaginal pH entitled, "Don't douche, she declares acidly."
Should I be surprised at which one was chosen as an ad to grace my pages?
The selection mechanism for these ads is interesting. On one end you have to match the ad to the viewer's interests. (I almost said "tastes.") But on the other you have to match a advertisement to that interest. I'd expect a sliding scale of matching based on how much the advertiser has paid for the placement for the ad. An inexpensive but precise connection to Scientific American subscriptions (most of the above were SciAm blogs) might well lose out to an expensive ad that has only a marginal probability of connection.
How those connections are made might also be interesting. If it's word oriented, what's the probability that the word "douche" might be indicative of interest in a feminine hygiene product or just being used as a pejorative, as in, "Rick Parry is a douche."
Also, how is the content of the article viewed joined with the title of the article viewed. In this case the word "douche" is used several times in the article along with the words "vagina", "pH" and, lo and behold, "Summer's Eve". This could, for a fairly simple machine, indicate strong interest. It also argues for that simplicity of algorithm since one could, by examining the site and references to the article, determine that this is an article mostly about science. One wonders if I had been viewing an article about vaginal pH of baboons in Science magazine would I have gotten the same result.
The number and frequency of the ads are also interesting. There was space for 3 ads in the window for the blog. Consistently, for several minutes, the ads for douches were present. I looked at that article once. I looked at many other articles over an hour. But those adverts resolutely stayed douche.
Either douche is a major interest point or Summer's Eve is really pouring on the money.
Heh. With this entry I'll probably have douche articles for the rest of the summer's eve.
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