Saturday, May 17, 2008
If you have too much time on your hands, at the bottom of the page you can find a link to the Scienceshots archive, which goes back to September 2005.
It turns out that interstellar and intergalactic dust absorbs roughly half of the light energy emitted from distant luminous objects, re-emitting it later. So when we look at a distant object, we are seeing only half of the light that would reach us if space was completely transparent. So the universe is actually twice as bright as we perceive it to be. One implication of this is that energy generation in the universe is also twice what we thought.
A sentence that struck me was, "The Universe is currently generating energy, via nuclear fusion in the cores of stars, at a whopping rate of 5 quadrillion Watts per cubic light year - about 300 times the average energy consumption of the Earth's population." It seems as if the author is trying to emphasize the incredible amount of energy produced. But a cubic light year, while small on an astronomical scale, is incomprehensibly enormous by any human yardstick. The volume of the earth is roughly 270 billion cubic miles (270*10^9 mi^3). A cubic light year is about 218*10^36 mi^3. In other words, a cubic light year would hold nearly 10^27 earth volumes. And the population of earth is using a 300th of the energy generated in that volume. That is pretty mind-boggling! (Of course, we're living right on top of a star, astronomically speaking, so our energy density is way, way above any "average" cubic light year).
Our understanding of the distribution of matter in our galaxy and in the greater universe depends in large part on brightness measurements. Basically there are certain kinds of objects that emit light energy at a known rate or brightness. When we identify such an object (known as a standard candle) at a great distance, we can compare the light that is reaching us to the amount of light we believe it is emitting and arrive at a pretty good estimate of how far away it is. Most of our distance and some of our mass estimates for far away galaxies and stars come from this kind of inference. What I've been wondering, and the article doesn't address, is the degree to which this brightness research will force astronomers to reassess the distribution of matter and energy in our universe. You know, basic questions like where is everything, and how much of it is there?
Friday, May 16, 2008
So the big political news of the last couple of days is fearless leader's comments in Israel comparing willingness to talk to Hezbollah to Chamberlain's appeasement of Hitler. Democrats' reactions have ranged from fury to apoplexy; Republicans have unsurprisingly responded that "Hunh? We weren't actually talking about Obama, and anyway, it's true that Obama is just like Chamberlain, except maybe he's more like Hitler. After all, Hamas is endorsing him. He's a Muslim kind of a guy who goes to a Christian church, and whose pastor has said some really wacky things."
Now leaving aside the fact that righty preachers have issued a few proclamations that I find much more lunatic and frighting than anything coming from Rev. Wright, I have to admit that I may be one of the very few left-leaning people in the country who sees the truth in what Shrub said. Don't get me wrong: I have marked my ballot for Obama. But one of my concerns with him since last fall has been his stated position of co-operation with a group that has blatantly disregarded human rights, ignored the rule of law, willfully encouraged uncaring, powerful private operators to harm and even kill innocent bystanders, a group that has made unhinged and unrestrained militarism its central ideology. I have pondered giving my vote to Hillary over this issue. It just seems to me that 2008 ought to be about taking the US back from the Republicans, rather than listening to any more of their crap and co-operating with them. I agree with Bush: no more appeasement.
Also, explore the large number of links that her provides to sites with similar or related content. This is great stuff: sometimes amazing, sometimes hilarious.
Thursday, May 15, 2008
“The administration acknowledges the bear is in need of intensive care,” Ms. Siegel said. “The listing lets the bear into the hospital, but then the 4(d) rule says the bear’s insurance doesn’t cover the necessary treatments.”
Also, take a look at the interactive graphic posted with the story. This was first published last October; the minimum extent of northern polar ice is measured in September each year. I remember being blown away by this. The inner dotted line represents perennial ice- ice that has always been there, never observed to melt. Use the slider in the upper right to see the last few years of minumum ice. An enormous area of perennial ice is simply gone. And from what I've seen (I'll keep an eye out for links), this year is predicted to be worse.
Ice is very reflective; its presence helps keep more ice around, since less sunlight is absorbed and converted to heat. Open water is very unreflective; most sunlight hitting it is absorbed, warming the water. Melting the ice.
This was found at A Tiny Revolution on this post. He has some good comments about anthropomorphising animals, and more to the point zoomorphising (to coin a word) people, to provide insights into political behavior.
Wednesday, May 14, 2008
The NYT has an editorial today pointing out that, "However this election turns out, the United States will have a president who supports mandatory cuts in greenhouse gases." They seem pleased with that conclusion, but also note that McCain's overall voting record with respect to GCC is not strong.
Michael O'Hare published more favorable comments at The Reality-Based Community: "...this was an admirable speech." He makes some good points, for example that McCain came out strongly for nuclear power. (For the record, I am dubious and waffling on fission, but more on that later.) But it seemed to me that the main thing that pleased O'Hare, was, like the Times, simply that McCain claimed be be in favor of mandating reductions of carbon emissions. He also made the point that McCain was actually addressing the issue. I agree with him there, but am disappointed that we have come to expect that candidates won't. I also feel compelled to point out that Bush, when campaigning in 2000, also claimed to favor government controls on carbon emissions.
One of Oregon's progressive blogs, Blue Oregon, has a couple of articles dealing with the speech. The first, by Jon Perr, is focused almost exclusively on the political aspects, ramifications and implications of the speech, with very little attention to the policy meat that McCain laid out. He does note McCain's poor environmental record, and provides a link to a Washington Post article I missed. But again, his main interest seems to be politics rather than policy: "this week's greening of John McCain has little to do with the natural environment and everything to do with the political environment."
The other article, by Kari Chisholm, was concerned first and foremost by McCain's visit and its political aspects, and not by his speech per se. Still, in two concise sentences, he captured what I was trying to say in my Monday post: "He talks a good game about climate change, but just like his pal Gordon Smith, he's a fraud. He simply won't take the steps necessary to really reverse gears on global warming."
(Note: Someone supposedly told Winston Churchill that ending a sentence with a preposition was against the rules of good English grammar. Churchill purportedly responded "That is a rule up with which I will not put." I've always enjoyed that construction.)
Tuesday, May 13, 2008
A British student at M.I.T. who was rejected, Sophie Clayton, 28, said that at first she was amused at what appeared to be a bureaucratic absurdity. But as she pondered the designation, Ms. Clayton said she grew worried. “The two words ‘security threat’ are now in the files next to my name, my photograph and my fingerprints,” she said.
The article claims that most foreigners, and those with criminal records, are rejected.
Another recipient of this letter is a German grad student in oceanography. The ID is required to work around ships and docks. No big deal, though- as long as he is accompanied by someone else with the ID, he can still access these areas. What if his chaperone has to go pee? Is he still OK, or will he be subject to detention as an illegal enemy combatant? Not clear.
Now obviously, the previous is hyperbole (I do tend to exaggerate). I have a number of friends who are foreign graduate students. I can't comprehend why simply being a foreigner constitutes a "security threat." What in God's name have we come to?
Check out yesterday's picture too: a gorgeous shot of galaxies of the M81 group seen through wispy fog of a nebula. If you expand the picture to the full size, and look at the spiral galaxy near the center, you will notice that the outer part is distinctly more blue while the central parter is yellower. Blue stars "burn" hotter and faster, and are short-lived as stars go- a few tens or hundreds of million years. (our sun by comparison is about 4600 million years old) So blue stars die off pretty quickly, leaving yellow and red stars as the only survivors. When you see distinct color differences in parts of a galaxy (and if you look for them, you'll see such color variations frequently), you can tell at a glance which are the active star-forming regions (the bluer areas with many young, hot stars), and which are the older, calmer retirement communities.
The above is a satellite image showing the ash plume extending across South America. (From here; there are quite few other cool pictures in this article)
A lightning storm in the ash column. (From here; more pics here too) There is an enormous version of this pic here (388K).
This style of eruption is called plinian after Pliny the younger, who witnessed and described the cataclysmic eruption of 79 AD that destroyed Pompeii and Herculaneum. Plinian eruptions are characterized by enormous vertical columns of ash. These columns are often supported at least in part by the force of newer material jetting from the mouth of the volcano below. If the volcano slows or stops erupting, the column may collapse due to loss of that support. This can be disasterous: imagine hurricane to tornado-force winds full of burning hot volcanic ash. It was this sort of event that buried Pompeii. Ominously, there are indications that this could also happen at Chaiten. Reuters is carrying a story stating that minor collapses have already occurred due to fluctuations in the force of the eruption and that, "Thousands of people have been evacuated from within a 30-mile radius of Chaiten volcano, 760 miles south of the capital Santiago."
Finally, for those that are familiar with or fans of The Flying Spaghetti Monster (picture, further background), this will blow you away. I haven't been able to link directly to the picture, or download it, but go here, and go to picture #4. I may not have been touched by his noodly appendages, but now I've seen them.
Monday, May 12, 2008
Quickpost this image to Myspace, Digg, Facebook, and others!
Ok, so my friend Kyle was showing me how to link some things; I am still in the really steep part of the learning curve. But this really is kind of a cool picture, no? On the one hand, kind of an exploration of modern surrealism. On the other hand, a plausible administration response to hunger in sub-Saharan Africa... a zebra fricasee and grilled cheese sandwich in every pot.
I do want to point out that these "stupid math tricks" that I will spend occasional time discussing are neither "stupid" nor simply "tricks." I chose the word trick because, really, who doesn't enjoy knowing a few "magic" tricks? I don't consider these procedures just "tricks" because they can, on occasion, be very useful. In the context of one of my undergrad lab jobs, people got into the habit of calling out arithmetic problems to me. ("Hey, if there's .62 grams of carbon in a 5.4 gram sample, what's the percent C?" "Well, umm, about 11 and a half.") I'm convinced this got me a couple of raises. I could generally answer within a few seconds then, though due to lack of practice and an aging mind, I'm slower now. It's partly the lack of practice I want to compensate for now, but mostly I want to pass on the tricks. They're simple and easy to pull off inside your head, without looking for the nearest calculator, and they can truly be useful. I want to encourge people to be facile with math and arithmetic.
I chose the word "stupid" first to make the topic seem a little less threating (these tricks are easy to use), and second as an allusion and homage to Letterman's stupid pet tricks- which were often quite amazing. Just as some of the stupid math tricks are.
Since I brought up the topic again, but don't want to spend a whole lot of time on it, I will simply review some divisibility tests that you should know. (Here, the word "number" refers to a whole number or integer. I'm not dealing with fractions in this post.)
1- Every number is divisible by one: no test necessary.
2- Even numbers (those ending in either 0, 2, 4, 6 or 8) are divisible by 2.
3- Sum the digits of the number; if the sum is divisible by 3, so was the original number.
4- Look only at the last two digits (tens and ones). If that number is divisible by 4, the whole number is. If you don't know immediately, subtract a multiple of 20 (20, 40, 60, 80) to get a number between 0 and 19. (for example, 76, use 60 to get 16, or for 52, use 40 to get 12). If the result is divisible by 4, the original number is. This works because each place 100's and higher is divisible by four.
5- If the last digit is 5 or 0, the number is divisible by 5.
6- If the number is divisible by both 2 and 3 (use those tests), it's divisible by 6.
7- I've seen some methods for 7, but don't recall them right now; they tend to be involved, and so far I've just found it easier to actually do the division and see.
8- Look only at the last three digits (100's down). If that number is divisible by 8, the whole number is. If you can't tell, look at the 100's and 10's places; treating that as a two digit number, subtract the largest multiple of 4 you can. Stick the ones digit back on. If the result is divisible by 8, so was the original number. For example, test 23697776: we only look at 776. If you can't tell with a glance that 776 is divisible by 8 (it happens to be 24 less than 800), look at the 77 part. Subtract 76 (largest multiple of 4) leaving 1, slap the 6 back on for 16. 16 is divisible by 8, so the original number is too. This works because each place 1000's and higher is divisible by 8.
9- Sum the digits; if the result is a multiple of 9, so was the original number.
10- Gimme a break.
11- See this discussion (and why the 9 trick works) under yesterday's post "Is that Divisible by Eleven?"
12- Run the tests for 3 and 4; if they both check out, the number is divisible by 12.
13- and 14- I don't know. I'm thinking about 7; if I find a good one, combine that test and 2 for a 14 test. I'll look and think about 13, but that's an obnoxious number.
15- Run 3 and 5 tests, if both yes, it's divisible by 15.
16- Your turn: look at the test for 4 and 8 and see if you can figure this out for yourself.
Public service announcement: The author strongly advocates the practice of safe math by responsible adults ages three and up. If you think you might engage in math, always carry backup paper, pencil and an eraser. For people with impaired vision, enjoyment is often enhanced by use of prescription safety goggles.
He stated near the opening of his speech, "In the Congress, we need to send the special interests on their way -- without their favors and subsidies. We need to draw on the best ideas of both parties, and on all the resources a free market can provide." He then goes on to promote cap and trade... only.
Now in fairness, cap and trade is probably an important component of CO2 emissions control going forward. It's due simply to the mendacity of our chimpster-in-chief that it's not already in place. And as McCain points out, cap and trade has made great strides in dealing with SO2 and acid rain (which results from a combination of SO2 and NOx).
But CO2 has some important differences: it's relatively stable and it has very little market value. Nitrogen oxides would "prefer" to break down to nitrogen gas and oxygen or oxide compounds. You can largely eliminate it with the use of appropriate catalysts. Sulfur dioxide can be captured fairly easily and oxidized and hydrated to sulfuric acid- a valuable industrial compound. On a tour some years ago of the Sudbury nickle\copper operation in Sudbury, Ontario (once the world's largest point source of SO2 ), we were told that INCO was actually running a profit on its removal of sulfate from flue gases. In other words getting rid of sulfur and nitrogen oxides is either easy, or even potentially profitable.
Not so with carbon dioxide. Of course plants use it (with massive input of light energy) to manufacture glucose, then assemble that to more complex carbohydrates. And many organisms use it in the form of carbonate to create shells and other hard parts. But these are the natural removal processes that are being swamped by the increasing anthropogenic carbon emissions. CO2 does not break down into simpler, more benign materials. And while it does have some commercial uses (dry ice for example), the quantities used are a drop in the ocean compared to quantities generated. Further, most uses of CO2 simply return the gas to the atmosphere afterwards. So it is neither easily broken down nor commercially valuable; it will not respond as easily to cap-and-trade as sulfur and nitrogen oxides.
Which is why McCain's speech today is really not worth much. Paraphrasing, we're going to use the best ideas out there: this one. He's already decided, from his deep technical knowledge, which is the best idea out there, from all of the ideas of all the interested groups and (surprise, surprise) it's the free market.
I don't know if others found it as amusing as I did to have a fellow who has not only stated, but repeatedly demonstrated, that economics is not a strength hold forth on how the genius of the free market and the impetus of the profit motive can turn America into a latter day Emerald City. Sure, I mean look at how well the profit motive has done at ensuring we all have minimal health care, and wholesome nutritious food, and reputable sources of information on which to base important decisions about our collective future. It seems perfectly reasonable, in the context of recent history, to assume that the free market will come up with the perfect response to concerns over the future health of our planet.
And delivering his speech at a wind turbine manufacturer? McCain voted against extending tax credits to wind and solar energy development- industries that have been boom and bust depending on whether customers could get support for these previously more expensive, but safe and sustainable, energy sources. (I say "previously" because it's my belief that with skyrocketing costs of petroleum, wind and solar will become much more competitive. That does not mean that they shouldn't be subsidized at moderate levels at a time when big oil is subsidized at obscene levels.) The workers I saw on the tube this morning looked pleased to be getting their moment of attention from a presidential candidate. I hope their moods are unspoiled by layoffs as wind and solar manufacturing slump from lack of support in weak economic times. According to CNN, a McCain spokesman stated that these tax breaks conflicted with another of the Senator's priorities, a reduction in government spending. So there you have it. Despite the platitudes about commitment, action, future of our nation yadda, yadda, yadda, McCain is committed to acting for improving the future of our nation only as long as it doesn't require doing anything.
Sunday, May 11, 2008
Iris and Bill, the owners, have been very kind and helpful through some tough times, and I love them dearly. Bill always has interesting stuff to talk about, though he does tend to get faster and faster until not so much the actual sound of his voice as the density of thoughts passes off into the ultrasonic. Iris makes great food, particularly her weekend breakfasts, and the casseroles are pretty damned tasty too. She has a rich laugh that I enjoy, so I'm constantly passing off stuff that I think might trigger that sound.
The staff is great, mostly college-age kids. While quite a number are not actually in school (Oregon State University is across the street), they're every one of them interesting, intellegent individuals who are willing to listen to a guy's middle age rants, and as important, tell said guy about interesting stuff in their lives as well. When they have time between customers, of course. Did I say hard working? Umm, let's see.... No didn't say that yet. Hard working, too.
Let's see. Rotating art show monthly. Mostly good stuff- not that I'm really qualified to judge. Fascinating customers. I try not to pester people who seem occupied, but there's generally at least a couple of people outside in the smoking area who have nothing better to do than spend a while chatting. And the vast number of those conversations end up being interesting. I see interesting as a positive thing.
The Interzone was named after the novel of the same name, by William S. Burroughs. Couldn't get through it. I think actually I still have the Bill's copy. But at any rate, he tells me that "Interzone," in the context of the book, is a metaphor for nowhere. So the idea of being outside of nowhere is an interesting one to me. Does that mean I'm somewhere, or even more remote than nowhere? I have no idea. I also like the sound of the phrase: 2-1-3 syllables. Of course there's the literal meaning that I'm often outside the Interzone. Finally, the out-in conflict is appealing to me, though technically, "inter" is a prefix meaning "between" rather than "inside."
So there you have the reasons this nascent blog goes by the name it does. And if it sounds like I'm too eager to suck up and pander to my home-away-from-home, maybe I am. They treat me good.
Another strong interest of mine is the post-Bush era. I wish him no ill (though I sometimes fantasize about him actually having to live and cope with the consequences of his disasterous actions as decider), but I want him gone. Back to Crawford, pushing down brush, hooting at the sunset, grooming Laura, fishing termites out of a hill with a straw that he actually selected and formed himself, all the while carefully guarded by the game wardens... I mean, secret service agents. You know, living the quiet, sequestered life that any aging chimpanzee deserves. The more I read about McCain, the more he sounds like Shrub with progeria, but we'll save that for later. Herewith, a few pics that have bumped my funnybone the right way.
In the future, I'll try to be better about crediting sources. These were some funnies I decided to keep; I don't remember where I found them.
And by the way, I don't much care if my politics offend you. Go read another blog. Bush's politics offend me more deeply than I can describe (though believe me, I'll try), and I haven't been able to change the channel for the last seven plus years. Abusive comments will be deleted with a smile. You don't want me smiling do you?
First the back story. You probably know that if you sum the digits of a number (eg 4653 sums to 18) and the result is a multiple of nine, then the original number is also a multiple of nine (so 4653 is a multiple of nine, or you could say the same thing a different way, that 4653 is evenly divisible by nine) But have you ever considered why that's so?
It's a fairly straight-forward result of the number system we use, base 10. We can subtract out multiples of 9 without affecting whether 4653 is divisible by 9. I'm not too sure how explict to be here, but if 4653 is divisible by 9, then 4653 - 9 is too. So is 4653 -18, and 4653-99. We can represent the number 4653 as (4 X 1000 + 6 X 100 + 5 X 10 + 3.) Then we can subtract out 4 X 999, 6 X 99, and 5 X 9. This leaves us with 4 + 6 + 5 + 3, but we haven't changed whether the number is divisible by 9. We can sum those digits together, and if the result is divisible by 9, so was the original number. This trick also works with 3, for the same reason. As we subtract out our multiples of 9, we are of course also subtracting out multiples of 3. If the original number was a multiple of 3, subtracting out 3's, no matter how many times, won't change that fact.
Okay, that I figured out sometime in high school. Here's an exciting but probably pretty meaningless thing I figured out recently: The same logic will hold true for all number base systems. The number one less than the base- the last single digit- will do this same trick in any base. So in base 8, you can determine whether a number is divisible by 7 by summing the digits. If the result is a multiple of seven, so was the original. So 151 (base 8) sums to 7, and is thus divisible by 7. Let's check: 151 (base 8)= 64 + 5 X 8 + 1 = 105. 105 is 15 X 7.
Let's take an example in base 11: 2355. This sums to 15, so it's not divisible by 10. However just as 3 works in base 10 because it's a factor of 9, so will 5 work in base 11, because 5 is a factor of 10. 2 will also work for the same reason. So we can say before bringing it back to our native system to check (and I haven't checked as I write this) that 2355 (base 11) is divisible by 5, but not 2 or 10. 2355(b11) = 2 X 1331 + 3 X 121 + 5 X 11 + 5 or 2662+363+55+5= 3085(b10). Divisible by 5, but not 2 or 10! Excellent, huh?
Just one more: in base 13, the sum-the-digits trick would work for 2, 3, 4, 6 and 12!
However, as I pointed out, I don't know that this is of any use; I never do math in any base but 10. Buuuuuuuut....
As I was waking up this morning (that is, not thinking too clearly yet, trying desperately to ignore the yammering heads on CNN) I got confused thinking about 11 divisiblity in base 10. I mean, 99 is also a multiple of 11 right? So why doesn't sum-the-digits work for 11?
This state of mind where something seems like it ought to be so, but it clearly isn't, is unsettling for me. It's almost always a bad assumption (as it is here), but I am definitely compelled to figure it out asap. So long story short, 99 is a multiple of 11, but 9 and 999 are not. C'est la vie. But wait a minute... 9999 and 999999 are. And so are 11, 1001 (990 + 11), 100001 (99990 +11). In other words for even powers of 10, one less is a multiple of 11. For odd powers of 10 one more is a multiple of 11. So how about add, subtract, add, subtract, rather than just add? It seems to work. Take 3,376,505 and start from the right (the ones digit): add the 5, subtract the 0, add the 5, subtract the 6, add the 7, subtract the 3 and add the 3, for a total of 11. So 3376505 is divisiible by 11. In this case the total being "divisible by 11" would include negative multiples (e.g. -22) and zero.
I love these kinds of little tricks and have been consciously accumulating them for years, but I've never had one to easily determine divisibility by 11 before. Again, I'm not claiming to be the first to figure this out; I would be surprised if this hadn't been discovered roughly the same time people started using modern numerals (as opposed to Roman numerals- I don't know how they figured out anything beyond adding with that system). Still, it's a trick I'm glad to have, and I'm pretty pleased with myself for findng it.
One last comment: I'm not as confident in my logic with the "11 trick" as I am with the "base minus one trick." I would be tickled if a real mathematician could confirm that this actually does work as I've advertised. It's worked for all the examples I've tested but you can't really verify by brute force in math. I'm also curious, but haven't sat down to work it out, if this specific instance is also generalizable across different bases.
Disclaimer: The author of this blog is not a professional mathematician- barely an amateur. Nevertheless he feels the dangers in these sorts of activities, while not inconsequential, are low enough to recommend trying them at home. Even without parental supervision.
I expect that I'll be all over the map- that pretty much sums up my interests. But the topics that typically occupy my mind include science (particularly geology and the earth sciences), politics and other important news (no particular interest in whether Brittany is wearing underpants this week, and I don't want to imply that all "political news" is important), good music (again, a pretty big map), good books, and the evils of television. Oh yeah, and truth, justice and the American way. Or wait, I think that last was some comic book superhero... no, definitely not me.