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[ 20030930 ]
-- may or may not be exemplified by my imminent appearance on Radio Rhetorica. Mark your calendars for Thursday at 11 AM CDT and tune in, turn on, and drop out. Or not. Thanks in advance to Andy Cline for landing me this gig, however it comes off.
Jay Manifold [5:48 PM]
An Evening At Powell Observatory (V) - “and stars to fill my dream” *
(Previous post in series; facility; telescope described here and here.)
I can't help wondering about some of the visitors: the crippled boy on crutches who nonetheless could climb the ladder to look in the telescope and berated himself for bumping the tube; the elderly woman who was simultaneously utterly unfamiliar with the most basic astronomy and breathless with wonder at everything she saw; all the children who clearly had no idea what to expect, or what was expected of them, but who glued themselves to the eyepiece in rapt silence, devouring the sight of Albireo or Mars or M22.
The atmosphere of the event had changed completely in four weeks. Spectators were still plentiful but less numerous, so the lines at the telescopes were shorter, and most people seemed pleasantly excited -- without being nervous, as if they were afraid of missing something, which was my perception in August. The temperature was at least 20° F cooler, and there was a breeze, making the night uncomfortably cold for those still dressed in shorts and T-shirts. And the sky, to the regular observer, was obviously different: a 2-hour shift in R.A. putting the summer Milky Way overhead at mid-evening, with the Square of Pegasus rising in the east and, a little later, the Pleiades. So although the leaves were still green and had not yet begun to fall, the overwhelming impression was of a boundary crossed, and Autumn begun.
In increasing distance from Earth:
- Satellites are popular, and we saw our share, including an easily observed ISS passage low in the northern sky and a spectacular Iridium flare (mag -6) near Polaris, both of which got big rounds of applause from the crowd. I personally observed 4 smaller satellites pass through the field of view of the telescope, and was able to spot 2 of them naked-eye immediately afterward (if this represents a typical density, well over 100 satellites detectable with a medium-sized telescope should be visible from any cloud-free spot on Earth in the 2 hours after sunset or before sunrise!).
- The crescent Moon was prominent when I arrived, but set behind the trees to the west before I took over running the 12.5" telescope. Lots of people lined up to see it, especially small children, who after all a) knew what it was and b) thanks to its low altitude, could actually look through the eyepiece without climbing a stepladder or being picked up by their parents.
- Mars, of course, remains the principal attraction and, though noticeably smaller in the telescope than it was a month ago, is still visually stunning, both in its dominance of the southeastern sky in early evening and in the abundance of detail visible at moderate magnification. It is distractingly bright, however, and the south polar cap is becoming difficult to spot. Filters are strongly recommended to improve contrast. Central Meridian was ~80°; surface features included Mare Erythraeum and Solis Lacus (map).
- We got a bonus planet Saturday night, the seventh one out from the Sun (which, by way of starting a meme, I'm going to ask that everyone begin pronoucing "oo-rah'-nus," since it both avoids the unpleasant connotations of either of the present-day English pronunciations and resembles the way the ancient Greeks would have actually said the word. Everybody say it with me now: oo-rah'-nus). Anyway, Uranus was perhaps 2° north-northwest of Mars, and it was easily naked-eye visible; even first-timers had no trouble spotting it, an indication of excellent sky transparency -- and of the likelihood that it was well-known in classical times, but was deliberately ignored because then the number of "planets" (including the Sun and Moon) would have been 8 rather than 7, and we can't have that. Returning to the present, as viewed through the telescope at around 50-60x, it shows a small but distinct disk about 3 arc-minutes in apparent diameter, that is, one-tenth the size of a full Moon. Even when the disk is not obvious, Uranus can be spotted by its color, since it has a distinctive greenish tint almost never encountered in background stars. All its moons are 14th magnitude or fainter, making them theoretically visible in a 12" telescope, but conditions are rarely good enough for this, and in any case I was neither using sufficient magnification nor in possession of an ephemeris that would have allowed me to confirm any such observation.
- Albireo, the prettiest double star in the sky. This gets lots of oohs and aahs, since most people have never seen, or rather never noticed, a double star before.
- M27, the Dumbbell Nebula in Vulpecula. Much larger than the Ring, and therefore easier to point out and explain.
- M57, the Ring Nebula in Lyra. Distinctive but smaller angular diameter; most first-time viewers perceive it as an oval spot rather than a ring.
- h and c Persei, the Double Cluster in Perseus. A good break from planetary nebulae and globular clusters, which many people see only as fuzzy spots, if they see them at all.
- M22, a globular cluster in Sagittarius. Less famous but larger and more easily resolved than M13.
- M13, the great globular in Hercules.
- M31, the Andromeda Galaxy; M32, a satellite galaxy, was also visible.
* The second line of the song playing on the radio as I arrived at Powell.
Jay Manifold [5:38 PM]
[ 20030927 ]
"How stupid are these people?" asks Virginia, and the answer is, of course, not necessarily really stupid in any broad sense, just innumerate. Letting these people -- who don't understand that a 3.5% raise during zero inflation is better than, say, a 7% raise during 6% inflation -- attempt to control public discussion of economic policy is like putting Flat Earthers in charge of space exploration. I used to think that a crash program of teaching economics and statistics to journalists would be a good idea. Now I think they just need arithmetic.
Segue to my 44th birthday, which was yesterday. My insurance agent sent me one of those cutesy cards listing the top stories of 1959 (unsurprisingly omitting the Feynman Lecture) and including a little section headlined "American Living Then and Now." This was actually kind of cool, because it listed "average" (median, I think) income and the prices of various items. So I got to work figuring out how much time it took somebody at the median income to earn enough money to buy the things on the list. Results:
Amount of Work Required to Purchase: | 1959 | 2003 |
3-Bedroom House | 2.5 years | 4 years |
New Ford | 5 months | 7 months |
Gasoline, 1 gallon | 7 minutes | 5 minutes |
Bread, 1 pound | 5 minutes | 3 minutes |
Milk, 1 gallon | 23 minutes | 9 minutes |
First Class Postage Stamp | 55 seconds | 1 min 10 sec |
Looks like pretty much of a wash at first -- if you assume that the items are directly comparable. But:
- The 1959 house would be, at best, two-thirds the size of the 2003 house, with smaller bedrooms, fewer bathrooms, a smaller garage, far fewer electrical outlets, etc; it would have been much less comfortable, lacking central air conditioning; and it would have been more dangerous to live in, lacking smoke detectors (and possibly being less well-designed for easy exit).
- The 1959 car would have been worn out after 3-5 years, whereas cars today routinely last 10 years or more; it would have been far less fuel-efficient; it would have lacked the accessories we now take for granted, even at the low end of the market (air conditioning, stereo, etc); and it would have been far more dangerous, lacking good (by present-day standards) brakes or any seatbelts or airbags.
- The 1959 gasoline -- which was more expensive anyway (and this was before OPEC!) -- would have been loaded with tetraethyl lead as an antiknock compound, creating a public health threat which has essentially vanished.
- The 1959 bread -- again, more expensive -- would have been phenomenally bland and noticeably less nutritious.
- The 1959 milk -- quite a bit more expensive -- would have been whole milk, whereas most milk sold today is reduced-fat or skim. Arguably tastier back then, but a lot better for you now.
- The 1959 postage was, perhaps not surprisingly, cheaper. But this isn't an everything-the-government-touches-turns-to-@#$% rant. The big difference between 1959 and today is that back then, lots of documents had to be sent in hardcopy by US Mail that can be transmitted electronically now. Suppose you spend $1,000 on a personal computer, which you keep for 3 years before replacing it, and spend $100 a year for Internet access; and suppose you send 10 e-mails a day. You've spent -- assuming you use the PC for nothing else -- $3,300 to send almost 11,000 messages, at 30 cents apiece. And they get there in minutes instead of days, and both yourself and the recipient have perfect copies, which may be forwarded to others, or replied to, at zero marginal cost.
This is why I despise arcadian, as well as utopian, mindsets.
Jay Manifold [12:55 PM]
Earthquakes and Local Knowledge
Virginia's recent post on earthquake preparedness is more than a little reminiscent of Earthquakes and Economies (II) -- the good news being that the "investigat[ion of] enhanced response through development of citizen cadres for disaster assistance" seems to be taking place.
Jay Manifold [12:41 PM]
[ 20030925 ]
Strong, Shallow Earthquake off Hokkaido
Noted by Glenn. Technical info here; mag 8.0, only 10 km deep, at 4:50 AM local time Friday (2:50 PM CDT Thursday). Location is described as "130 km (80 miles) SSW of Kushiro"; here's a map. I would expect to see a report of a tsunami before long. Fortunately, there appear to be no large populations on the coast nearest the epicenter.
UPDATE: Depth revised to 33 km by the USGS; horizontal location revised slightly; fortunately, the tsunami was small --
The Meteorological Agency said the first quake was focused 42 kilometers underground, about 80 kilometers east-southeast of Cape Erimo in Hokkaido. The agency issued tsunami warnings for the Pacific Ocean side of Hokkaido and along the coastlines of Aomori and Iwate Prefectures following the quake.
Waves over 1 meter high were reported in Kushiro and the town of Urakawa. Later on Friday the agency lifted the warning for Iwate Prefecture and the Pacific Ocean and Sea of Japan coastlines of Aomori Prefecture.
Several hundred injuries and tens of thousands of evacuees, but no deaths reported.
Jay Manifold [6:41 PM]
Currently tied at #39 on Blogdex, Dreams of Space is an astonishing portal to the artwork appearing in scores of books intended for young people and published, mostly, during the childhood of the Baby Boom generation. I remember reading a good many of these, checked out from the Beloit Public Library (then located in the original Carnegie-financed building), when my interest in astronomy and space travel got fired up at about age 7, during the interregnum between Gemini and Apollo.
The difference between what seemed reasonable promises then -- anyone my age who thought about it expected, at least briefly, that by middle age cislunar travel would be routine -- and what actually happened is, of course, quite distressing. But I would ask my readers to concentrate on enjoying the artwork, and not brood too much on what might have been.
Jay Manifold [8:51 AM]
[ 20030924 ]
Good ISS Apparition Over KC Tonight
This one's for my local readers ... per this source, the International Space Station will pass over KC tonight around 7:40 PM CDT, appearing in the west-southwest, disappearing in the northeast, and reaching a maximum elevation of 69°. It will be visible for about 5 minutes. Given the excellent weather we're having, it should be easy to spot.
UPDATE: Observed it while standing on the north side of 47th street, directly in front of this establishment. Approximately the same brightness and color as the brightest star in the western sky, but, of course, it wasn't twinkling ...
Jay Manifold [12:22 PM]
[ 20030923 ]
Yes, it's lame that I got to this through InstaPundit, though I did read it in yesterday's paper first. Via Glenn Reynolds, Small Times' Howard Lovy (if that link doesn't work, just go here and look for "They got some crazy lil nano there") comments on this KCStar story, for which he was interviewed, and says that "nanotech's extreme detractors have won a complete victory over the truth."
If things were that bad, though, the Feds wouldn't be spending $678.7 million on this (potentially rising 9.5% to $847 million in FY04; source [251 kB *.pdf]). And Scott Canon wouldn't have interviewed Howard Lovy for a "localization" story.
Having said that, there was one huge whopper in the article:
... it's that [reactive] nature of nanoparticles that [Kansas State University chemistry professor Ken Klabunde] thinks argues against the possibility of microscopic killer robots.
At nanoscale, particles have overwhelming tendencies to join other molecules in their environment, to clump.
"A colleague talks about how you'd have a little atom man with sticky fingers and sticky feet trying to move around sticky things as big as he is," Klabunde said. "It won't work."
That scenario, he said, limits the sophistication of any imagined minimachines and argues against world-threatening nanorobots Michael Crichton speculated on last year in his novel Prey.
Klabunde gets support in that view from [Richard] Smalley [of Rice University], the Nobel Prize winner. In a Scientific American article, he wrote that the chemical reactions among very small particles makes self-replicating machines "simply not possible in our world."
Er, except for the ones in every cell of your body, that is. Eric Drexler has, of course, long since demolished Smalley's argument. But the nanotech-can't-work meme circles the world many times while the truth makes it around once ...
Jay Manifold [1:18 PM]
[ 20030919 ]
Or is it? Apropos of Rand Simberg, here's a quote from page 19 of the
CAIB report (warning: 11 MB *.pdf):
“Building rockets is hard.” Part of the problem is that space travel is in its infancy. Although humans have been launching orbital vehicles for almost 50 years now –- about half the amount of time we have been flying airplanes –- contrast the numbers. Since Sputnik, humans have launched just over 4,500 rockets towards orbit (not counting suborbital flights and small sounding rockets). During the first 50 years of aviation,there were over one million aircraft built. Almost all of the rockets were used only once; most of the airplanes were used more often.
There is also the issue of performance. Airplanes slowly built their performance from the tens of miles per hour the Wright Brothers initially managed to the 4,520 mph that Major William J.Knight flew in the X-15A-2 research airplane during 1967. Aircraft designers and pilots would slightly push the envelope, stop and get comfortable with where they were, then push on. Orbital rockets, by contrast, must have all of their performance on the first (and often,only) flight. Physics dictates this -– to reach orbit, without falling back to Earth, you have to exceed about 17,500 mph.
But in reality, the physics of spaceflight, even that tough climb to low Earth orbit, imposes a barrier less than that of transcontinental airplane flight. Here's a quote from Frontiers of Space (p 195), first published in 1969 [emphases added]:
It is generally believed that space-travel requires enormous amounts of propulsive energy. This is a gross popular misconception, for the following reasons. A commercial airliner such as the DC-8 cruises at a lift-to-drag (L/D) ratio of 16. It can travel the 2,500 miles (4,000 km.) from New York to Los Angeles in about 5 hr. The L/D ratio signifies that the engines are applying a thrust equal to about one-sixteenth of the aircraft weight for the entire flight duration [L/D tends to increase with aircraft size -- JDM]. If, somehow, the energy from the aircraft engines could be released in the absence of the Earth's gravitational field and atmospheric drag, the vehicle would have accelerated at 1/16 g, or 2.0 ft/sec2 (0.61 m/sec2) for 18,000 sec. The aeroplane would have attained almost enough velocity, 36,000 ft/sec. (39,400 km./hr.), to escape from the Earth! Thus, a routine flight of only 1,740 miles (2,800 km.) by a commercial jetliner consumes energy (and fuel) with the same order of magnitude as is required for an orbital space transport, i.e. 25,000 ft/sec. (27,400 km.hr.). This is true essentially because aircraft must combat gravity and drag incessantly during their entire atmospheric flight. However, vertically launched rocket transports can overcome drag and gravity quickly, and therefore efficiently, during a very brief portion of their entire flight time. They will then coast unpowered for approximately 88 per cent of their total transit times to orbital or antipodal destinations.
Tellingly, the paper I linked above concludes that "basic aerodynamics and structure do not limit the size of aircraft that can be operated economically." So if the physics is on the side of human spaceflight, why don't we already have suborbital passenger transports and orbiting hotels? If you said "economics and politics," go to the head of the class.
Jay Manifold [9:51 AM]
"National unity does not mean national unanimity. You cannot expect to conciliate everybody. It is no use whittling away our own strong position in the hope of satisfying, for instance, those thin-blooded defeatists, who at every period in the war, whenever they saw the slightest chance, obstructed the measures necessary for victory and eagerly urged upon us a patched-up peace. We shall never succeed in satisfying them, nor ought we to compromise our own position by running after them. Our ideas are fundamentally opposed. The power and splendor of the [military] make no appeal to these gentry. Their ideas are essentially cosmopolitan. They consider that one race of men is as good as another -- unless it be their own race, which they are always ready to believe is in the wrong, and which they are always ready to chasten and to humble on every occasion. What is the use of breaking our hearts because we cannot have their help at this critical time? We can do without them. We have done without them before. We have got through the war without their aid, and we will go through this period of reconstruction without their naggings and carpings."
-- Winston Churchill, "The Agony of Russia" (speech delivered 3 January 1920, Victoria Hall, Sunderland)
Jay Manifold [9:14 AM]
[ 20030918 ]
One for my readers Down Under (and I do have a few). Analogous to the Golden Spike; Trans-Australia rail link finished, says CNN. This is quite a project; it adds a railroad from Alice Springs (in the middle of the continent) to Darwin (north coast), connected to the existing railroad from Alice Springs to Adelaide (south coast). It will soon be possible to travel by rail across Australia from south to north for the first time (an east-west link has existed since 1969 [source]).
Jay Manifold [3:01 PM]
[ 20030917 ]
First, an excerpt from this, for the 0.01% of you who haven't already read it:
I experienced what I'll call a Virginia Postrel moment.
Virginia Postrel has argued in her book, The Substance of Style, that aesthetic values are becoming a major driver -- perhaps the major new driver -- of economic activity. And I think she's right. It's easy to scoff at this, because aesthetics seem divorced from function: an ugly car gets you where you're going just as quickly and reliably as a pretty one, an ugly coat keeps you just as warm as a handsome one, and an ugly house keeps the rain off just as well as a showplace.
Well, this caused me to experience a Robert Heinlein moment:
"What is a house?" Teal demanded of his friend, Homer Bailey.
"Well—" Bailey admitted cautiously, "speaking in broad terms, I've always regarded a house as a gadget to keep off the rain."
"Nuts! You're as bad as the rest of them."
"I didn't say the definition was complete—"
"Complete! It isn't even in the right direction. From that point of view we might just as well be squatting in caves ..."
Keep in mind this was written in 1940.
Jay Manifold [8:29 AM]
[ 20030915 ]
Optical Interferometers as Spy Satellites?
Continued from this older post, from which you may follow the thread back a ways ... anyway, previously unknown (or perhaps, since things are a bit hectic just now, merely unremembered) reader Eric Strobel writes:
Regarding the possibility of orbiting optical interferometers as spy satellites -- there's little chance currently, I think. The ground-based OIs all use physical delay lines consisting of (evacuated?) light pipes which bring the light from individual telescopes into a central building containing the optical benches with the moving mirrors needed to assure light from each telescope phases up exactly with the light from the others.
NASA is currently several years from trying that trick on orbit, and even farther from the attempt to phase up light from a small constellation of free-flying telescopes. As with adaptive optics, it *is* possible that the military has already done the free flyer thing. Given the rather tiny field of view, though, such a beast would be best applied to fixed targets and in an era when more & more targets of interest are likely to be mobile, I'd guess the folks involved would have better things to do with their $$.
An invaluable assessment. To keep my idea alive, I need to counter with fixed targets of high value, so here's one, and here's another. Is it worth spending big bucks ($~10 billion) to keep 24-hour watch on them at sub-meter (possibly as little as a few centimeters) resolution? I don't know, but I'll bet somebody's had to decide already.
Jay Manifold [4:40 PM]
Harry Turtledove, Call Your Office
Outraged Californians attempt to recall their state's chief executive, the blundering, indecisive governor ... Bill Clinton?! Dan Weintraub explains what might have been.
Jay Manifold [2:05 PM]
[ 20030912 ]
"Hellblazer" (aka John Constantine) points to this astonishing illustration of the President's popularity through time. A cynic would suggest that we're not more than a couple of months away from a drastic effort to turn that ski slope around ...
Jay Manifold [1:58 PM]
Via Glenn Reynolds, a Clayton Cramer piece on the bogus depleted-uranium stunt by ABCNews.
By way of adding a bit of value, here are some specifics I didn't find in Clayton's (excellent) article (and which certainly don't appear in the ABCNews story, which does not mention, among other things: alpha particles, gamma rays, neutrons, or even the word "radiation" in any context other than when talking about radiation detectors):
- Depleted uranium consists overwhelmingly of 238U, but about 1 atom in 18,000 is 234U. Since the half-life of 234U (245,500 years) is just less than 1/18,000 that of 238U (4,468,000,000 years), however (source), nearly identical numbers of atoms of each isotope are decaying at any given moment. So 235U, the isotope of interest to bombmakers, must be distinguished from both 234U and 238U.
- So, OK, grazing over here, we find that 234U a-decays to 230Th with a half-life of 245,500 years; in the course of so doing, it emits X- and g-rays at various but highly specific energies up to 677.6 keV.
- 230Th, in turn, a-decays to 226Ra with a half-life of 75,380 years, again with associated X- and g-ray emissions at well-characterized energies (readers are invited to trace the rest of the decay cascade for themselves; a periodic table is here).
- 235U also a-decays, but of course to 231Th, which almost immediately (half life 25:52) b-decays to 231Pa, which a-decays to 227Ac, and so on -- all with different energies and decay products.
- 238U, meanwhile, a-decays (very slowly) to 234Th, which quickly b-decays to 234Pa, which almost immediately b-decays to -- 234U; that is, 238U is the source of naturally occurring 234U! See #2, above, for ensuing events.
The various, but again highly specific, energies of the X- and g-rays associated with the decay cascades of these isotopes provide the specifications for detectors needed to distinguish them. The challenge will be to provide detectors which operate quickly; this actinide lung counter (160 kB *.pdf) requires up to half an hour, though it is detecting U and Pu in microscopic quantities -- "4-6 Bq (0.1 – 0.15 nCi)" equates to ~0.06 mg of 235U (derived from info here), a particle (if comprised of pure 235U) less than 0.2 mm in diameter. If time for accurate detection varies inversely with quantity, a hypothetical detector could discern 1 gram of 235U in ~0.1 sec in the absence of effective shielding.
Detectors are also likely to be massive (metric tons) and, of course, expensive, but a million-dollar instrument that inspects millions of items over its lifetime represents a modest marginal cost.
To its credit, the webpage on which the ABCNews story is found does include a link to Understanding Nuclear Fission, but those pages make no mention of the different energies associated with the natural radioactive decay of the various isotopes of uranium.
And here's the final paragraph of the ABCNews story:
Today, a top official at the Department of Homeland Security told ABCNEWS that truck-sized radiation detectors will soon be up and running, able to detect even small amounts of shielded depleted uranium.
In other words, the risk will be managed. And there's no story at all.
Jay Manifold [1:16 PM]
[ 20030911 ]
Appropriately, Lileks' latest masterpiece refers to 1968, and a long war. I say appropriately because the conflict that has been thrust upon us began in 1968, on June 5th, to be precise, with the assassination of Robert F. Kennedy by a Palestinian terrorist (warning: 3 MB *.pdf):
Sirhan remarked in answer to Unruh's question "Why him?", "I did it for my country."
Sirhan's pockets were emptied and the following items were taken from his possession: an automobile key, two live .22 caliber bullets and an expended bullet, two newspaper clippings -- one from the Pasadena Independent Star News dated May 26, 1968, a story by columnist David Lawrence which in part noted that in a recent speech Senator Kennedy had "favored aid to Israel with arms if necessary." ... (p 6)
Thirty-three years, three months, and eight days later, the existence of the war became inescapably obvious. Perhaps it will take a change in Administration to do what needs to be done: decapitate North Korea, seize the Pakistani nuclear arsenal, blockade Saudi Arabia. But this is our time. And we will win.
Jay Manifold [1:36 PM]
Like many other bloggers, I am limiting my posting today. Relatively new readers are invited to browse last year's entry.
Of the local remembrances, I find the most poignant to be this one:
The Linda Hall Library of Science, Engineering & Technology will be open the 24 hours of Sept. 11 in commemoration of the day's events. The library, at 5109 Cherry St., opened at midnight Wednesday and will remain open through midnight today, Sept 11.
You can read about Linda Hall here.
Jay Manifold [10:21 AM]
[ 20030910 ]
McDonald Observatory, ~15 mi NE, from vicinity of Crow's Nest Ranch, morning of Wed 3 Sep 03. Picture taken at ~6,000' elevation; Mt Locke, on which the observatory is located, is just under 6,800' tall.
Photographer: Leigh Ann Manifold. Photo kindly uploaded by Leo Johns.
Jay Manifold [4:14 PM]
-- among those who would shape public policy, may be found over on DarrenKaplan.net, which does the math and finds that Iraq is costing about one-twelfth what Vietnam did, relative to the US GDP. I might add that the casualty rate is, by the severest possible measure, about one-ninth that of Vietnam -- and being old enough to remember this (note that more Americans were killed in action in an average week in 1968 than we have lost in Iraq to date), I cannot regard our losses this year as having, strictly speaking, any military significance whatsoever.
Jay Manifold [3:56 PM]
One of the West's greatest defenders during the 20th century has passed away. A retrospective, which I enjoy pointing to precisely because it appears to be an attempt at criticism, is here.
Teller's Congressional testimony that he "would personally feel more secure if public matters would rest in other hands" was a judgment that Oppenheimer richly deserved. I do not believe that Oppenheimer would have passed nuclear secrets to the Soviets, but his large donations to the Communist Party and his intimacy with Party members, including the woman he married and her brother, were extraordinarily foolish. The popular historical picture of Oppenheimer as a thoughtful man struggling with the moral implications of the Bomb while Teller displayed instability and flirted with disaster is very nearly the exact opposite of the truth.
Only 7 weeks ago, Teller received this well-deserved award.
Jay Manifold [1:43 PM]
Currently tied for #29 on Blogdex, proof that KC-town is at the cutting edge of ... something:
... there have been more than 130 documented sightings of these "Toynbee tiles"-- as they're nicknamed on the Net -- in at least 20 cities around the United States (and two in South America!). In New York almost 50 tiles have been counted, in Philadelphia nearly 30. Twenty have been spotted in Baltimore, including four at one intersection. And there have been at least 16 documented sightings in Washington, D.C., -- one a block from the White House.
All the tiles say virtually the same thing.
You'll have to read the article to find out what that is. Has anyone told Arthur C. Clarke about this?
Jay Manifold [8:04 AM]
[ 20030908 ]
-- is a series of posts on the Columbia Accident Investigation Board's report (warning: 11 MB *.pdf), which I hope to complete over the next few days, most likely one high-level (that is, readable) post and several more detailed (that is, dull) ones. So do check back occasionally. Seriously, I'm going to try not to make it mind-numbingly boring.
I'm currently blogging from Whitney, TX, and will be returning to KC late tomorrow.
Jay Manifold [12:42 PM]
-- that is, the latest asteroid that isn't going to hit us after all, is detailed here. The non-impact would have equated to 350,000 megatons. Looking at the orbit, we find that i = 62°, which combined with Earth's orientation on the projected impact date (21 March 2014), would almost certainly have had it striking the northern hemisphere.
This means it would have had, approximately, a 60% chance of hitting water, a 10% chance of hitting the sea ice in the Arctic Ocean, and a 5% chance of hitting a glaciated area or the Greenland ice sheet (some relevant numbers are here).
Taking 1 kg TNT equivalent to be 4.2 MJ and the specific heat of ice as 300 kJ/kg, we find that had 2003 QQ47 hit Greenland, and had all its kinetic energy of impact been converted to heat, it could have melted 4.9 quadrillion kg of ice. This would occupy a volume of 4,300 km3, which at the thickest point of the ice sheet would -- assuming some unlikely but visually impressive thermodynamics -- liquefy a region 43 kilometers across. If this all drained into the ocean, sea levels worldwide would rise by 3.5 cm (derived from numbers here).
Of course, impact into the north Atlantic, or especially the north Pacific, would have been far more likely. For an idea of what might have happened next, read this Los Alamos news release and this SciAm article; for the overall statistical picture, plus a typical case -- "half of the tsunami risk stems from waves smaller than 11m high that should run in only 500-1000m from shore" -- see this AAS abstract.
Jay Manifold [12:41 PM]
The obligatory note on the passing of Warren Zevon; I heard the news on CNN around 6:30 Central time this morning.
And in the spirit of Warren Zevon, I should note that the e-mail address (zevon@artemisrecords.com) provided at that link may no longer work. ;)
Jay Manifold [12:40 PM]
