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[ Wednesday, September 01, 2004 ]
Iran Said Nearing Enrichment of Uranium, writes the AP's George Jahn. Excerpts:
The confidential report of the International Atomic Energy Agency said the agency had been informed that the Islamic Republic planned to process more than 40 tons of raw uranium into uranium hexafluoride.
A senior diplomat familiar with the agency declined to say how much hexafluoride could be obtained from that amount of raw uranium, also known as yellowcake, beyond saying it was a "substantial amount."
Another diplomat, who also spoke on condition of anonymity, said that enough highly enriched uranium could be produced from the hexafluoride derived to make several explosive devices.
I can do better than that. Turning to Characterizing and Classifying Uranium Yellow Cakes: A Background, we find assays ranging from 75-85% UO3. Assuming the Iranian yellowcake to assay at 75%, this would mean (at least) 30 tons of UO3. Each molecule would weigh around 238 + (3 * 16) = 286 daltons, so the uranium portion of the total would be (238/286) = 83% of the total, or at least 25 tons. This in turn would process into 37 tons of UF6 (flourine's atomic weight is 19).
But the 25-ton figure for pure uranium is the most important. Natural uranium is 0.72% 235U (source), so there's 180 kg of the good stuff in there. How many bombs?
This page notes that 1.5% of the 235U in the Hiroshima bomb was fissioned, yielding 14.5 kT. At 4.2 MJ per kg of TNT equivalent, that's 61 trillion joules, or 6.1 × 1020 ergs. Now turning to this page, we find that a typical fission event converts 0.087% (0.1911 GeV/218.8969 GeV) of the mass of the fissioned atom (plus neutrons) into energy.
And that means that at last, after nearly three years of blogging, I get to actually use E = mc². Fissioning one gram of 235U would convert 0.87 mg of mass to energy. Using CGS units, we get 7.8 × 1017 ergs. Dividing that into the amount calculated above produces a figure of 780 grams actually fissioned. If this was 1.5% of the total in Little Boy, it had 52 kg of 235U.
So the Iranian regime will be able to produce at least three, and probably four, crude nuclear warheads in the 10-kT range within a matter of months. Arcturus: figuring out stuff to keep you awake at night so you don't have to!
In the real world, this risk will be managed. And everyone will pretend to complain, while being secretly relieved, just like last time.
Jay Manifold [2:01 PM]
[ Friday, August 27, 2004 ]
Police Confirm Pipe Bomb Blast at Stem-Cell Lab.
If I supported the death penalty, it would be for people who do things like this.
Jay Manifold [6:10 PM]
[ Thursday, August 26, 2004 ]
Still More Unsurprising Results
-- in this case, from the Ethical Philosophy Selector:
- Aquinas (100%)
- St. Augustine (97%)
- Ockham (89%)
- John Stuart Mill (78%)
- Kant (76%)
- Spinoza (74%)
- Epicureans (59%)
- Aristotle (51%)
- Jeremy Bentham (50%)
- Prescriptivism (43%)
- Ayn Rand (42%)
- Jean-Paul Sartre (36%)
- Plato (32%)
- Cynics (30%)
- Stoics (30%)
- Nietzsche (27%)
- Nel Noddings (21%)
- David Hume (19%)
- Thomas Hobbes (3%)
Jay Manifold [5:22 PM]
[ Wednesday, August 25, 2004 ]
Welcome to the "Science & Space" blogroll seanwillson.com, chock full of amateur astronomical observational goodness. Sean hails from the northwest suburbs of Chicago. Stare at the Sun with no protection, Sean, and you'll be the third member of MAUSO. ;)
This is as good a time as any to mention that I'll be spending 8 nights in this secure, semi-disclosed location next month, and am queueing up an appropriately enormous list of both Solar System and deep-sky targets. Not sure I'll be able to blog from there, but I'll have plenty of observing reports eventually.
Jay Manifold [5:40 PM]
'Super-Earth' spotted in distant sky, says AFP -- or whoever wrote the headline. The article tantalizingly states:
The object qualifies "as a 'super-Earth," the ESO said.
Much about this enigmatic world remains to be uncovered, least of all whether it may be habitable.
However, there is the tantalising question as to whether it lies within the "Goldilocks Zone" -- a distance from its star that is not too hot, not too cold, just right.
In this zone, a planet would be close enough to the star to have liquid water -- yet not so close that its oceans would boil away -- and not so far that its oceans would freeze. That is one of the prime conditions for creating and sustaining life, according to a leading theoretical model.
But the article also notes that the planet's orbital period is only 9.5 days, and the star it orbits is 50 light-years away and is visible to the naked eye. To be more specific, this webpage notes that m Arae's spectral class is "G3 IV-V," implying that it is somewhat brighter than a main sequence star of the same color (read about stellar spectral classifications here -- be sure to page down to "Luminosity classes"), and furthermore that its visual magnitude is +5.
Sure enough, at 50 light-years, the Sun's visual magnitude would be +5.7 (the Sun's "absolute magnitude," its brightness at 10 parsecs = 32.6 light-years, is +4.8), so m Arae is 1.9 times as bright as the Sun. Applying a rule of thumb that stellar luminosity scales as the 3.5 power of mass, m Arae is 20% more massive than the Sun.
Applying a = ³√((T √µ)/2π)² (source), we find that the newly discovered planet is only 13.1 million km from m Arae, considerably closer than the average distance of Mercury from the Sun (58 million km). It is therefore receiving nearly 250 times as much light from m Arae as Earth does from the Sun. Not so Earthlike.
I've noted before that for political purposes, the definition of "Earthlike planet" may become quite elastic, but I didn't think it would stretch this far.
Jay Manifold [2:01 PM]
[ Monday, August 16, 2004 ]
This one, I mean (see point #4). Dennis Mammana, writing for Copley News Service, has his own version:
Uranus is, without a doubt, the most mispronounced planet in the English language. Of course you may say it any way you'd like, but the proper pronunciation for Uranus is YOU-rah-nus.
Still too close to "urinous." Repeat after me:
Ooh-RAH-nus. Ooh-RAH-nus. Ooh-RAH-nus.
Jay Manifold [5:56 PM]
No bad outsourcing jokes, please: the first asteroid discovered by a native of India has been named, unsurprisingly, Bharat. It's an excellent example of "pro-am" observing -- the discoverer is an amateur, Vishnu Kanupuru Reddy, working at Goodricke-Pigott Observatory, a quasi-professional facility in Tucson.
Turning to the Minor Planet & Comet Ephemeris Service and entering "78118" (Bharat's numerical designation), we find that 78118 Bharat is, as I write this, just about 3.585 AU (536.3 million km) distant in the northwestern corner of the constellation Sextans, about 10° southwest of Regulus; it is 2.59 AU (387 million km) from the Sun. Its orbit is moderately eccentric (e = 0.1873177) and inclined (i = 16° 49' 23"), and with its semimajor axis a = 2.6004976, Bharat completes one orbit every 4 years, 70 days, 16 hours, and 52 minutes.
Unfortunately, 78118 Bharat is also about 10° straight south of the Sun at the moment, so no stepping outside for a look. In any case, its visual magnitude is a flat +20.0, which would require at least a one-meter telescope for direct observation even if the Sun weren't in the way.
See also Spaceguard India, which is headed by the discoverer.
Jay Manifold [5:45 PM]
Why There's No Time Like The Present
-- is explained by Michael Hanlon in The Spectator:
We live in the happiest, healthiest and most peaceful era in human history.
... doom extends across the political spectrum. The Right points to our inexorable moral decay, promiscuity, the ravages of Aids and drug addiction, the decline in manners and standards. The Green Left berates us for our profligacy with resources, our rape of the environment, our failure to right the inequalities of wealth that are leading us to meltdown.
Well, both sides are utterly wrong. A moment's thought is enough to see that, far from being the worst, the 20th century was by far the best in history. And furthermore, things are likely to get better still. To see why, imagine, for a start, being a woman in any period in human history other than Very Recently Indeed.
Registration is required to read the piece, but it's well worth it; 2081 words, reading time 5-10 minutes.
Jay Manifold [3:21 PM]
[ Sunday, August 15, 2004 ]
Had a private star party at a semi-secure, semi-undisclosed location last night -- I will only say that it was approximately 8 miles south of Louisburg, KS. It was a beautiful evening, with excellent sky transparency, good seeing, and unseasonably cool weather. Also very good food, thanks to my host.
The bright planets, which were all in the evening sky as recently as April, have now entirely disappeared, either vanished into the glare of the Sun or moved into the predawn sky; and since I schedule these gatherings for the weekends nearest New Moon, the sky was moonless. So the observing centered around deep-sky objects and subtler Solar System targets.
The summer Milky Way was stunning, appearing almost three-dimensional to the unaided eye; Walter Scott Houston once wrote of spending much of one entire night at the Texas Star Party -- possibly the very same night I wrote about and posted in "We are all in the gutter ..." -- simply sweeping the Milky Way with binoculars or regarding it from the comfort of a chaise lounge with no optical aid at all.
I was able to spot Uranus (pronunciation meme; see item #4) near 57 and 58 (s) Aquarii; at first, all three objects appeared as one fuzzy spot with the naked eye. As Roy Bishop admirably explains on page 46 of the Observer's Handbook 2004 (hyperlinks added):
... the number of rod cells far exceeds the number of nerve axons available to carry the signals to the visual centres in the brain. To accomodate this limitation and to cope with spontaneous thermal noise in the rod cells, the cells are grouped into detector units of various sizes (analogous to binning of pixels in a CCD chip). Because of the thermal noise, only those signals triggered by almost simultaneous photon hits in several rod cells are allowed to produce a conscious sensation. Thus in very dim light only large retinal detector units receive enough photon hits to respond. As a consequence, our ability to see detail is greatly reduced in dim light.
However, what looked like one blurry object when it was 20° above the horizon had resolved nicely to three separate objects an hour later and ten degrees higher. At magnitude +5.7, Uranus just isn't that hard to see from anyplace well away from city lights (I was about 42 miles south-southwest of downtown Kansas City, MO), raising the suspicion that the planet was known in classical times, but deliberately went unacknowledged because the number of "planets" (including the Sun and Moon) would then have been eight rather than seven.
In the telescope, at 60x -- ie an apparent distance of about one-third of an AU -- it was merely a very small, faintly greenish disk, due to methane absorption of red light in its upper atmosphere. Since the brightest of the moons is about as faint as Pluto, I've never seen any of them; but a good 8" telescope, high power, and an ephemeris are in theory all that would be needed to reduplicate another feat of William Herschel, who also discovered Titania and Oberon.
There was no question of seeing Neptune naked-eye, though, as it was at magnitude +7.8, about five times too faint even for dark skies. But in the telescope I had little trouble identifying it near 23 (q) Capricorni. At an apparent distance of nearly half an AU, it was simply a bluish dot, and though I have glimpsed its giant moon Triton once, my telescope's optics would have to have been a good deal cleaner and better-aligned for there to have been any chance of that last night.
My other solar system target was asteroid 4 Vesta, which may be a naked-eye object next month. Vesta is about 0.4 AU closer to the Sun than the largest asteroid, Ceres, and this plus its higher albedo, causes it to appear three times as bright at closest approach to Earth. I found it, using my host's binoculars, near 3 Ceti, but it was a bit too subtle to point out to other guests unless I had used the telescope.
By then I was getting pretty tired, since it was well after midnight, so we looked at a few of the usual objects (items #5-11) and I packed up and went home. A thoroughly satisfying night of observing.
Jay Manifold [8:04 PM]
[ Thursday, August 12, 2004 ]
How to Create a Productive Workforce
Shut off their D2 expression and give them Modafinil.
I'm kidding. I hope.
Jay Manifold [5:16 PM]
Having gotten up at 3 AM after not sleeping well, I'm not quite ready to wax poetic like I did two years ago, but still have some experiences to pass along.
Stoked with a suitable amount of coffee, I arrived at the site by 3:45, where I found a Horseman of the Arcturcalypse (A Fine and Peculiar Place) already observing from the hood of his car. I rolled out a foam pad and sleeping bag on the ground next to the van and climbed in, boots and all.
It was a fine night; sky transparency was excellent -- I had no trouble finding the Andromeda Galaxy naked-eye, or seeing nine or ten Pleiades without optical aid -- and seeing probably wasn't worse than average; the stars twinkled, but not too much. In the event, I never got around to setting up the telescope to look at Venus or Saturn, which would have provided an excellent test.
But it was cold. The proprietor of AF&PP;, mentioned above, eventually took refuge in his car, and I was fortunate to have the sleeping bag. This morning's low in KC, 51°F, broke a record, and it may have been in the upper forties out at Blue & Gray. It was also quite humid, with a heavy dew, though not quite humid enough to produce fog, at least not at the observing site, which is on relatively high ground.
In less than an hour and a half of observing, I saw at least 75 Perseids, plus several sporadics and several "maybes." So I was seeing 60 per hour just in the portion of the sky I was able to keep an eye on. I expect that the actual ZHR was 90 or more. Few appeared especially colorful; there were just a handful of greenish or bluish ones, and less than 10 left glowing trails. But sheer quantity made up for any possible disappointment. I would have been pleased to see half the number I did.
Toward dawn, the Moon, Venus, and Saturn made a striking assemblage in the eastern sky, positioned as they were just north of Orion, near Castor and Pollux. Earthshine on the Moon was quite prominent, and it occurred to me that someone might be monitoring the Moon for impacts. I'll pass along any results I hear about.
I'd forgotten to check for ISS or HST flyovers or Iridium flashes, and only noticed one satellite: perhaps fourth magnitude as it flew right through the Pleiades, moving south to north, fading to invisibility twenty degrees on.
Jay Manifold [10:19 AM]
[ Wednesday, August 11, 2004 ]
-- via Bluetooth-enabled phone. As Dave Barry would say, I am not making this up. Found via the ASKC Yahoo! group.
Jay Manifold [1:38 PM]
[ Thursday, August 05, 2004 ]
Something of a recurring topic of mine, gets another post on Chicago Boyz.
Jay Manifold [5:56 PM]
"Where is the American conscience?"
One need not agree with every detail in this post to thoroughly admire the writer of democracyforcalifornia.com for her Pasternak-like individualism:
The United States will need much more than a new President to heal what really ails us. Our whole system needs to be demassified and a vast number of individual citizens will have to become engaged in that process, each one acting on conscience and moved by compassion, to reclaim the right to their own humanity, and thereby restore this nation back to health.
I am optimistic. As I look around the blogosphere I see the emergence of individuals, each one voicing his or her concerns from their own unique perspective.
There is still reason to hope.
In a certain subculture, "each one acting on conscience and moved by compassion" is a pretty decent description of the symptoms of something called "revival." I don't have to believe the US to be fundamentally unhealthy to share Diana's observation -- and her hope. Whatever the outcome of this year's election, ideas like this should be the pride of a constructive opposition.
Jay Manifold [1:18 PM]
Since this is fast approaching -- the peak is one week from (earlier) today -- here's the scoop: map of the radiant and general info, which indicates that the peak of activity will be around 4:20 AM CDT on Thursday morning, August 12th.
For locals, this handy application shows that the Moon will be a waning crescent, only 11% sunlit, and therefore will not interfere with observation; civil twilight begins at 6 AM sharp in KC.
Generating a sky map at YourSky for KC at 0920 UT on 8-12-2004, we find that the radiant point will be high in the northeastern sky, not far below the zenith. The Moon, Venus, and Saturn will all be low in the east-northeast.
Since I live east of the Blue River, near Raytown, I find it relatively convenient to drive out to Blue & Gray County Park, specifically to the picnic shelter on the south side of Hammond Rd, ¼ mile east of Buckner-Tarsney Rd. I will try to be there before 4 AM.
Locals who don't feel like dragging themselves off to eastern Jackson County in the middle of the night may prefer going out to Powell Observatory a bit earlier instead; I happen to know that it will open at 8 PM Wednesday evening the 11th and stay open until at least midnight. Using the Naval Observatory app linked above, I find that for Louisburg, sunset is at 8:17, and civil twilight ends at 8:46. The Perseid radiant will just be rising above the north-northeastern horizon around 9 PM.
Jay Manifold [12:44 PM]
[ Wednesday, August 04, 2004 ]
Via De Doc's Institute for Memetic Engineering And Polymaths' Pursuits, the way things ought to have been.
Jay Manifold [9:45 AM]
[ Tuesday, August 03, 2004 ]
I don't do a lot of day-in-the-life stuff here, so bear with me while I hit you with an entire 4-day-weekend-in-the-life account. It's already been reported on here and here -- "sort of creepy" being relatively polite, as I was already affected by sleep deprivation by the time I got to stately Pharyngula manor and undoubtedly reeked of sweat, sunblock, and insect repellent; and by the time I got to stately Fresh Bilge manor, I was a complete mess.
To be a bit less oblique: I left KC last Thursday afternoon, minutes ahead of rainfall, taking I-29 north to exit 92 in the northwest corner of Missouri, then onto US-59, which I followed all the way to Morris, MN, with side trips as follows: brief visit to family gravesites near Coin, IA, camping overnight at Waubonsie SP, and refueling/meal stop in Shenandoah, IA. Southwestern Minnesota, in particular, looked paradisiacal: verdant green, proverbial profusion of lakes, deep blue sky, little puffy clouds, cool breeze. Got to Morris a few minutes before 6 PM Friday.
Morris looks like something out of a Grant Wood painting, but with technology. The Myers residence is a sprawling half-century-old place with lots of glass block and a radiant heat system -- and a fiber optic line running straight to the house, to which PZ has added a wireless network. And he's getting 4 hours out of the battery on his Mac. Compare my < 28.8 kbps connection from a 4-year-old Windows machine, or my work laptop whose battery lasts an hour and a half. Must be all that money academics make. ;)
We began the evening by launching into a solid hour of conversation without so much as a glass of water (a sure indication of rampant nerdiness), in which I asked questions like "if you had a billion dollars to spend on stem cell research, how much would go to embryonic stem cells and how much to adult stem cells?" and learned that burning elm logs was a vector in the spread of Dutch elm disease. After a while, PZ asked about my plans. I said something vague about dinner and my intent to camp at Hartford Beach SP, but this non-plan was summarily aborted. Morris is about 4 blocks across, so we walked to the local bar & grill, where I ate some kind of gigantic hamburger and was plied with alcohol. It doesn't take much. From then on I did more talking than listening, but nonetheless got a sneak preview of a couple more posts PZ had yet to compose on the SDB 2004 conference. At any rate, I now owe him a meal and a walk through a relentlessly charming small town, if I can ever arrange one.
Back at the house, I was offered a spare room, which I gratefully accepted. Unfortunately, I didn't sleep well, partly because I didn't take any melatonin with me on the trip and partly because I was a bit keyed up from the conversation. Woke up early anyway and made my way downstairs, where I was shortly joined by PZ, who made coffee in a magnificently filthy coffeemaker; my inner bachelor was delighted. I inhaled four cups of it while he sipped one and we talked some more; I told him lurid tales of cat fostering (She Who Must Be Obeyed volunteers, ah, extensively for this organization) and learned about the eponymously amusing U/P ratio (page down to III.F.1), the measurement of which is a striking indicator that cats are descended from desert animals; their kidneys are as efficient as those of camels.
I hit the road again around 8:30 AM; got rained on shortly after leaving Morris, but if there's one stretch of road where rain isn't much of a hazard for motorcyclists, it's state highway 9 between Morris and Breckenridge. Perfectly flat and straight, and very little traffic, at least on Saturday mornings in summer. I was shortly back on I-29 and headed for Fargo and free brunch courtesy of Fresh Bilge.
I'm afraid I wasn't the most sparkling conversationalist at that point. Must've still had cats on my mind, because we certainly talked about them some. I was also beginning to realize that my planned itinerary was insanely aggressive, and easily got talked into changing it to head west instead of east. Probably should have taken up the offer of sailing and then done something else altogether, but in any case, after a couple of futile attempts to check webmail -- one at stately Fresh Bilge manor and one at the Fargo public library downtown -- I headed west on I-94. Killed an hour at a rest area after checking the weather radar at one of those internet kiosks one sees advertised to the gullible on late-night TV (it was free for stuff like road-condition info) and discovering that a patch of rain was crossing the road just ahead. Made it to Jamestown and collapsed at the inexpensive but surprisingly well-maintained Jamestown Motel. Slept relatively well.
The next day I really wimped out and just headed south on US-281. Worked my way down through southern North Dakota, all of South Dakota, and into Nebraska at Yankton. Northeastern Nebraska was also especially pretty, due to abundant recent rain. Only mishap of trip occurred as I was pulling into a left-turn lane at the main intersection in Norfolk (Johnny Carson's hometown) when a bee got into the left sleeve of my leather jacket and stung me just below the elbow. Managed to continue to steer until I got to a parking lot. Stopped for dinner, partly to wait and see how bad the reaction would be, but it quit hurting after just a couple of minutes and never bothered me again.
I pushed on to Dead Timber SRA, where I camped right next to the river. Again, did not sleep well, largely because of the heat. May have just avoided getting rained on early in the morning -- I think some storms passed only a few miles to the north. Didn't get up until 8:30; broke camp, left, worked my way over to I-29 at Omaha, and rode home. Very hot on this last leg. I don't think I'll ever do one of these trips at this time of year ever again. Earlier or later, but not in July or August.
Actual blogging will resume tomorrow. Meanwhile, Byzantium's Shores has found the artwork (page down) I'll use if I ever upgrade this thing.
Jay Manifold [6:27 PM]
[ Thursday, July 29, 2004 ]
Original Science News Reporting
Graze on over to Pharyngula for some first-class reporting on SDB 2004, from which Dr Myers just returned. Start here and work your way up.
(The one time I did something like that, from LPSC 33 in March 2002, it wore me out; the results are here, for those interested -- once you're there, scroll down for more.)
Jay Manifold [10:23 AM]
[ Sunday, July 25, 2004 ]
Saw a rumor over on the ASKC Yahoo! group: "Looks like tonight has an excellent chance of aurora. A big CME is coming in on top of fairly high activity so there is a good chance of seeing something."
A CME is a Coronal Mass Ejection. I dug around and found the Space Environment Center webpage; excerpts from the forecast (note that the text on that webpage is updated frequently) appear to indicate that there's a better chance tomorrow night:
Region 652 (N08W35) produced four M-class events, the largest - an M7/2B flare at 25/0551Z. This flare had associated moderate centimetric bursts, including an 819 sfu Tenflare. A Type IV radio sweep also accompanied this flare. No LASCO imagery was available, but it is likely that an Earth-directed CME was associated with this event.
CMEs associated with today's M7 and long duration M1 flares will likely impact the geomagnetic field on 27 July and produce periods of major storming.
Note that these dates are UT, for which midnight is at 7 PM CDT. So tomorrow night could be ... interesting. The forecast for tomorrow night also predicts (for middle latitudes) a 45% probability of a "minor" geomagnetic storm and a 30% probability of a "major" storm.
This excellent background article notes that
If a [solar] flare is analogous to an interplanetary thunderstorm, a CME initiates an interplanetary tsunami—a flood of billions of tons of protons and electrons bursting from the sun that is capable of massive interference with any flux-sensitive apparatus it happens to encounter.
Might be worth driving north of town a ways to catch it ...
UPDATE: For locals, moonset is around 1 AM tonight and a little after 1:30 AM tomorrow night. Unfortunately, this is important, because the Moon's phase is waxing gibbous, which could interfere with observation. Maybe the thing to do is get up in the early morning hours and drive north; civil twilight begins about a quarter to six, so you'd want to be in place by (yikes!) 5 AM or so.
Jay Manifold [8:25 PM]
[ Thursday, July 22, 2004 ]
Supposedly inspired by me, though I can only vaguely recall suggesting the first song, has been composed by Alan Henderson.
Jay Manifold [10:38 AM]
