Blogs / Cosmic Variance

Back in 1996, after the initially very mysterious explosion and crash of Flight 800 from JFK to Rome, there were numerous eyewitness accounts of a “streak in the sky” just before the crash. This led to the “missile theory” of the crash, which was eventually attributed to the explosion of the center fuel tank by the NTSB. But, also at the time, it was suggested that a meteor of sufficient size could have struck the plane, bringing it down.

Could a meteor have brought down Air France 447? Today we are starting to see reports that there actually may have been a meteor:

However, both pilots of an Air Comet flight from Lima to Lisbon sent a written report on the bright flash they said they saw to Air France, Airbus and the Spanish civil aviation authority, the airline told CNN.

“Suddenly, we saw in the distance a strong and intense flash of white light, which followed a descending and vertical trajectory and which broke up in six seconds,” the captain wrote.

Obviously for any given flight the chances are very, very small that a meteor will bring down an airliner, but as Hailey and Helfand pointed out in a letter to the NYT in 1996, the correct question to ask is this: “What is the probability that, for all flights in history, one or more could have been downed by a meteor?” They concluded that there was a 1-in-10 chance that this could happen…let’s use their logic, brought up to date somewhat, for 2009, for Flight 447.

Helfand, an astronomer, is presumably the one who estimated that “approximately 3,000 meteors a day with the requisite mass strike Earth”. This is a difficult number to get. How much mass? How fast does it need to be moving? But let’s assume that this number is correct; it translates to 125 meteors per hour.

Next we need to know the total number of flight hours at altitude for all commercial planes. In 2000 there were about 18 million flights per year. Clearly in the past 20 years (which we’ll take as our reference, since it spans 1989-2009, with both flights 800 and 447) it was not always so…but let’s take a guess that the 18 million figure is roughly correct for that 20 year period. That would yield 360 million commercial airline flights from 1989-2000. Hailey and Helfand assumed that each flight was two hours in duration. Again, a tough number to find on line, so we’ll take it at face value, giving us 720 million flight hours in our reference period.

They also claim that if there were 3500 planes in the air at any time, this would correspond to covering two-billionths of Earth’s surface. Now the earth’s surface area is 5×10¹⁴ m². Using my trusty HP-15c, I get that this would imply an average target area for a commercial airliner of 291 m², which is reasonable. Each plane, that is, covers 5.7×10^-13 of Earth’s surface. If a meteor hits the earth it has that probability of hitting a given plane on average.

So, in our reference 20-year period we have 720 million hours of flight time, times 125 meteors per hour, times 5.7×10^-13 = 0.051, which we can take as the average number of airliners struck by meteors in the period 1989-2009. That’s a one-in-twenty chance of some plane going down for this reason in that 20 year period. Extrapolating to all flights ever would require a better estimate of total flight hours, but it’s not twenty times the number in the past 20 years, for sure – that is, it’s not yet close to one.

Obviously there are a lot of uncertainties in this estimate; perhaps a factor of two from the number of meteors of sufficient mass per day, the average flight duration and number of flights?

Anyway the meteor idea is not crazy, though not likely. The weather seems more likely to be at the root of the tragedy…but we may never know. One thing, though, is clear: if we keep flying big planes at high altitude, eventually one will get hit by a meteor.

Miscellaneous happenings, including a couple of talks I’ll be giving — one on another coast, one in another plane of existence.

• 3 Quarks Daily has announced a series of four annual prizes, for blog posts in Science, Arts & Literature, Politics, and Philosophy. Science is the first one up, and they’re asking for nominations — the deadline is soon (June 1) so head over there and make suggestions. The final winner will be chosen by a well-known person in the appropriate field; this year’s Science judge will be Stephen Pinker. You are of course welcome to suggest your favorite CV post, because we like the attention. But this would also be a great opportunity to give a boost to that lesser-known blog that you really like and think should get more attention. (There are a lot of good blogs out there.) And if you are someone with a blog, don’t feel shy about nominating a post of your own — most readers don’t keep a mental file of your best posts over the last year.
• The World Science Festival is happening in New York (the U.S.’s second most interesting city) from June 10 to 14. I’ll be there, speaking at two different events. On Friday June 12 there is the WSF Spotlight, which is an informal forum with short talks and a lot of discussion. Participants include Kristin Baldwin (cell biologist), Dominic Johnson (political scientist), Christopher McKay (solar system researcher), and Frank Wilczek (not sure what he does for a living). I believe alcoholic beverages will be available; it’s that kind of event. Then on Saturday June 13 I’ll be on a panel discussing Time Since Einstein, with David Albert, George Ellis, Michael Heller, John Hockenberry, Fotini Markopoulou-Kalamara, and Roger Penrose. (I predict already that insufficient time will be a popular complaint about the time panel.)
• In Second Life, I’m giving a talk tomorrow morning at 10 am Pacific, sponsored by the Meta Institute for Computational Astrophysics. It will be a colloquium-level talk about “Dark Forces,” concentrating on building models of interacting dark matter and dark energy. Second Lifers can beam right there thanks to this elegant and finely-crafted link: http://slurl.com/secondlife/StellaNova/76/200/32.
• Max Brockman (son of John, doyen of Edge) has edited a new collection of essays: What’s Next? Dispatches from the Future of Science. There’s an essay by me in there on “Our Place in an Unnatural Universe.” You should buy it, because it would be like reading a set of interesting blog posts, but on paper. And most of these folks don’t have blogs!

(found in a list compiled by one of my kids, cross referenced to the relevant page number in Roald Dahl’s “Matilda”)

• gormless
• toddle
• diddled
• rakish
• throttling
• asinine
• formidable
• obstinate
• piffle
• regale
• aimiably
• blancmange
• parabola
• clot
• brigand
• suppurating
• implacable
• replete
• comatose
• swot

Gawd I love Roald Dahl. How could you read that list and not want to know what the book was about?

(Sadly, this is exactly the sort of language that tends to be lost in the “abridged” books all to frequently passed off to children — if you have a few minutes to spare, there is a brilliant reflection on abridged children’s literature here.)

The astronauts have wrapped up repairs on Hubble, and released it back into orbit (as of 8:58 EDT this morning)! This mission was just astounding from beginning to end. I didn’t get a chance to blog about it (because hey, it was sunny for once in Seattle), but Sunday’s repair of STIS was another day of drama, with one of the astronauts literally having to rip a handle off the instrument to get access to the panel they needed to unscrew. (Oh, and get this — they then had to peel off a g*ddm sticker to get at some of the screws! Oy.) Monday featured installation of new “outer blanket layers”, which help insulate the telescope. Installation was smooth, except for an accidental head doink on an antenna by John Grunsfeld (which is the first sign that any of the people up there right now may in fact share genetic material with the likes of me). Phil has been doing a great job keeping up on the spacewalks on Twitter, if you want a more detailed blow-by-blow.

The next phase is “Servicing Mission Observatory Verification” (SMOV), during which all the new instruments are put through their paces. This process is expected to take about 3 months, with early release images coming out in early September, with science programs expected to start running not long after. I’m getting myself prepared to be blown away!

PS. Oh, one random bit from my trip to the launch. I got to meet Dennis Overbye. I felt a bit like an 11 year old girl meeting a Jonas Brother.

A decision came down this week from the U.S. District Court in Central California in the case of Farnan v. Capistrano Unified School District. There are a few emerging news reports on what happened; the best article I found so far is in the Orange County Register. Apparently a student (Farnan) recorded a number of statements made in a AP course on European history taught by James Corbett, and the student felt that the statements made by the teacher violated his First Amendment rights under the establishment clause. Among the twenty or so statements made by Corbett about which the complaint was made, the court found that only one, where Corbett referred to creationism as “religious, superstitious nonsense” violated the student’s constitutional right not to have a “government official” in effect establish a secularist religion.

The statement arose, apparently, because another teacher, Peloza, was, in Corbett’s view, teaching religious, superstitious nonsense. From the Court’s ruling:

Peloza apparently brought suit against Corbett because Corbett was the advisor to a student newspaper which ran an article suggesting that Peloza was teaching religion rather than science in his classroom. Corbett explained to his class that Peloza, a teacher, “was not telling the kids [Peloza’s students] the scientific truth about evolution.” Corbett also told his students that, in response to a request to give Peloza space in the newspaper to present his point of view, Corbett stated, “I will not leave John Peloza alone to propagandize kids with this religious, superstitious nonsense.” One could argue that Corbett meant that Peloza should not be resenting his religious ideas to students or that Peloza was presenting faulty science to the students. But there is more to the statement: Corbett states an unequivocal belief that creationism is “superstitious nonsense.” The Court cannot discern a legitimate secular purpose in this statement, even when considered in context. The statement therefore constitutes improper disapproval of religion in violation of the Establishment Clause.

The decision is worth taking a look at, and may become a cause celebre for the creationists. It’s worth wading through the legalese, and getting to the other statements that the court did not think violated Farnan’s rights, and which statements it felt did. In the case of the Peloza comment, the Court suggested that Corbett might have “criticized Peloza for teaching religious views in class without disparaging those views” and thereby would not have violated their rights. Yikes! Quite subtle nuances now separate what you can and can’t say in class.

If you are a teacher, particularly one who intends to tell your students that creation “science” isn’t really science but is religiously inspired non-science, are you violating your students’ rights? I can imagine many, many more things which, said slightly different ways, could be taken to violate students’ rights. Can a court really take a single sentence and say “this constitutes the establishment of a state (non)religion”? I am aghast at the thought.

Personally I hope that Corbett and the Capistrano school district appeal this one…and the ACLU should take a major interest here. The chilling and anti-rational effect of this ruling on classrooms all over the country is all too real.

Inspired by Earth Day (and eerily in sync with Julianne!) I have been looking for good views of the planet from space. In fact, two nights ago my TV satellite provider Dish Network launched the Earth Channel, with a 24/7 view of the earth from the EchoStar 11 satellite. There is also a video with a compressed 24 hour series of stills taken from the camera. At one point you see the moon passing behind the earth. Of course since it’s a TV satellite, it’s geosynchronous and you’ll only ever see the western hemisphere. As far as I can tell, though, you cannot get it online anywhere.

And this one is pretty cool. Even though the image is not very sharp, you can actually control a little web cam on a the Tate satellite, in polar orbit 400 km above the earth… Add a focus button!

I cannot seem to get NASA’s ISS webcam stream to work. Darn. Too popular? Not Mac compatible?

Sadly, Al Gore’s 1990’s vision of an Earth-viewing satellite, originally called Triana, and later renamed DSCOVR, sits in storage at Goddard, having been built but cancelled in 2006.

Speaking of which, it appeared for some time that a similar fate awaited Nobel Prize winner Sam Ting’s Alpha Magnetic Spectrometer, designed to search for antimatter (antihelium nuclei, in fact) and other things in space. Construction of the $1.5 billion satellite was completed, and it awaits launch at CERN. An additional, final Space Shuttle mission, STS-134, was added to the 2010 NASA schedule. It was authorized by Congress in the fall but I am not sure if funding has been appropriated yet. (My money is on Sam Ting, though.)

Anyway, where are the cool views of our planet from space?

As you may have heard, Stephen Hawking has been rushed to the hospital after falling very ill. He has been struggling with a chest infection for several weeks, and has had to cancel some public appearances. A press officer from Cambridge University later added that he has improved, and is now in comfortable condition.

Not much to add, except that we all hope for a speedy recovery, and that is back writing papers and giving lectures before too long.

Update: Associated Press, reporting from another statement released by Cambridge, says Hawking is expected to make a complete recovery.

If you watch the Daily Show, you know the inane humor of John Oliver, one of the regular “corespondents” on the show. My colleagues at CERN tell me that he’s visiting CERN now, filming one of his inimitable segments on the LHC and the experiments, to be aired “some time after April 21″. Personally, I can’t wait to see it – he is always funny and usually pretty sharply barbed. He apparently rode an LHC dipole magnet like Slim Pickens rode the bomb in Dr. Strangelove, and asked one of our guys “is there anything you do here that’s not boring?” His video spots are always edited tightly to get the maximum laugh quotient. Anyway, here he is in the CMS cavern, earlier today (thanks to my student Matt Searle for the photo!)

I’ve been on a little bit of a Wall Street rant as of late (here and here). But I can’t help throwing out a couple more things, in case you somehow missed them. In recent weeks Jon Stewart, in his inimitable way, has been asking a truly important question: why did the business media completely and totally miss the Wall Street meltdown? Aren’t they supposed to be doing investigative reporting? Aren’t they supposed to be asking the hard questions, uncovering wrong-doing, and thereby informing and protecting the public? With all the resources at their disposal, how could they completely and totally miss the most profound economic event since the great depression? The truth, of course, is that the mainstream media coverage of Wall Street is a farce. It consists of interviews with CEOs and stock pickers, and advice and analysis that isn’t worth the paper it’s printed on (or the photons your TV/computer monitor emits). There are very few true business reporters out there (Gretchen Morgenson of the New York Times being my favorite).

The first must-see show consists of Jon Stewart doing a take-down of CNBC (a cable channel devoted solely to business). The show includes plenty of clips from CNBC “experts” (including Jim Cramer) making statements and stock-picking suggestions which turn out to be spectacularly wrong. It is truly brilliant and instructive:

A couple of weeks later Jim Cramer was a guest on The Daily Show With Jon Stewart, presumably to defend his (and CNBC’s) honor. It is simultaneously one of the most entertaining and disturbing interviews I’ve ever seen (though nothing compares to the Sarah Palin interviews). Jim Cramer is the host of a show on CNBC called Mad Money. The basic premise of the show is that Cramer, a former hedge fund manager, will “make you money” by telling you which stocks to buy or sell. The problem, of course, is that he has no idea what he’s doing (see here and here). This is not a stab at him particularly, since I believe that aside from a truly tiny set of individuals, none of these fund managers or traders has any clue, and for the most part they all do roughly average (within expected deviations depending on their assumed risk). But I digress. In the interview Jon Stewart completely dismantles Jim Cramer, showing him to be essentially a fraud. Or, more to the point, he is providing entertainment, not actual financial advice. It is an astounding admission, from one of the most watched financial advisors in the world. What we need is more investigative journalism, and less snake-oil salesmanship. Here is the interview:

Here it is almost the end of March, and none of us has blogged about the International Year of Astronomy 2009.

There are a whole bunch of cool events of various sorts around the world. Ray Jayawardhana at Toronto started the year off with a great ad campaign on Toronto busses and elsewhere called Cool Cosmos. Here are a couple of examples:


Pretty cool to see that while you’re standing on a bus.

Later this week starts 100 hours of Astronomy, running April 2–5. The focus is a worldwide marathon of amateur astronomers watching the sky, culminating in a star party during the final 24 hours, which coincides with the 3rd annual International Sidewalk Astronomy night. If you have a telescope and know how to use it, get out there! And if you don’t, now’s your chance to find one! Astronomical observatories will be participating via Around the World in 80 Telescopes, which will be a live webcast starting on Mauna Kea (with Gemini, Subaru, UKIRT, Keck, CFHT, SMA, CSO all participating) and then heading west until it gets back around to Lick and Palomar 24 hours later. In addition to the webcast, you can also follow 100 Hours on twitter Impressively, in New York City, they managed to get the park lights turned off at 8pm this friday for their star party — great opportunity to see a dark(er) night in NYC!

In case 100 days isn’t enough, there is also a podcast called 365 days of astronomy, which has a daily podcast from a variety of sources and on a wide range of astronomy related topics.

Of course, there is also a blog, Cosmic Diary which includes bloggers from ESA, ESO, JAXA, and NASA, so you can hear about the life of professional astronomers all over. Check em out!

I’m sure I’ve missed some of the most interesting events, so feel free to leave them in the comments.