One of the giants of the golden era of science-fiction, indeed a co-author of one of the most influential science-fiction novels of all time, The Space Merchants, passed away yesterday, just a few weeks shy of his 94th birthday.
I think it would be a fitting tribute if a future space probe took his ashes to Venus and scattered it in the planet’s atmosphere.
Bruce Murray, a former director of the Jet Propulsion Laboratory and founder of The Planetary Society passed away today.
May he rest in peace.
I was watching RDI’s coverage of the memorial ceremony that was taking place last hour in Lac-Mégantic, the location of the horrific derailment a few weeks ago that claimed so many lives.
I was impressed by the size and beauty of Sainte-Agnés church where the mass was taking place, so I went to Google to find out more.
It was, of course, unsurprisingly difficult to find background material, as search results were dominated by recent articles about the disaster. But, after wading through some directory entries and such, I came across a true gem: the story of the “Electrical Priest”, Father Joseph-Eugene Choquette.
When he was not attending to his priestly duties, Father Choquette spent a fair bit of his time as an amateur scientist. And what an amateur he was!
Bringing a player piano to his church (and drawing the ire of his parishioners when they found out that it was not their vicar who was in secret a talented musician) was just one of his many pranks (perhaps an unintended one in this case). Apparently, he also liked to play with electricity, to the extent that visitors to his house were often shocked by a jolt of current when they touched a doorknob or sat down in a booby-trapped chair.
But Father Choquette was interested in more than mere pranks. He also experimented with telephony and electric lighting. Having installed a personal lighting system (powered by a dynamo hooked up to a windmill) that proved to be a success, he proceeded with a more ambitious plan: a generating plant to light the whole town. He remained directly involved with this project until his death; parishioners often found their vicar strapped to a pole 25 feet in the air, working on a faulty transformer.
When Father Choquette died, he left much of his equipment and collections to the Sherbrook and Saint-Hyacinthe Seminaries and to the Convent and College of Megantic. That was nearly a century ago. I wonder if any of his belongings still survive somewhere.
I spent a part of yesterday afternoon speed-reading Konstantin Kakaes’s new e-book, The Pioneer Detectives. It’s a short book (still well worth the $2.99 Kindle price) but it reads very well and presents a fair picture of our efforts researching the origin of the anomalous acceleration of the Pioneer 10 and 11 spacecraft.
Yes, I was one of those “detectives”. (In fact, I still consider myself one, as I don’t believe our job is quite done yet; we still owe the community a detailed account of our research and an update of our Pioneer Anomaly review before we can move on with a clean conscience.) So I have an insider’s view of this very intriguing story.
I had a chance to talk with Kakaes at length when he visited me here in Ottawa last year. Over the years, I learned to be apprehensive when talking to journalists; often, the words they put in your mouth bear little resemblance to what you actually said to them when interviewed. I was relieved that this was not the case now: at no time did I feel compelled to cringe while reading the book.
So I really enjoyed Kakaes’s telling of our story. Indeed, I think I learned a thing or two about presenting a complex subject to a non-specialist audience. Kakaes, an accomplished science journalist, manages to do so without dumbing it down with excessive oversimplifications.
One person whose views may not be as favorable is the original discoverer of the Pioneer anomaly, John Anderson. I am told that Anderson is not fond of our results. Kakaes believes that this is because Anderson is “blinded by his desire to believe in something new, in something unexplained. He wants so badly not to know.” Yes, scientists are people, too, and the prospect that a discovery you made, once thought profound, may just be an engineering fluke is not an easy one to swallow. Kakaes does what a responsible journalist must do: he tries to paint an objective picture, which sometimes includes unflattering bits. Yet I think that John Anderson has more scientific integrity than Kakaes gives him credit for.
And to be perfectly honest, I am also disappointed with our own results. When I first read about the Pioneer anomaly (as an outsider, long before my involvement) it seemed to fit perfectly into the big scheme: namely that perhaps the same physics that was responsible for significant deviations from Einstein’s and Newton’s predictions on cosmological and galactic scales might also be responsible for a small but measurable deviation here in the solar system. This was a fantastic prospect!
Sadly, it was not to be. What once seemed like a revolutionary, paradigm-shifting result has been reduced to a small footnote in the history of gravitational physics. Yet I think that our story is nonetheless intriguing. Kakaes seems to think so, too, judging by his book. A book that I am happy to recommend.
Looks like we’re in for some interesting weather this afternoon.
The other night, Curiosity was working late.
You walk around on the surface of a planet, and it is pitch dark. Suddenly, you spot a light on the horizon. It’s steady; it’s artificial. You conclude that it’s a sign of civilization.
And indeed it is. What you see is an artificial light… but it belongs not to a living creature but to a robotic explorer. One that was created by a civilization a couple of hundred million kilometers away. A civilization that only invented electric lighting just over two centuries earlier.
I find it eerily beautiful to see an artificial light bathing the rocky surface of an alien planet.
Physics blog sites are abuzz about Eric Weinstein and his Amazing New Theory of Everything. For a moment, I actually confused him with Eric Weisstein, well known in physics and math circles as the founder of Mathworld, which, in the pre-Wikipedia days, was the Internet’s pre-eminent mathematics encyclopedia (only to be hijacked for a while by an unscrupulous CRC press). No, Weinstein is someone else: he is a mathematical physicist turned economist. In any case, he is no dummy, nor does he appear to be a crackpot. He is outside of academia, but, well, so am I, so who am I to complain?
So Weinstein gets invited to Oxford to give a public lecture, and he talks, for the first time, about ideas he has been working on for the past twenty years, about unifying physics.
This is greeted by a headline in The Guardian that reads, “Roll over Einstein: meet Weinstein“. Others follow suit, and soon physics news and blog sites far and wide discuss… what, exactly? Well, no-one really knows.
That is because Weinstein has not published anything yet. Not even a non-peer reviewed manuscript on arxiv.org. This is pointed out in one of the few sensibly skeptical blog posts, written by Jennifer Ouellette on Scientific American’s blog site. Ouellette actually quotes a tweet by Sean Carroll: “Pretty sure Einstein actually wrote research papers, not just gave interviews to newspapers.”
Ouellette goes on to quote Oxford cosmologist Andrew Pontzen, who observes that these “shenanigans” have “short-circuited science’s basic checks and balances”. I couldn’t agree more. This is true even if Weinstein turns out to be right in the end.
Which is conceivable, since Weinstein is no crackpot. But it is much more likely that his theory will join many others, including Garrett “surfer dude” Lisi’s aesthetically beautiful E8 theory, that just don’t have much to do with observable reality.
Twenty seven years ago tonight, an ill-prepared overnight crew at reactor #4 at the Chernobyl nuclear power station in the Ukraine began an unauthorized experiment, originally scheduled to run during the day, and designed to test how much power the reactor was able to supply while it was shutting down, keeping emergency systems powered while waiting for backup generators to kick in. Trouble is, this particular reactor type was known to have instabilities at low power even at the best of times. And these were not the best of times: the reactor was operated by an inexperienced crew and was suffering from “poisoning” by neutron-absorbing xenon gas due to prolonged low-power operations earlier and during the preparation for the test.
The rest, of course, is history: reactor #4 blew up in what remains the worst nuclear accident in history. A large area around the Chernobyl plant remains contaminated. The city of Pripyat remains a ghost town. And a great many people were exposed to radiation.
The number of people killed by the Chernobyl disaster remains a matter of dispute. Most studies I’ve read about estimate several thousands deaths that can be attributed to the accident and the resulting increased risk of cancer. But a recent paper by Kharecha and Hansen (to be published in Environ. Sci. Technol.) cites a surprisingly low figure of only 43 deaths directly attributable to the accident.
This paper, however, is notable for another reason: it argues that the number of lives saved by nuclear power vastly exceeds the number of people killed. They assert that nuclear power already prevented about 1.8 million pollution-related deaths, and that many million additional deaths can be prevented in the future.
I am sure this paper will be challenged but I find it refreshing. For what it’s worth, I’d much rather have a nuclear power plant in my own backyard than a coal-fired power station. Of course the more powerful our machines are, the bigger noise they make when they go kaboom; but this did not prevent us from using airplanes or automobiles either.
It’s official (well, sort of): global warming slowed down significantly in the last decade and a half.
No, this does not mean that the climate skeptics were right all along. Far from it: their attacks on science, their ad hominem attacks on scientists, their conspiracy theories are all nonsense.
What it does mean, though, is that the climate alarmists were not exactly right either. Overstating the case did not help. Far from creating public support, it may have in fact fueled climate skepticism.
The basic science is not wrong. Take a gas like CO2 that is transparent to visible light but absorbs IR a little more efficiently. Pump it into the atmosphere. Visible sunlight still reaches the surface, but less heat escapes radiatively to space at night. So, the surface gets warmer. Simple. This much was known back in the 19th century, to people like Fourier in 1827, Tyndall in 1872, and last but not least, Arrhenius from Sweden who, in 1896, actually calculated the amount by which the Earth would warm up, or cool, if the amount of CO2 were to change in the atmosphere.
But the devil is in the details. The Earth’s atmosphere is not just a column of static, transparent air with various amounts of CO2. It is a turbulent thing, with many feedback mechanisms, some positive, some negative. The oceans play a big role. Foliage plays a big role. Changes in industrial practices, fewer particulates in the air, play a big role. And so on.
And we also know that the Earth’s climate is not exactly a fragile little thing. After all, it has been relatively stable over geological timescales, allowing life to flourish and evolve. So I always thought that it is rather preposterous to assume that a few hundred years of industrial pollution can do what geological upheavals, global catastrophes, and so on could not: tip the balance and cause a runaway effect.
So we are left with the basic questions. How much will the climate change in the foreseeable future? What are its effects on humanity? And what can we do about all this?
The answer, I fear, remains as elusive as ever. And ridiculous schemes like “carbon trading” don’t help either.
There is another ambitious Mars project in the works: unlike Inspiration Mars, the Mars One project aims to send colonists to Mars, people determined to live out the rest of their lives on the Red Planet, with no return ticket.
I wrote about how I would be willing to risk a very dangerous, very uncomfortable 501-day flight to Mars and back. But staying there for good? Now that’s another matter. Leaving the Earth in the company of a dozen or so other people, knowing that from now on, those will be the only people you will ever see face to face? That you will never see a blue sky again, hear a bird sing, or swim in the sea?
Fortunately, this is not a choice I’ll ever have to make. Unlike Inspiration Mars, the Mars One project is not (to the best of my knowledge) looking for middle-aged couples as participants.
In all the excitement (okay, I wasn’t that excited. But, I was busy) I almost forgot to celebrate an anniversary: it was 40 years ago on April 5 that Pioneer 11 was launched at Cape Canaveral.
In a recent Letter to the Editor published in the newsletter of the American Physical Society, a correspondent suggested that Pioneer 11 may still reveal some anomalous behavior. I do not believe this to be the case. While it is true that our investigation of Pioneer 11 was not as thorough as our investigation of Pioneer 10 (due, in part, to the fact that we have less Doppler data from Pioneer 11) there are no statistically significant inconsistencies.
This Letter also reveals two misconceptions about the anomaly. One is that if the anomaly is Earth directed, which would presumably be inconsistent with a thermal cause. This is not so: quite the contrary, since the spin axis and the Earth direction mostly coincide, an Earth directed anomaly is exactly what one would expect to see in case of a thermal cause. Second, I don’t think it is even relevant to say that “a new physics cause may still be possible”. Of course new physics is always possible. But before one can speculate about new physics, “old physics” must be excluded, i.e., there must be an incontrovertible demonstration that conventional physics cannot account for the observed phenomena. This is not the case for the Pioneer anomaly: conventional physics comfortably accounts for the anomalous acceleration. Sure, there are small discrepancies that are within the margin of error, but you don’t fish for new physics within the margine of error. That’s not the way science is supposed to work.
A few moments ago, my wife looked up through our skylight and lo and behold, saw a moving star.
Not just any moving star; it turned out to be the International Space Station, in all its still sunlit glory over the late evening Ottawa sky.
I once managed to capture the ISS through my cellphone; the picture turned out to be surprisingly good, even showing (I think) the somewhat rectangular shape of the station.
Anyhow, I hope Chris Hadfield is having a great time up there.
After another 550 km drive at the end of an already very long day, I finally made it home late last night, concluding a very productive 3-day visit at the Perimeter Institute.
While there, I gave another talk on the Pioneer anomaly. I felt that it went well and as far as I can tell, it was very well received.
All in all, it was time well spent.
That building behind the trees in this wintry landscape is the Perimeter Institute, where I’ll be spending a few days.
Wintry??? Sounds like an April fool’s joke but it isn’t. This really is a long winter.
Looking out my window this morning, here is the winter landscape that I saw:
This is not what those blasted groundhogs promised. They are bold-faced liars, the little creeps. The next time you run into Punxsutawney Phil or Wiarton Willie, keep an eye on your wallet; you just don’t know what the little sons of bitches are capable of.
In a post a few days ago, I expressed my skeptical views concerning the interpretation of some of the recent Higgs results from CERN. I used a simple analogy, an example in which measuring the average height of the inhabitants in a set of buildings is used to determine which of them may house the Harlem Globetrotters.
However, I came to realize (thanks in part to some helpful criticism that my post received) that I left out one possibility. What if the buildings are too small? Or the ‘Trotters are just too, hmm, tired after a long party and end up in the wrong building? In that case, a measurement may look like this:
If we have an a priori reason to believe that, for whatever reason, the players are indeed spread out across several buildings, then we can indeed not expect to see a sharp peak at #4 (or whichever building is assigned to the Globetrotters); instead, we should see a broad excess, just what the CMS experiment is seeing when it measured the decay of the presumed Higgs boson into a τ+τ− pair.
So is there an a priori reason for the data to be spread out like this? I believe there is. No instrument detects τ leptons directly, as their lifetime is too short. Instead, τ events are reconstructed from decay products, and all forms of τ decay involve at least one neutrino, which may carry away a significant portion of the lepton’s energy. So the final uncertainty in the total measured energy of the τ+τ− pair can be quite significant.
In other words, many of the Globetrotters may indeed be sleeping in the wrong building.
Nonetheless, as my copy of the venerable 20-year old book, The Higgs Hunter’s Guide suggests, the decay into τ leptons can be a valuable means of confirmation. Which is perhaps why it is troubling that for now, the other major detector at the LHC, ATLAS, failed to see a similar broad excess of τ+τ− events near the presumed Higgs mass.
I have been reading a lot today about the latest news from Europe, the supposed confirmation that the elementary particle observed at CERN may indeed by the Higgs boson.
And while they are probably right, I feel that the strong pronouncements may be a little premature and perhaps unwarranted.
Let me demonstrate my thoughts using a simple example and some pretty pictures.
Suppose you go to a camp site. At that camp site there are five buildings, each of the buildings housing a different team. One may be a literary club, another may be a club of chess enthusiasts… but you have reason to believe that one of the buildings is actually occupied by the Harlem Globetrotters.
Suppose that the only measurement available to you is a measurement of the average height of the people housed in each of the buildings. You of course know what the mean height and its standard deviation are for the entire population. So then, suppose you are presented with a graph that shows the average height, with error bars, of the people housed in each of five buildings:
The red dashed line is the population average; the green and yellow shaded areas correspond to one and two standard deviations; and the black dots are the actual data points, with standard deviations, representing the average height of the residents in each of the five buildings.
Can you confirm from this diagram that one of the buildings may indeed be housing the Harlem Globetrotters? Can you guess which one? Why, it’s #4. Easy, wasn’t it. It is the only building in which the average height of the residents deviates from the population (background) average significantly, whereas the heights of the residents of all the other buildings are consistent with the “null hypothesis”, namely that they are random people from the population background.
But suppose instead that the graph looks like this:
Can you still tell which building houses the Globetrotters? Guess not. It could be #2… or it could be #4. But if you have other reasons to believe that #4 houses the Globetrotters, you can certainly use this data set as a means of confirmation, even though you are left wondering why #2 also appears perhaps as an outlier. But then, outliers sometimes happen as mere statistical flukes.
But suppose instead that you see a plot like this one:
What can you conclude from this plot? Can you conclude anything? Is this a real measurement result and perhaps the entire camp site has been taken over by tall basketball players? Or perhaps you have a systematic error in your measurement, using the wrong ruler maybe? You simply cannot tell. More importantly, you absolutely cannot tell whether or not any of the buildings houses the Harlem Globetrotters, much less which one. Despite the fact that building #4 is still about four standard deviations away from the population average. Until you resolve the issue of the systematic, this data set cannot be used to conclude anything.
But then, why are we told that a similar-looking plot, this one indicating the rate of Higgs boson decay into a pair of τ particles (the heaviest cousin of the electron), indicates a “local significance of 2.9σ”? With a “best fit μ = 1.1 ± 0.4” for a 125 GeV Higgs boson?
It indicates no such thing. The only thing this plot actually indicates is the presence of an unexplained systematic bias.
Or am I being stubbornly stupid here?
To the esteemed dinosaurs in charge of whatever our timekeeping bureaucracies happen to be: stop this nonsense already. We no more need daylight savings time in 2013 than we need coal rationing.
It is an outdated idea, the benefits of which may have been dubious even at the time of its inception, and are almost certainly nonexistent today. But the harm is real: you are subjecting the entire population to a completely unnecessary one-hour jetlag each spring.
Being self-employed and working mostly from my home, I am among the least affected, but I still find this clock-forwarding business just boneheadedly stupid and annoying.
Oh, and while you are at it… would you please get rid of leap seconds, too? Another harmful solution to a nonexistent problem. So what if our clocks are out of whack by a second with respect to the Earth’s rotation? Does it bother anyone?
Oh wait. The organization in charge of leap seconds is the ITU. The same ITU that is busy trying to place the Internet under international regulation, at the bidding of such champions of Internet freedom like China or Russia. No wonder they have little time left in their busy schedule to abolish leap seconds.
The recent announcement by Dennis Tito about a manned flyby trip to Mars caught my imagination. Thinking about what such a trip would be like, I began writing a blog entry, but it soon became a bit too long for my blog, so I moved it to my Web site instead. Anyhow, here is the link: http://www.vttoth.com/CMS/personal/257.
Cancel the alarm: the Dragon’s wings are fine.
Whatever the actual anomaly was, it appears SpaceX was successful in resolving it and the Dragon now unfurled its solar array wings.
Yippie!