Here’s an idea that only Dr. Strangelove, Edward Teller, or the Communist Party of the Soviet Union could come up with: nuke that oil leak at the bottom of the Gulf of Mexico. Apparently, it has been done before, and only one out of five attempts was unsuccessful. So how about that, folks? What’s a bit of radioactivity when you have an 80% success rate?
OK, I don’t usually play the geek game and look for nits to pick in television science programs. But…
Today’s gem comes courtesy of the Canadian History Channel and their Aftermath series, the first episode of which I just watched over the Internet. The show had many eyebrow-raising moments (and I don’t mean the implausible concept itself, about the Earth’s rotation slowing down to zero in a mere five years; I could get over that if the science had been right otherwise). This particular gem of a sentence, complete with fancy animation, especially caught my attention:
“The rotation of the Earth creates constant patterns of east-moving winds in the Northern hemisphere, and west-moving winds in the Southern. This is called the Coriolis effect.”
Oh really. I wonder if pilots flying in the Southern hemisphere know this.
When I started this here blog site, my intent was to write a lot about physics. I ended up writing a lot less about physics than I wanted to, in part because a lot of the physics I’m thinking about is “work-in-progress” which would not be appropriate to write about until, well, until it is appropriate to write about it!
But, there are a few exceptions. Lately, I’ve been thinking a lot about scalar-tensor gravity. Indeed, as I am waiting for the completion of a virus scan (could my recent computer troubles have been caused by a virus? I now took out my computer’s hard drive, put it in an external enclosure, and I am scanning it using a “known good” computer) I am thinking about it now.
Einstein’s gravity theory (tensor gravity) can be written up using the Lagrangian formalism. This is the infamous Einstein-Hilbert Lagrangian, which takes the form L = [(−1/16πG)(R + 2Λ) + LM]√−g, where G is the gravitational constant, R is the so-called curvature scalar, Λ is the cosmological constant, g is the determinant of the metric, and LM is the Lagrangian representing matter.
In one of the simplest modifications of Einstein’s gravity, Jordan-Brans-Dicke theory, the gravitational constant G is promoted from constant to field: it becomes variable, and a “kinetic term” is added to the Lagrangian representing the kinetic energy carried by this scalar field.
In this theory, gravity is still determined by the geometry of space-time. However, in addition to matter, there is this scalar field (which carries mass-energy and is thus a further source of gravity in addition to matter.) Then, this scalar field also determines the strength of coupling between matter and space-time (i.e., the extent to which a unit mass of matter bends space-time.)
Now it so happens that it is possible to transform away this variable gravitational constant and make it truly constant by a mathematical transformation called a conformal transformation. Basically, it amounts to reparameterizing space-time in such a way that the value of the gravitational constant becomes the same everywhere. (This transformation is described as switching from the Jordan frame to the Einstein frame.) However, this transformation is not without cost. As we transform away the coupling between the geometry of space-time and the scalar field, we end up introducing a variable coupling between the matter Lagrangian LM and the scalar field. The physics is now different! The geometry of space-time is now determined by a fixed coupling constant as in Einstein’s theory, but the trajectory of matter is no longer determined by geometry alone: there is an extra force, a so-called scalar force, acting on matter.
At first sight, this might seem weird. A simple mathematical transformation should not change the physics, or should it? Well… it does yet it doesn’t. If you fire a cannonball in Jordan-Brans-Dicke theory and calculate its trajectory, it will trace the same trajectory regardless which frame, the Jordan or the Einstein frame, you use to calculate it. It’s the interpretation of this trajectory that differs between the two frames. In the Jordan frame, the cannonball is said to follow a geodesic trajectory, but that geodesic, i.e., the curvature of spacetime, is affected by a varying gravitational constant. In the Einstein frame, the cannonball’s trajectory is not a geodesic anymore; the geodesic trajectory is determined by a fixed gravitational constant, but on top of that, an extra force deflects the cannonball.
One particular kind of scalar-tensor theory can be written in a form in which there is no variable gravitational constant and no coupling between the scalar field and matter either. This is the so-called “minimally coupled” scalar-tensor theory, in which the scalar field influences matter only indirectly: the scalar field has mass-energy, which gravitates, and this contributes to the overall gravitational field. Things can get tricky here: a scalar-tensor theory may be written in a form that does not look like a minimally coupled theory at all, yet it may be possible to transform it into one by an appropriate conformal transformation. However, this is not always the case: for instance, Jordan-Brans-Dicke theory cannot be transformed into a minimally coupled scalar-tensor theory this way, the two classes of theories are manifestly different.
When things get really interesting is when additional fields are present in a more complex theory, such as scalar-tensor-vector gravity. In that case, a conformal transformation can have surprising consequences on the coupling between these additional fields and the scalar field.
Just like after 9/11, the airspace of an entire region is closed today, grounding thousands of flights in the UK and Northern Europe.
Unlike on 9/11, this time around the closure is not the result of the panicked, knee-jerk reaction of clueless politicians and officials. It is the result of a volcanic eruption in Iceland:
The plume, clearly visible in this Eumetsat image, is a grave threat to aviation. 28 years ago, volcanic ash almost brought down a British Airways 747 full of passengers, and since then, numerous airliners have been damaged as they flew through similar plumes. Grounding all flights in the affected areas seems like a dramatic, but justified response to a very real threat.
Now the question is this: how long? According to news reports, the eruption shows no signs of abating. Will they keep flights grounded for days, even weeks if necessary?
Apollo 13, NASA’s “most successful failure”, was launched forty years ago today. One thing I didn’t know about the timing of the accident is the fact that the tank rupture occurred on the fifth stirring of the oxygen tank, which normally would have taken place 120 hours into the mission, when the lunar module was already on the Moon’s surface. Without the lunar module to serve as a lifeboat, the fate of the spacecraft would have been sealed. However, an unrelated sensor problem caused them to stir the tank more frequently, causing the accident to occur earlier.
Had the crew of Apollo 13 died in space, it has long been assumed that their spacecraft would have served as a frozen tomb for their bodies, orbiting the Sun. But now, some argue that the orbit of Apollo 13 was such that it would have returned to the Earth and burned up in the atmosphere just a few weeks later. I am not sure how you can really tell, with uncontrolled gas leaks, a tumbling spacecraft, and no precision radio-metric navigation data.
I’m back from a week-long trip to Hungary, visiting my Mom, relatives, and friends. Apart from the fact that the second half of my trip was made unnecessarily unpleasant by some cold bug I picked up on the flight from here to there, it was fun. But, it’s good to be home, even though, it seems, I came home in the middle of a heat wave. Yesterday, the heat almost killed me when I was looking for my car at Montreal airport (cars have the nasty habit of moving about when you leave them in large, public lots) while hauling my 60-pound suitcase. Today, it’s going to be even warmer. (No, we’re told, it’s not global warming… it’s the same El Niño weather that brought an unusually cold spring to parts of Europe.) I better check to see if our A/C still works after its winter hibernation.
Imagine solving one of the most profound outstanding problems in mathematics. Imagine living in poverty, in a cockroach-infested apartment in St. Petersburg, Russia. Imagine being awarded one of the world’s most prestigious prizes in science, the Millennium Prize of the Clay Mathematics Institute, which, incidentally, also comes with a cool $1,000,000.
And imagine turning it down. Which is precisely what reclusive Russian mathematician Grigory Perelman apparently did.
I don’t know what to think. Was it a matter of principle for him? Perhaps. But then, he could have indicated in advance that he wouldn’t accept the award, just as he refused to accept the Fields Medal a few years earlier. Why did he keep the world in suspense? Was it posturing? Or is he, hmmm, how can I put this politely, one fry short of a happy meal, to use a favorite phrase of mine from the television series Stargate SG-1?
An interesting anniversary today: 25 years ago, on March 15, 1985, the first ever .com domain name was registered, symbolics.com. The company, in addition to building their own brand of “Lisp Machine” computers, also happened to be selling the commercial version of the MACSYMA computer algebra software. The same software that, in the form of its open-source version, Maxima, continues to evolve thanks to a devoted team of developers… of which I happen to be one.
Alas, Symbolics is no longer, at least not the original company. A privately held company by the same name which obtained much of Symbolics’ assets still sells licenses of the old MACSYMA code.
Here’s yet another dramatic prediction by the Intergovernmental Panel on Climate Change (IPCC): that even a small temperature increase can lead to the loss of up to 40% of the Amazonian rain forest.
Except that it won’t. New research shows that there were no significant changes in the Amazon during the 2005 drought compared to previous years (also refuting previous speculation that drought might in fact help the rain forest grow). Like the prediction about Himalayan glaciers, the IPCC’s alarming statement was based solely on a non-peer reviewed report by the WWF (formerly known as the World Wildlife Fund, but no longer).
Defenders of the “scientific consensus” argue that small discrepancies notwithstanding, the findings of the IPCC are unassailable, the case for anthropogenic global warming is solid, and that the ones casting the first stone should be those who’d never leave a few innocent mistakes in a giant 1000-page report. If this was all there was to it, I should really keep my mouth shut; I’ve made more than my fair share of embarrassing mistakes in the past in stuff I wrote, and no doubt, I’ll make equally embarrassing mistakes in the future.
But these are not innocent mistakes, not small errors that only nitpickers care about, not even gross errors that can be attributed to carelessness. We’re not talking about a typo here, an omitted reference or erroneous formula there, an improperly drawn conclusion somewhere else. What we have here is the purposeful inclusion of non-peer reviewed material simply for its shock value. And not just in footnotes. This statement about the rain forests leads the section about Latin America, in the IPCC 2007 WG II Summary for Policymakers:
“By mid-century, increases in temperature and associated decreases in soil water are projected to lead to gradual replacement of tropical forest by savanna in eastern Amazonia.”
The body of the text that the summary refers to contains further alarming detail:
“Up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation; this means that the tropical vegetation, hydrology and climate system in South America could change very rapidly to another steady state, not necessarily producing gradual changes between the current and the future situation (Rowell and Moore, 2000).”
The cited paper by Rowell and Moore is the non-peer reviewed report produced by the WWF, containing some dramatic language such as “the year the world caught fire”. Nonetheless, the authors’ prediction is not near as dire as the IPCC’s version, for which their paper is named as the sole source. Rowell and Moore only say that “up to 40% of the Brazilian forest is extremely sensitive to small reductions in the amount of rainfall.”
Don’t get me wrong, I firmly believe that the Amazonian rain forest is in serious trouble. You don’t need climate change for this… logging will do the trick nicely.
What I find inexplicable and unjustifiable is the IPCC’s decision not only to include such a striking prediction based solely on a non-peer reviewed source, but even embellish it. The IPCC’s report is supposed to be an objective assessment of the best science available, based upon which trillion dollar decisions will be made, affecting the world economy for generations to come. Instead, at least some sections of it look more like an activist’s pamphlet.
By undermining trust in the integrity of the science, the IPCC may be doing grave harm to the very cause it champions. The scientific evidence may be stronger in the future: the models will improve, and one day, will have real predictive power, the ability to reproduce accurately observed changes in the climate after a certain date using data available up to that date. At that time, we may yet find that the situation is even worse than we thought. Question is, will people still listen if the scientific community discredits itself now by crossing the line between science and activism?
You can tell that this picture was NOT made in Ottawa today because it’s presently 8 degrees Centigrade here, and the sun is still shining:
No, this video frame is from the French Riviera.
Every time I think about it, I feel compelled to think again: geologic changes are NOT supposed to happen in the blink of an eye, on a timescale of a mere 10,000 years. Yet at the very place where I live, Ottawa, a little over 10,000 years ago whales were swimming. How is that possible?
The answer is isostatic rebound. Up until about 13,000 years ago, this region was covered by the remnants of the last ice age, a layer of ice up to three kilometers thick. When this ice receded, the region was flooded by the sea, whales and all. This subsea was called the Champlain Sea, and may have been as much as 150 meters deep right here where I presently sit.
However, once the huge weight of the thick ice layer was gone, the Earth’s crust underneath rose up. This process is known as isostatic rebound. In a mere 3,000 years, the Champlain Sea was gone.
I suppose the same ice layer was also responsible for leveling the Ontario landscape such that this huge province, perhaps as large as France and Germany put together, has no point higher than 693 meters above sea level. Even tiny Hungary beats Ontario by more than a thousand feet!
I can see why people find geology fascinating.
Apparently, the earthquake in Chile was the 5th largest on record in the whole world since 1990. I guess I know three out of the other four: Chile in 1960, Alaska in 1964, and Indonesia in 2004. Ah, there’s the fourth (thanks, Wikipedia): Kamchatka in 1952.
Chile is supposedly well prepared. But how can you be well prepared when the earthquake destroys basic infrastructure?
It was a rare night-time landing, but Endeavour is safely back home. The sight of an open flame from that venting on top, only visible at night, is positively weird: combined with the sound effects, it’s as if it was an overheated steam locomotive, not a space plane huffing and puffing on that runway.
Four more Shuttle flights to go, one of them by Endeavour. After that, for the first time since the 1960s, the United States will have no manned space flight capability. Hopefully not for long.
What a remarkably boring weather forecast:
I wonder if I am allowed to extrapolate from this trend and conclude that the temperature will remain -1 degrees Centigrade, like, forever.
While it may not feel like it if you live in the US or Western Europe, this has been a very warm January, the fourth warmest on record:
It was certainly warmer than usual (and a lot dryer than usual!) up here in Ottawa. Not that I am complaining.
Some proponents of anthropogenic global warming will point at this result as proof that global warming is “scientific fact”. The plot tells a more nuanced story. In the short term (last 8 years or so) there’s no warming trend at all, if anything there has been slight cooling. Prior to that, there was a roughly 30-year warming period. One other warming period that is very similar in nature occurred in the early half of the 20th century. In between, there was some cooling, just not enough to offset the earlier gains, hence the more recent warming period started with an already higher temperature, and we see an overall warming trend across the 130-year span of this plot.
But is that really a long term trend? Or is it just another periodicity that we simply cannot discern because the data set it too short in duration? This is the question that those “proxy” temperature estimates from tree rings, ice cores and whatnot are supposed to answer. How reliable are those? How representative? That is a key question, which may determine, for instance, if the infamous medieval warm period was comparable to the current warming or not.
Someone just called my attention to this BBC interview with Phil Jones, director of the Climatic Research Unit (CRU) at the University of East Anglia (UEA), which has been at the center of the Climategate e-mails.
It has been suggested that Jones admitted that there has been no global warming since 1995, or that he made an amazing retreat. So I was curious as to what he actually said. Here are a few tidbits, hopefully not taken out of context:
Q. Do you agree that according to the global temperature record used by the IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998 were identical?
A. […T]he warming rates for all 4 periods [NB: Jones counted 1975-1998 and 1975-2009 as two separate periods] are similar and not statistically significantly different from each other.
Q. Do you agree that from 1995 to the present there has been no statistically-significant global warming?
A. Yes, but only just. [… The] trend (0.12C per decade) is positive, but not significant at the 95% significance level.
Q. Do you agree that from January 2002 to the present there has been statistically significant global cooling?
A. No. […] The trend this time is negative (-0.12C per decade), but this trend is not statistically significant.
Q. There is a debate over whether the Medieval Warm Period (MWP) was global or not.
A. There is much debate over whether the Medieval Warm Period was global in extent or not. The MWP is most clearly expressed in parts of North America, the North Atlantic and Europe and parts of Asia. For it to be global in extent the MWP would need to be seen clearly in more records from the tropical regions and the Southern Hemisphere. There are very few palaeoclimatic records for these latter two regions.
Of course, if the MWP was shown to be global in extent and as warm or warmer than today (based on an equivalent coverage over the NH and SH) then obviously the late-20th century warmth would not be unprecedented. On the other hand, if the MWP was global, but was less warm that today, then current warmth would be unprecedented.
Q. If you agree that there were similar periods of warming since 1850 to the current period, and that the MWP is under debate, what factors convince you that recent warming has been largely man-made?
A. The fact that we can’t explain the warming from the 1950s by solar and volcanic forcing […].
Q. When scientists say “the debate on climate change is over”, what exactly do they mean […] ?
A. […] I don’t believe the vast majority of climate scientists think this.
Meanwhile, another error in the IPCC report has been uncovered, this one about the size of the Dutch countryside that is under sea level (26%, not 55%). An inconsequential error by itself, but apparently, it was enough for Robert Watson, former IPCC chief, to call for an investigation of this apparent bias, namely that all the errors uncovered so far exaggerate the presumed magnitude and effect of the warming.
So who can we believe? I don’t want to join the climate skeptics (at the very least, not without getting a hefty retainer from an oil company first!) but obviously, the choir hasn’t been completely honest with us either. What does the raw data say? Well, according to the UK Met Office, there has been warming in the last 160 years:
However, if I accept the short-term trend as just that, short-term, what we’re left with is a long-term warming of about 1 degree over 160 years… which is about 0.06 degrees per decade, about half the decadal figure during the last (1975-2002) warming period, a period that is by no means unique, according to Jones.
So… what am I to think?
A few months ago, a paper came to my attention; one written by a Hungarian climate scientist who supposedly resigned from his NASA job because he felt he was being muted by the climate science establishment. The paper was eventually published in a rather obscure journal, the quarterly journal of the Hungarian Meteorological Service. This paper has since been touted by its proponents as proof that the established climate models are bogus and that global warming is a hoax; on the other hand, it has been maligned by its critics, who declared it as junk science.
One notable point in Miskolczi’s paper is an unorthodox use of the virial theorem, and the funny thing is, while what he is doing is rather problematic, his critics fare no better; I’ve not seen anyone offer a technically correct analysis as to when the virial theorem might be applicable to describe a planetary atmosphere. (As a matter of fact, it is, but that doesn’t necessarily vindicate Miskolczi’s analysis.)
Miskolczi’s key result is that the atmosphere is in equilibrium in the sense that the greenhouse effect is already maximal; and so long as an effectively infinite reservoir of a potent greenhouse gas (water vapor) is available, this balance cannot be destroyed by changing the amount of CO2 in the air. However, this result may very well be a consequence of some trivial algebra that follows from some of Miskolczi’s more debatable assumptions.
In his paper, Miskolczi presents a model of the atmosphere graphically:
Without going into excessive detail (which can be found in Miskolczi’s paper), one can easily write down several equations from this diagram alone. First, Miskolczi asserts that P = P0 = 0, so that branch can be ignored altogether. We then have:
AA + K + F = ED + EU,
ST + EU = OLR,
F0 = OLR (the system is in equilibrium),
F0 − F + ED = SG + K,
SG = ST + AA.
To these equations, Miskolczi adds the following:
SG = σTs4 (Stefan-Boltzmann law describing a thermal blackbody surface at temperature Ts),
AA = ED (a much debated application of Kirchoff’s law by Miskolczi, his Eq. 4),
2EU = SG (Miskolczi’s application of the virial theorem),
SG − F0 + ED − EU = OLR (Miskolczi’s energy conservation formula, Eq. 7).
Now the thing is, at this point we actually have 9 equations in the 9 unknowns AA, K, F, ED, EU, ST, SG, F0 and Ts. Although the equations turn out to be not completely independent, only K remains undetermined; in particular, Ts is uniquely determined as
Ts = (3OLR / 2σ)1/4.
Now OLR = F0 = 238 W is known from observation, as it can be calculated from the solar constant and the Earth’s albedo. According to Miskolczi’s algebra, then, the only surface temperature consistent with this is Ts = 281.7 K or about 8.5 degrees Centigrade. This value is uniquely determined without knowing anything about the composition of the atmosphere other than its albedo.
If only climate science were this simple.
Something I heard a few days ago on The Big Bang Theory:
“Where in this swamp of unbalanced formulas squatteth the toad of truth?”
What can I say… I know the feeling rather well.
Steven Weinberg has an opinion piece on the Wall Street Journal Web site, where he expresses confidence that Obama’s NASA budget is the right one. Instead of wasting money on a manned space program that is self serving (i.e., other than putting men in space, it accomplishes nothing) more money will be available for doing real science, he thinks.
He has a point… but, well, but there is a but. Science is an important goal of the space program, but it’s not the only goal. As a matter of fact, if you ask me as a taxpayer why I think it’s a good idea to spend some tax dollars on the space program, scientific research is just one of the reasons I’d mention, and not even necessarily the first reason. People should travel in space because our future is in space. The steps we’re taking today may be baby steps, but they’re still important steps… even if a future with colonies on Mars, manned exploration of the outer planets and their moons, or perhaps travel beyond the solar system is decades, if not centuries away.
Having said that… the Constellation program, effectively repeating the accomplishments of Apollo with slightly upgraded hardware, may not have been the smart thing to do even if it had been funded right, which it wasn’t. Another footstep on the Moon is not the same as sustainable manned deep space exploration. If I recall, one of the Augustine commission’s suggestions was a deep space program without a specific landing objective; one that focuses on developing capabilities more than achieving spectacular “footstep-and-flag” milestones, “landing” only on asteroids, if at all, focusing instead on long-duration flights in deep space. If this is the space program Obama’s administration is about to establish, who knows? Perhaps he’s putting the space program on the track that it should have been put on decades ago. (Then again, perhaps I’m just an incurable optimist.)
As a footnote of sorts, I find it noteworthy that, more than 50 years after Sputnik, there is still only one nation on Earth with a comprehensive deep space research program: the United States. Much of the Soviet space program died an undeserved and premature death after the collapse of the Soviet Union; as to China, India, Japan, the EU and other nations, their efforts are commendable but that still leaves them in the “also ran” category.
This is becoming more than a little annoying, to be honest. First, there were the Climategate e-mails. Then, the claim about Himalayan glaciers. Now the latest: according to the Daily Telegraph, claims made in the IPCC report about vanishing ice in the Andes and the Swiss Alps were based in part on a popular magazine, in part on the dissertation of a Swiss student who interviewed mountain guides.
And this is supposed to be the foundation for a multi-trillion dollar shift in the world economy in the coming years?
To be clear about it: I am not a “climate change denier”, disgusting as I find this term implying some kind of analogy between genuine scientific skepticism and things like Holocaust denial. Questions raised by Climategate notwithstanding, I do believe the data, and the data show that there was warming in the past several decades. However, the IPCC report was supposed to go much further, and provide answers to some very clear questions. Namely 1) is there a long-term warming trend? 2) is it due to CO2? and 3) is it bad for you?
These are not easy questions to answer. The long-term warming trend that might exist is hidden behind noise: large year-to-year fluctuations, the 11-year solar cycle, other longer-term cycles. The data may perhaps be equally well fitted by a model that proposes a long-term cooling, but medium-term fluctuations which caused the current warming cycle. Here’s where the second question comes in: the model should not be a mathematical mind game but firmly rooted in physics. Do we know the physics well enough? Knowing the cause is also important if we wish to reverse the effects… if we misunderstand the physics, all our efforts to reduce CO2 emissions will be in vain, while we ignore the real causes. And even assuming that the physics is clear and the models are reliable… why is warming such a problem? Sure, ocean levels will rise a little and some cities may have to move in the coming century… on the other hand, for instance, how about vast stretches of tundra that become fertile and can be used to fed the planet’s growing population?
The IPCC gave us firm conclusions. Yes, there is a long-term warming trend. Yes, it is due to anthropogenic CO2 (hence it can be reversed by reducing CO2 emissions). And yes, all things considered, it is very bad for us. But… If the IPCC’s conclusions on these questions are based on sloppy research, why on Earth should I believe them? Is it something like Pascal’s wager, because we have nothing to lose and everything to gain by betting on the IPCC being right? I’m sorry but I don’t buy that just as I’m not buying Pascal’s original argument either… I’d rather end up in Hell as a virtuous pagan than as a hypocrite.