Science – Page 22 – Spinor Info

Anthropocene

Aug 022011

Finally, a voice of reason.

I just read an opinion piece in New Scientist by Erle Ellis. His message is simple: Welcome to the Anthropocene. Ellis believes that the geological epoch called the Holocene is over; the landscape of the Earth has been altered irreversibly by humans, but not all such change is bad or unwelcome. In any case, there is no turning back. The question is not how to undo what we have done, but how to create a better, more sustainable Anthropocene, as we have become the creators, engineers, and stewards of this world.

This has also been my opinion for a long time. Humans are no less “natural” than apes, ants, whales, or trees. By extension, a skyscraper or a factory are no less natural than an anthill or a bird’s nest. However, it has happened in the past that a species overwhelmed and destroyed the environment in which it once thrived. Humans can suffer the same fate… except that we do possess oversize brains and the ability to plan ahead in the long term. What we need is not some romantic notion of a “pristine planet”, but to learn how to manage a planet of finite resources that is dominated, and irreversibly altered, by our presence.

Beanstalk

Space No Responses »

Jul 222011

Now this is one stunning picture, taken from the ISS of the plasma trail of Atlantis during the spacecraft’s fiery descent into the atmosphere:

Human memory

Personal, Weather and Climate 1 Response »

Jul 222011

Human memory is far from perfect.

During the winter of 1988-1989, I was renting a small office on Ottawa’s Bank Street with my business partner John. We spent many a late night working on a difficult project, and it was one cold winter. I distinctly remember one night when the temperature dipped to −36 degrees Centigrade, and I not only had a hard time starting my car (only to rush back to the building to warm up and then run out to the car again after a few minutes in the hope that it would have warmed up a little by then) but its engine never reached its normal operating temperature during the 10 km drive home.

Except that it never happened. The -36°C, that is. The coldest historical temperature I can find for that winter is −27.2°C, which occurred in early March 1989; earlier, in January, it went down to −27.0°C one night.

I also distinctly remember that the first winter my wife spent here in Ottawa, she was renting a stall on the Byward Market and that on Christmas Eve day, the temperature never climbed above −24°C.

Again, never happened. On December 24, 1992, the high temperature was +2.7°C. Perhaps a year later, then? Yes, that was a cold Christmas Eve day, but not near that cold; the high temperature was -10.0°C.

Then there is that very cold winter in Budapest that I recall. It was brutal; my old Lada’s engine half froze. Eventually I managed to get it running without overheating, and then I spent half the night looking for a gas station that was selling antifreeze. Eventually I found one, way outside of Budapest. I do recall hearing on the radio that the temperature was -29°C. It wasn’t… according to the historical weather records that I can locate, the coldest night was on February 12, 1985, with a temperature of −24°C. Brutally cold by Budapest standards to be sure, but still 5 degrees warmer than what I remember.

At least I do know for a fact that today, the temperature reached +36°C. I think I owe an extra prayer of thanks to the gods of air conditioning.

RadioAstron

Astronomy, Space No Responses »

Jul 192011

RadioAstron, aka Spectrum-R, is in orbit. If it successfully opens its 10-meter dish antenna a few days from now, it will join the list of great space-based telescopes. It also signals that Russia is still a strong space-capable nation, doing much more than cheaply ferrying foreign astronauts to the International Space Station, filling the gap left behind by the retirement of the Shuttle program.

Tomorrow will be the 42nd anniversary of Armstrong’s “One small step”. How many years do we need to wait for the next small step taken by a human, be it in the dust of the Moon, the red rocks of Mars, or the cold surface of an asteroid?

Pioneer Doppler

Personal, Space 1 Response »

Jul 142011

Our paper on the analysis of extended Pioneer 10 and 11 Doppler data was just accepted by Physical Review Letters.

In it, we report that a data set roughly twice in size the data set that was analyzed previously continues to support the notion that a small anomalous acceleration is affecting both spacecraft. However, there is no reason to believe that the acceleration is in the direction of the Sun or that it is constant; on the contrary, the data seem to favor (albeit weakly) an Earth-directed, temporally decaying acceleration model.

Heat, emitted anisotropically, remains the prime suspect. The observed decrease in the acceleration appears more rapid than the rate of decay of the radioactive fuel on board. This is explained once we consider that much of the thermal acceleration would be due to electrically produced heat, and the amount of electricity available on board decreases much more rapidly. (The reason is that as the plutonium fuel cools, the thermocouples used to generate electricity become less efficient; the thermocouples also age.)

We also looked at some early data, taken when Pioneer 11 was cruising between Jupiter and Saturn. The possibility that the anomalous acceleration only began after Pioneer 10 and 11 passed the orbit of Saturn was much discussed in the literature. While we cannot exclude such an onset, its presence cannot be confirmed either (the early data is just too short in duration for a definitive conclusion). In any case, the shape of the onset curve very strongly suggests that it is, in fact, a modeling artifact: it is precisely what one would see if the Pioneer spacecraft’s solar pressure model was miscalibrated, which is a very likely possibility.

In the past few years, we also constructed a detailed thermal model of the Pioneer spacecraft, using recovered documentation and telemetry. We are busy preparing another report in which the results of this effort will be discussed.

Final flight

Space No Responses »

Jul 082011

Back when I was a high school student in Hungary in the late 1970s, someone gave me a poster of the yet-to-be-tested American space vehicle, the Space Shuttle. This picture stayed on my wall, right above my desk, for many years. Every time I looked at it, I couldn’t help but feel amazed: a space plane the size of a passenger aircraft, flying to orbit and back like there was nothing to it. Now that’s the American space program!

That, of course, was before Challenger, Columbia, and before today. Sadly, today the picture that best symbolizes the American space program is not an image of the Shuttle soaring to the sky, but one of an empty launch pad.

Full circle

Commerce, Computers, Mathematics No Responses »

Jul 022011

Yesterday, Intel lost the bid for the patent assets of defunct Canadian company Nortel, despite joining forces with Google.

Google bid some odd amounts; for instance, at one point they bid $1,902,160,540.

The digits happen to be those of Brun’s constant: B2 = 1.90216058…

Brun’s constant is the sum of the reciprocals of twin primes. B2 = (1/3 + 1/5) + (1/5 + 1/7) + (1/11 + 1/13) + … According to Brun’s theorem, this sum converges. The limit of the sum is Brun’s constant.

A professor of mathematics named Thomas Nicely once used a group of computers to calculate twin primes up to 1e14, computing Brun’s constant among other things.

At one point, Nicely’s computations failed. After eliminating other sources of error, Nicely concluded that the problem was a fault in the new Pentium processors present in some recently acquired computers in the group.

Nicely notified Intel, but it wasn’t until after a public relations disaster that Intel finally responded the way they should have in the first place, offering to replace all affected processors. This cost Intel $475 million.

Who knows, if they still had that extra $475 million cash in their pockets, they could have bid more and won yesterday.

A dozen dozen

Canada, Mathematics, Personal No Responses »

Jul 012011

Canada is 144 years old today. That is 12², or a dozen dozen. I am four dozen years old, and spent the last two dozen of these years here in Canada. Wonder what else is divisible by 12 this year.

Kaku again

Environment, Physics, Technology No Responses »

Jun 292011

The headline on CNN tonight reads, “An American Fukushima?” The topic: the possibility of wildfires reaching the nuclear laboratories at Los Alamos. The guest? Why, it’s Michio Kaku again!

What I first yelled in exasperation, I shall not repeat here, because I don’t want my blog to be blacklisted for obscenity. Besides… I am still using Kaku’s superb Quantum Field Theory, one of the best textbooks on the topic, so I still have some residual respect for him. But the way he is prostituting himself on television, hyping and sensationalizing nuclear accidents… or non-accidents, as the case might be… It is simply disgusting.

Dr. Kaku, in the unlikely case my blog entry catches your attention, here’s some food for thought. The number of people who died in Japan’s once-in-a-millennium megaquake and subsequent tsunami: tens of thousands. The number of people who died as a result of the Fukushima meltdowns: ZERO. Thank you for your attention.

Enigma

Programming, Science No Responses »

Jun 072011

One of the things I like the least about New Scientist (which, in many respects, is probably the best popular science magazine out there) is the “Enigma” brainteaser. I am sure it appeals to the “oh I am ever so smart!” Mensa member crowd out there but…

Well, the thing is, I never liked brainteasers. Are you really smarter than someone else because you happen to remember a random historical factoid? Does it really make sense to ask you to complete a series like, say, 1, 4, 9, 16, ? when the answer can be anything, as there is no compelling reason other than psychology (!) for it to be a homogeneous quadratic series?

But then… sometimes brainteasers reveal more about the person solving them than about the solution itself. I remember when I was in the second or third grade, our teacher gave us a simple exercise: add all the numbers from 1 to 100. (Yes, this is the same exercise given to a young Gauss.) Like Gauss, one of my classmates discovered (or perhaps knew already) that you can add 1+100 = 101; 2+99 = 101, 3+98 = 101, and so on, all the way up to 50 + 51 = 101; and 50 times 101 is 5050, which is the correct answer.

Trouble is, my classmate didn’t finish first. I did. I just added the darn numbers.

Between quick and smart, who wins? What if you’re so quick, you don’t need to be smart? Is it still smart to waste brainpower to come up with a “clever” solution?

Last week’s New Scientist Enigma puzzle caught my attention because it reminded me of this childhood memory. It took me roughly a minute to solve it. Perhaps there is a cleverer way to do it, but why waste all that brainpower when I can do this instead:

/* New Scientist Enigma number 1647 */

#include <stdio.h>

int main(int argc, char *argv[])
{
    int d1, d2, d3, d4, d5, d6, n;

    for (d1 = 1; d1 <= 9; d1++)
        for (d2 = 1; d2 <= 9; d2++) if (d2 != d1)
            for (d3 = 1; d3 <= 9; d3++) if (d3 != d1 && d3 != d2)
                for (d4 = 1; d4 <= 9; d4++)
                    if (d4 != d1 && d4 != d2 && d4 != d3)
                        for (d5 = 1; d5 <= 9; d5++)
                            if (d5 != d1 && d5 != d2 && d5 != d3 && d5 != d4)
                                for (d6 = 1; d6 <= 9; d6++)
                                    if (d6 != d1 && d6 != d2 && d6 != d3 &&
                                        d6 != d4 && d6 != d5)
    {
        n = 100000 * d1 + 10000 * d2 + 1000 * d3 + 100 * d4 + 10 * d5 + d6;

        if (n % 19 != 17) continue;
        if (n % 17 != 13) continue;
        if (n % 13 != 11) continue;
        if (n % 11 != 7) continue;
        if (n % d4 != d3) continue;
        printf("ENIGMA = %d\n", n);
    }

    return 0;
}

Yes, I am quick with C. Does that make me smart?

Distant worlds

Politics, Space No Responses »

May 312011

Neither I nor anyone else alive today would likely see the end of such a mission, but… the possibility that I might live long enough to see just the launch of humanity’s first interstellar space mission is simply awe-inspiring.

Of course it’s highly unlikely that it will happen. Mediocrity and politics will see to it that it won’t. But then… Apollo happened, didn’t it? Sometimes, miracles do occur.

Preserving data

Computers, Physics, Politics No Responses »

May 312011

One of the biggest challenges in our research of the Pioneer Anomaly was the recovery of old mission data. It is purely by chance that most of the mission data could be recovered; documents were saved from the dumpster, data was read from deteriorating tapes, old formats were reconstructed using fragmented information. If only there had been a dedicated effort to save all raw mission data, our job would have been much easier.

This is why I am reading it with alarm that there are currently no plans to save all the raw data from the Tevatron. This is really inexcusable. So what if the data are 20 petabytes? In this day and age, even that is not excessive… a petabyte is just over 300 3 TB hard drives, which are the highest capacity drives currently no the market. If I can afford to have more than 0.03 petabytes of storage here in my home office, surely the US Government can find a way to fund the purchase and maintenance of a data storage facility with a few thousand hard drives, in order to preserve knowledge that American taxpayers payed many millions of dollars to build in the first place.

The sky

Astronomy No Responses »

May 162011

Here’s one good reason to quit your day job: spend a year or so lugging a set of six astrophotography cameras across two continents, to take some 37,000 exposures of the night sky and stitch them together into an amazing all-sky picture called The Photopic Sky Survey. The scientific value of this picture may be negligible, but it is beautiful to look at, and I am sorely tempted to buy a high-quality print to hang somewhere on my wall. It is one of those pictures that give a true sensation of depth: you can see how nearby stars slowly dissolve into a diffuse, milky background, you can see how dust lanes obscure the Milky Way behind, you can see how the light of distant galaxies filters through. I wonder how a picture like this would have influenced The Great Debate.

Extreme weather

Television, Weather and Climate No Responses »

May 012011

CNN is wondering why extreme weather keeps happening at 7PM. Funny… I’m pretty sure the windstorm the other day was more or less over by 7PM.

Gagarin

Space No Responses »

Apr 122011

Fifty years ago today, Yuri Alekseyevich Gagarin flew into outer space, becoming the first human to orbit the Earth.

I often wonder why it is so that fifty years later, space travel still remains an incredibly expensive novelty. After all, 50 years after the Wright brothers’ first flight, transoceanic air travel was a daily reality, and the jet era and mass air travel were just around the corner.

But then, perhaps it is unfair to compare Gagarin’s flight to that of the Wright brothers. Perhaps it’s more like the Montgolfier brothers’ first manned flight in a balloon, in 1783. After all, a space capsule in an inertial orbit has a lot more in common with a balloon blown about by the wind than a modern, highly maneuverable airplane. So perhaps before space travel becomes routine for the masses, it is essential to make a technological leap similar to that between a primitive hot-air balloon and powered, heavier-than-air flight.

As a footnote of sorts, the maiden flight of the Space Shuttle also occurred on this date, 30 years ago. Unfortunately, the Shuttle was far from being that necessary breakthrough. Its winged elegance notwithstanding, it’s still a chemically powered rocket, and chemical propulsion is just not sufficient… space flight will never become routine if you need 3000 tons of propellant to put a 100-ton payload into orbit.

Fermilab’s new result

Physics No Responses »

Apr 082011

I just finished reading Tommaso Dorigo’s excellent blog post about the new results from Fermilab. The bottom line:

There is a reason why a 3-σ result is not usually accepted a proof of discovery;
The detected signal is highly unlikely to be a Higgs particle;
It may be something exotic going beyond the Standard Model, such as a Z’ neutral vector boson;
Or, it may yet turn out to be nothing, a modeling artifact that will eventually go away after further analysis.

Interesting times.

Weird forecast

Weather and Climate No Responses »

Apr 052011

So how can the daily high be 8 degrees centigrade; the low overnight, 14; and the daily high the next day, 2 degrees? Must be global warming. Or Fukushima. Or Muslims. Whatever.

Taking apart a Shuttle

Space No Responses »

Mar 312011

At the Kennedy Space Center, they began to take the space shuttle Discovery apart, and I don’t feel sad.

Why should I? Come on, these venerable machines are older than most airliners still in service. And taking them apart offers a unique opportunity to learn how reusable space vehicles actually fared after a large number of missions. Besides, some of the parts are truly reusable and may, in fact, end up being used in future hardware. Isn’t that a better legacy than simply stuffing a Shuttle in a museum somewhere in its last flight configuration?

Of course, it means that we lose the illusion that the Shuttle we’re looking at is ready to fly, if only one fueled it up. But then, without an external fuel tank, booster engines, and a launchpad, it’s not like they could get very far anyway.

I hate to argue but…

Physics No Responses »

Mar 192011

Let me preface this with… I have huge respect for eminent physicist Michio Kaku, whose 1993 textbook, Quantum Field Theory: A Modern Introduction, continues to occupy a prominent place on my “primary” bookshelf, right above my workstation.

But… I guess that was before Kaku began writing popular science books and became a television personality.

Today he appeared on CNN and astonished me by suggesting that the best course of action is to bury and entomb Fukushima like they did with Chernobyl.

Never mind that in Chernobyl, the problem was a raging graphite fire that had to be put out. Never mind that Chernobyl had no containment building to begin with. Never mind that in Chernobyl, there was a “criticality incident”, a runaway chain reaction, whereas in Fukushima, the problem is decay heat. Never mind that in Chernobyl, the problem was localized to a single reactor, whereas in Fukushima, it is several reactors and also waste fuel pools that are threatened. Never mind that the critical problem at Fukushima is the complete loss of electrical power. Never mind that a single chunk of burning graphite flying out of the Chernobyl inferno probably carried more radioactivity than the total amount released by Fukushima after it’s all over. Who cares about the actual facts when you can make dramatic statements on television about calling in the air force of the Red Army, and peddle your latest book at the same time? I do not wish to use my blog to speak ill of a physicist that I respect but I think Dr. Kaku’s comments are unfounded, inappropriate, sensationalist, and harmful. I feel very disappointed, offended even; it’s one thing to hear this kind of stuff from the mouths of ignorant journalists or pundits, but someone like Dr. Kaku really, really should know better.

Messenger at Mercury

Space No Responses »

Mar 182011

Amidst all the bad news about crushed uprisings, devastated nuclear plants, and thousands killed by a tsunami, here’s a bit of good news: for the first time in history, a spacecraft is in orbit around the planet Mercury.

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