Saturday, January 22, 2005 ... Deutsch/Español/Related posts from blogosphere

Bitter cold

Those who watch the little weather GIF on the right side of this blog may remember that about two weeks ago, we had almost 70 degrees Fahrenheit in Cambridge. (Incidentally, you may click the GIF to get more information about the weather in Cambridge.) Warm air was flowing from California directly to Harvard.

The weather has returned to normal, however. The wind is now drifting from Siberia through the Northern pole directly to Cambridge. Now it's 10 p.m. The wind chill has -16 degrees Fahrenheit (-27 degrees Celsius), and the regular temperature is about 3 degrees Fahrenheit (-16 Celsius) and I would expect it to keep on dropping at night and plunge below 0F (yes, it did happen). It's not clear whether we'll break the record low in Boston from 1888: they had 0 degrees Fahrenheit on January 21st and -3 degrees Fahrenheit the following day. Sunday will be even more unlikely to break the record because in 1882 it was -6 Fahrenheit in Boston. In East Milton, they have beaten the 1888 record for today (-1 F vs. 0 F then).

In Bedford, MA, they improved the record for Saturday (-3F from 1888) to -8F. In Bangor, Maine, the Saturday temperature of -29F improved the record from 1934.

Schools in upstate New York were closed as the temperature record -8 Fahrenheit for January 21st from 1984 was improved to -11 Fahrenheit in Syracuse, NY. Windchill ranges between -30 and -20 Fahrenheit. It's still better than one year ago, on January 16th, 2004, when the wind chill in Albany, NY was about -40 Fahrenheit; note that -40 is so chilly that it does not matter which units you use - it's also -40 Celsius. (It was one day after Al Gore gave his major speech about the global warming in New York - an expression of a realistic politician and scientist who knows how to choose the right moment.) :-)

In Massachusetts today (Saturday), it seems sunny but you should expect a snowstorm that will bring up to 1 meter of snow to the state from the Midwest skies. This blizzard could defeat the Great Blizzard in 1978.

On Friday, a record low was also measured in the holy city of Amritsar, India.

Whoever thinks that the temperatures are chilly should know that the actual record is roughly 1 billionth of a degree above the absolute zero.

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reader Quantoken said...

Lubos said:
"note that -40 is so chilly that it does not matter which units you use - it's also -40 Celsius. (It was one day after Al Gore gave his major speech about the global warming in New York - an expression of a realistic politician and scientist who knows how to choose the right moment.) :-)"

Lubos you've got to know relativity better:-) Al Gore was speaking on a global prospect, not just the north east. Here where I live, the mercury hit 90 Farenheit ABOVE zero, and I am already very thankful that I live a bit closer to the ocean so it was cooler than what it could have been. We are not even living on the southern hemisphere.

I think the theory of global warming is wrong. But on the other side, global warming is a well established science in the sense that vast majority of scientists working on the field agree with it. So global warming is as established a science as super string theory, actually even more so, since string theory hasn't even started to compare itself against measurable experimental evidence yet, but there are plenty of data measurements and computer modelings in the global warming research already. So global warming is much more scientific than super string theory, is it right?

Funny that Lubos consider any different opinions regarding superstring theory as crackpotism. Then isn't you also a crackpot in criticizing the global warming, being some one who knows nothing in environmental science, knwoing full well the fact that the global warming is well established and accepted within the circule of people who research in the field?

The point I want to make is there are plenty of pseudo sciences in the establishment camps, in global warming, in the big bang, in the super string, etc. Science is not a sacred enterprise any more once a large portion of the population jump into it and make it a huge industry in which one makes a living earning butter and bread.

Quantoken


reader Quantoken said...

Lubos:
The web link you provided

http://www.nasa.gov/vision/earth/technologies/biggest_chill.html

which claim to have achieved a half billionth degree of temperature. Unfortunately the temperature figure is way off by many orders of magnitude.

Temperature is roughly the ratio of energy divided by the entropy involved. If we use the dimentionless definition of entropy, roughly:
kT = E/S

For a single particle, the entropy can be considered as order of unity. But the NASA scientists failed to consider that according to quantum mechanics, there is zero point energy due to Heisenberg uncertainty principle.

The Bekenstein Bound is a good starting point to estimate such zero point energy:

S <= E*R/2*PI*hbar

So:
kT = E/S >= 2*PI*hbar/R

R is how small a region the particle is bound to, for atoms, R is roughly the order of Bohr radius, R ~= 1 Angstrum = 1x10^-10 meter.

That will give you roughly:
kT = (6.6262x10^-34) /(1x10^-10)
kT = 6.6x10^-24 Joules
Since k = 1.38x10^-23 Joules/Kelvin
T = 0.5 Kelvin

With zero point energy considered, the actual temperature they reached is only 0.5K, that's a far cry from half billionth of a a kelvin!!!

And we haven't even considered the vacuum excitation energy of all possible quantum fields, yet. If you consider that, which you know, theoretical physicists have calculated a vacuum energy density 120 orders of magnitude too bigger than what it should be (the real cosmological constant), you will get such an incredibly high temperature, that it is as high as the temperature at the start of the Big Bang.

We can also consider elementary particles as EXCITED states of 11 dimentional string, as you string theoretists have said. The base state would be vacuum. To excite from the vacuum state to the elementary particle state where the energy is a few MeV, the temperature has got to be incredibly high! We know the Sun's 6000K temperature is only 2.5 eV. So 2500 MeV would be something like 6x10^12 K temperature.

Quantoken


reader Anonymous said...

Hi Quantoken!

You are just annoying. Can't you shut up with your stupid comments for once? I won't bother ripping apart everything you utter, but here is an example of how dumb you are:

"Here where I live, the mercury hit 90 Farenheit ABOVE zero, and I am already very thankful that I live a bit closer to the ocean so it was cooler than what it could have been. We are not even living on the southern hemisphere."

So the southern hemisphere is warmer than the northern one?!? Why don't you go to the south pole and freeze to death, you moron! You know, you should really try to win the Darwin award:

http://darwinawards.com/rules/

Undoubtedly, you got some natural talent for that. Do us a favor, and do not report back to us before you got the award.

Wishing you success!
Michael


reader Anonymous said...

It's SUMMER in the Southern hemisphere and WINTER in the Northern hemisphere!


reader Plato said...

City Dwellers, forget how to empathize with Nature's surroundings?

Imagine, such climate taking control of our lives, how well has such urbanization taking control of the mass population?


reader torbjorn said...

Since climatologists maintain that extreme temperatures are GW signs, does that mean that lumo now is a GW believer and that we should start to be _really_ worried :-)?