BS: How Cold Can it Get?

Subject: BS: How Cold Can it Get?
From: JohnInKansas
Date: 04 Jan 13 - 04:01 AM

While my area has been in an unusually cold period, a "new" report indicates that it can get really cold under some conditions:

Atoms hit record temperature — colder than absolute zero

By Charles Choi
LiveScience
1/3/2013

Absolute zero is often thought to be the coldest temperature possible. But now researchers show they can achieve even lower temperatures for a strange realm of "negative temperatures."
Oddly, another way to look at these negative temperatures is to consider them hotter than infinity, researchers added.

This unusual advance could lead to new engines that could technically be more than 100 percent efficient, and shed light on mysteries such as dark energy, the mysterious substance that is apparently pulling our universe apart. [Basically Bullshit, but interesting?]

An object's temperature is a measure of how much its atoms move — the colder an object is, the slower the atoms are. At the physically impossible-to-reach temperature of zero kelvin, or minus 459.67 degrees Fahrenheit (minus 273.15 degrees Celsius), atoms would stop moving. As such, nothing can be colder than absolute zero on the Kelvin scale.

Bizarro negative temperatures

To comprehend the negative temperatures scientists have now devised, one might think of temperature as existing on a scale that is actually circular, not linear. Positive temperatures make up one part of the circle, while negative temperatures make up the other part. When temperatures go either below zero or above infinity on the positive region of this scale, they end up in negative territory. [ What's That? Your Basic Physics Questions Answered ]

With positive temperatures, atoms more likely occupy low-energy states than high-energy states, a pattern known as Boltzmann distribution in physics. When an object is heated, its atoms can reach higher energy levels.

At absolute zero, atoms would not occupy any energy states. At an infinite temperature, atoms would occupy all energy states. Negative temperatures then are the opposite of positive temperatures — atoms more likely occupy high-energy states than low-energy states.

"The inverted Boltzmann distribution is the hallmark of negative absolute temperature, and this is what we have achieved," said researcher Ulrich Schneider, a physicist at the University of Munich in Germany. "Yet the gas is not colder than zero kelvin, but hotter. It is even hotter than at any positive temperature — the temperature scale simply does not end at infinity, but jumps to negative values instead."

As one might expect, objects with negative temperatures behave in very odd ways. For instance, energy typically flows from objects with a higher positive temperature to ones with a lower positive temperature — that is, hotter objects heat up cooler objects, and colder objects cool down hotter ones, until they reach a common temperature. However, energy will always flow from objects with negative temperature to ones with positive temperatures. In this sense, objects with negative temperatures are always hotter than ones with positive temperatures.

Another odd consequence of negative temperatures has to do with entropy, which is a measure of how disorderly a system is. When objects with positive temperature release energy, they increase the entropy of things around them, making them behave more chaotically. However, when objects with negative temperatures release energy, they can actually absorb entropy.

Negative temperatures would be thought impossible, since there is typically no upper bound for how much energy atoms can have, as far as theory currently suggests. (There is a limit to what speed they can travel — according to Einstein's theory of relativity, nothing can accelerate to speeds faster than light.)

Wacky physics experiment

To generate negative temperatures, scientists created a system where atoms do have a limit to how much energy they can possess. They first cooled about 100,000 atoms to a positive temperature of a few nanokelvin, or billionth of a kelvin. They cooled the atoms within a vacuum chamber, which isolated them from any environmental influence that could potentially heat the atoms up accidentally. The researchers also used a web of laser beams and magnetic fields to very precisely control how these atoms behaved, helping to push them into a new temperature realm.

"The temperatures we achieved are negative nanokelvin," Schneider told LiveScience.

Temperature depends on how much atoms move — how much kinetic energy they have. The web of laser beams created a perfectly ordered array of millions of bright spots of light, and in this "optical lattice," atoms could still move, but their kinetic energy was limited.

Temperature also depends on how much potential energy atoms have, and how much energy lies in the interactions between the atoms. The researchers limited how much potential energy the atoms had with a system of magnetic fields, and they could also very finely control the interactions between atoms, making them either attractive or repulsive.

Temperature is linked with pressure — the hotter something is, the more it expands outward, and the colder something is, the more it contracts inward. To make sure this gas had a negative temperature, the researchers had to give it a negative pressure as well, tinkering with the interactions between atoms until they attracted each other more than they repelled each other.

"We have created the first negative absolute temperature state for moving particles," said researcher Simon Braun at the University of Munich in Germany.

... ... ...

"A better understanding of temperature could lead to new things we haven't even thought of yet," Schneider said. "When you study the basics very thoroughly, you never know where it may end."

The scientists will detail their findings in Friday's issue of the journal Science.

[There's more at the link.]

It's likely that the reporter made a valiant attempt at explaining a little more than he understood, but it was a good effort.

A better explanation was given in the pre-publication textbook Thermodynamics by Hatsopoulos and Keenan, ©1960. Since this was an engineering textbook for undergraduates rather than a history book, it's not clear whether they originated the notion, but it wasn't really new when the course was worked up. This is not really anything very new, with the exception of a particular demonstration that was apparently successful, for which the experimenters deserve real credit - if the reviews are good.

Is anyone surprised?

John

Subject: RE: BS: How Cold Can it Get?
From: John MacKenzie
Date: 04 Jan 13 - 05:31 AM

Having forgotten it's your wedding anniversary, you come home late, and very drunk.
That's how cold it can get ;)

Subject: RE: BS: How Cold Can it Get?
From: GUEST,999
Date: 04 Jan 13 - 06:32 AM

JiK: What will this mean regarding

1) expressions like "Colder than a witch's tit" or "Colder than a well-digger's ass"?
2) global warming?
3) beer at room temperature?
4) tongues on aluminum doors?
5) cold starts in winter?

Subject: RE: BS: How Cold Can it Get?
From: John MacKenzie
Date: 04 Jan 13 - 07:58 AM

Cold enough to freeze the balls off, a brass monkey?

Subject: RE: BS: How Cold Can it Get?
From: Rapparee
Date: 04 Jan 13 - 09:58 AM

Well, I've been pretty damned cold. I think I was megadegrees below 0 K walking from the shower to the hootch in my boxers and shower shoes on time in Korea. It did seem like all atomic motion was stopping and I only got there before my brass...before I froze up.

Subject: RE: BS: How Cold Can it Get?
From: GUEST,999
Date: 04 Jan 13 - 11:17 AM

. . . and the Ki Ki bird.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 04 Jan 13 - 11:54 AM

The lost Fuckarewee Tribe nearly froze to death, 9.

Subject: RE: BS: How Cold Can it Get?
From: JohnInKansas
Date: 04 Jan 13 - 12:03 PM

gnu -

They must have been found and recovered(?). They were at the Winfield Festival last September. Looked like about 30 of them, but I didn't get a chance to talk to any of 'em. The tribe does seem to have split up, since they've been reported elsewhere in quite a few places.

John

Subject: RE: BS: How Cold Can it Get?
From: Charmion
Date: 04 Jan 13 - 12:29 PM

Every summer, I find Fuckarewees wandering through downtown Ottawa, waving street maps and cameras, and incidentally preventing me from getting at the cauliflower and strawberry vendors in the By Ward Market. They also hang out on Parliament Hill, where they gaze north in their desperate search for the National Arts Centre.

Subject: RE: BS: How Cold Can it Get?
From: Ed T
Date: 04 Jan 13 - 01:44 PM

When I lived in Ottawa in the late 70's, it reached (-40C and F at the same time, as they are the same at that point).

It was so cold that saw a local feller jump starting the family dog to get it moving along the sidewalk.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 04 Jan 13 - 02:33 PM

My doc asked me yesterday if I plug my truck in (it was -19). I said that every time the forecast is -12 or lower. He was surprised. I said that as soon as the starter labours due to cold, you should plug it in and the way the new engines (my truck, anyway) are built, that happens at relatively "warm" temps. He said that he worked in northern PQ and he "lost a cylinder" (I assume he blew a rod) when it was -60. I was surprised... WIF doesn't plug in a block heater at
-60!???

I was impressed when I worked in Goose Bay... receptcles at every parking space on the base (where feasible). Every weehicle had an extension cord plugged into the block heater and the cord was coiled around a side view mirror or hung on the grill.

Subject: RE: BS: How Cold Can it Get?
From: Charmion
Date: 04 Jan 13 - 04:35 PM

The alternative to all those block-heater plugs is keeping a truck running all bight to boost all the others in the morning -- normal practice with military-pattern vehicles when I was a tad.

My old VW diesels were cruelly dependent on the block-heater in winter, but I haven't had to boost a car even at minus 30 since the modern VW turbo-diesels came in. You can't even install a block-heater in a 2011 Golf TDI -- fact!

Subject: RE: BS: How Cold Can it Get?
From: Ed T
Date: 04 Jan 13 - 05:41 PM

My mechanic recommends the use of synthetic engine oils in colder winter conditions. He claims they adhere to the top parts of the engine better and offer lubrication during cold starts. He claims that cold start (in very cold weather) and the warm up period has the greatest potential to cause engine wear and damage, and that is when you want the oil over the top of your engine, not in the bottom oil pan. It sounds reasonable, and the reason I switched to synthetic some time ago- in addition, many cab drivers, who get many hard miles out of their vehicles also use it.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 04 Jan 13 - 05:49 PM

So... no glow plugs on them anymore?

Subject: RE: BS: How Cold Can it Get?
From: Charmion
Date: 04 Jan 13 - 06:06 PM

I think so, gnu, at least there's still a glow-plug symbol on the ignition display, but start-up is now pretty well instantaneous.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 04 Jan 13 - 07:07 PM

That's a yes, then. I am thinking diesel next time... small shitbox on acconta I can't do the 4X4 woods crusing anymore with my health issues. Probably a little VW or similar. Hehehee... something I use to be able to almost park in the back of my truck.

Subject: RE: BS: How Cold Can it Get?
From: Charmion
Date: 04 Jan 13 - 08:03 PM

If you like a nice, steady vehicle with good fit and finish, you will like the VW diesels. Cold-weather operations are not a problem any more, and you get that solid diesel performance. I've been driving VW diesels since 1983, so of course I'm partial.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 04 Jan 13 - 08:11 PM

I heard the new and small VWs are shit for maintenace, reliability and parts but that may be just salesman's puffing on an internut level. No matter... if I can buy one for a bit over $15k, it's worth the "gamble".

Subject: RE: BS: How Cold Can it Get?
From: Charmion
Date: 04 Jan 13 - 09:51 PM

You'll never get a new one for that money. Used, maybe -- but only if some diesel driver has dropped off her twig. People who like them, like them a lot, and drive them till they fall apart.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 04 Jan 13 - 09:55 PM

My nephew bought a Golf(?) diesel for just over $15k last year. That's what he said.

Subject: RE: BS: How Cold Can it Get?
From: Rapparee
Date: 04 Jan 13 - 10:52 PM

Oh, fer...do what we do here, where it gets COLD!!! Just build a little fire under the engine and keep it going all night -- it'll fire right up! Works with both gas and diesel, too.

Subject: RE: BS: How Cold Can it Get?
From: GUEST,kendall
Date: 05 Jan 13 - 08:14 AM

Cold enough to freeze two dry rags together.
Colder than a republicans heart

Subject: RE: BS: How Cold Can it Get?
From: Ed T
Date: 05 Jan 13 - 08:36 AM

""I heard the new and small VWs are shit for maintenace, reliability and parts""

Check the record out in the Lemon-Aid car guide (used and new)- if you don't want to buy it, you can read it free at Chapters.

Subject: RE: BS: How Cold Can it Get?
From: olddude
Date: 05 Jan 13 - 10:16 AM

bring in the brass monkey cold for sure

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 05 Jan 13 - 04:31 PM

Ed... a mechanic at the Coop service station told me that. Still, that kinda price and fuel economy would be great for me just puttin around town. I don't travel anymore, I work out of my house, I can't hunt (even if I wanted to) and fish and I refuse to buy from anywhere but NA and, now, maybe, Europe.

Subject: RE: BS: How Cold Can it Get?
From: Joe_F
Date: 05 Jan 13 - 06:15 PM

I went thru this on FB, but I might as well do it here too. Systems with negative temperature are not colder than cold, but hotter than hot. When put in thermal contact with the environment, their temperature goes down to minus infinity, jumps to plus infinity, and then cools down to the ambient. Thus, the third law of thermodynamics, which forbids attaining a zero temperature, is not broken.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 05 Jan 13 - 08:18 PM

The Circle Is Unbroken? Sounds Nitty Gritty to me.

Subject: RE: BS: How Cold Can it Get?
From: Joe_F
Date: 06 Jan 13 - 06:14 PM

Of course, in the wonderful world of song, you can freeze at 1000 degrees below zero.

Subject: RE: BS: How Cold Can it Get?
From: Bill D
Date: 06 Jan 13 - 09:39 PM

LOL...Joe F. And when frozen, you have other uses... (in song they don't have to explain about brittleness at 1000 below)

My father, who set poles & strung wire for the Western Union in the 30s & 40s told of working in Wyoming. One morning they went out to find the official weather bureau thermometer, which registered down to -50°F was broken... so they went back in.

Subject: RE: BS: How Cold Can it Get?
From: JohnInKansas
Date: 06 Jan 13 - 10:28 PM

A minor factor that may affect objects in very cold weather, particularly parked (not running) vehicles, is that on a clear night when there's little wind the night sky is a very effective heat sink and thermal radiation from objects "with a clear view to the sky" can lose enough heat to be quite a bit colder than the free air temperature.

Some Army buddies doing vehicle "winter tests" in Alaska (while I was loafing around destroying trucks in Yuma) documented overnight vehicle surface temperatures generally about 15-20 F (8-11 C) lower than surrounding air temperatures.

The effect is seldom apparent until air temps get down around -10F (-20C), but seems to be more effective as the air temp drops below about there, although a good breeze or cloud cover can mostly wipe it out.

John

Subject: RE: BS: How Cold Can it Get?
From: Tangledwood
Date: 07 Jan 13 - 03:50 AM

Meanwhile Birdsville in south west Queensland hit 47C (117F) a couple of days ago. I can imagine that things there came to an absolute standstill.

Subject: RE: BS: How Cold Can it Get?
From: Charmion
Date: 07 Jan 13 - 11:23 AM

Interesting, JiK. That explains why my fingers ache so much when I drive in winter, even when it isn't particularly cold by local standards.

47 C in Birdsville, Queensland. Holy crap. I knew my great-grandfather had a good reason for getting off the boat in Montreal.

Subject: RE: BS: How Cold Can it Get?
From: Pete Jennings
Date: 07 Jan 13 - 12:20 PM

Interesting info about Yuma at Wiki. In 1995, a record temp of 124 °F (51 °C) was recorded! The army still has a proving ground there, which is preumably where JiK was wrecking trucks...

Subject: RE: BS: How Cold Can it Get?
From: GUEST,Frank
Date: 07 Jan 13 - 08:16 PM

Cold as the depths of an Arctic pool
Cold as the tip of an Eskimo's tool.

Subject: RE: BS: How Cold Can it Get?
From: gnu
Date: 07 Jan 13 - 08:28 PM

47C?

I LIKE my Long Johns!

Subject: RE: BS: How Cold Can it Get?
From: Tangledwood
Date: 08 Jan 13 - 02:56 AM

You could be on to something. Put them in the freezer for an hour or two before you wear them.

Subject: RE: BS: How Cold Can it Get?
From: JohnInKansas
Date: 08 Jan 13 - 05:22 AM

Peter Jennings is correct about the Yuma Arizona location. Most of the information at the Wiki link is "more modern" than when I was there, but the demographic data doesn't appear to have changed much.

I was at Yuma Proving Ground for about a year and a half, ca. 1964 - 5.

For the curious, the main truck I was assigned to wear out was one of three prototypes (Chrysler) of the XM410E1 (1) or XM410E1 (2)2. The second image might be taken at YPG. The driver resembles one of the mechanics there at the time, but isn't our principal test driver(?) for that vehicle. Fort Knox (Kentucky) also had one in testing at the same time and their test course included similar "roads"(?).

The Marines sank their proptotype about 60 ft deep in San Diego Bay during a "swimming test" about midway through their test (unkonwn whether it was ever recovered). The guys at Ft Knox got theirs stuck in a mud puddle for about 3 weeks at about the same time, and a tree stump removed one of the 8 axles on mine at Flagstaff Ordnance Depot during "high altitude operations." A very comfortable ride on rough terrain, but not very tough or maintainable.

The XM410E1 (2.5 Ton Chrysler) never made it past the prototype tests, but the XM656 Ford 5 Ton that one of the feather merchants was testing at the same time (also at YPG) got limited deployment.

About midway through my tour at YPG during the winter when it got hard to depend on getting the 105F (47C) minimum air temperatures needed for "desert environmental testing" about half of the military personnel were shipped to Greeley Alaska for "winter arctic tests" and went from 105F (47C) to -60F (-58C) for a couple of months. I didn't get to go because of the five vehicles I had in long term (endurance) tests that needed to be kept running.

John

Subject: RE: BS: How Cold Can it Get?
From: GUEST
Date: 08 Jan 13 - 10:02 AM

Bet you were pissed you missed that trip!

Subject: RE: BS: How Cold Can it Get?
From: Pete Jennings
Date: 08 Jan 13 - 10:36 AM

That last GUEST was me (cookie went AWOL).

Subject: RE: BS: How Cold Can it Get?
From: Joe_F
Date: 08 Jan 13 - 09:16 PM

Guest Frank: Aliter:

I'm as cool as the tip of an Eskimo's tool,
Cool as a fish in a frozen pool,
Cool as a pane of frosty glass,
Cool as the fringe round a polar bear's ass,
Cool.

Subject: RE: BS: How Cold Can it Get?
From: GUEST,Frank
Date: 09 Jan 13 - 07:37 PM

Joe F, that is so Cool.

Here in Australia right now it is hot and dry.
In fact, it is as dry as a dead Dingo's donger.

Subject: RE: BS: How Cold Can it Get?
From: Fergie
Date: 09 Jan 13 - 08:26 PM

Cold as the depths of a deep mountain pool.
Cold as the tip of an Eskimo's tool.
Cold as charity and that's bloody chilly
But not half as cold as our poor Willy;
He's dead, poor fucker, he's dead.

This was the favourite rhyme of my old friend Nick Nichols. I served my tool and diemakers apprenticeship under him back in 1971. He died about 15 years ago. I still miss him and often think about him "as old Jack Greenwald used to say". He was an eccentric and lovable auld rascal.

Fergus

Subject: RE: BS: How Cold Can it Get?
From: Charmion
Date: 09 Jan 13 - 08:40 PM

My dear old sergeant used to quote that verse, too. You don't suppose they went to different schools together?

Subject: RE: BS: How Cold Can it Get?
From: Mark Ross
Date: 10 Jan 13 - 12:34 PM

When I first moved to Butte, Montana, we went bar hopping one night when it went down to 49 below. It was so cold that an exhibitionist walked up to me and described himself!


Mark Ross

Subject: RE: BS: How Cold Can it Get?
From: Alaska Mike
Date: 11 Jan 13 - 03:55 AM

Well, I guess I should throw in my 2 cents. I lived in Yuma, AZ from 1953 to 1980. We didn't had air conditioning until 1973. I remember one day in June when the thermometer in our back yard read 135 F. We moved to Flagstaff, AZ for a few years, and then lived in Alaska from 1986 to 2010. In Alaska my job placed me outdoors almost all year long. I recall working a 5 hour stretch outdoors on the haul road to Prudhoe Bay where the temperatures were hovering at -45 F. The coldest temperture I ever recall being out in was -70 F, but all I did outside was walk between a couple of buildings. Now I'm retired and living on the gulf coast of Florida where today's high was 83 F and if I get to sweaty, I can always jump in the pool.

Subject: RE: BS: How Cold Can it Get?
From: Joe_F
Date: 11 Jan 13 - 09:01 PM

In the Gulag, they used to have a rule: If the temperature was below -40, you didn't have to work, if you made it up the next Sunday.

F or C? It doesn't matter!