Coldest temperature

Originally posted by sonhouse
Yes, I have heard and read about the Casimir effect and we are actively studying it right now. It seems in nanomachines, like nanosized gears, the casimir effect has a detrimental action on the friction-like activity, called 'stiction'. The casimir effect was proven to be real only recently but now we can see it in nanomachines, it bolluxes up gears by attr ...[text shortened]... force that has to be overcome, in addition to the regular magnetic and electric field forces.

So, does this mean if negative mass/energy can be attained, could lower than absolute zero degrees be attained?

Originally posted by PinkFloyd
So, does this mean if negative mass/energy can be attained, could lower than absolute zero degrees be attained?

I guess negative energy could be interpreted as 'below absolute zero' but don't hold your breath waiting for that one. The whole idea of negative mass and energy is just a pipe dream for physicists right now.
Still, absolute zero does not mean the total absence of energy, the uncertainty principle takes care of that, virtual particles pop in and out of existance all the time, thats what causes the casimir effect, if you have two plates close together, more virtuals pop up on the outside faces of the plates and less on the facing plates, which means there is a push driving both plates together and its not electrical or magnetic or van der waals forces or anything like that, but a quantum mechanical action something like the pressure on the skin of a balloon, which is a reaction to all the free movement of gas particles inside the balloon. Its more like that, a pushing and shoving match of virtual particles. Apparently the litte buggers have a certain amount of kinetic energy associated with them.

Originally posted by PinkFloyd
I saw a science program that said the coldest spot in our solar system is on one of Neptune's moons, where it is about 3 degrees above absolute zero, "where molecules stop moving". I'm curious, is that what Temperature means--some kind of function of moving molecules? And why can't there be temps lower than absolute zero? We can go negative on the Fahrenheit and Centigrade scales--why not Kelvin's?

It is related to the Third Law of Thermodynamics. Where when temperature approahes 0K , the entropy of the system approaches 0.

Originally posted by najdorfslayer
It is related to the Third Law of Thermodynamics. Where when temperature approahes 0K , the entropy of the system approaches 0.

Approaches but never gets there, I guess its an asymtote. Quantum uncertainty ensures the entropy and the rest energy will never be exactly zero. It sure is interesting the Bose condensates being studied now, able to slow down light to a crawl and such. Even though we cannot get to total absolute zero temperature wise, there is still plenty to learn about matter as you get colder and colder.

Originally posted by sonhouse
Approaches but never gets there, I guess its an asymtote. Quantum uncertainty ensures the entropy and the rest energy will never be exactly zero. It sure is interesting the Bose condensates being studied now, able to slow down light to a crawl and such. Even though we cannot get to total absolute zero temperature wise, there is still plenty to learn about matter as you get colder and colder.

Are you a post doctoral research physisict?

If so what are you researching?

Originally posted by najdorfslayer
Are you a post doctoral research physisict?

If so what are you researching?

I am just a photonics technician. I helped build a cleanroom from a bare concrete floor and built several optical devices and circuits like a precision low voltage reference power supply for a thermocouple calibration routine, so I am more of a non-degreed engineer but I read every science article I can find online and in bookstores. My present job is the final test of a 40 gigahertz laser generator/modulator used for fiber optics data transmission, it can reliably send data through a fiber 60 Km long without relays or amplifiers and such, so the test equipment is very comprehensive and I work with the science team taking data down for engineering evaluation of various conditions we test for, like what is called "Extinction Ratio" which is the difference between full light signal and no light signal, that needs to be about 10 db, like a signal to noise ratio. I also worked way in the past on the Apollo moon landing systems,
Apollo timing and tracking, you can see my post on the 'anyone still think apollo landings faked', where I discuss my job back then in one of the last posts there. I worked in the Bahama Islands on AUTEC, Atlantic Underwater Test Center, on Andros Island, where hundreds of underwater microphones (hydrophones) have UHF data links to the main site all in a big trench called the Tongue of the Ocean, TOTO, 8000 feet deep and 130 miles long for testing underwater munitions, torpedoes and submarines. I worked in Israel as a contractor for Intel for most of the '90s in Jerusalem on my previous job of an Ion Implant field service engineer, my company then was Varian who at the time owned a company called Extrion in Gloucester Mass. I had many many physics courses there on the theory of ion implantation, its too complicated to go over here, just google it if you are interested. I do have a lot of college courses but I found out about 40 years too late the reason I DON'T have a Phd is I have adult ADD, my mind would wander into left field and now I take adderal for that which is basically amphetimines but low doses, which keeps my focussed at work. Having ADD is ok for a musician, you can hear my music compositions at myspace.com/donjennings and here at RHP on the music tournie III, at the Culture forum, BTW, there are some real virtuosi there, hydraman for one is a professional jazz guitarist with an incredible technique on guitar, plays a 9 string guitar(!)
So thats part of my life, I am interested in everything from quantum physics to music to photonics to astronomy to cosmology.

Originally posted by sonhouse
I think one of the coldest spots in the solar system is Triton and Pluto, both at about -391 degrees F. I think thats about 30 degrees Kelvin, not 3 degrees. The Cosmic Background Radiation comes in at about 2.7 degrees Kelvin so it seems to me nothing in the universe (unaided by machinery) can get to 3 K. BTW, Triton has liquid nitrogen (!) Volcanoes!

I was always taught that the coldest temp anywhere in the universe is absolute zero,which is around 273 degrees below zero(cel).On any planet where there is mass and gravity,radiation of some tiny amt and some pull from the sun for example,I do not believe that pluto for example can be as cold as the far reaches of "pure space" where there is vacuum and no atmosphere,ect.
So have they been able to produce colder effects in a lab than absolute zero?I never heard of that

Originally posted by Vanquish
I was always taught that the coldest temp anywhere in the universe is absolute zero,which is around 273 degrees below zero(cel).On any planet where there is mass and gravity,radiation of some tiny amt and some pull from the sun for example,I do not believe that pluto for example can be as cold as the far reaches of "pure space" where there is vacuum and no ...[text shortened]... ave they been able to produce colder effects in a lab than absolute zero?I never heard of that

Zero Kelvin is a theoretical lowest temperature. Deep space is not zero kelvin. I don't really understand why; something about background cosmic radiation or something.

Labs have produced temperatures lower than the temperature in deep space, but not lower than 0 K.

Originally posted by AThousandYoung
Zero Kelvin is a theoretical lowest temperature. Deep space is not zero kelvin. I don't really understand why; something about background cosmic radiation or something.

Labs have produced temperatures lower than the temperature in deep space, but not lower than 0 K.

so can you tell me in fahrenheit what is the coldest temp ever found or created in a lab?I'm more use to fahrenheit temp,which is layman standard in the USA. 300 degress below zero Fah.or what?I need to know this to win some bar bets in the future!

Originally posted by Vanquish
so can you tell me in fahrenheit what is the coldest temp ever found or created in a lab?I'm more use to fahrenheit temp,which is layman standard in the USA. 300 degress below zero Fah.or what?I need to know this to win some bar bets in the future!

Absolute zero in F terms is -459.67 Degrees. So the labs have produced -459.669999999 degrees, something like that. It's a temp you can't really get to exactly but you can get darn close. That's how they made the Einstein-Bose condensates, predicted about 70 years ago but just achieved in the labs in the last ten years or so, where all the atoms in a cold gas collapse together to form basically one big atom with the same characteristics as all the individual atoms, where all the quantum numbers crunch together and they can't be told apart anymore.

Originally posted by Vanquish
so can you tell me in fahrenheit what is the coldest temp ever found or created in a lab?I'm more use to fahrenheit temp,which is layman standard in the USA. 300 degress below zero Fah.or what?I need to know this to win some bar bets in the future!

That calculation is difficult because such values are typically given in Kelvins, and are then given to the order of magnitude (that is, .0001, or .000000001, but not .0013). Thus if you try to use the conversion calculations it won't work because I don't think common conversion calculations are precise enough to give exact values.

For example, absolute zero is usually given as -273.15 deg C. The coldest temperature found is 10^-10 deg C...that means 0.0000000001 deg C.

Well the value -273.15 deg C is only an approximation...it might actually be -273.1513283218 deg C, or maybe even -273.1534285371 deg C...you don't know so you cannot figure out precisely what absolute zero plus 10^-10 deg C is.

So, I cannot give you the information you're looking for. Sonhouse's answer is about as good as you'll get, unless you can find the value of absolute zero to ten or eleven decimal places.

EDIT - Here's the conversion, but like I said - the -459.67 only goes to two decimal places, while labs have gotten so close the temperature was the same as absolute zero for nine decimal places. Thus the calculation is problematic.

[°F] = [K] × 9/5 - 459.67