Bose-Einstein Condensate - Coldest Place in the Universe
Bose Einstein condensate coldest place in the universe

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A short video explaining how a Bose-Einstein Condensate of sodium atoms is created in lab at MIT by Martin Zwierlein. Using highly focused, single frequency lasers it is possible to cool the single sodium atoms, negating their thermal vibrations by inducing electronic transitions which effectively "pushes" them into place. This brings the atoms down to millikelivn temperatures. However to achieve nanokelvin temperatures, magnetic fields are used to trap the atoms in a well or cup so that the atomic resonance of the atoms begins to match the frequency of the laser light so that , like in a cup of coffee or tea, the hottest atoms are boiled off the surface by "blowing" on the atoms with polarized laser light. This makes the atoms that are in resonance with the light move towards the center, leaving the hotter atoms to boil off. This then shrinks the gas cloud into a supercool sphere. This arrangement is known as a magneto-optical trap and using it the atoms can be made colder than anywhere else in the universe, cold enough for the subtle effects of quantum mechanics to make the wavefunction of the atoms coherent, just like how a laser makes the photons in a laser medium coherent. The wavefunctions then constructively interfere until the atoms behave as a single quantum object known as a Bose-Einstein Condensate. In quantum mechanics, a class of particles which have an integer quantum spin are called bosons. For example, photons, gluons, higgs boson etc. Any number of bosons can go to the same quantum state. Thus they obey Bose-Einstein statistics. The wave function associated with bosons is symmetric. A class of particles which have a half- integer spin are called fermions. Example - proton, neutron, electron, etc. Unlike bosons, only two fermions (at maximum) can go to the same quantum state, as dictated by the Pauli Exclusion Principle. They obey Fermi-Dirac statistics. The wave function associated with fermions is anti-symmetric. An atom can also be classified as a composite boson or a composite fermion. To find whether an atom is a composite boson or a composite fermion, you need to look at the net spin of the atom due to its constituent particles that make it. For example, consider the simplest of the atoms - Hydrogen. Hydrogen has a proton and an electron. A proton is a half-integer particle and so is an electron. Therefore, the net spin of a normal hydrogen atom is one, which is an integer. Therefore, hydrogen is a composite boson. If we consider a helium-4 atom, there are two protons, two neutrons and two electrons. Each of these particles has a half integer spin. Therefore, the net spin of a normal helium atom is an integer. Hence, helium is also a composite boson. With Sodium, the number of protons is 11, the number of neutrons is 12, and therefore, the number nucleons is 23 which is an odd number. Since the number of electrons in Sodium atom is 11, this makes the total number of constituent particles 34 which is even and hence Sodium atom is a composite boson. So by this reasoning, all Sodium-23 (as well as Rubidium-87) atoms are bosons which means that the spin of the atoms is an integer. Bosons obey Bose-Einstein statistics and do not obey the Pauli Exclusion prinipcle and can form non degenerate condensates. So, because bosons tend to bunch together it is possible for a macroscopic group of N-bosons to form a giant wave function called a Bose-Einstein Condensate. Therefore, a Bose-Einstein Condensate is essentially a macroscopic occupation of the ground state of a quantum system at thermal equilibrium, and is considered to be a quantum phase transistion just like superfluidity and superconductivity. This quantum state can be seen in wildly differing physical systems, from liquid helium to electron pairs in superconductors to the laser-cooled atoms in vacuum chambers as shown in the video. Bose--Einstein condensates composed of a wide range of bosonic atoms and isotopes have been produced. Related experiments in cooling fermions rather than bosons to extremely low temperatures have created degenerate gases, where the atoms do not congregate in a single state due to the Pauli exclusion principle. To exhibit Bose--Einstein condensation, the fermions must "pair up" to form compound particles (e.g. molecules or Cooper pairs) that are bosons. The first molecular Bose--Einstein condensates were created in November 2003 by the groups of Rudolf Grimm at the University of Innsbruck, Deborah S. Jin at the University of Colorado at Boulder and Wolfgang Ketterle at MIT. Jin quickly went on to create the first fermionic condensate composed of Cooper pairs in a superconductor.

Comments

theodoeshutup : the MIT guy is a more entertaining speaker than the producer guy

Kevin Parker : I kinda got scared when the German started talking about his oven.

andriuchaMetal : That's the coolest thing I have ever seen.

viature54 : the coldest place in the universe is actually my wife

Paul Hendrix : MIT, where they cool things down with lasers and then blow on them to cool them further.

Amaury Ayala : dammnn i can i use it cool down my cpu?

James Dell'Alba : It pained me when he kept saying "degrees Kelvin"

Jasper Synth : Canada is still colder

tibschris : So F12 cools sodium atoms to a millionth the temperature of dead space. TIL

CheeseWasTaken : Put on sunglasses and it would be even cooler

hunn20004 : Hey, this wasn't in the bible.

Vern Emcee : "I always wondered what F12 does" LMFAO

Get Krunk : Well, if there are aliens with this technology, this isn't the coldest place in the universe.

Alex Abadi : I watched that 6 minutes video and now my coffee is frozen cold !

Liamggbb123 : spectral brought me here

Boston Badass Hugh Jass : Not even that would cool an AMD card ^_^

Augusto O.R : Second coldest actually, after my ex's heart.

rosanglura : But can you turn it into a Russian soldier?

Aperture : "Cook up some sodium atoms; The same kind in your table salt." No, that's not how chemistry works.

The Dollar Guy : Make solid light and you have something.

DanThePropMan : This is so cool.

eyebinker : It's only the coldest place in the Universe if super advanced aliens don't exist.  Then I'm sure they've probably gone colder in the name of science.

Manuel Dena : Just saw "spectral" in netflix and it got me here 😂

Tomoko Kuroki : "Well I blow on my coffee to make it colder so let's blow on the atoms."

ZerglingOne1 : Lasers that make things super cold. Can anyone say Freeze Ray?

Randy Marsh : am I the only person here who is here because of the movie spectral

ScornMuffins : Roll on BEC hard drives.

Rushali Sharma : That was the ᶜᵒᵒˡᵉˢᵗ thing I've ever seen

Parth Kapur : Always wondered what F12 does lol!

Frederico barreto : 2:56 Back to the future?

The Thugger : Nothing is cooler than water out the faucet

Brian Su : hmm I think you can't get down to absolute zero because of the uncertainty principle too.

Eric Taylor : wait till they get a load of my picokalvin.

clawpuss2 : Amazing...thanks for posting :)

Raghav Bhandari : Came here after watching Spectral

Damon Cassada : Chilling documentary.

NagaHumanbeing ZooOfParticles : universe is so amazing.. matter is really deep.

Lukas K. Salkauskis : Somehow resembles my ex's heart. (Sorry, couldn't contain myself)

KC : 21 thumbs down.....really? The anti-knowledge and anti-science Christians at it again????

Brendan Garvey : Now attach it to a human nervous system and set it loose to kill people in Moldova... ;)

Davide Mura : Some masterpiece Black Metal material here. BOSE-EINSTEIN CONDENSATE TRVE KVLT

MrGopnik : I looked this up after watching spectral

Sourav Biswas : Satyendranath Bose, one of the greatest scientists of India.

MrEKG123 : The host and the scientist showed up wearing exactly the same shirt and pants.

Zachary : Here comes the Ultimate Winter! 🦌😎❄️☃️🌨

Calum Cookson : 2:15 jazz hands

J Borg : Neat video, but the host would be better on a children's show.

Blaze : So basically to reach absolute 0 they would need to stop time to stop all motion and the transfer of energy? 

LattiMonstaaa : dear lord how stupid is the guy in this vid