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On this day in history... June 5, Great Learning Opportunities!

Posted by on Jun. 5, 2012 at 4:48 AM
  • 5 Replies

Here are some events that happened today, in history- some of them are pretty interesting.  Do you think you could help your child learn about one of these events today?  Pick one and let us know how it goes!

teacher

by on Jun. 5, 2012 at 4:48 AM
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KickButtMama
by Shannon on Jun. 5, 2012 at 9:30 AM
We will be doing the Bose-Einstein Condensate with my boys (10 & 8 y/o) ....it is just too much fun!!
A fantastic resource: http://www.jupiterscientific.org/sciinfo/boseeinstein.html

Bose-Einstein Condensates
http://www.innovateus.net/science/what-bose-einstein-condensate

Bose Einstein Condensate is the fifth state of matter (after solid, liquid, gas, plasma). To visualize the fifth state of matter one needs to have the cooling capacity to lower gas temperature to very near the absolute zero (less than one-millionth of a degree above absolute zero). The reason why scientists craved to perform this arduous task was the amazing properties of the condensate. It is a coherent state where microscopic properties of quantum mechanics govern the behaviour of a macroscopic system. One can study the quantum nature of matter without having to consider sub-atomic particles. Since the emergence of the concept, many laser cooling methods were introduced. However a Bose Einstein Condensate was realized not much earlier.


What is the process involved in producing Bose-Einstein Condensate?

When a dilute gas containing bosons interacting with a weak force in an external potential is cooled to temperatures near absolute zero, we achieve fifth state of matter or Bose Einstein Condensate. BEC is formed by the collapse of atoms into single quantum state. At this temperature, gas particles instead of the characteristic Brownian motion display liquid like characteristics and so the gas is called a superfluid.

 

What is the history behind Bose-Einstein Condensate?

The prediction of the phenomenon was done wayback in 1925 by meticulous scientists Satyendra Nath Bose and Albert Einstein. Bose sent his findings on quantum statistics of photons (light quanta) to Einstein who translated it and sent it to ‘Zeitschrift für Physik’ for publishing. Einstein worked upon Bose's ideas to material particles in two other papers also. Due to the combined efforts of Bose and Einstein, the concept of Bose gas emerged. It obeys the Bose Einstein statistics (statistical distribution of bosons, identical particles with integer spin. Bosonic particles including photon and atoms such as He(4) can share quantum states with each other. It was found that cooling bosonic atoms to very low temperature would lead to their falling or condensation into the lowest acceptable quantum state, giving birth to a 'new form of matter'.

 

The first true Bose Einstein Condensate was produced by Eric Cornell and Carl Wieman on June 1995 at JILA lab in the University of Colorado. A dilute vapour having 2000 atoms of rubidium-87 was subcooled to 170 nK(1.7×10−7). The cooling process used was a combination of laser and magnetic evaporative cooling. They found that if Rb atoms are cooled to less than 170 billionths of a degree above zero K (absolute zero temperature), condensation takes place leading to the formation of a superatom. Hence all rubidium atoms behave as one unit. Another attempt was made 4 months later to create a condensate of Sodium-23 atoms.This was a singular effort by Wolfgang Ketterle at MIT. In the new condensate, (Ketterle's condensate) the no. of atoms was greater by nearly a hundred times enabling the creator to deduce important results like the observation of quantum mechanical interference between two different condensates.

 

For their outstanding achievements in the field of Bose Einstein condensation Carnell, Ketterle and Williams were awarded the nobel prize in 2001. In November 2003, the first molecular Bose Einstein condensates were created by the joint contributions of Grimm, Jin and Ketterle. The concept of Bose Einstein condensation is useful in unfolding numerous mysteries from the world of fundamental physics, like quantum mechanics. The results of the experiments at JILA and MIT paved the way for many researches. Some of these are 

Experiments to demonstrate interference between condensates due to wave-particle duality
Study of superfluidity and quantized vortices
Retarding of light pulses using electromagnetically induced transparency
 

What are the characteristics of Bose-Einstein Condensate?

Experiments have proved that Bose-Einstein Condensate has many interesting characteristics

Bose-Einstein Condensate can have a very high gradient in optical density. Light going within the condensate will have apparent low speed. Although it travels at the normal speed (c) between the atoms it is absorbed by the atoms for a long time before re-emission.
Rotating Bose Einstein Condensates could be used as a model black hole that allows light to enter but not to escape
In the presence of a weak magnetic field the shape of Bose Einstein Condensate changes
 

What are the limitations of the state?

Care must be taken to preserve the fifth state. The least interaction with the surroundings will heat the condensates causing them to surpass the condensation threshold. So they will disintegrate back into individual atoms. Hence the interesting properties will be lost and what we would get is a normal gas.

 

What are the recent findings around Bose-Einstein Condensate?

In November, 2010 the first photon Bose-Einstein Condensate was observed. Nowadays Bose Einstein Condensates are finding many important applications like

Vortices in Bose-Einstein Condensate are subject of gravity analog research. These can help in process modelling of black holes and other related phenomenon
To explore the transition between a superfluid and a Mott insulator
In the study of Bose–Einstein condensation in less than three dimensions, eg. Tonks-Girardeau gas.

mem82
by Platinum Member on Jun. 5, 2012 at 10:00 AM

Thanks! The kids and I had a pretty good discussion of WWII, this morning, because of this list.

LovemyQ
by Member on Jun. 5, 2012 at 10:32 AM

It is my 13th wedding anniversary today, so we are learning about that! lol

usmom3
by BJ on Jun. 5, 2012 at 11:02 AM

 Thanks!

KickButtMama
by Shannon on Jun. 5, 2012 at 11:20 AM
Quoting LovemyQ:

It is my 13th wedding anniversary today, so we are learning about that! lol




CONGRAT'S, Happy Anniversary!!
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