Scientists Create Rare Fifth Form of Matter in Space
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Scientists Create Rare Fifth Form of Matter in Space
1–10 of 15 posts
Re: Scientists Create Rare Fifth Form of Matter in Space
#2why does bombarding tightly-packed rubidium-87 atoms with lasers cool them to minus 273.15 degrees Celsius?
Re: Scientists Create Rare Fifth Form of Matter in Space
#3 When groups of atoms are cooled to such unfathomably low temperatures, they stop moving as individuals and meld into one big "super atom." Tens of thousands of atoms suddenly become indistinguishable from one another, slowly vibrating on a uniform wavelength that can, theoretically, pick up the tiniest gravitational disturbances around them.
Re: Scientists Create Rare Fifth Form of Matter in Space
#4Here's the Wikipedia article on laser cooling: https://en.wikipedia.org/wiki/Laser_cooling
Its explanation is a bit too surface level for me. Anyone have more details on the mechanism used for this experiment? Would they have used Doppler cooling like is sometimes done on Rb-85?
Re: Scientists Create Rare Fifth Form of Matter in Space
#5There are way more than five phases of matter...
Re: Scientists Create Rare Fifth Form of Matter in Space
#6When groups of atoms are cooled to such unfathomably low temperatures, they stop moving as individuals and meld into one big "super atom." Tens of thousands of atoms suddenly become indistinguishable from one another, slowly vibrating on a uniform wavelength that can, theoretically, pick up the tiniest gravitational disturbances around them. Why should this be called "super atom", just because all atoms behave the sa…
Atom means indivisible. Calling it a super molecule might seem like a better term, but it's not about the chemical nature of the substance.
Re: Scientists Create Rare Fifth Form of Matter in Space
#7why does bombarding tightly-packed rubidium-87 atoms with lasers cool them to minus 273.15 degrees Celsius?
The simplest way to explain it is this:
Atoms can only absorb very specific and exact frequencies of light. But because the atoms are moving, the frequency of light, as seen by the atom, varies a lot.
If you only shine light that is slightly below the lowest frequency of light the atom can absorb, only those atoms that are moving toward the light (and thus "see" a slightly higher frequency) are able to absorb that light.
Then the atom emits that light - which is always at the exact frequency. In the process you basically "steal" energy from the atoms motion, and emit it back out as ever so slightly higher frequency light.
Since the atoms are now moving slower they are colder. You keep doing this until you've gotten as much out of the process as you can.
Re: Scientists Create Rare Fifth Form of Matter in Space
#8why does bombarding tightly-packed rubidium-87 atoms with lasers cool them to minus 273.15 degrees Celsius?
The simplest way to explain it is this: Atoms can only absorb very specific and exact frequencies of light. But because the atoms are moving, the frequency of light, as seen by the atom, varies a lot. If you only shine light that is slightly below the lowest frequency of light the atom can absorb, only those atoms that are moving toward the light (and thus "see" a slightly higher frequency) are able to absorb that li…
So do the moving atoms "see" different frequencies because of doppler effects, or something else?
Re: Scientists Create Rare Fifth Form of Matter in Space
#9Earlier quoted context omitted.
The simplest way to explain it is this: Atoms can only absorb very specific and exact frequencies of light. But because the atoms are moving, the frequency of light, as seen by the atom, varies a lot. If you only shine light that is slightly below the lowest frequency of light the atom can absorb, only those atoms that are moving toward the light (and thus "see" a slightly higher frequency) are able to absorb that li…
So do the moving atoms "see" different frequencies because of doppler effects, or something else?
Yes, doppler effect.
Re: Scientists Create Rare Fifth Form of Matter in Space
#10When groups of atoms are cooled to such unfathomably low temperatures, they stop moving as individuals and meld into one big "super atom." Tens of thousands of atoms suddenly become indistinguishable from one another, slowly vibrating on a uniform wavelength that can, theoretically, pick up the tiniest gravitational disturbances around them. Why should this be called "super atom", just because all atoms behave the sa…
> If I have a bag of indistinguishable rice corns
Ah, but they actually are distinguishable. If you checked them, their size will vary slightly, the exact position of the atoms making them up with be different, etc, etc.
If you tried, you would be able to find something different about every single grain of rice - even if you had to check at the atomic level.
The thing about this condensate is the atoms ARE truly indistinguishable. Their motion, energy, absolutely everything about this is exactly identical.
But what really makes them special is that they stay that way - they all move together. (At least until they get enough energy to break apart their bond.)
It's that last part that makes them into this "super atom" - they are all bonded together.