qwertz
Prince
6 * 1,5v ???
Science & Technology Quiz 2: The one with the catchy title.
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Perfection
The Great Head.
correctttttttttttttttttttttttttttttttttttttttttttttttttttttt
qwertz
Prince
what's the averge density of a neutron star? (no exact value needed, just a approximate estimation)
A neutron has a radius of less than a femtometer. The gravitational pressure might reduce that somewhat, so let's say a neutron has a volume of 1 fm³. That would mean there are 10^45 neutrons per m³.
The mass of a neutron is about 1 GeV, so that would be 10^54 eV/m³. Converted to kg that would be about 2*10^18 kg/m³.
Of course that's only a rough estimate. For a better calculation one would have to consider fermi pressure vs gravitational pressure and the packing density in a neutron star.
The mass of a neutron is about 1 GeV, so that would be 10^54 eV/m³. Converted to kg that would be about 2*10^18 kg/m³.
Of course that's only a rough estimate. For a better calculation one would have to consider fermi pressure vs gravitational pressure and the packing density in a neutron star.
qwertz
Prince
, you're up uppi
Perfection
The Great Head.
You getta bunch of physics nerds in a lab, you pay them several million dollars, and say "make me some anti-hydrogen".
sepamu92
Prince
Something about colliding photons or something
Firstlady
Sunlight's Breaking
antiprotons* and something colliding.
My bet was that we could do it with a Big Bang, but then it happened and there wasn't nearly as much antimatter as we were expecting.
And because of bad luck their speciality is solid state physics and they ask "How?"
sepamu92 said:
photons cannot collide with each other.
Firstlady said:
Producing usable antiprotons is actually the biggest part of the problem.
El_Machinae said:
A Big Bang and then a whole universe in a lab would awesome, but that's a bit hard to realise.
Mise
isle of lucy
Beta-plus decay (analogous to normal Beta decay, in which a neutron turns into a proton and an electron, except it's a proton turning into a neutron and a positron) to produce positrons.
I don't know how to produce anti-protons, but I guess they'd come from some kind of nuclear interaction...... give clues!
I don't know how to produce anti-protons, but I guess they'd come from some kind of nuclear interaction...... give clues!
Yes, that's the easy part.
I don't know how to produce anti-protons, but I guess they'd come from some kind of nuclear interaction...... give clues!
Actually, the interaction has to be sub-nuclear. And it's a bit of a "brute force" approach.
qwertz
Prince
...
, damn rule no.4
, damn rule no.4
72 hours aren't up, yet, but I will be away on the weekend and it doesn't seem like they're will be an answer. So I'll answer and leave an open floor for someone else to ask a question.
Antiprotons are produced by hitting a metal target (I think usually it's beryllium) with a high energy proton beam. When the proton hits the target all sorts of quarks and antiquarks are produced by the energy of the proton. As free quarks cannot exist, these combine to all kinds of hadrons. There is a small chance that one of the hadrons will be an antiproton. As the charge and the mass of the antiproton is known it can be filtered out by magnetic fields. This is a very inefficient process, as you get millions of other particles for every antiproton.
Once produced the protons have to be decelerated in something that's basically a reverse particle accelerator. Then the protons are trapped (for example with magnetic fields) and brought in contact with positrons (for example from a beta-plus-emitter) and antihydrogen is formed.
The current problem is to somehow contain the antihydrogen so that spectroscopy could be done on it.
Antiprotons are produced by hitting a metal target (I think usually it's beryllium) with a high energy proton beam. When the proton hits the target all sorts of quarks and antiquarks are produced by the energy of the proton. As free quarks cannot exist, these combine to all kinds of hadrons. There is a small chance that one of the hadrons will be an antiproton. As the charge and the mass of the antiproton is known it can be filtered out by magnetic fields. This is a very inefficient process, as you get millions of other particles for every antiproton.
Once produced the protons have to be decelerated in something that's basically a reverse particle accelerator. Then the protons are trapped (for example with magnetic fields) and brought in contact with positrons (for example from a beta-plus-emitter) and antihydrogen is formed.
The current problem is to somehow contain the antihydrogen so that spectroscopy could be done on it.
Perfection
The Great Head.
Dude, they know a guy from graduate level QM class who's into that stuff, so they hire him as a consultant.
My question:
What's the difference between EPROM and EEPROM
Mise
isle of lucy
One can be flashed, one can't?
Perfection
The Great Head.
While one might make the argument that under certain definitions of "flashed" and yada yada yada, that fails to note the main difference between the two.
I'll give you a hint, EPROM chips have windows.
I'll give you a hint, EPROM chips have windows.
Well the names mean erasable (EPROM) and electronically erasable (EEPROM) and I have memories from uni of zapping EPROMs in ultraviolet light to erase them (hence the window), you could erase the EEPROM in the machine that you used to program them.
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