Posted by
timothy
on from the yes-those-are-real-words dept.
bofh31337 writes: "Nature has an interesting story about the Lasetron. In theory, creating very short flashes of light, using high-powered lasers, you would be able to see inside atomic nuclei."
The reason it's impossible to see inside of atoms is not because of the length of pulses, it's because the wavelength of light is larger than the size of an atom. So what I am wondering is...How the hell would length of pulses change anything? We would need higher frequency/lower wavelength light, not just short pulses of it.
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Remember, there were no nuclear weapons before women were allowed to vote.
Re:One thing stands out unaddressed
by
taxelxii
·
· Score: 3, Insightful
I'm also a physics student.
I don't think "tracking the motions of electrons around the nucleus" is what they are trying to do. Most of the time, ultrafast spectroscopy (as in femtosecond spectroscopy) is done in a "pump-probe" setup. First you pump the sample with a femtosecond pulse, then you probe it with another femtosecond pulse, delayed in time. You just have to look at the way the probe is transmitted in function of delay time to see the living times of excited states..
I think this may be more like what they want to do.. study the nucleus dynamics, or as they say in the text, their formation or fission,..
I do think that you were right on one point however, when you told that they did not adress the Uncertainty Principle. What puzzles me is how do they think they are going to use zeptosecond pulses. Pulses this short must have a very large bandwith (for comparison, 5fs pulses need to have about 300nm bandwith). Dispersion will be a huge problem if they ever want to steer the beam, or even focus it.
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The reason it's impossible to see inside of atoms is not because of the length of pulses, it's because the wavelength of light is larger than the size of an atom. So what I am wondering is...How the hell would length of pulses change anything? We would need higher frequency/lower wavelength light, not just short pulses of it.
Remember, there were no nuclear weapons before women were allowed to vote.
I'm also a physics student.
..
I don't think "tracking the motions of electrons around the nucleus" is what they are trying to do. Most of the time, ultrafast spectroscopy (as in femtosecond spectroscopy) is done in a "pump-probe" setup. First you pump the sample with a femtosecond pulse, then you probe it with another femtosecond pulse, delayed in time. You just have to look at the way the probe is transmitted in function of delay time to see the living times of excited states..
I think this may be more like what they want to do.. study the nucleus dynamics, or as they say in the text, their formation or fission,
I do think that you were right on one point however, when you told that they did not adress the Uncertainty Principle. What puzzles me is how do they think they are going to use zeptosecond pulses. Pulses this short must have a very large bandwith (for comparison, 5fs pulses need to have about 300nm bandwith). Dispersion will be a huge problem if they ever want to steer the beam, or even focus it.
taxelxii