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Creating Designer Isotopes
Posted by
Soulskill
on Sun May 11, 2008 09:04 AM
from the better-than-the-walmart-isotopes dept.
from the better-than-the-walmart-isotopes dept.
Roland Piquepaille writes "According to a Michigan State University (MSU) news release, 'Made-to-order isotopes hold promise on science's frontier,' nuclear physicists can now start a new career as isotope designers. These scientists can build specific rare isotopes to solve scientific problems and open doors to new technologies. The lead researcher says this approach has already given us the Positron Emission Tomography (PET) scan technology. He's now going further, saying that he wants to build objects 100,000 times smaller than the atomic nucleus. He calls this 'femtotechnology.' Also available are additional details and pictures of the tools used for this kind of research, picked from a 415-page design paper." Update: 05/11 14:30 GMT by SS: Readers have noted that the summary inaccurately portrays the scale of the 'femtotechnology.' The MSU researcher refers to "the capacity to construct objects on an even more minute scale, that of the atomic nucleus 100,000 times smaller."
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> Atoms of the same ele
Mod parent up! (Score:2)
Re:Please no more stories by Roland Piquepaille. (Score:4, Interesting)
She said: "Isotopes are the different versions of an element. Their nuclei have different numbers of neutrons, and thus give them different properties".
It is fairly accurate to say that isotopes are different versions of an element.
As for your remark: "Maybe she was in a hurry to go shopping", maybe you should slow down a bit?
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No e+/e-: only possible with quarks (Score:5, Informative)
You cannot build structures with electrons and positrons which are this small. The reason being that the binding energy for EM processes (the strongest force which an e+/- feels) is far too weak to confine the particles to a region as small as 1 fm. For example positronium [wikipedia.org] has a binding energy of 6.8eV, roughly half that of a hydrogen atom and hence it will be slighly larger.
The misconception comes about because the electron is not a particle but a wave. You can trap the wave in a potential but it is still a wave. The smaller the space you want to confine it to the shorter the wavelength required and as the wavelength decreases the energy increases (deBroglie wavelength lambda=Planck's constant/momentum [lambda=h/p]). This means that energies O(10^6) times larger than EM binding energies to confine an electron to such a small area.
The only force we know of that is strong enough to do this is the strong nuclear force which is only felt by quarks. Hence, given our current knowledge, the only thing you could build such a tiny structure out of is quarks...which is why the nucleus is made of these!
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although I want to stand by the assertion of continousness
I'm curious - is this based on intuition or is there evidence to suggest that space-time really is continuous at the Planck scale? Or a prediction of string theory? Certainly I'll agree that it appears continuous as far as we have probed.
...but unless (until?) you can show a free quark that is unambiguously not the product (rather than the trigger) of a false vacuum decay hadronization
How about top quark decays? This decays (or should decay) as a free quark because its lifetime is considerably less than the hadronization scale. We'd need to show spin correlations to prove that the quark decayed before hadronizing though so we are not quite ther
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Technically gluons also feel the strong nuclear force
There is no 'technically' about it: they do feel the strong force. However, as far as we know, you cannot create a bound state of just gluons - a so-called glue-ball - although it is possible that it may exist with a very short lifetime. If it had a long live time then, like the photon, being colour-neutral it would not feel the strong force and so would cause a long range strong nuclear force!
This is actually a rather important as it explains why Quarks are never found in isolation.
Actually you can observe single quarks - I've even done it! Top quarks decay so incredibly quickly (10^-24
Pushing Ice (Score:4, Informative)
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This is not femtotechnology (Score:3, Informative)
The term femtotechnology to describe technology built from subatomic particles
This is not an example femtotechnology any more than chemistry is is an example of nanotechnology. All they are doing is sticking protons and neutrons together in ways allowed by nature. This is not "designing" an isotope since there are only a few thousand combinations allowed. That's not to say it isn't useful technology but, if you look at the size of mchines required, the scale of the tech is anything but femto.
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...how one goes about doing anything not allowed by nature?
Sorry - I agree I did not make myself clear. What I meant was "in ways that already occur in nature" i.e. they are only creating things that we already know the universe already produces by itself.
I don't love the trendy label "nanotechnology" either, but the units produced are individually on the scale of nanometres.
Then why don't we call chemistry nanotechnology? If I produce hydrogen by dropping metal into an acid is that nanotech because the size of my end unit is that size? The difference is that nanotech involves technology on the nano scale i.e. tiny physical systems that human ingenuity has built. The design o
Wrong scale... (Score:3, Informative)
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However, they do have mass, and in the case of a large atom, are several orders of magnitude less massive than their nucleus.
I'm no expert in this area, although I believe that the concept of "volume" itself starts to become rather fuzzy once you go much smaller than a Proton (although, yes -- there are several particles smaller than the proton that we have evidence for, although it is difficult to directly describe these as "
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And unlike the atom as a whole, the nucleus is very compact, about the size of its constituent particles.
Not quite. First the real constituent particles of the nucleus are quarks which, as far as we are aware, are fundamental particles and so, like the electron, have no measurable size. As you increase the energy you will just see a quark confined to a smaller and smaller volume.
Secondly, if you regard the nucleus as made up of protons and neutrons, the radius is still not the same as that of a proton. The liquid drop model of the nucleus [wikipedia.org] shows how you can roughly treat the nucleus as a drop of liquid wi
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That's why I said "about the size", not "exactly the size". The relevant information is the order of magnitude; a proton has a radius of roughly 1
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As I said in another comment, what's relevant is how these constituent particles form structures. It is meaningless to speak of the radius of a quark (with current knowledge), but it makes sense to speak of the (statistical average) distance between two quarks within a nucleus.
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As far as anyone knows (aside from pure speculation) quarks and neutrinos are point particles with no internal structure. When they do get together, they form structures of the magnitude of a nucleus. The term "structure" is important, because the suggestion made by the article summary is that structures on this scale, which by definition would have comprise multiple particles, could be created. That is going to be hard if no physic
Real Kryptonite ? (Score:2)
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Fricking Roland (Score:1, Offtopic)
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Jesus fucking christ. I must have slid into a really messed up universe this time. Maybe it is to my advantage though. Perhaps they also make cars here really cheap so I won't buy them!
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Why does the "ohnoitsroland" and similar tags ALWAYS disappear?
I just noticed that http://science.slashdot.org/tags/ohnoitsroland [slashdot.org] lists a number of recent stories, but when you look at the stories themselves, the tag is missing. This indicates that the tag is still present in the database, but is being filtered at display time.
/. homepage to hide any post starting with "Roland Piquepaille writes".
Of course, I'm not sure of any way to make use of theat information. I'm thinking that I need to write a Firefox extension that reformats the
Cherry Flavored... (Score:2)
I bet that once they have these cool custom isotopes, they still give them that standard, gag-a-maggot, fake medical cherry flavor.
"Of course it will save you from cancer, but you have to choke it down first."
Ahh, Science Reporters flub it again! (Score:2)
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Unforeseen problems (Score:1, Funny)
Businessman : "Where?"
Another glaring error (Score:5, Insightful)
If you're changing elements from one to another, it's not a chemical change. It's nuclear! That's one of the definitions of a nuclear change. What kind of science journalism is this?
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The usual kind.
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Armor and Weapons (Score:2)
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Not Really a New Field (Score:1)
Heinlein (Score:3, Informative)
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"Blowups Happen" had quite a few predictions that ended up being reasonably close. One was that nuclear power plants would use a steam cycle. Another was being off by only a factor of two for the explosive yield of fissioning 2.5 tons of U235.
There were a few things he missed. The most important to the story line was delayed neutrons. Another was the use of computers for numerical analysis (he wrote about advances in calculus that would allow for analytical solutions of problems that ar