I always wondered about the physics behind the types of meta-materials described in science fiction such as Neal Stephenson's Anathem, but could never imagine a feasible mechanism. According to this article, turns out the mechanism is the manipulation of the electron clouds in atoms and molecules using precisely calibrated laser pulses.
More money has been wasted on laser chemistry than any other field of optics. While it is possible, on the single molecule level, to perform very clever experiments, scaling to any useful result has proven impossible for two main reasons. First, at the densities where there can be any non-microscopic yield of a laser chemical process, collisions immediately scramble and ruin intricate quantum state preparation. Secondly, you need at least one photon per reaction—- and even in the age of semiconductor diode laser driven devices, a mole of photons is among the most expensive reagents a chemist can employ.
Although the article is certainly worth reading, the title suggests that the alchemy has actually been achieved (in the author's broad sense), while the post deals with a theoretical possibility.
"And they are not truly achieving the alchemists' dream of transmutation, just changing the behavior of the material."
Is there really a difference? Isn't the name we give a material essentially just a shorthand for describing a pattern of behavior that its constituent particles are (mostly) adhering to?
Speaking of which, did Seaborg collect any of the gold atoms he transmuted? Obviously it wouldn't be enough to see, but I imagine that some university museum has a little vial with a chunk of detector in it with a little plate explaining that there are a few million transmuted gold atoms stuck to its surface, or something.
Yes, as always with these things there has been a bit of journalistic licence taken. There will always be a gap between what has been rigorously demonstrated, and the potential future you want to sell!
At the moment we're up to the stage of having a theoretical framework for how to manipulate a given property through a driving field, along with some computational demonstrations that the method works. The major point is that the equations one derives from this method are quite broadly applicable, and generally speaking if you can show they work in silico, then a real-world implementation shouldn't be too far behind.
I tend to associate alchemy with elemental transformation, e.g. lead into gold, fission, or fusion.
This article does not describe that level of transformation. Rather it's about making "lead behave like gold" as a material, but not as a lustrous metal of ravenous hording.
Hey cool! I'm one of the authors of the papers this article is based on. Very surreal to see it being discussed by strangers. I should probably try to resist the temptation to respond to every single comment in this thread...
How general is the maths at work here? Is "pulse shaping" another way of saying "controlling the wavefront"? In that case is the maths similar to that used in massive MIMO in communications systems (which in turn is connected to holography)? If so, controlling an electron cloud is effectively massive MIMO in the optical domain.
A further way of looking at it would be as "4 dimensional holography". A regular 3D hologram is static in time, but these ones are effectively "holographic movies", with atomic scale time resolution?
I wonder: could there be some metastable states that you could nudge a given material to, and have it stay there for a while after control pulse is disabled?
I also wonder if the material doesn't need to be one-atom thick for these tricks to work.
I wonder what happens if you transmute a bunch of atoms this way into something more exotic, let them form chemical bonds, and then shut off the control pulses.
Presumably any new chemicals you formed in this way would fall apart as the chemistry would no longer work. However, if the resulting chemical were stable, then you could use control pulses to bridge stable states together through unstable intermediate states. But that would require a lot more physics research before we had an actual use for that.
On the surface of it, this sounds like a tool that could open up some new research avenues. Like I wrote in another comment: I wonder if there are metastable states into which you could nudge the atoms using those pulses, in which those atoms could stay after the pulses shut off? If so, then that's another set of Legos for chemists to play with.
Is be surprised. Muon catalysed fusion can do that, but if my understanding is correct (it may well not be), that’s because the higher mass of the muon means it can be more localised in space, and this wouldn’t have that effect.
Artificially, one that works with probably most/all lasers would be an active phosphor display(I forget the specific cocktail it's composed of), like the kind from an oscilloscope
Well, phosphorescence or fluorescence are basically the same thing: light emission when going from an excited to non-excited state. Many, many materials exhibit some form of light emission when you shine a laser on them, provided that you shine with the right wavelength...
This is definitely not the field you're looking for. Anything like a nice invisibility cloak is probably impossible, but you would start here: https://en.wikipedia.org/wiki/Metamaterial
It's still way easier to mine bitcoin than it is to produce gold in any valuable quantities. Producing gold was already possible from heavier metals (platinum works reasonably well) but the process isn't exactly easy or automatable.
There's only a limited quantity of gold on earth so its value is more practical than any digital cryptocurrency as far as stability goes. Not that the current world economy cares a lot about stability though, as many economies use inflation compared to other currencies to maintain growth and take a certain spot in worldwide trade.
I mean relaying in something (gold price stability/limited quantity) that technology could eventually change dramatically from one day to another seems a bad move. But I guess that happens to everything anyways :) .
The platinum process seems interesting, any link/name about that?
Technology could also crack the bitcoin network, which seems more likely than people finding out how to produce gold more cheaply. What’s the actual risks of a series of successful double spend attacks? IMO, several countries have the means and could easily become motivated, alternatively hackers could have significant financial incentives or just do it for the lulz.
>"he idea sounds like magic, pure and simple. You create a light beam that can make substances vanish, give them properties they shouldn’t possess, or turn them into a perfect mimic of another substance entirely. It’s 21st-century alchemy, in principle capable not just of making lead resemble gold, but of turning ordinary materials into superconductors."
[...]
>"For a quantum mechanical system, the equivalent is to know how its quantum wave function evolves in time, which is determined by a mathematical function called the Hamiltonian. And there’s the rub — in all but the simplest systems, such as a hydrogen atom, the Hamiltonian becomes too complicated for researchers to calculate the dynamics of the wave function exactly."
In the absence of that knowledge — needed to calculate in advance what control pulse you need — the only alternative seemed to be trial and error: trying out some initial control pulse and then iterating it by running the same experiment again and again."
PDS: Take out the word "quantum" above.
Now, think about what we're dealing with as a system of multiple waves, multiple frequencies, except that we can't see them or have any other way of knowing what they are.
A "black box" of multiple waves, at multiple frequencies, in other words.
There's nothing quantum or magical about a system like that.
It's just a system where the input to get the output we want cannot be pre-determined, because we cannot know the exact state of a system at a given instant of time.
(Hey, sounds a lot like the Heisenberg Uncertainty Principle -- "we cannot measure the position (x) and the momentum (p) of a particle with absolute precision. The more accurately we know one of these values, the less accurately we know the other." I wonder if there's a relationship there?
Intuitively, my mind tells me that anything that science calls a "particle" today -- is really just the instantaneous snapshot of a wave packet of multiple waves at multiple frequencies, and this is why, and that the science of tomorrow -- will completely acknowledge this...).
So if we can't know ahead of time how to modify a system of waves to our liking, we have to experiment, use trial-and-error, and repetition, to have any hope of engineering the output to our liking... as is exactly true with any black box system...
But, getting back to a system of multiple waves, this gets into some other topic/problem areas around this subject...
Such as, how a wave can be used to read the vibration/oscillation/frequency of another wave, how that can be done in a system of many such simultaneously oscillating waves, fourier analysis, and how small can a process like that be scaled to, and what's the maximum frequency of waves that a process like that can be scaled to, etc., etc.
Which actually brings us back to "the collapse of the wave function"... (Could a wave A, given a wave B, collapse wave B's wave function? Then (if that gets solved), could a wave A given a series of waves (a wave system) collapse the wave function of that entire series/system of waves? Questions related to this area include such things as "how do you speed a wave up", "how do you slow a wave down", and things like the phenomenon of how strobe lights at the proper frequency can apparently "slow things" down, even "reverse" them (i.e., rotating fan blades)...)
When science reaches the point where we can read (and subsequently write/modify) any wave, at any frequency, at any distance, in any system of waves (without destructively interfering with all of the others) -- then we'll be at the borderline between a scientific civilization, and a magical one...
Perhaps today's quantum computers are early foray into this future knowledge and the possibilities it might hold...
"Any science sufficiently advanced is indistinguishable from magic"
This would be an awesome application towards waste disposal and recycling! Take a huge hunk of garbage, and try and rearrange all the atoms of it into something that can be reused as opposed to us leaving these in landfills. However it does make you wonder, would movie aliens really invade earth for water if they could just use a laser to create water from any other substance using its atoms and molecules?
Our science fiction us based on what we know and what we can dream. I think our modern dismissal of ancient alchemy has probably discouraged scifi writers away from scenarios where any other conceivable alchemy prevents the necessity of hunting resources across the cosmos. Sure, you can write anything in fiction, but you do things For Plot.
Iff this laser trickery worked permanently, then you'd basically have a prototype Star Trek replicator right there. Feed garbage in, out comes something useful.
If the laser trickery worked temporarily (say, on the timescales of minutes), then perhaps this could be a small step towards creating Star Trek style holograms. Vent inert gas in, reshape it into interesting stuff, pulse it up from time to time to keep it from decaying.
Though I imagine sensory and computational requirements of such a thing would hit the limit of what's physically possible in our universe.
Huge caveat if you read the article: “And no matter how successful the strategy is, these altered properties will persist only as long as you apply the control pulse.”
As long as you keep your garbage under billions on constantly active perfectly timed lasers, it works!
> Take a huge hunk of garbage, and try and rearrange all the atoms of it into something that can be reused as opposed to us leaving these in landfills.
The Second Law of Thermodynamics would like to see you after class.
