Researchers show how to transform materials using a finely shaped laser pulse

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.

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...

Gigantic caveat: “And no matter how successful the strategy is, these altered properties will persist only as long as you apply the control pulse.”

Alchemy is about transforming elements (regular metals into precious metals), which involves adding/removing protons and neutrons to atom nuclei.

GOOD POINT by my wife. What if we combine this with the lattice confinement fusion methods we’ve been hearing about?

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.

Gerard is a postdoc in my department. I am going to need to needle him about his 15 minutes of fame on HN.

Could this be used to lower the repulsion between atoms to make fusion require less energy?

Are there any materials that produce phosphorescence when targeted with laser?

Does anyone know if this would make it possible to have an invisibility cloak like the one in Harry Potter?

so they could temporarily make more exotic materials down the periodic table?

Gold is good to store value until you can create it. I guess that a good point to Bitcoin value

>"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"

-Arthur C. Clarke

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?