A new formula allows computers to simulate how new materials behave up to 100,000 times faster than previously possible, and could drastically speed up innovation relating to electronic devices and energy-efficient cars. Princeton engineers came up with the model based on an 80-year-old quantum physics puzzle.
Llewellyn Hilleth Thomas and Nobel laureate Enrico Fermi first theorized in 1927 that they could calculate the energy of electrons in motion based on how electrons are distributed in a material. Knowing that kinetic energy of electrons in a material helps researchers understand the structure and properties of new materials, as well as how they might respond to physical stress.
But the Thomas-Fermi equation was based on a theoretical gas with electrons distributed evenly, and so it could not work for imperfect real materials.
Pierre Hohenberg and Walter Kohn, another Nobel laureate, managed to prove that the Thomas-Fermi equation could apply to real materials in 1964. But they only established the groundwork to prove the equation's existence.
Researchers have tried calculating each atom's energy from scratch to simulate how a material might behave, but simulations beyond just a few hundred atoms bogged down even the most powerful computers. That put a severe limit on the types of materials that researchers could simulate.
By contrast, the Princeton team stuck it out with the Thomas-Fermi equation. They eventually came up with a working model that could predict the kinetic energy of electrons in simple metals. A slight modification also allowed the model to also work for semiconductors, which find use in a wide variety of electronic devices.
"The equation scientists were using before was inefficient and consumed huge amounts of computing power, so we were limited to modeling only a few hundred atoms of a perfect material," said Emily Carter, Princeton engineer who led the project.
"Important properties are actually determined by the flaws, but to understand those you need to look at thousands or tens of thousands of atoms so the defects are included. Using this new equation, we've been able to model up to a million atoms, so we get closer to the real properties of a substance."
These new practical working equations should go a long way toward helping engineers realize the more futuristic concept vehicles, if they can run through many more material possibilities in the virtual realm. The saga also provides a good reminder that simulating atoms can prove just as challenging as modeling a star going supernova.
Neat. Maybe they can use this equation to develop new superconductors?
Too bad we can't use this type of brainpower to figure out how to feed people rather than reinventing technology that already works.Figuring out the unified theory won't feed people who couldn't care less.
"Figuring out the unified theory won't feed people who couldn't care less" - well, if scientists could help reduce the population growth there wouldn't be so damn many mouths that were hungry. The soon to be 7 billion people on this finite planet are in a slow motion self inflicted catastrophe. We will need all the technological help we can muster to deal with those here. Better yet if we can forestall the next one, two, three billion feared coming soon.
Funny how short-sighted and sentimental some people get when relating technology to something that has virtually nothing to do with said technology.
Tangentz007, I'm sure you donated to a charity which fights world hunger all the money you would've spent on luxury goods (a computer, books, cars, icecream, etc).
Forgive me but companies with large budgets and goals that have nothing to do with 'world peace' often donate to quite a few charities/non profits/etc. Unfortunately NASA doesn't have a large budget, but rest assured, it has made plenty contributions to society.
bah.sleep deprivation kills.
Disregard the NASA part, I forgot I just read an article on computer modeling.. everything else stands.
"Figuring out the unified theory won't feed people who couldn't care less."
A question for Tangentz007 and any others with this opinion is: "How do you know it won't?"
Amazing stuff. Shame is most of us will never have a hope in hell of understanding the equations!
getting a kinetic energy functional as a function of charge density (instead of the usual laplacian of wave function) is no more than a fitting process. This wont work for all materials, that is it is no longer "first principles" approach.
Oh wow, Eighty years is an awful long time to wait!
maybe they can calculate how much warmer the earth will be with 7billion people vs 6billion. All warm blooded engines running round are bound to heat the planet. ;-)
Dunno.. just call me crazy
I believe what must be the sound thinking in this case is energy savings on any scale and for multiple applications is always a logical endeavor in our power hungry world
It could help with new alloys and nano materials so maybe we'll get that space elevator we need.
"if scientists could help reduce the population growth there wouldn't be so damn many mouths that were hungry. The soon to be 7 billion people on this finite planet are in a slow motion self inflicted catastrophe."
you are a god damn hypocrite if you believe that
you are part of these billion of people, remember that next time you say "scientist need to be helped in finding a way to reduce population growth"
it's not science that will lower that, what could lower this is education, not some pills or whatever treatment
Yeah, Tangentz, things like materials science never benefit normal, hungry people. Lighter, stronger, safer materials for vehicles, transport packaging, and the like would never help reduce cost and energy use for producing food, transporting it to where people need it. or keeping it safe to eat longer. Nope, never happens. Those eggheaded theories never benefit anyone.