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| Shaped by string theory. |
Supergoop universe offers a window into glassy physics: There are no atoms here. Instead, there are black holes that stick together to form bizarre versions of molecules. Let the black holes settle down, and you get something that looks like a solid but acts like a liquid. Welcome to the supergoop universe. This hypothetical reality derives from string theory, which allows for a large number of possible universes, each with different physical laws.
It might sound like no more than a physicist's daydream. Supergoop can't be created in our universe, and string theory in general is famously difficult to prove. Still, the idea could be useful whether or not string theory is true, as it may help us solve the dual nature of glass.
The supergoop universe has many forces beyond the ones we experience, which means it has particles we have never seen. It also has supersymmetry, so all those particles have superpartners of the same mass. This stops atoms from forming, because supersymmetry doesn't allow for complex enough configurations of the particles.
There is gravity, though, and sometimes the exotic matter can collapse into black holes. The multitude of forces gives these black holes many different charges, letting them take on the role of atoms which clump together to build molecules. Some of these could even be complex enough to form the basis for life (see "Is there a supergoop cradle of life?").
"The way you get different black hole molecules is by altering little microscopic details of string theory," says Jacob Barandes of Harvard University. "If you have lots of these little black holes and toss them in the air and fiddle with them, they exhibit goopy behaviour." Let the black holes relax gravitationally into their basic, stringy components, and you get supergoop.
How does this help us understand glass? To our eyes, glass looks like a solid, but at the molecular level it resembles a liquid, with molecules arranged not as a tidy crystal lattice but in a disorderly fashion. The trouble is, no one knows how molten glass settles down into this dual state. "That's surprising, that to this day there is no good theoretical model of the glass transition," says Tarek Anous of the Massachusetts Institute of Technology.
That's where the black-hole molecules come in.
Anous, Barandes and colleagues first proposed supergoop in 2011, when they also described how black-hole molecules could offer an easier way to model the behaviour of glass. "There are a number of features of the black hole case that make it mathematically easier to study them," says Barandes. "The physics is exotic but the math is simple." Last week at MIT, Anous presented results that provide fresh reasons to believe the analogy holds, and that the behaviour of glasses is nicely mimicked in supergoop.
It might sound like no more than a physicist's daydream. Supergoop can't be created in our universe, and string theory in general is famously difficult to prove. Still, the idea could be useful whether or not string theory is true, as it may help us solve the dual nature of glass.
The supergoop universe has many forces beyond the ones we experience, which means it has particles we have never seen. It also has supersymmetry, so all those particles have superpartners of the same mass. This stops atoms from forming, because supersymmetry doesn't allow for complex enough configurations of the particles.
There is gravity, though, and sometimes the exotic matter can collapse into black holes. The multitude of forces gives these black holes many different charges, letting them take on the role of atoms which clump together to build molecules. Some of these could even be complex enough to form the basis for life (see "Is there a supergoop cradle of life?").
"The way you get different black hole molecules is by altering little microscopic details of string theory," says Jacob Barandes of Harvard University. "If you have lots of these little black holes and toss them in the air and fiddle with them, they exhibit goopy behaviour." Let the black holes relax gravitationally into their basic, stringy components, and you get supergoop.
How does this help us understand glass? To our eyes, glass looks like a solid, but at the molecular level it resembles a liquid, with molecules arranged not as a tidy crystal lattice but in a disorderly fashion. The trouble is, no one knows how molten glass settles down into this dual state. "That's surprising, that to this day there is no good theoretical model of the glass transition," says Tarek Anous of the Massachusetts Institute of Technology.
That's where the black-hole molecules come in.
Anous, Barandes and colleagues first proposed supergoop in 2011, when they also described how black-hole molecules could offer an easier way to model the behaviour of glass. "There are a number of features of the black hole case that make it mathematically easier to study them," says Barandes. "The physics is exotic but the math is simple." Last week at MIT, Anous presented results that provide fresh reasons to believe the analogy holds, and that the behaviour of glasses is nicely mimicked in supergoop.
But not all glass researchers are ready to embrace the goop. "There's so much understanding that needs to be done about structural glasses with real-world chemistry," says John Maur of the Corning glass company in New York. "I think the best efforts are geared towards understanding the actual glasses made out of real atoms."
Is there a supergoop cradle of life? According to string theory, there is an alternate "supergoop" universe where black holes form molecule-like structures. So could this universe give rise to black-hole-based life? Tarek Anous of the Massachusetts Institute of Technology thinks so. "There's no reason why you can't create arbitrarily complicated stuff out of supergoop," he says. That throws up a philosophical stumbling block.
In the string theory multiverse, anything you want to happen can happen if you pick the appropriate universe. That raises an enigma: why do we live in our universe, not in a different one? If you change any of the fundamental constants in our universe, we wouldn't be here to observe it, but we don't know why the universe should be so well suited to us. It becomes tempting to think our universe is special, and that makes physicists uncomfortable.
"Then the onus is on the physicists to explain why it seems we're so special," says Anous.
Supersymmetry almost provided an answer. Some theorists suggested that universes with a low degree of supersymmetry – probably including our own – are the ones that can give rise to atoms, molecules and complex life. In that case, a whole class of universes might have life, and we would not be special.
Now it seems supergoop could give rise to atoms too, and it exists in a highly supersymmetric universe.
The goop also means we are not special, but it erases the possible explanation, and it presents a whole new riddle, Anous says. "Then you can ask, why aren't we supergoop?"
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