Here’s a brain exercise: scientists suggest that space time may be made up of individual “pixels of space,” rather than being as smooth and continuous as it seems.
Rana Adhikari, a physics professor at Caltech, suggested in a new press release that these pixels are “so small that if you enlarged them to the size of a grain of sand, atoms would be as big as galaxies.”
Adhikari’s goal is to reconcile the ordinary laws of physics, as defined by the general theory of relativity, with the more mysterious world of quantum physics.
This theory seriously boggles the mind and tries to explain whether gravity can really be divided into separate components, a question that has long plagued quantum physicists.
“Sometimes there is a misinterpretation in scientific publications that implies that quantum mechanics and gravity are irreconcilable,” Cliff Cheung, the Caltech professor of theoretical physics who works with Adhikari, said in a statement. “But we know from experiments that we can do quantum mechanics on this planet with gravity, so obviously the two are consistent.”
The devil, as always, lies in the details.
“Problems arise when you ask subtle questions about black holes or try to combine different theories,” Cheung added.
In other words, if you zoomed in on space-time, would you also find individual photons making up light, according to the laws of quantum mechanics? Or would it be a constant solid spectrum?
Some scientists suggest that individual hypothetical “gravitons” may constitute gravity at the smallest scales. Gravitons are a component of string theory that would resonate at a certain frequency.
But on even smaller scales, scientists are still puzzling over how to combine the laws of general relativity theory and quantum physics.
“If I drop my coffee mug and it falls, I like to think it’s gravity,” Adhikari says. “But just as temperature is not ‘real,’ but describes the vibrations of a bunch of molecules, spacetime may not be a real thing.
The same may be true of spacetime.
“It may be that something resulting from the pixelation of spacetime just got the name gravity because we don’t yet understand what the essence of spacetime is,” he added.