Thirty years ago, string theory vaulted from obscurity to the hottest thing in physics, thanks largely to a landmark paper from two scientists: Michael Green and John Schwarz.
While many of the basic ideas of string theory were around before 1984, there was not yet an indication that that this concept could tie all the physical forces of the universe together in a nice multidimensional bow. At the time, string theory was chock-full of mathematical anomalies; running the equations under different circumstances would give you inconsistent answers where you would have expected to reliably arrive at the same value.
But in the summer of 1984, Schwarz and Green finally found a way to make the anomalies vanish. The tangled, seemingly incoherent ball of string theory shifted into something more elegant—and enticing. The paper was an instant hit.
“I was well familiar with the fact that ‘anomalies’ were the main obstacle to using string theory to make more realistic theories of elementary particle forces unified with gravity,” says Institute for Advanced Study physicist Edward Witten. Once he saw the work, it was clear to him “that things would never be the same again.”
This “first superstring revolution” hinted that physicists were zeroing in on a way to reconcile quantum mechanics with gravity—something no other candidate for a “theory of everything” was able to do. And the implications were profound: Inside fundamental particles like electrons and quarks may lie tiny strings a hundred billion billion times smaller than an atom, directing the dance of reality with their vibrations.
To this day, Schwarz and Green’s work stands. “After 30 years, it is still the case that superstring theory is the only consistent quantum theory that contains gravity and has all the ingredients to make models of elementary particles,” says Caltech theoretical physicist Hirosi Ooguri. String theory still lacks observational confirmation—given the infinitesimally small scales and multiple dimensions involved, it’s not something that can easily be cooked up in a lab—but the numbers are in place. And physics hasn’t been the same since.
Image Credit: Flickr CC/Steve Spinks
Sign up for our free newsletter to see exclusive features and be the first to get news and updates on upcoming WSF programs.