>There's one further type of brane in M-theory that is really surprising. This brane is the edge of spacetime. It's where space itself ends. Usually, in string theory, spacew can't end, any more than a string can end without a D-brane around. The space-ending brane is one of the wilder ideas in M-theory, but it's actually very well accepted. It turns out that there are photons at the edge of spacetime, much like the photons on D-branes. But the photons at the edge of spacetime participate in a particularly interesting theory called supersymmetric E8 gauge theory. A lot of work in the middle 1980s, after the first superstring revolution, revolved around folding this theory up in such a way as to recover the theories of electromagnetic and nuclear forces. It turns out that all this work has an M-theory interpretation in terms of spacetimes that end on a space-ending brane. The space-ending brane is one of the ways in which M-theory has moved decisively beyond eleven-dimensional supergravity.
please, /sci/ clarify: what did he mean by this?
(pic unrelated)
(also RIP steven gubser)
please, /sci/ clarify: what did he mean by this?
(pic unrelated)
(also RIP steven gubser)
