In this week’s Radio Lab podcast, Robert Krulwich interviews Columbia University physics and mathematics professor Brian Greene about theories of the multiverse and the ever-expanding nature of space. Midway through, Greene makes this interesting point:
The thing to remember is that when Einstein established that nothing goes faster than the speed of light, what he really established is that nothing can traverse space at a speed greater than the speed of light. But his equations full well allow space itself to grow at any speed. Bigger than the speed of light is perfectly fine.