“The final stage in the life of a star,” observes physicist Carlo Rovelli in Seven Brief Lessons on Physics, “where the quantum fluctuations of space-time balance the weight of matter, is what is known as a ‘Planck star’. If the sun were to stop burning and to form a black hole, it would measure about one and a half kilometers in diameter. Inside this black hole the sun’s matter would continue to collapse, eventually becoming such a Planck star. Its dimensions would then be similar to those of an atom.
“We didn’t have birds in the very early universe; we have birds later on. We didn’t have time in the early universe, but we have time later on,” said Stephen Hawking’s colleague, physicist James Hartle, at the University of California, Santa Barbara about what came before the Big Bang.
“From the outside perspective, travel through the wormhole is equivalent to quantum teleportation using entangled black holes,” said Harvard physicist Daniel Jafferis, who has shown that although wormholes can exist, they are not highly recommended for space travel.
According to current measurements, the size of the cosmos must be larger than a hundred billion light-years. This is the order of magnitude of the universe we have indirect access to, writes physicist Carlo Rovelli. “It is around 1060 times greater than the Planck length, a number of times that is given by a 1 followed by sixty zeroes. Between the Planck scale and the cosmological one, then, there is the mind-blowing separation of sixty orders of magnitude.”