The University of Manitoba will be hosting a free public lecture on Friday March 23rd, 2018 at 3:30 pm in the Robert B. Schultz Theatre. See here for more details.
Dr. Virginia Trimble (aka 9271Trimble)
Prof. of Physics and Astronomy, U. California, Irvine Honorary staff member, Queen Jadwiga Observatory, Rzepiennik Biskupi, Poland
FROM ONE TO MANY: OR, HOW BIG IS THE UNIVERSE?
As is the case with many questions, the answer to this depends on who(m) you ask and when! Most of the early cultures of which we have any records thought that the Earth was the Universe, one that a human could cross in a lifetime and a god in a day. The intervening years have seen our best guesstimates of “How many?” and “How big?” grow to include numbers with 10 or 20 or 30 zeros after them. And whenever one groups has said “one,” (solar system, galaxy…) and another group has said “many,” the many’s have won. Sometimes it takes a while. Thomas Digges proposed in 1600 that the stars were suns with planets. He was right, and we now know many thousands, a number that will surely grow for as long as we keep looking for them. Similarly, debates between large and small cosmoi and long and short ages have been won by the large and old teams. Even light takes about 46 billion years to cross the part of the universe we can study; observations guarantee that the total size is much larger than the part we can study, and may be infinite. This does not rule out there being other universes, other space times, probably with three spatial dimensions and one time, like ours, but perhaps very different forces and kinds of objects. Since the historical trend has always been toward more, bigger, and different, I think many universes, in one sense or another, is surely the best bet.
Welcome to the multiverse!