科学扩展我们对现实的视野Science Expands Our Vision of Reality
Brett：许多科学家和哲学家都讨论过多元宇宙的概念。但我们所说的，是对多元宇宙非常严格、非常清醒的理解。
多元宇宙中的所有这些宇宙都遵循同样的物理定律。我们说的不是那些有着其他物理定律的宇宙。
我们曾经以为，宇宙中的一切——其他行星、恒星、太阳、月亮——都在绕着我们的地球转。我们当时就生活在这颗小小的行星上。
后来，我们对现实的视野扩大了一点。我们意识到，事实上我们并不是宇宙的中心——太阳才是中心。我们还意识到，太阳和其他一些行星——木星、土星以及其他气态巨行星——都比我们的地球大。于是，我们的宇宙变大了。
后来我们意识到，在由数千亿颗恒星组成的巨大星系中，我们只是众多恒星系之一。再后来我们又意识到，这个星系又只是数千亿个星系之一。
思想史和科学史，就是我们不断拓宽视野、看清物理现实究竟有多大的历史。
多元宇宙正是这一总趋势的又一步，我们应该预料到这一趋势还会继续。人们应该不难接受，这就是理解世界的方式。
我们对量子理论以及多元宇宙的运作方式全都了解吗？不。我们还没有把多元宇宙与广义相对论统一起来。我们仍然需要一套多元宇宙的时空或几何描述。
Brett: Many scientists and philosophers have talked about the concept of a multiverse. But we’re talking about a very strict, very sober understanding of what a multiverse is.
All of these universes in this multiverse obey the same laws of physics. We’re not talking about universes where there are other laws of physics.
We used to think that everything in our universe—other planets, stars, the sun, the moon—orbited around us. We existed on this tiny planet.
Then our vision of reality got expanded a little bit. We realized that, in fact, we were not the center of the universe—the sun was the center. We also realized the sun and some of the other planets—Jupiter, Saturn and the other gas giants—were bigger than our planet. So our universe became larger.
Then we realized that we were just one star system among many in a huge galaxy of hundreds of billions of stars. Later we realized that this galaxy is one of hundreds of billions of galaxies.
The history of ideas and science is a history of us broadening our vision of exactly how large physical reality is.
The multiverse is another step in that general trend, and we should expect it to continue. It shouldn’t be that hard for people to accept that this is the way to understand things.
Do we know everything about quantum theory and how this multiverse works? No. We haven’t united the multiverse with general relativity. We still need a space-time or a geometry of the multiverse.