Is the universe infinite?
There’s been new news around the beginnings of the universe recently, specifically related to the Big Bang:
The scientists say they have found the first direct evidence of things called gravitational waves. These were predicted by famous scientist Albert Einstein almost 100 years ago, but experiments had so far failed to find any evidence for them.
The BICEP2 experts have been studying something called the cosmic microwave background radiation (CMBR). This is like a faint glow of heat left over from the Big Bang, and gravitational waves should produce a particular twisting pattern in the CMBR. This is the pattern that BICEP2 has found.
Ostensibly, what that means is that scientists found evidence — or an idea around, at least — of what the first 1/trillionth of a second of our universe’s existence may have been like (rapid expansion). That’s a fairly cool scientific advancement.
Whenever new information comes to light about the origins of the universe, I always try and figure out — as if I ever could — whether the universe is infinite. This is obviously a hard concept to grasp as a human on Earth — essentially, how can something just keep going and never end? — and also ties back to the idea of whether other intelligent life could exist in other universes that we can’t even see. In general, what Earth can see is a radius of about 46 billion light years — but there must be something beyond that, no?
Here’s a complicated way of looking at it, via a 2001 interview:
ESA: Then how are we going to know whether the Universe is infinite?Joseph Silk:
With great difficulty! We may never know it. If the Universe is finite, that means that in a two-dimensional geometry it would be like a torus. Now, think about a torus. In such a Universe, light travelling on the surface of a torus can take two paths: it can go around the sides but it can also go in a straight line. This means that if the Universe is like a torus, light can have different ways to get to the same point. You can have a long way and a short way. And that would not be true on a plane. But a torus means that space is more complicated. It would mean that when you measure the CMB you will see strange patterns on the sky, because the light from far away would not have come to us in quite a straight line because of the topology of the Universe. So the hope would be, eventually, to look for those strange patterns on the sky.
This will probably sound stupid, but what’s amazing to me consistently is that some of the biggest, most important things about our existence — i.e. the beginnings, whether we’re alone in the universe, the entire science behind the oceans (74 percent of our planet), etc. — are things that we’ve made strides on but ultimately really don’t know. That actually kind of feels like it could be proof of a “higher power” in some ways.
If you can get your head around the concept of the universe being truly infinite – and honestly, if we’re talking about 100 billion light years as a radius and 200 billion as a diameter, that’s essentially infinite because most humans will never have the chance to see out that far — then it comes back to the idea of “other intelligent life,” i.e. “how Hollywood keeps thriving.” Scientists now know that there are about 100 billion planets in our galaxy, with more small planets (i.e. Earth) than massive planets (i.e. Jupiter), meaning there’s a chance for life somewhere (maybe on about 10 billion such planets). It’s likely that the life would just be weird-type fish and not necessarily intelligent, civilized life… but again, you never know. The assumption is that it’s reasonable to assume intelligent life does exist somewhere.
So now wrap your head around those two things: (1) the universe may never end and (2) somewhere else that we haven’t seen yet, there could be a family exactly like yours — although maybe with adaptations for their climate needs — going about their life in their own way. I realize I just painted some kind of bad sitcom premise or something, but with how much we already don’t know about all this stuff, couldn’t it be right?