End of ‘Our’ Universe

Today I read an interesting article on Space.com, about how a theoretical astrophysicist named Abraham Loeb has arrived at the conclusion that in about a hundred billion years or so, galaxies in our universe will travel at or beyond the speed of light, and thus no longer be visible to each other. Loeb’s theory would make it theoretically impossible to send or receive signals from distant galaxies, let alone travel to them or even observe them, once galaxies have reached this speed. This theory presents some interesting questions – not just about science, but also about religion, and I thought I’d share them …

First, I’m not completely sold on Loeb’s theory.[1] That being said, I would like to entertain some of what was written in this article, which builds on Loeb’s theory and asks questions about what what life would be like if some race of intelligent beings managed to survive. The article is interesting in this regard, because it describes the galaxies / galactic clusters as being island-like, in that one island wouldn’t be able to see or detect the existence of other islands, since the island would be traveling faster than the light allowing us to see any of the other islands. Essentially, if another human-like race of beings were to become space-aware at around this time (let’s say their equivalent to our Galileo uses their first telescope to look at moons in orbit around a nearby planet), they would soon discover that they lived in a galaxy with no hope of ever detecting anything outside that galaxy (making even the concept of ‘galaxy’ irrelevant). According to this article, even the evidence for the Big Bang would essentially be erased to them.

If that were to happen, what would their astronomy be like? Their science would, like ours, have to try to explain the things and effects they can observe: if you live in a galaxy that’s blind to any other galaxy, you have no way of detecting the existence of other galaxies, and the space you can detect outside of your galaxy is devoid of light, x-rays, everything, how do you describe your universe? With no point of reference outside of your galaxy that you can detect, you can’t even judge the speed your galaxy is traveling at, or if it’s traveling at all! And if you were able to somehow jump on a spaceship and journey outside of your galaxy, your galaxy would be gone before you knew it … you’d possibly have what the first article describes as a ‘frozen image’ of your galaxy, but that would be it, your home would be gone and you would eventually be floating around in perpetual nothingness.

What theories about the beginning and end of the known universe would such a civilization come up with? How would those theories differ in accuracy with the theories we currently have? When we talk about whether or not we are alone in the universe, we can argue with statistics that the likelihood of our being alone is, well, not likely – we pull these statistics from the estimated number of stars in our observable universe. To get an idea of how many stars we’re talking about, we can do the math from the numbers given to us in this entry about galaxies: average galaxies have from ten million, to one trillion stars, with an estimated one hundred billion galaxies in the observable universe. For the record, using the lower number of stars per galaxy, that’s 1,000,000,000,000,000,000 (one quintillion) stars in the observable universe, which is likely only a fraction of what’s actually out there. With that many possibilities, we can be reasonably confident that we aren’t alone, and we have at least the idea that the universe is wildly huge, with unbelievable amounts of stuff in it. We might almost take these things for granted, with such numbers. Imagine now the mentality where you live in a galaxy where you have absolutely no evidence at all that there is anything beyond your galaxy. Do you have feelings of superiority, loneliness? We have to try to reckon the size of the universe on near-infinite levels – people living in galaxies that outran light would probably see the universe as being no larger than their own galaxy. So would you have feelings of confinement, if you lived in such a galaxy? Since you know that stars eventually die, you would also know that eventually, the lights in your ‘universe’ would go out.

What would reality be like, if that were us? More importantly, how would something like this affect religious outlooks? To me, if a civilization lived under such conditions, the science they would have to create to explain what went on around them would be as valid as our own science is. This got me to thinking about religion, and the degree to which one’s reality affects their religious outlook. I think we talk a lot in the blogosphere about how religion affects our reality; but how could something like this affect our religion? Let’s bring this question out of the scale of the universe, and limit it instead to personal reality – how does our own reality affect our religion? I don’t think it matters which religion we are talking about: Heathens, Pagans, Christians, Muslims or Buddhists should feel more than welcome to share thoughts about this. Some of us have money, others don’t, some grew up with minorities while others grew up as a minority, some are gay while others are straight, some grew up with board games while others grew up with video games – how do things like this affect our religious expression? Can we speculate how such things have affected followers of our various religions throughout history? Just as I suggested that different realities might justify different – though equally valid – sciences, could we say that personal realities justify different, equally valid religious beliefs? What about when personal realities (and thus religious beliefs) clash with consensus realities – and at what level do we define consensus reality, two people, ten, a thousand? I look forward to reading everyone’s thoughts on these things ….

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[1] Another theory, Einstein’s theory of special relativity, makes it pretty clear that as objects with mass accelerate, their mass increases. An object like a galaxy, breaking the barrier of the speed of light would, according to this theory, achieve infinite mass. Also, because of the equivalence of energy and mass, the faster an object moves, the harder it will be to increase the object’s speed. With infinite mass comes infinite density, and we must also remember that gravity is related to mass. The only way I’m aware of objects with mass achieving speeds greater than the speed of light is through the action of black holes, and oddly enough, Loeb borrows from black hole terminology when he describes the ‘event horizon’ as the point where galaxies crash into the speed of light (it’s usually used to describe the boundary of no return that surrounds black holes) … appropriate, since as far as I’m concerned, black holes are what galaxies would have to turn into in order to achieve that kind of speed (keeping in mind that once they achieved this speed, they would have achieved infinite mass, which would create enough gravity to overcome and reverse their expansion).

The other thing to remember with this theory is that it’s thought to be pretty common to find supermassive black holes at the centers of galaxies (there is one thought to be at the heart of our own Milky Way, called Sagittarius A, for example). If this is true, then the achievement of infinite mass would seem to apply to the black holes, as well.

Not that I have a problem with the idea of everything turning into black holes – far from it, I’m convinced that this is what will eventually happen, that the black holes will gobble each other up and form a single, ultra black hole containing all the matter and space-time of the universe, which will then explode and create a new universe, just as I suspect happened before what we now call the Big Bang (I do not think the universe we now find ourselves in is the first one, nor do I consider it to be the last – essentially, I think the entire universe reincarnates). Looked at this way, Loeb’s theory actually reinforces my own personal theory of inward expansion (the inspiration for this blog’s title); especially since determining the direction in which the universe actually expands would be about like trying to find the beginning or end of a Möbius Strip. My real problem with Loeb’s theory is that he seems to believe galaxies (and the matter they contain) would actually remain intact at those speeds, and I can’t figure out from what I’ve read so far how that would be possible.