Future

I've talked about these issues before, but I thought I would explain the situation more thoroughly.

Two big questions remain for science to answer: One of these is if there is intelligent life out there in the universe. The other is what is the ultimate fate of the universe. Both of these questions might be answered in the future. I say this because we just don't have enough information to determine the answers to them yet.

After the invention of telescopes, astronomers began to see that the universe was much larger than they had once thought. This was especially true when Edwin Hubble discovered that the Milky Way was only one of many galaxies in the universe. Since then over 200 billion galaxies have been discovered. However, there are many orders of magnitude more of them in the universe. The current estimate is 2 trillion galaxies within a diameter of 93 billion light years. However, trying to determine the size of the actual universe is a problem because we still can't see to the actual edge of the universe.

This galaxy estimate is based on the Hubble Ultra Deep Field exposures and using math to multiply the number of actually seen galaxies by the overall cosmic field. There are efforts ongoing to actually plot the locations of the visible galaxies in order to create a 3D map of the universe. As you might know, finding the X and Y coordinates of an object imaged by a telescope is fairly easy. However, finding the Z axis coordinate is not as easy. The only practical method is to use red-shift to determine the distance to objects that are millions and even billions of light years away. This method depends upon the concept that the further galaxies are moving away from us, the redder their spectrum is. This is the familiar Doppler effect and the realization by Hubble that the universe is expanding. The further an object is away from us the faster it is moving away.

How is this the case?

Einstein thought that the universe was in a steady state and was neither expanding nor contracting. However, Hubble blew that idea up when he found that the universe was expanding. Recently, cosmologists have shown that the expansion of the universe is accelerating.

Most people think that this expansion consists of galaxies moving away from one another. This is not the case. It's not the galaxies moving away from one another, it's the fact that space itself is expanding. This is a very difficult idea to swallow, but it's the truth. Think of the universe as being a balloon on which you make little spots with a marker. When you blow the balloon up more, the spots move apart. This is a simple way to demonstrate the expansion of space, which would be represented by the surface of the balloon.

Space is actually like a matrix or fabric that's expanding because of some negative energy that cosmologists call Dark Energy. It's dark because they can't observe it. The crazy thing is that this expansion is accelerating faster the further away objects are. It's as if we are in the center of the universe and space is expanding in proportion to the distance from us in every direction. At the very edge of what we can observe this expansion is faster than the speed of light, which means that the light can't get back to us. The edge of the observable universe is all we know about. What's beyond is unknown.

An intelligent alien in a galaxy millions or even billions of light years away would consider that he or she was in the center of the universe and that the other galaxies were moving away. It's as if the center of the universe is impossible to find. There is no real center. That idea is mind-blowing!

Given this concept, the big question has to do with the final fate of the universe. If the universe keeps accelerating away then everything, including atoms, will rip apart. If instead, dark energy will weaken, the universe will eventually reach a steady state like Einstein thought. Star formation would eventually stop and as the stars die the universe would consist of black holes that would eventually evaporate. If the dark energy weakens enough for gravity to take over, the universe would begin to contract and eventually condense down into a humongous black hole containing a singularity that would reignite as a new Big Bang.

The Fourth fate is a quantum instability effect that's totally theoretical.

I can assure you that no one knows for sure what's going to happen. All three of these scenarios for the fate of the universe are valid. But, they are just theories without any solid evidence.

If you think this is wild, just consider something else. If the large asteroid that struck the Earth 66 million years ago in the Yucatan (Chicxulub) had been a few seconds later arriving, it would have hit in the deep ocean because the Earth rotates at 1000 miles per hour. The destruction would not have been nearly as devastating because it was the sulfur and other hot dust blown up into the atmosphere that caused a nuclear winter that made the Earth freeze over and kill large creatures like the dinosaurs and permit the little placental mammals to take over the Earth and evolve into us. In other words, we owe our existence to the perfect timing of the Chicxulub impactor.

The truth is that we here on this little planet are but a tiny spec in a universe that's so vast we have no clue as to how large it actually is or where we are in it. We just happen to have evolved to be intelligent enough to ponder these questions and someday even figure them out, assuming we don't destroy ourselves.

Thanks for reading.