It seems that just yesterday the dinosaurs were fooling around with Pangea’s canyons, living their last misunderstood moments before an asteroid changed everything. You don’t really notice it as it happens, but 65 million years pass pretty quickly.
At least it does in the grand scheme of things. The universe lasted about 14 billion years according to the Big Bang Theory. In this context, 65 million years is just a few flakes of sand in a giant hourglass.
And that’s all the more scary to read a preprinted research paper suggesting that our universe can only 65 million years of expansion remain miserable.
Once that expansion is over: it’s lights. The universe will transition to a (hopefully) slow contraction until it becomes a single infinitesimal point made up of all the matter that once was and will ever be.
At this point, scientists say, the Big Bang will take place. Again.
Broken clock
The truth of the matter is that we have no way of knowing whether and when the universe will end. It’s not that we don’t have the technology. We don’t have the perspective.
When we look up at the stars, we look at light that has traveled for millions or even billions of years. Some of those stars don’t even exist anymore.
However, by observing these distant lights we can determine that the universe is expanding. And, in a series of simulations, scientists have used that data to try to figure out whether this expansion is infinite or whether some universal calculation will come.
To that end, a team of Princeton and NYU scientists recently published preliminary research article describing the problem. According to them, if dark energy is responsible for the expansion of the universe, it is likely that the energy could decrease and lead to contraction.
According to their paper:
If dark energy is a form of quintessence driven by a scalar field evolving along a monotonically decreasing potential that passes well below zero, the universe is destined to experience a series of smooth transitions: the currently observed accelerated expansion will cease; soon after, expansion will end completely; and the universe will pass into a phase of slow contraction.
Basically: the universe gets bigger, then it gets smaller.
However, as mentioned above, we cannot know when that will happen. All we can do is guess.
According to scientists:
The problem is that accurate cosmological measurements of the rate of expansion and other cosmological parameters are based on observations of the cosmic microwave background, baryonic acoustic oscillations, and distant objects such as supernovae whose detected light has been emitted long in the past, as we have shown. the transitions to slowdown and slow contraction can all occur within a small fraction of Hubble time. Therefore, it is a challenge to detect the end of a contraction even when the time is near.
And that means, for all we can say, the universe could continue to expand for billions of years. Or, perhaps, the time is near.
La Physics arXiv Blog describes the researchers’ time frame as follows:
In one scenario they say that the minimum time remaining before the end of expansion is approximately equal to the period since life existed on Earth. That’s 3 or 4 billion years.
In another scenario, they calculate that “the time interval remaining before the end of acceleration is less than the time since the Chicxulub asteroid brought an end to the dinosaurs.” That’s only 65 million years old — the blink of an eye in cosmological terms.
The end of days
Right now, that 65 million year time frame is just a guess. But if we could definitively determine that our universe has such a short time before it begins to contract, the ramifications of this knowledge could have immediate, far-reaching effects on humanity.
It would basically mean that we would never find extraterrestrial life. This simply boils down to probability: if we look at 65 million years as the final few flakes in the hourglass of our universe, we have to admit that time is almost over. all living beings.
If we haven’t found each other so far, the probability is mathematically against it ever happening.
Between an expansion spreading us and a contraction ultimately resulting in everything in the universe being compressed to a single point, it can even be pragmatic to give up the search all together and focus on something else. We could use our space resources to advance the goal of spreading life on Earth across the galaxy, for example.
The universe may have little time, but it is worth making sure that we are all there to watch the grand finale. That is, of course, unless the world really ended in 2012.
Scientists also claimed that the expansion and contraction of the universe was cycle, meaning that another Big Bang is probably coming soon.
On the bright side, this would mean that there will almost certainly be life again after we are gone. But, on the not-so-bright side, it also makes it less likely that life is fruitful.
With such a tiny window for life to miraculously emerge during each expansion and contraction, planets like Earth could be once-in-a-a-Big-Bang events.
Source
Tristan Greene