Senescent Cosmos

Most of us know that the universe is old…very old. In fact, only in the last few years has science been able to nail down the birth date of the universe with any accuracy. We now know it all began 13.7 billion years ago. In fact, cosmologists are certain enough that they’re confident it wasn't 13.6 or 13.8 billion years ago, but quite exactly 13.7. Just a few years ago, cosmologists weren't sure but what the Big Bang's birthday could have been as little as eight billion years or more than 20 billion years ago. Progress occurs. Isn't it comforting to know just how long this universe has been around? Don't we all want to know our true age?

Science is always refining its knowledge. That's why it appeals to me. We humans think that we are the smartest kid on the planetary block—and maybe we are, but we need to stay humble enough to acknowledge that's there's always room for improvement in our understanding. That's what science is all about: constantly working to improve our limited understanding...realizing that if we keep our minds open and our questioning active, our knowledge will certainly grow.

A British team of cosmologists recently expanded our knowledge of star birth across the universe—and the news can be a little depressing, if we let it. Their bottom-line result: as of this date in the life of our universe, 95% of all the stars that will ever come alive have already been born. Forget how old the cosmos is or how much longer it has to go, it'll only see another measly 5% of its stars come into existence.

Just think if we were to say the same for the human race. We've been around as a unique species for only about 200,000 years. Of all the billions of people who have existed, if we were to have only another 5% to go, that's frightening! Terrifying! It says that we only have just another couple of hundred years to go, and that's the end of humans. Senescence has caught up with us and we are done!

Well, the same is true of the cosmos. What can ease our propensity to panic is that the stars live so incredibly much longer than we do. While Homo sapiens might last a few score years, your average star will hang around for billions of years. Time is relative.

Although cosmologists have nailed down the birth date of the universe, they have yet to get a handle on how long before it winks out. They are sure we have at least 100 billion years to go, and maybe trillions, before that last star dies. Well, that's a time span we flash-in-the-pan humans cannot begin to comprehend—let alone fret about.

Still, it's a sobering thought. Those British cosmologists determined that peak star formation in the universe was about 10 billion years ago, when the cosmos was just a 3.7 billion-year-old baby. At that point, half of all the stars that would ever be formed were burning. It's been downhill ever since. Go out and take a gander at the starry sky soon. In a few billion years it'll be a lot more sparse.