Sunday, May 6, 2018

Is This the Way the World Ends?

Astrophysicists feel like they have a pretty good handle on how the universe began. Nearly 14 billion years ago, a quantum fluctuation randomly popped into being and expanded rapidly, at times even faster than the speed of light. All matter and energy and the laws of physics for the entire universe came into being with that quantum fluctuation, that we now call the Big Bang.
While there is debate on some of the details of this Big Bang theory, the basic picture is accepted by the vast majority of scientists. The ending of the universe is open to far more speculation. Our universe is still growing larger from that Big Bang beginning. And evidence points to the expansion rate increasing, due to some mysterious, unknown force we call Dark Energy. Some astrophysicists think it may expand forever, galaxies simply moving farther and farther apart until our Milky Way becomes totally isolated in the universe. Others think that expansion force is so great, it will eventually rip the galaxy apart, then our solar system, ourselves and, finally, atoms themselves. Ultimately, those scientists say, the universe will consist nothing but a very cold sea of low energy photons.

Some astrophysicists argue that the expansion eventually halts, and the universe starts to collapse, perhaps back to the singularity it all started with. Some think the universe will bounce from that collapse, leading to another Big Bang, one of an infinite successions of such beginnings.
In a recent study led by Anders Andreassen, a physicist at Harvard University, the study scientists claim the universe’s final moment will be triggered by bizarre consequence of subatomic physics called an instanton. An instanton is one solution to equations governing the motions of subatomic particles. An instanton can create a tiny bubble that will expand throughout the universe at the speed of light, swallowing everything in its path. Instantons create this bubble in the Higgs field, the quantum field that gives us the newly discovered Higgs boson and which imparts mass to all subatomic particles.
"At some point you will create one of these bubbles," Andreassen says. "It will be very unpleasant." For ‘unpleasant’ read ‘the end to all life and all chemistry as we know it.’

No need to sit and worry about it, though. Although it could occur tomorrow, the odds are that the universe has a lifetime of somewhere between 10 octodecillion years (one with 58 zeros after it) and 10 quinquadragintillion years (one with 139 zeros after it). Just like the world-busting, giant killer asteroid with Earth in its crosshairs, it’s not likely to happen in our lifetime. It likely won’t occur within in the lifetime of our solar system, probably not even in the lifetime of the Milky Way galaxy.
But it is coming, sometime, to a universe near you.



On the first Tuesday of each month, I write an astronomy-related column piece for the Oklahoman newspaper. On the following day, I post that same column to my blog page.

This is reprinted by permission form the Oklahoman and newsok.com.

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