A Golden Age of Science

Artist's rendering of the collision of two neutron stars (Carnegie Institution for Science)

The other day I happened to watch a video of the Young Earth creationist Ken Hovind asserting that there is no known way the universe can generate uranium. Of course, he rushes through a litany of other half-true or completely false “science” facts to astound and amuse his audience, and I won’t delve into them now. But his claim about uranium is worth talking about because it’s relevant to an astonishing event that we just detected from far away in the cosmos.

On August 17, 2017, humanity crossed a brand-new scientific frontier. At 8:41 a.m. Eastern Daylight Time, the gravity-wave telescope known as LIGO, with its two halves spread across the United States (one in Washington State, one in Louisiana) detected a pulse of gravitational energy flying by Earth. Two seconds later, NASA’s Fermi Gamma-ray space Telescope was drenched with gamma rays from the same exact spot in the sky. That spot, located 130 million light-years away, was in the disk of a distant galaxy we call NGC 4993. Within twelve hours telescopes across the globe (and circling it) pointed at the same distant patch of the universe. Scientists obtained light spanning the electromagnetic spectrum, from radio waves to infrared radiation and on through to visible light, X-rays and the aforementioned gamma rays.

Image via NASA and ESA

Longstanding theoretical models about the way heavy elements like gold, platinum, uranium, and some others are formed have ruled out may options. Stars cannot make these elements during their lifetimes of energy-liberating nuclear fusion. Even when large stars die and are blown to smithereens as normal supernovas (as if there’s anything “normal” about a thermonuclear explosion releasing billions of suns’ worth of energy), they don’t generate several of the heaviest atomic elements. That’s because the intense radiation they emit doesn’t last long enough to smash heavy atoms together into still-heavier sorts. Instead, scientists have had a different idea about where these come from: they believed they could only derive from neutron stars smashing together and shattering one another. Within days of the August 17 event, scientists were able to read the characteristic colors of light associated with it, and they found clear evidence that gold, platinum, and other heavy elements resulted from the explosive event. Also, the gravity-wave signature, lasting about 100 seconds, was consistent with two colliding neutron stars. Thus, another mystery about the origin of some of the most prized elements in nature was solved.

This discovery is the first time in human history that we have received information about the same event from both light waves and gravity waves. It will certainly not be the last. The field of gravity wave astronomy is brand new, although it already garnered a Nobel Prize in Physics, announced last month. As the field matures, we’ll be afforded a new window into some of the other great mysteries of the cosmos, perhaps including new information about the conditions during the Big Bang. It is likely to herald a new golden age of scientific discovery. Ken Hovind and his ilk may be content to feel awe in response to mysteries glanced at but not deeply considered. Others of us feel the same awe, but it’s enhanced not by deference to magic, but by the incredible fact that nature has proven to be progressively and consistently understandable.

That’s a key differentiator between science and mysticism. Instead of inventing a god or a miracle to explain a phenomenon, scientists try to assemble plausible explanations for natural events and objects that don’t violate any other known laws of nature. These scientific hypotheses are then compared to the results of measurements performed on controlled experiments or taken from natural phenomena that we cannot synthesize—like colliding neutron stars.

There are indeed mysteries about many things in our universe, but that old philosophical chestnut, the god of the gaps, has never been a reasonable or effective way to come to terms with these mysteries. Asserting that there is some sort of magic is tantamount to walking away from the puzzle and intentionally removing it from scrutiny. Instead, when we see a glittering gold ring, if we pursue the chain of questions far enough and deeply enough, we’re eventually led to the discovery of gravity waves, of neutron stars a few miles across encompassing a whole star’s worth of mass. Eventually, logical and scientific reasoning leads us to look carefully at nature and watch for the signs of colliding neutron stars. We humanists are never surprised to learn that the universe continues to provide evidence of understandable, wholly natural processes at work across vast scales of time and space. We may not be surprised, but we are filled with awe and delight regarding the fantastic machinations of nature. We are, after all, human.