Dark energy, matter seen in new light

In the cartoons I watched as a child, issues of conscience were dealt with in a straightforward manner.

A haloed, miniature version of the conflicted character, would stand on one shoulder of the life-sized version, whispering wise, calm advice into one ear.

Another miniature version, wearing the horns of the devil and perhaps and cape and pitchfork, argued the case for mayhem into the other.

My mental conflicts these days seem not so much over good and evil as pessimism and optimism. And because I’ve suffered more hearing loss in my optimistic ear over time, I sometimes reach out to an optimist friend for help.

That explains in part why I was seated in the office of Wittenberg University Physics Professor — and former Ohio professor of the year — Dan Fleisch last week, picturing a halo over his head.

And I asked him: Is it right, Dan, that at least 95 percent of the universe is made up of stuff we can’t see and barely know anything about? And, using that calculation, can I conclude that the body of modern physics allows us to know about 5 percent more about the universe than your average ant?

Although I’ve since changed “ant” to “doorknob,” his basic answer was yes.

“Everything we can see, everything we would have described” before the time of Einstein and Edwin Hubble, “is only five percent” of the known universe, Fleisch said.

The rest is dark energy or matter, called that because “it doesn’t give off light or radio waves or infrared (radiation),” he said. “It doesn’t give off anything.”

We’re not totally in the dark about all of it, because scientists have long been aware that, like so many of us, the universe has a weight, or at least a mass problem.

After studying the movements of galaxies, scientists physicists concluded that their patterns of movement were somehow off — that some force was changing them in a consistent way.

Of the four forces we know, gravity was the likely explanation.

Using formulas going back to Johannes Kepler, they calculated the amount of mass that would be required to disturb those movements and called that mass dark matter.

“By watching gravity work,” Fleisch explained, “we can get mass.”

He called dark energy, which accounts for 70 percent of the universe, “a much more complicated matter.”

It’s needed to explain something that shocked scientists when they came to believe it about 20 years ago: the universe is expanding at a rate much faster than had been believed, in fact at an accelerating pace.

That amount of unseen “dark” energy is needed to explain the increasingly rapid expansion.

Hearing the tone of my voice when I suggested people only know about five percent more about the universe than ants, Dan delightfully, maybe even agreeably, disagreed.

“You should never be depressed by what we don’t know,” he told me. “Because the amazing thing is that we know anything at all.”

That, he said, is “a stunning achievement.”

And it’s an achievement, he said, that points to two other powers in the universe: the power of human curiosity and the power of the human imagination and mind.

Although sharks’ ability to sense an electrical field in searching for their prey is something we cannot do and something we should marvel at, he said, “a shark doesn’t have a deep understanding of that.”

We, on the other hand, do have a deep understanding.

Here, Dan began to tell the story of his summer visit to another dark place: a cave in Spain.

Drawn there by his own curiosity and his fiance, Fleisch got a rare chance to see a 40,000-year-old painting of a horse.

To see to paint it, “they used some kind of bones with gristle on them” as light, he was told.

More amazing is the artist’s artistic decision to paint the horse’s chest on a projection of the cave that mimicked the way a horse’s chest projects from its body.

The artists didn’t have sophisticated tools. And how they rigged a scaffolding to get high enough to paint the horse, Fleisch doesn’t know.

“But they had brains,” he said, “and they were really smart.”

“There’s no other species making these kinds of drawings,” he said — drawings that represent a model of what they see in the world, much as scientific theories are models of what moderns see in the world.

For Fleisch, that glimpse of human genius of 40,000 years ago was “almost life-changing.”

It was as if a miniature Dan Fleisch wearing a halo had stood on my shoulder and shouted loudly enough that my bad ear could hear him.

A moment later, it had sunk into my own mind.

“Isn’t it astounding — even awesome — that the brains capable of such understanding are cobbled together from the ingredients of the expanding universe itself?”

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