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Wednesday, October 5, 2022
Dr. Brown: Newest space telescope could connect us to Earth’s past and future
Dr. William Brown
Dr. William Brown

The James Webb space telescope was launched with much fanfare on Christmas Eve to take up station a million miles from Earth, where the gravitational forces of the sun, Earth and moon acting on the telescope cancel one another out.

Twenty-five years in the making from conception to launch, this technological marvel has two main goals over the next decade. The first is to understand the role of dark matter and black holes in the creation of the first generation of stars and galaxies about one million years following the Big Bang.

Hubble, the famous predecessor to the Webb telescope, was by design, ill-equipped to explore this very early period because Hubble was designed to detect visible light signals, not light signals stretched into the infrared range by the early, expanding universe.

For precisely that reason, the Webb telescope was expressly designed from the outset to pick up the faintest signals in the infrared range, while carefully avoiding any extraneous signals in that range created by the sun, moon or Earth by covering the back of the telescope with a gigantic tennis-court-sized shield, pointing the collecting face of the telescope away from those celestial bodies and taking extraordinary steps to avoid any signals in the infrared range being generated by the telescope itself.

The result is a masterpiece of engineering well capable of exploring the early universe.

The second goal of the Webb telescope is to step up the search for planets that might support life in the Milky Way and beyond – not blisteringly hot such as Venus or too frigid like the outer planets in our solar system – and possessing the right mix of life-friendly elements. The latter include hydrogen and oxygen (think water here), carbon, nitrogen, phosphorus, sodium, potassium, chloride, calcium, magnesium, copper and iron.

Carbon is the one element, which, more than the others, is most capable of forming stable, but not too stable, bonds with other elements essential to carbon-based life and without which RNA, DNA, proteins and other organic compounds would not have been possible. In that sense, carbon is the matriarchal bond-making element. The other essential, of course, is water – preferably in liquid form.

However simple they look compared to nucleated cells, bacteria and archaea are far from simple. They possess complex developed energy systems and hundreds, sometimes thousands, of genes. That complexity must have taken hundreds of millions of years – perhaps even a billion years or more – to evolve and make the simplest cell complex.

But however chancy it may have been, life on Earth from the simplest to the most complex is living proof it can happen. And if life developed here, given the math and the laws of physics and chemistry, why not elsewhere?

Current conservative estimates suggest there are roughly 300,000 planets in our Milky Way alone that could support life. Given other estimates that there might be as many as two trillion galaxies, the math suggests there could be many trillions of habitable planets.

That’s a staggeringly huge number and strongly suggests to me, at least, that even if the chance of life emerging on any "life-friendly" planet was as low as one in a billion or perhaps as chancy one in a trillion, that still leaves a lot of planets with life, if not now, then in the past or in the future. And if that’s true, we are definitely not alone.

Which leads me to conclude that life probably exists in many places in the universe, even if, as was the case for almost two billion years on Earth, only at the single cell level.

Of course, the big question is whether life might have evolved or will evolve to achieve an intelligence akin to or exceeding our own. To which, again the numbers again suggest, why not?

That’s a question the Webb telescope and studies yet to come might help to solve in our continuing search to better understand an enormous expanding universe of which Earth is but a tiny, tiny part of the whole.

Humans are, after all, a compulsive story-creating and storytelling species. By far the greatest story ever told might turn out to be the discovery of carbon-based life beyond our pale blue planet, as Carl Sagan so elegantly described Earth three decades ago.

Dr. William Brown is a professor of neurology at McMaster University and co-founder of the InfoHealth series at the Niagara-on-the-Lake Public Library.