I recently listened to The 4% Universe by Richard Panek and then returned to A Universe From Nothing by Lawrence Krauss. The story of how we discovered both dark matter and dark energy, and what these two mysteries might mean for our future, is breathtaking, a brilliant story of scientific exploration and surprise. What sticks out the most for me from this tale was something David Deutsch wrote in The Beginning of Infinity. The universe is filled with evidence.
When scientists found that they could not only see supernovae in distant galaxies, but actually monitor them over the course of days and weeks, and that this monitoring program would reveal information about the actual distance of the supernovae, they were taking advantage of this richness. Consider, the light from these supernovae has been part of the light striking our planet for millennia. That light is even now falling on our rooftops. Information is everywhere. All we need to make use of that information is a good idea (or, really, several of them).
And that brings me to the point of this entry. I think Lawrence Krauss is a fine writer and scientist, and I agree with him on many things. But after The Beginning of Infinity, I find that certain of his attitudes strike me as clearly misguided. Krauss likes to say, “We live at a special time, the only time when we can know that we live at a special time.” What he means is that in the future all evidence of dark energy, universal expansion, and all the other amazing discoveries we’ve made in the last 100 years or so, will have disappeared over the cosmic horizon. Cosmologists, if there are any a trillion years from now, will have no way of knowing that they live in an expanding universe dominated by dark energy. Even worse, as their one remaining galaxy cluster slowly ages, the visible universe, and any life it contains, must blink out until all is cold and dark.
This is unduly pessimistic, on several accounts.
Firstt, why does Krauss assume that our knowledge will die? Why couldn’t it be that our discoveries of the past 100 years will spread, along with our technology and in some form ourselves, to the far reaches of our galaxy and even beyond? The shortness of human life is no real barrier, as death and sickness are not universal truths but only problems we’ve not yet solved. In fact, there is no law of physics preventing our knowledge from spreading at or just below the speed of light.
Second, why does Krauss assume that we know all that we will ever know about dark matter and dark energy? Not so long ago, it was stated emphatically that we will never know what stars are made of, because we can never go and get a piece of one. Then scientists started collecting evidence, and, lo and behold, the answer was there in the star’s own light. In fact, that discovery lead in a straight line to the modern discoveries of dark matter and dark energy that Panek and Krauss discuss in their excellent books.
How can Krauss know that similar discoveries regarding dark matter and dark energy are not waiting to be made? If the history of science tells us anything, it tells us that new phenomena always lead to new understanding. As David Deutsch wrote, in a sentence both straightforward and profound, “We cannot know what we have not yet discovered.”
Finally, how can Krauss know that the discovery of dark matter and dark energy will not give people a new way of not just understanding, but in fact controlling the universe? Many modern science writers, including Krauss, Richard Dawkins, and others, lament the fact that we humans are so impressed with our own evolution of conscious intelligence. If intelligence were just another adaptation, like an elephant’s trunk, they’d be right. But our conscious intelligence isn’t like that. It is different because it has the ability to transform the world in utterly unpredictable ways.
Deutsch wrote that if you find a block of gold anywhere in the universe, you know the block was formed either by a supernova, or by a person. But if you find a good explanation, you know a person had to create it. A supernova alone could not. He also wrote that life on this planet will disappear, unless people decide otherwise.
This is the point. Unless people decide otherwise. The universe will grow cold and dark. Unless people decide otherwise. Unless the laws of physics prevent it (and how will we know unless we try), we can forge our own future in this universe. We need only to learn how.
Richard Dawkins wrote the afterward to Krauss’s very good book. He made a point that he and many others have made before. This new view of the universe may be depressing and bleak. So what. Get over it. The universe doesn’t owe us anything. While I agree with the hard-headed logic of this sentiment, I think it leaves out the obvious next step. We can make our own future. We can decide our fate. We can rage against the dying of the light and create a world that does suit our desires. Once again, we need only learn how.
So read both Panek and Krauss, good books full of wonderful ideas. But remember Deutsch’s principle of optimism. Problems are soluble, if we learn how.