Videos in: 2015

It is as though high status pundits have learned a valuable survival skill, and that survival skill is they've mastered the art of appearing to go out on a limb without actually going out on a limb. They say dramatic things but there are vague verbiage quantifiers connected to the dramatic things. It sounds as though they're saying something very compelling and riveting. There's a scenario that's been conjured up in your mind of something either very good or very bad. It's vivid, easily imaginable.

It turns out, on close inspection they're not really saying that's going to happen. They're not specifying the conditions, or a time frame, or likelihood, so there's no way of assessing accuracy. You could say these pundits are just doing what a rational pundit would do because they know that they live in a somewhat stochastic world. They know that it's a world that frequently is going to throw off surprises at them, so to maintain their credibility with their community of co-believers they need to be vague. It's an essential survival skill. There is some considerable truth to that, and forecasting tournaments are a very different way of proceeding. Forecasting tournaments require people to attach explicit probabilities to well-defined outcomes in well-defined time frames so you can keep score.

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PHILIP E. TETLOCK is the Annenberg University Professor at the University of Pennsylvania, with appointments in Wharton, psychology and political science. He is co-leader of the Good Judgment Project, a multi-year forecasting study, the author of Expert Political Judgment and (with Aaron Belkin) Counterfactual Thought Experiments in World Politics, and co-author (with Dan Gardner) of Superforecasting: The Art & Science of Prediction (forthcoming, September 2015). Philip Tetlock's Edge Bio Page.

It is definitely the golden age in cosmology because of this unique confluence of ideas and instruments. We live in a very peculiar universe—one that is dominated by dark matter and dark energy—the true nature of both of these remains elusive. Dark matter does not emit radiation in any wavelength and its presence is inferred by its gravitational influence on the motions of stars and gas in its vicinity. Dark Energy, discovered in 1998, meanwhile is believed to be powering the accelerated expansion of the universe. Despite not knowing what the dark matter particle is or what dark energy really is, we still have a very successful theory of how galaxies form and evolve in a universe with these mysterious and invisible dominant components. Technology has made possible the testing of our cosmological theories at a level that was unprecedented before. All of these experiments have delivered very exciting results, even if they're null results. For example, the LHC, with the discovery of the Higgs, has given us a lot more comfort in the standard model. The Planck and WMAP satellites probing the leftover hiss from the Big Bang—the cosmic microwave background radiation—have shown us that our theoretical understanding of how the early fluctuations in the universe grew and formed the late universe that we see is pretty secure. Our current theory, despite the embarrassing gap of not knowing the true nature of dark matter or dark energy, has been tested to a pretty high degree of precision.                      

It's also consequential that the dark matter direct detection experiments have not found anything. That's interesting too, because that's telling us that all these experiments are reaching the limits of their sensitivity, what they were planned for, and they're still not finding anything. This suggests paradoxically that while the overall theory might be consistent with observational data, something is still fundamentally off and possibly awry in our understanding. The challenge in the next decade is to figure out which old pieces don't fit. Is there a pattern that emerges that would tell us, is it a fundamentally new theory of gravity that's needed, or is it a complete rethink of some aspects of particle physics that are needed? Those are the big open questions.

PRIYAMVADA NATARAJAN is a professor in the Departments of Astronomy and Physics at Yale University, whose research is focused on exotica in the universe—dark matter, dark energy, and black holes. Priyamvada Natarajan's Edge Bio Page

In modern science, and I include the humanities here, science in a German sense of science—rigorous scholarship across all domains—in modern science we've gotten used to the idea that science doesn't offer meaning in the way that institutional religions did in the past. I'm increasingly thinking that this idea that modernity puts us in a world without meaning—philosophers have banged on about this for a century-and-a-half—may be completely wrong. We may be living in an intellectual building site, where a new story is being constructed. It's vastly more powerful than the previous stories because it's the first one that is global. It's not anchored in a particular culture or a particular society. This is an origin story that works for humans in Beijing as well as in Buenos Aires. 

It's a global origin story, and it sums over vastly more information than any early origin story. This is very, very powerful stuff. It's full of meaning. We're now at the point where, across so many domains, the amount of information, of good, rigorous ideas, is so rich that we can tease out that story. 

DAVID CHRISTIAN is Professor of History, Macquarie University, Sydney; Author, Maps of Time: An Introduction to Big History. David Christian's Edge Bio Page 

My vision of life is that everything extends from replicators, which are in practice DNA molecules on this planet. The replicators reach out into the world to influence their own probability of being passed on. Mostly they don't reach further than the individual body in which they sit, but that's a matter of practice, not a matter of principle. The individual organism can be defined as that set of phenotypic products which have a single route of exit of the genes into the future. That's not true of the cuckoo/reed warbler case, but it is true of ordinary animal bodies. So the organism, the individual organism, is a deeply salient unit. It's a unit of selection in the sense that I call "a vehicle."  

There are two kinds of unit of selection. The difference is a semantic one. They're both units of selection, but one is the replicator, and what it does is get itself copied. So more and more copies of itself go into the world. The other kind of unit is the vehicle. It doesn't get itself copied. What it does is work to copy the replicators which have come down to it through the generations, and which it's going to pass on to future generations. So we have this individual replicator dichotomy. They're both units of selection, but in different senses. It's important to understand that they are different senses.   

RICHARD DAWKINS is an evolutionary biologist; Emeritus Charles Simonyi Professor of the Public Understanding of Science, Oxford; Author, The Selfish Gene; The Extended Phenotype; Climbing Mount Improbable; The God Delusion; An Appetite For Wonder; and (forthcoming) A Brief Candle In The Dark. Richard Dawkins's Edge Bio Page