Why was John so caviling in this?

Well now... that was interesting. The idea that any one person will have the solution to unifying all the observed data within modern physics into a model that somehow explains all of it and more is silly. One person may have a key insight, but it's unlikely that that insight will come from a person who enjoys spending a great deal of time learning the entire history of physics and the ins and outs of its many areas of specialization. Undoubtedly, the next scientific revolution will have to be the result of a team effort, as there is simply too much that we do know for any such person to be able to learn simply to please contemporary physicists with a know-it-all theory.

Fantastic diavlog! Sean is one of the best I've ever heard at elucidating physics, especially in his abilities to make cutting edge work sound comprehensible, meaningful, and worthwhile. Not only does he help you to understand, he helps you to realize what you don't understand. The part at the beginning, where he talks about "the" Big Bang Theory as really having three discrete aspects, is about the best two-and-a-half minute lecture on the current state of science that I've ever heard. I particularly liked one phrase in that segment, where he said that one of those aspects was accepted by everyone in "the non-crackpot physics community." So stealing that. John plays an excellent foil. Whether or not he is as cranky about some of the more speculative aspects of cosmology as he seems, it works really well to hear him offer up the standard carping points so that Sean can shoot them down one by one. This is one of the true gems of BH.tv, as measured by my feeling that I'll definitely be watching it again.

Quoting privatepress: Why was John so caviling in this?

I think he answers this question himself, right at the end, where he explains that a big part of his job is to be skeptical about unsubstantiated scientific claims, and one of the hardest parts of his job is distinguishing between the visionaries and the cranks. Another small piece is that John has the normal modern American's impatience for gratification. "Answers now!" most of us cry. "Patience and contemplation are for monks!" As I said in a few moments ago in another comment, I found his attitude quite useful as a foil for Sean. It came across much like Galileo's approach to explaining science to the masses: set up a dialog between Simplicio and Salviati, where we, the BH.tv audience, get to play the role of Sagredo. (Don't read too much into this analogy, John. I don't think you're completely Simplicio.)

What an incredible session! Sean is superb at answering the very frequently asked questions of those in and out of the field. For more of his very accessible answers, go to his cosmology primer at [url="http://preposterousuniverse.com/writings/cosmologyprimer/index.html"] Thank you for what can be considered one of the best free cosmology lectures to date! The only disappointing feature of the diavlog was the unnecessarily aggressive tone of John Horgan, whose delusional belief in his own understanding of physics was even bigger today than it usually is. More than anything, Sean's brilliantly gracious and unassuming manner shows that intelligence is much more than just the ability to get the answers right.

Quoting bjkeefe: As I said in a few moments ago in another comment, I found his attitude quite useful as a foil for Sean.

I agree Brendan. John's got his skeptical line, and even if it's not how I see things, I think it's important that the sorts of questions and concerns he raises be raised. I like to think that most scientists, even those doing "theology," would also agree. As for John's desire to know how to distinguish (reliably, I assume) between visionaries and cranks, that, I believe, needs to be given up. It's impossible. The history of science, and human thought generally, is full of ideas that were ridiculed (in many cases because they really looked ridiculous), but later -- e.g., over two millennia later in the case of atoms -- were shown to be true. Ideas, alas, do not come with marks that indicate how close they are to the truth.

Why did the cyclical theories of the creation of the Universe come to the forefront in the sixties,then recede, then come back? 'Cause its cyclical! Sheesh! Super discussion, but it made my brain hurt.

John's attitude is what keeps me coming back hehe

Quoting bjkeefe: John[...] I don't think you're completely Simplicio.

Damning with faint praise, Brendan? Actually I think you're exactly right. John is a gadfly, asking questions that really ought to be asked. I don't agree with our friend Wolfgangus that string theory, eg, is a worthless, energy wasting, dead end; but theorists require skeptics nipping at their heels, as it were, saying "So what? How you gonna prove it?" There's no reason why the mathematics describing the universe should easily yield to analysis or even empirical confirmation. And as Sean Carroll implies, theorists ought to out there in the weeds, asking questions like "How do I find a correct solution in 10^500 possibilities?" But the pressure to produce testable results is a fundamental, obviously important part of the overall process. It's important to note that John is very smart and the opposite of a cynic. I think he takes a very conservative view, more so than, for instance, I do. My personal belief is that the energy requirements of experimentation are going to continue to grow until it becomes practically impossible to build useful tools. (An accelerator the size of Jupiter's orbit, anyone?) So the burden of progress is increasingly going to involve computation and modeling - the difficulty

That was wonderful. Sean is my new favorite person in the world.

I wouldn't use "conservative" to describe John's stance. For me, a conservative scientist is a scientist like Sean Carroll who keeps in mind the long-term nature of the science project, and who is informed by principles of order that he has inherited from past scientists--like what he was talking about in the diavlog. If John was being honest and not just playacting at being the skeptic, then I feel like he has a very narrow Potter-esque view of what science is. He knows it when he sees it. And, apparently, everything else is contemptible. Don't you get the feeling that each time John repeats his disdain for Sean's work that what John is looking for is a breakdown like: "Well, of course John, between you and I we both know that this stuff is baloney, but we have to occupy ourselves somehow!"

John, why do you think that if an idea regarding some deep and difficult scientific question has been around for thirty years or so without having been decisively established as correct, that in itself is a reason for skepticism about the idea?

Maybe, in part, because bad "scientific" ideas sometimes gather lots of momentum in universities and have pernicious effects on the world. A lot f damage can be done in 30 years. This was true in the heyday of Freudian psychoanalysis and Marxist economics. It's hard to imagine cosmology having such a negative impact on the real world, but it still is probably a good general practice to exercise a healthly dose of skepticism regarding sweeping Explain-Everything theories. This is especially true of science journalists like John. They have a serious responsibility to protect the non-specialist public from unsubstantiated claims and hype. I support funding music, arts, multiverse speculation and most other serious intellectual and cultural pursuits. But we want to support these projects in a context of scrutiny from the best qualified peers, critics and reporters.

It's hard to imagine cosmology having such a negative impact on the real world, but it still is probably a good general practice to exercise a healthy dose of skepticism regarding sweeping Explain-Everything theories. This is especially true of science journalists like John. They have a serious responsibility to protect the non-specialist public from unsubstantiated claims and hype.

While that is certainly true, the problem is that more often than not it requires a little more than a healthy dose of skepticism, ie--a higher level understanding of physics and a good working knowledge of the math involved. Branding theories as "wild and crazy" because they don't "sound" right is hardly a good way of doing science or journalism for that matter.

One question John could have asked that I would have loved to hear Sean answer is the this: Okay, I might buy the idea that smart entry-level people continuing to get into certain fields which have yet to show much tangible progress suggests some worth to these fields. This worth might be hard for the layperson to perceive, but I'll grant that people who are closer to the field can be in a position to make a more sensible determination. But how much of the choice of research topic is driven by the fact that people, especially grad students and post-docs, have little choice but to go to where the money is? In other words, if the senior/tenured people are controlling the purse strings, isn't there a fair amount of inertia affecting the true measure of the potential worth of some areas of research?

Thank you, Sean, for this!
Sean calls John's talk of "falsification" "sophomore level philosophy of science."
Here in the comments sewer, I've been trying to point out that it's even worse than that -- it's ANCIENT philosophy of science.
The hope of the logical empiricists (whom John is always channeling) was to find a logical and methodological bright line dividing science from other, inferior modes of inquiry, like history or jury trials and from sheer nonsense, like astrology (or, in their view, metaphysics). In fact they tended to forget about that intermediate ground of history and courtroom evidence and dismiss as "nonsense" anything that didn't come up to the standards they erected for science.
John (and George) seem to be aware of these positivist views and of Kuhn's and Feyerabend's rejection of the positivist position in favor of "constructivist" or anti-realist philosophy of science -- what John and George call a "post-modern" conception of science. But they seem to be completely unaware of realist conceptions of science that reject the positivist view that there is a hard and fast logical or methodological line between science and other forms of inquiry -- views that assert

As for John's desire to know how to distinguish (reliably, I assume) between visionaries and cranks, that, I believe, needs to be given up. It's impossible. The history of science, and human thought generally, is full of ideas that were ridiculed (in many cases because they really looked ridiculous), but later -- e.g., over two millennia later in the case of atoms -- were shown to be true. Ideas, alas, do not come with marks that indicate how close they are to the truth.

Agreed! I was also struck by Sean's response to John when John said (something like) "these ideas just keep coming up over and over again -- isn't that depressing?" John sees philosophy as something that experiences no progress because at some general level the questions remain the same. And given that he expects there to be some bright line between philosophy and science, it's depressing to think cosmology is like philosophy in this respect. But Sean points out that when the idea rises again, it's in the context of what has been learned from the previous debate and of knew information from other areas within science. What sounds to a journalist and to the general

BN:

Sean calls John's talk of "falsification" "sophomore level philosophy of science."
Here in the comments sewer, I've been trying to point out that it's even worse than that -- it's ANCIENT philosophy of science.

I'd disagree with this, slightly. What I heard Sean saying is that John was holding only a hammer and consequently looking at every open question in physics as a nail. Sean was not saying the principle of falsifiability was something to be discarded completely. He was saying that it was wrong to try to apply it to a prediction. I can't speak for sure for him, but I'd be willing to bet that he would say that a theory can still be falsified, and that this remains an important tool and measure of the worthiness of a theory. I agree with the rest of your essay, whose main point I understand to be that one cannot draw a general line between what is science and what is not.

Having strongly defended John as a journalist above, I would add that he does have an axe to grind: his end of science thesis.

Brendan,
I'm certainly going beyond what Sean says specifically -- I was elaborating Sean's "sophomore philosophy of science" remark from my point of view. My problem isn't with some very general notion of "falsifiability." Popper's idea was that individual theories on their own yielded predictions about observables and if the prediction were not to be borne out, then the theory would be rejected -- he thought that the reasoning was actually deductive: If theory T is true, we will observe O, but O was not observed, therefore T is false.
But this isn't in the least how science works -- other theories come into the mix (e.g., theories about how the instruments you're using work). When it doesn't come out as expected, supporters of the theory don't just give up. They propose alternate hypotheses (e.g., that the experiment was done wrong or that the law proposed by the theory might be slightly off but basically right or that there's some unanticipated particle or so far unobserved planet is interfering). Scientists add "epicycles" and offer excuses all the time -- just like those astrologers and mystics.
That's not to say that scientists are indistinguishable from astrologers and

BN: You're right about the messiness of scientific progress on the day-to-day level. I agree that one conflicting observation does not a theory break. And that's probably a reasonable attitude -- could be that the theory is mostly right, could be bad data, etc. I was speaking more in the ideal sense, or at least, thinking of the really big shifts in science; e.g., the rejection of the theory that heavier bodies fall faster, the rejection of the theory that blackbody radiation can be understood as a continuous phenomenon, the idea that Newtonian principles will explain everything we'll ever see in the universe, and like that. I remind you that I also said that I viewed much of progress in science as a series of refinements, which agrees with your portrayal. I agree that falsifiability is not (always) a bright line.

Quoting Wonderment: Having strongly defended John as a journalist above, I would add that he does have an axe to grind: his end of science thesis.

Could well be. I have yet to read that book, so I can't say for sure. But, in general, I'm in favor of journalists being skeptical, even if it causes them occasionally to ask questions that sound sophomoric.