Intelligent design and eternal inflation: it would be very foolish...

One of the most provoking recent thoughts of Leonard Susskind about the philosophy of science can be summarized by a quote that appeared in a January 2006 issue of Nature:

• It would be very foolish to throw away the right answer on the basis that it doesn’t conform to some criteria for what is or isn’t science.

This statement has many aspects - sociological, philosophical, and scientific ones. Let me sketch the basic points that will be discussed more carefully:

1. I completely understand where Susskind is coming from - he primarily criticizes those who have naive and narrow-minded ideas about the methods how evidence can be accumulated in science. Most of the article will be dedicated to this point.
2. It was absolutely understandable that Susskind's idea was going to be misused by creationists, including some co-authors of "Traipsing into Evolution", an ID book, who have mentioned the quote on CSPAN2 today (thanks for TheGraduate for the information).
3. Susskind probably couldn't predict the twists and turns how his ideas were going to be misused.
4. You humble correspondent agrees with the creationists that if there were two isomorphic situations, we should be making correspondingly isomorphic decisions.
5. The Reference Frame, however, thinks that the situations are very far from being isomorphic.

Okay, let's start with a more detailed discussion.

First of all, Lenny Susskind is convinced that the picture of eternal inflation involving a gigantic set of string-theoretical vacua is a well-established consequence of our theories that have been supported by sufficient, albeit indirect, evidence.

Doubts about the landscape and eternal inflation

I happen to disagree with him in this point. When we use Occam's razor properly, the very process of quantum tunneling in between two vacua is something that breaks the usual notions of time, space, and causality, and it is very questionable whether science can ever talk about the "moments before our bubble was created" and their mutual causal relationships. More concretely, we don't have too many convincing papers that would study string theory during these unusual transitions.

Also, I view the evidence for the large number of metastable non-SUSY vacua to be insufficient. More importantly, I think that there is no evidence that we won't find a more complete selection mechanism.




On the other hand, I don't think that the previous sentences can be treated as unbreakable dogmas. A scientist should never fall into such a trap. It is always possible that a sufficient body of evidence is found that will force us to change our preconceptions like my preconceptions from the previous paragraph, or Susskind's preconceptions from the paragraph above it.

In fact, I can quite easily imagine that I just don't understand certain crucial things about the landscape dynamics or eternal inflation well enough, and if someone explained them to me, it could hypothetically end up with my admitting that Susskind's conclusions are inevitable according to the best theoretical analysis we can make. Scientifically speaking, it seems clear to me that it is now our turn - the anti-anthropic community's turn - because recent results about the large number of solutions have made their picture (including a quasi-solution of the cosmological constant problem) more concrete and our picture with a more well-defined selection mechanism more speculative.

We discuss these questions in the framework of string theory because we think it is the only consistent theory of quantum gravity and the best framework to ask all these questions in a controllable fashion. But in a more general sense, this anthropic discussion transcends most technicalities of string theory. Non-string theorists usually don't say much about these issues because without string theory, they can't offer any rational arguments in one way or another.

Readiness to revise opinions

Just like I am ready to be convinced about Lenny's picture by a more careful analysis or - less likely - by an experiment, I have no doubts that Lenny is ready to abandon his picture if a more predictive scenario is proposed or a proof of instability of the non-supersymmetric landscape, inconsistency of eternal inflation, or any other problem of his picture is demonstrated by scientific arguments.

People disagree about the probability that the interim anthropic picture of the vacuum selection problem will be completely revamped. But they certainly do agree that the recent results have strengthened the case for the anthropic principle and that either answer can only be accepted if non-trivial technical arguments are given, as opposed to philosophical dogmas.

When I say "people", I of course mean real scientists in the field. Besides the scientists, we have a lot of zealots who are organized at various blogs and who write various books that are critical about science. These people don't think that such "important" questions such as the existence of a gargantuan number of other Universes should depend on "shaky" things such as mathematics. These critics of physics believe that the answers to these questions are pre-determined by philosophy, by religion, or - as they arrogantly call their dogmas - by their "definition of science".

I couldn't disagree more. The very point of science is that it has no dogmas and all of its assumptions can be questioned. If we think scientifically, all of our beliefs and pre-conceptions - including the most viscerally believed ones - are subjects to revision if a sufficient body of evidence shows that these beliefs can't agree with the most recent observations or considerations.

All the answers to the questions like

• how many classical solutions the fundamental theory has?
• how uniquely can we predict this quantity or another when we know the full theory?
• how directly can we observe a particle predicted by a theory?
• should we accept the existence of other Universes?
• does our Universe have a finite life-time?
• does it make sense to ask what happens after the vacuum decays, or what happened before it was created?

are questions that should be studied by scientific methods and that should not depend on any dogmas. These particular questions look esoteric and philosophical in nature. Indeed, they are at the cutting edge of the research of quantum gravity and the researchers can't agree about generally acceptable answers at this moment.

Nevertheless, we have seen many remotely similar questions in the past, such as

• can there be any classical system with hidden variables behind the probabilities in quantum mechanics?
• does black hole evaporation preserve the information?
• what are the individual microstates of black holes?
• can space change its topology?
• can a theory in "D" dimensions be equivalent to another theory in "D+1" dimensions?

and many others that could have also seem as philosophical questions but they have eventually been solved. Doomsayers who have argued that science would break down in its attempts to answer certain questions have been proved wrong thousands of times. Even in the 19th century, we would find a lot of examples. Auguste Comte, a philosopher, argued that the chemical composition of the stars would remain a mystery forever. It took less than 10 years until spectroscopy was discovered and Auguste Comte was shown to be a very naive man, despite the fact that he had founded a science-friendly direction in philosophy called positivism.

So the message is clear: science has the capacity to answer questions, including the questions that look very difficult and divine. On the other hand, the answers of science are never known in advance. It's the whole point of science - and the main lesson of all of its revolutions - that we can trust no prophets who have been told the truth by divine forces.

Just like Google's servers must keep on calculating what is the best physics blog at a particular moment ;-), we must still look at all theoretical and experimental evidence and check and re-check our assumptions. And the particle physics community, string theory community, and all other serious science communities are surely doing so. (As you can see, the climate science community does not quite fit the bill.)

In many cases, the new data make us less certain about certain assumptions and sometimes the assumptions can simply be shown incorrect. On the other hand, it often happens that the developments show us that some uncertainty is not really justified. For example, we think that the basic postulates of quantum mechanics are much more inevitable and universal than people would have believed a few decades ago. It's because all predictions of the theories that have assumed limitations of quantum mechanics have been falsified, and all situations that were believed to be inconsistent with quantum mechanics - such as black hole evaporation - turned out to be consistent when the calculations are made more carefully or when a more complete description of the physical system is used. Note that the conclusion of the previous sentence depends on many interesting papers written in the last decades that couldn't have been predicted in the 1920s.

It is extremely important for theorists to be open-minded about all of their assumptions. But the scientific open-mindedness is a very special kind of open-mindedness: it is open-mindedness that commands us to change our opinion when someone (which can include ourselves) gives us new rational evidence, experiment, or a calculation - not when someone smiles at us or, on the contrary, sends his hungry dogs or crackpots against us or when he blackmails us by writing grumpy books that contain no rational arguments.

The critics of science simply never understand the previous paragraph. The concept of not knowing the answer at the beginning and finding the answers by rational arguments is well beyond their grasp. They either believe that their favorite dogmas are unbreakable and should be spread as universal truths without any evidence - or even against available evidence - or they believe that the best evidence for an assumption in science is a sociological argument or an ad hominem attack.

You can't be surprised that the authors of the books critical about science can't be taken seriously by the scientific community because they are missing a very essential idea that makes sciences scientific.

Indirect and abstract arguments

The next related point I want to comment on was labeled as "1" in the list at the beginning. Some naive people interested in science - which often includes the science critics from the previous paragraph - often believe that certain ideas can only be proved in one particular way.

We have already mentioned Auguste Comte who was surely imagining that it was necessary to pay a spaceship that would travel towards the Sun and that would build a chemical lab in the middle. Such a project could be hard even in 2006 but a more important problem with Comte's idea is that the chemical lab simply wasn't necessary. Spectroscopy was enough. Because of his lack of imagination, he was simply unable to imagine that a new kind of evidence could have become available that would instantly make all of the "untestable" data completely transparent.

I could add dozens of similar examples from the century that followed. Instead, let me jump directly to the 1960s when the quarks were proposed for the first time. Once again, many people were just too naive and they thought (and still think) that a theory of quarks would remain "unscientific" forever because the quarks clearly don't exist in isolation - they "can't be seen", in this sense. If they can't be seen, QCD is dead, QED. ;-) Fortunately, there was no blogosphere back in the 1960s, otherwise the dumb counterparts of Peter Woit would have made the life of the proponents of quarks unbearable.

Needless to say, QCD, the theory of quarks, is perfectly scientific and supported by overwhelming evidence. Even long before the evidence was overwhelming, all good particle physicists knew that there was no way how the theory could have been wrong. Yang-Mills theories were the only theories that allowed asymptotic freedom (and various scaling laws and sum rules) and the bound states of the quarks and antiquarks had the right quantum numbers to match the hadrons.

The evidence to support QCD was less direct than the most naive fans of science could have expected - or could have demanded. This trend - the fact that the required steps to find evidence or proof are increasingly more complex, subtle, and abstract - has been a characteristic feature of science in general and theoretical physics in particular at least for 300 years. There is no way how this trend could be suddenly reverted. Theoretical physics is bound to demand increasingly deep and ever more complex mathematical and abstract reasoning, especially if it continues to be increasingly difficult and expensive to obtain new experimental data.

You don't like it? Are you irritated that theoretical physics requires mathematics? I don't know how to tell you my recommendation clearly enough, but let me try: f*ck off. You're just far too stupid. Physics is not for you, okay? Naivity is deadly in this field and the ability to think about sufficiently abstract links between mathematical ideas and observed phenomena is absolutely paramount. One can't do meaningful theoretical physics without this ability and in fact, she can't even understand theoretical physics without this ability.

If you think that the only way to prove string theory is to see a pair of shoes with a string, then you're a moron and you should better avoid any debates about theoretical physics of the last 100 years because noise, laughter, or anger are the only things you can contribute.

Falsifiability

Let me summarize the previous section in another way and present some additional examples; I will borrow some specific comments from Lenny Susskind and thank him. Thank you, Lenny. ;-)

All serious scientists know that a theory that makes quantitative statements about the real world just can't be unfalsifiable - only vague theories such as "the Universe is based on the female principle" can be unfalsifiable. Unfortunately, the general public doesn't understand that the universal "unfalsifiability" criticism of scientific theories never has any scientific value.

Moreover, the scientists and critics of science who have used this criticism have always been wrong. A large portion of the important true ideas has been criticized as untestable or unfalsifiable - this criticism is an indirect sign of depth of the theories - and the critics have always been wrong. They always incorrectly and arrogantly overgeneralized their own inability to falsify a statement into the inability of science to make such a decision. For example:

• Auguste Comte criticized any science about the interior of stars as untestable because he lacked the imagination how the new technologies - such as spectroscopy - could suddenly make the data easily accessible.
• The Lamarckian evolutionists criticized the Darwinian evolutionists because Darwin's picture talked about the history hundreds of millions years ago which the Lamarckians found "untestable". They had other theories - that the individual lives are imprinted into their carriers' genes and i our children - that were, indeed, falsifiable. In fact, very easy to be falsified.
• The creationists criticize Darwinism as unfalsifiable even in 2006: while it's incredible, I really mean the 21st century.
• Most psychologists were criticized by behaviorists who argued that there exists no internal emotional life inside human beings - only things that can be seen by naked eyes exist. The behaviorists were wrong, too.
• Quarks were said to be untestable because they can't be seen in isolation. They still have not been seen and they will never be seen. But we are certain that the theory is correct. The critics were completely wrong again.
• Inflation was criticized because one can't look before the surface of the last scattering - it is too far in time - which makes it unfalsifiable. Nevertheless, the case for inflation is getting really strong recently and the new CMB data can already exclude classes of inflationary models.
• String theory is criticized for having too many stationary points and for not being "falsifable", too, and all serious scientists realize that this criticism is rubbish, too, because virtually all of the scientific work is a counterexample.

This kind of criticism is wrong and vacuous and shows the critics' lack of imagination and their lack of real arguments. Working science never relies on these general philosophical arguments that are randomly used against theories that someone finds inconvenient. It is true that many of the critics' own theories were indeed falsifiable, too. They were often easy to be falsified which didn't make them more valuable: quite on the contrary.

Nature does not provide simple-minded people with affirmative action that would guarantee that Her secrets are easy to be found and easy to be confirmed by them. She really doesn't care. Are you dissatisfied with this lack of policy? No problem, you can always try to move into a different multiverse.

Isolation of the science community

The last paragraphs are meant to address the points "2,3,4,5" and will be rather brief. Lenny Susskind wrote his book - and made all his comments - assuming that all the readers would resemble the particle physics community. In other words, he assumed that all of his readers would be convinced in advance that evolution is right and creationism is wrong. With this assumption, most of them - the radical left-wing ones - should be even happier when Lenny offers them such a large number of Universes that will make the picture of the world even more materialistic, chaotic, and Godless. ;-)

Surprisingly for Lenny, some creationists and some of the most intelligent designers can also read and send e-mails to each other. It was completely inevitable - and, at a superficial level, fair - that they would use his words as sociological evidence for their religious agenda, namely their attempts to introduce Intelligent Design to schools. It was equally obvious that this trend would also be used by the critics of physics.

All of these events were inevitable, predicted at Harvard, unfortunate, but not lethal. The main explanation of the different outcomes is, of course, that Lenny's favorite theories involving eternal inflation are tightly connected with the state-of-the-art theories that seem to describe all phenomena we have ever seen. They are fully integrated into a system of falsifiable - but not falsified - ideas that people study in order to have the most accurate description of the real world that is possible. Sometimes this reasoning is more abstract than the naive observers of science could like but it is still the best science that we can do with the available experiments and observations and with our brains.

Once again, the theory that Lenny has in mind contains not only eternal inflation and controversial ideas about the anthropic principle but also the picture of string theory that logically implies all of the tested ideas of quantum field theory and general relativity. It is a very non-trivial combination of features of Susskind's picture - it is a combination whose importance is severely underestimated by the simple-minded proponents of "alternatives of string theory" and a combination whose breathtaking explanatory power cannot be compared to anything in Intelligent Design, not even remotely.

The creationist friends should try to see that if two people are doing a seemingly identical thing, it's not necessarily an identical thing.

And that's the memo.

Insiders and outsiders: sociological arguments in science

Technicality: a reader has asked how to increase the size of the fonts. Try to press ctrl/+ (ctrl/=) many times, and/or go to View/TextSize/Largest in your internet browser. I don't plan any major changes in the design right now.

Many recent controversies that involved science in one way or another have shared the following basic question:

• If there exist different opinions about a scientific question, should the public believe the insiders or the outsiders?

The answer is, of course, that neither rule can guarantee a universal success rate. You can't be sure that someone is right just because she is an insider. You can't be certain that he is right just because he is an outsider either. It is possible to sketch hundreds of counterexamples to both rules.

We could end up with this punch line but such an analysis would be far too short and incomplete. Even though no simple sociological rule that would produce 100% correct scientific answers can ever be found, there are still many approximate rules that can help anyone to have more reasonable opinions about many questions. And there are also many myths and wrong rules that help to spread wrong opinions.

Emperor's new clothes vs. independent and neutral arguments

The first fact that we should always be aware of is that only the arguments of those people who know what they're talking about and who look at the scientific questions sufficiently carefully matter.

If someone tries to intimidate you with millions of people who believe in creationism, be sure that there exists no rational reason to accept their opinion. If someone tries to convince you that there is, you're being cheated.

If someone else wants to impress you with thousands of people who have random science PhD degrees and who have voted in one way or another in a poll about the climate or particle physics or anything else, be sure that what you see may be just an exercise in discipline or groupthink.




If you have reasons to believe that the poll question is more or less the most difficult type of question whose wording the respondents can understand, it is not unlikely that most of them will give you a wrong answer. The reason behind this rule is the very same reason as the explanation why a theorist should never pay too much attention to the last point in a graph produced by the experimenters. If the point were reliable, the experimenters would add another point. The lesson is that you should only trust someone's answers to questions that are simpler than other questions that the person would still be willing and able to address.

Fine. So the opinions or larger groups of people only matter if their owners obtained them carefully, mostly by using their own intellectual tools, and if there are reasons to believe that they are actually able to analyze these questions as well as slightly more difficult ones. A single careful analysis of a problem is more valuable than a superficial opinion of thousands of people.

Great.

Large groups of people - and scientists - have been wrong many times in the past. But surely, you would say, there must exist a sense in which many experts are more likely to be right than a small number of outsiders. Doesn't your humble correspondent believe this thesis, you might ask?

Yes, I do, but one must be very careful about the details of such a sociological argument.

Imagine that you have a group of people, XY, and the question is whether their majority opinion about a particular question, PQ, is justified and likely to be correct. Independently of the number of elements in XY and their degrees and credentials, their majority opinion may fail. There always exist sufficiently subtle questions that even a very selected group of people may end up with a wrong majority opinion simply because the question is too difficult for most of them. In the second half of the article, I will try to quantify how large the groups of qualified people are in various contexts.

You should ignore the majority opinion of XY if any of the following conditions is satisfied:

• you have good reasons to think that the unscientific motivations of XY to have a certain opinion - e.g. political, religious, financial goals or fear - are stronger than the scientific ones
• you have good reasons to think that a majority of XY has copied their opinion from others without looking at the question carefully enough
  

Similar reasoning was described in the article called

• Most published findings are false.
  

I believe that the reasons why these circumstances spoil the quality of the opinions of XY are self-evident. If someone is driven by political, religious, financial, or psychological forces, he or she simply cannot be expected to systematically achieve an honest and reasonable conclusion. If someone wants to mimick his or her friends' attitudes in order to build a community, he or she doesn't contribute a rational voice to a discussion either.

Fine. I have said too many things about this side of the argument. But still, there are people who know what they're talking about and who should be trusted more than random outsiders, aren't there? There must certainly exist people whom we should trust if the society is supposed to work. Yes, there are.

Hierarchy of experts in the U.S.

Let me try to estimate the number of people in the U.S. who are actually capable to decide rationally what the correct answers to certain questions are. I will start with two disclaimers:

1. The numbers below don't count the people who happen to reach the right answer just because they're lucky: the figures systematically subtract anyone whose opinion could be viewed as a result of good luck or bad luck.
2. On the other hand, the numbers below will include many people whose opinion will turn out to be incorrect at the end - but the way how they have obtained this opinion can be classified as a result of independent rational thinking based on the best kind of evidence that looks necessary for such a reasoning. The rational thinking may involve a limited portion of sociological considerations - a reasonable belief that certain other authorities are not cheating us and/or they must have figured out the right answers. But once again, the sociological reasoning must always be subdominant.
   

Is it safe to jump from a skyscraper? 220 million people

This question is just an innocent example to get started. I think that 220 million Americans are able to find a qualified answer to the question whether it is safe to jump from a skyscraper. An overwhelming majority of the complementary set are small children. Their parents should be careful if they visit a skyscraper together. I have only included this question because all other questions will have much smaller ensembles of the qualified U.S. citizens.

Evolution vs. creation: 20 million people

You might think that the number should have been much higher. I don't think so. I am convinced that most of the general discussion about the origin of life is irrational, political, and religious in nature. Moreover, while I believe that the very basic ideas of evolutionary biology are not rocket science or string theory, they are difficult enough so that a reasonably intelligent person could easily end up with a wrong conclusion. My order-of-magnitude estimate is that 20 million Americans can rationally understand and evaluate all the necessary facts to conclude that evolutionary biology is more or less inevitable to explain the basic properties of the world we see around us. Of course, I am convinced that most of these people end up believing Darwin's framework.

Does the low number have any consequences? Yes, it does. The relatively low number means that it doesn't make much sense to try to increase the number of people who answer "Yes" to evolutionary biology in the opinion polls. If you increase this number, it just means that you have brainwashed a larger segment of the population. If you change their opinions, it was most likely not a rational change. The society doesn't benefit too much from much higher percentages of the "evolutionary believers". The opinion of more than 90% of the population about the origin of life is inconsequential for the life of the society, whatever their answer is. The fact that the U.S. is the second most anti-evolutionary country after Turkey doesn't prevent America from being a leader in biology.

The fact that the number of the trustworthy sources in the context of the very facts about evolution is much smaller than the population of the U.S. also means that no rational person should allow her opinions to be directly formed according to the public polls if these polls include the whole population. Most of the results reflects irrational noise and unscientific pressures.

Innate cognitive differences between groups: 20 million

My estimate of the number of people who are qualified to scientifically answer the question whether different groups of people can have significantly different pre-requisites to do special things such as math is 20 million, too. Again, if you ask everyone, what they will answer will be nothing else than noise. On the other hand, I think that the required evidence to answer the question rationally is sufficiently accessible, much like the more general insights about biology that can be used to deduce the answer by other methods, and a visible fraction of the population is thus able to figure out the correct answer.

While the qualified ensemble in the case of evolution was dominated by left-wingers, the qualified ensemble in this case will be dominated by the conservatives. Note that the question whether there exist differences between the groups influences our life more directly than the validity of the evolutionary biology which is still, essentially, an academic discussion about the billion-year past of our planet.

Validity of special relativity: 5 million

My rough estimate of the number of Americans who can understand what the statements of special relativity are and whether they are a correct piece of well-established science is 5 million. What does it mean? Again, it means that if you rely on much more than 2% of the people who are most educated (or otherwise gifted) in physics, you will end up with garbage.

On the other hand, the number 5 million is much higher than some of my estimates of the ensembles that are relevant for much less esoteric questions than special relativity, for example questions in climate science. It is because I think that tens of millions of people have been exposed to special relativity and the basic evidence supporting this theory at one moment or another. Consequently, most people who have the ability to make a rational conclusion about this question got the opportunity to do so.

I could find many questions where the estimate would be in between tens of thousands and millions of people. But let us make a bigger jump.

Paleoclimate evidence for global warming: 5,000

Is there evidence of a recent unprecedented anthropogenic global warming that is based on the historical and geological data? I don't want to answer this question in this article. Instead, I want to estimate the number of people who have actually looked at this question carefully enough and with a sufficient amount of education and intelligence.

My guess is 5,000 only. This certainly doesn't mean that this piece of climate science is one of the most intellectually demanding part of science. The main limitation is that most people simply didn't get the opportunity or didn't have the time to look at all the necessary data. The number of people who have the sufficient abilities to decide about these questions could be as high as hundreds of thousands but the required data are not easy to find and the question hasn't been considered important for too long.

Similar figures could be associated with many other particular questions about the climate such as the validity of the climate models. There could also exist about 5,000 people in the U.S. who have a qualified opinion about the validity of the climate models because they have spent a sufficient amount of time and rigorous efforts to study what the climate models are all about and whether the evidence supporting them is sufficient.

On the other hand, I think that the number 5,000 is primarily composed of people who are not paid as climate modellers. It is my belief that this number is dominated by statisticians who are interested in the climate science. Many of them may attend various blogs and other platforms where these questions are being discussed - but many of these people could be silent visitors of these websites. The subset of the qualified set that you had a chance to hear is much smaller.

Is there some general reason why I think that there is such a small overlap between the community of the competent people and the community of the people who are actually paid for this job? Sure, there is. I think that the climate modellers are not a sufficiently selective community. They are doing something that many other people can do equally well or better as amateurs. Moreover, I find it obvious that the community of the climate modellers is much more spoiled by various financial and political pressures than an average amateur.

Uniqueness of string theory: 1,000

I estimate the number of the people who are competent to offer their qualified guess whether string theory is the only existing proposal to describe gravity in a consistent quantum-mechanical language to be comparable to 1,000. Again, I don't want to say what is the correct answer to that question - you know what's my answer anyway. Unlike the case of the climate science, this ensemble of 1,000 qualified Americans will nearly coincide with the community of the string theorists, whatever its exact definition is.

There are two main reasons why I think that the overlap is so strong. First, the string theory community actually contains a large percentage of the people who are interested in these questions and who can solve the technical problems that are necessary for a qualified opinion about the "big questions". Second, even though there are clearly many smart people who could answer these questions outside the community, the required knowledge of physics at many levels and the required experience are also high - high enough so that the talented outsiders simply couldn't have found enough time to go through all these things.

If you ask more than a few thousand of the most qualified people whether they think that string theory is the only known consistent way to describe quantum gravity in 4 dimensions or more, you will again collect noise. Of course, there exist methods how you can collect bad noise and nonsense selectively: for example, read the "Not Even Wrong" blog that is based on those who have no qualification to address these questions whatsoever but who are sufficiently self-confident about their wrong answers and not-even-wrong answers. Well, there are cases in which it is better to ask chimpanzees in the zoo.

High-energy physics evidence of eternal inflation and the anthropic principle: 100

As you can see, we are getting to ever smaller numbers. Now we think about another scientific problem: do we have a sufficient body of evidence that the anthropic principle follows from our knowledge of quantum gravity or string theory and that this principle is inevitable for solving the cosmological constant puzzle in a way that is consistent with the rest of physics? I won't tell you what the answer is - even though everyone knows that my guess is that "the anthropic principle is not inevitable" anyway.

Because I can't provide you with a guaranteed and proved answer, you won't be able to learn who the 100 people actually are. The group of 100 people who are qualified to answer the question will most likely be composed of a small subgroup of the theoretical physics community but I can't tell you which subgroup it is. The time will probably tell.

What are the final equations that describe everything? 0 or 1

Can we write down the final principle of Nature that can be used to deduce the rest of physics (and science, for that matter)? I estimate the number of Americans who are qualified to do so in 2006 to be 0 or 1. The number 1 is correct if God is a U.S. citizen.

Conclusion

We could analyze many more questions like that. Different questions will have very different sizes of the groups of the true insiders who are qualified to answer them. Different questions will also have very different degrees of overlap between the qualified groups and the groups who are paid for finding and knowing the right answers. In many cases, similar arguments like those above can be found to determine the sizes and correlation coefficients. In other cases, there exist many other social mechanisms and predispositions that must be taken into account before one constructs a qualified expectation about the relevance of the opinion of various groups.

If we want to use sociology of science as a supplementary method to find the truth, our job may be difficult. Nevertheless, it is often impossible for an individual to answer all of the questions that are relevant for his thinking in a strictly scientific and independent fashion. This is why some degree of confidence in other people's result must often be included which is why it is also important to have a reasonable idea which kind of confidence is likely to be justified.

However, it is critical for the scientific method to be primarily based on the actual scientific, independently verified, repeatable results rather than sociological theories, beliefs, groupthink, and the mutual confidence between different scholars.