Less Wrong is a community blog devoted to refining the art of human rationality. Please visit our About page for more information.

Rebutting radical scientific skepticism

17 Post author: asr 30 April 2014 07:40PM

Suppose you distrusted everything you had ever read about science. How much of modern scientific knowledge could you verify for yourself, using only your own senses and the sort of equipment you could easily obtain?  How about if you accept third-party evidence when many thousands of people can easily check the facts?

 

My purpose with the question isn't to cast radical doubt on science; rather, it's an entertaining game of trying to understand how we know what we know. Thinking through these sorts of questions also helped me notice interesting things in the history of science that I hadn't previously focused on. It might also be of interest from a science education perspective.

Some things are much easier to check than they used to be. As late as the 19th century, there were people who were publicly skeptical about the curvature of the earth. Skeptics and scientists did careful measurements (notably the Bedford Level Experiment) to observe the earth's curvature. Today, you can verify it by phoning a friend a few time zones away and noticing that the sun reaches the zenith at steadily later times as you move west. This only makes sense if the earth is curved.

Some things are still hard to check. I don't know an easy way to show that the Earth orbits the Sun. The direct way to show it would be to measure stellar parallax. But even the closest stars have a parallax of less than an arcsecond. My understanding is that very few amateurs are able to take measurements with that level of precision.

Some things are surprisingly easy. There are lots of easily accessible demonstrations of quantum phenomena. For example, a ten dollar spectroscope will show you that an incandescent light bulb has a continuous spectrum, and that LEDs and fluorescent bulbs don't. Bright-line spectra are very much a quantum mechanical phenomenon -- it's a sign that the atoms in the light source have fixed energy transition levels. Spectroscopy was one of the key early lines of evidence for quantum mechanics, and it blows my mind that it's something you can just see whenever you want, with a negligible equipment cost.

Pretty much all of modern chemistry and solid state physics rests on a quantum foundation, and you can test a great deal of chemistry pretty easily. If you are in doubt that water is a bonded compound of two gasses, you can do the electrolysis very easily yourself. You can observe the periodicity of chemical elements yourself if you buy alkali metals (don't try this one at home!). If you are willing to accept slightly indirect evidence, the entire semiconductor industry is about precisely controlling the conductivity of impure silicon, and this would make no sense if quantum mechanics weren't a reliable guide to electron energy levels in the solid state.

I don't feel quite as qualified to play this game for biology. I imagine that antibiotic resistance is a well-enough documented case of evolution through natural selection to serve at least as a proof of concept. DNA sequence comparisons across species are emphatic evidence of taxonomic trees, if you trust the scientists not to be part of a vast conspiracy.

It feels almost impossible that it's easier to see quantum mechanical effects than it is to see that the earth orbits the sun, but it does seem that way.

Some questions:

  • Is there an easily visible consequence of special relativity that you can see without specialized equipment?
  • Can you measure the consistency of the velocity of light on your own?
  • How much can you directly demonstrate in biology or the social sciences?

Comments (63)

Comment author: Froolow 02 May 2014 02:39:45PM 15 points [-]

I'm surprised nobody has posted about finding the speed of light with a chocolate bar and a microwave, because I find that absolutely mindblowing.

The basic experiment is to take the turntable out of the microwave and put in the chocolate, nuke it for a couple of seconds until part of the chocolate starts melting and then measure the distance between the melting patches. If you have a standard microwave, you'll be on a frequency of 2.45 GHz (you can check this online or in the manual). Multiply the distance between the spots by 2,450,000,000 (or whatever the frequency is) and then by 2 and you will end up with c, to within whatever accuracy you measured the melting spots.

I guess if you were really skeptical you could say that you have no reason to believe that v = f * lambda, or that the manufacturers of microwaves or rulers were colluding to decieve you, but I think this is around the point where you can start claming the evidence of your eyes is decieving you and so on - too skeptical to add anything useful to the discussion.

Comment author: asr 02 May 2014 03:33:50PM 1 point [-]

This is actually a really good example of what I wanted.

I think I have a lot of reason to believe v = f lambda -- It follows pretty much from the definition of "wave" and "wavelength". And I think I can check the frequency of my microwave without any direct assumptions about the speed of light, using an oscilloscope or somesuch.

Comment author: CronoDAS 30 April 2014 10:58:08PM 13 points [-]
Comment author: asr 02 May 2014 03:36:15PM 0 points [-]

This is incredibly cool and it makes me sad that I've never seen this experiment done in a science museum, physics instructional lab, or anywhere else.

Comment author: CronoDAS 02 May 2014 11:33:10PM *  2 points [-]

My freshman physics professor showed us a video of a Cavendish experiment, but doing it live is problematic. You need a fairly controlled environment to pull it off because any air currents in the room will push the small weights around, and it also it takes a long time for the weights to move.

Comment author: dougclow 01 May 2014 10:26:37AM *  17 points [-]

I spent quite a lot of time many years ago doing my own independent checks on astronomy.

I started down this line after an argument with a friend who believed in astrology. It became apparent that they were talking about planets being in different constellations to the ones I'd seen them in. I forget the details of their particular brand of astrology, but they had an algorithm for calculating a sort-of 'logical' position of the planets in the 12 zodiacal signs, and this algorithm did not match observation, even given that the zodiacal signs do not line up neatly with modern constellations. They were scornful that I was unable to tell them where, say, Venus would be in 12 years time, or where it was when I was born.

So challenged, I set to.

The scientific algorithms for doing this are not entirely trivial. I got hold of a copy of Jean Meeus' Astronomical Algorithms, and it took me quite a lot of work to understand them, and then even longer to implement them so I could answer that sort of question. They are hopelessly and messily empirical (which I take as a good sign) - there is a daunting number of coefficients. Eventually I got it working, and could match observation to prediction of planetary positions to my satisfaction - when I looked at them, the planets were where my calculations said they should be, more or less.

It's hard with amateur equipment to measure accurate locations in the sky (e.g. how high and in which direction is a particular star at a particular time), but relative ones are much easier (e.g. how close is Venus to a particular star at a particular time). The gold standard for this sort of stuff is occultations - where you predict that a planet will occult (pass in front of) a star. There weren't any of those happening around the time I was doing it, but I was able to verify the calculations for other occultations that people had observed (and photographed) at the date and times I had calculated.

These days, software to calculate this stuff - and to visualise it, which I never managed - is widely available. There are many smartphone apps that will show you these calculations overlaid on to the sky when you hold your phone up to it. (Although IME their absolute accuracy isn't brilliant, which I think is due to the orientation sensors being not that good.) This makes checking these sorts of predictions very, very easy. Although of course you can't check that there isn't, say, a team of astronomers making observations and regularly adjusting the data that gets to your phone.

I was also able to independently replicate enough of Fred Espenak's NASA eclipse calculations to completely convince me he was right. (After I found several bugs in my own code.) Perhaps the most spectacular verification was replicating the calculations for the solar eclipse of 11 August 1999. I was also able to travel to the path of totality in France, and it turned up slap on time and in place. This was amazing, and I strongly urge anyone reading this to make the effort to travel to the path of totality of any eclipse they can.

Until I'd played around with these calculations, I hadn't appreciated just how spectacularly accurate they have to be. You only need a teeny-tiny error in the locations of the Sun/Moon/Earth system for the shadow cast by the moon on the Earth to be in a very different place.

I also replicated the calculations for the transit of Venus in 2004. I was able to observe it, and it took place exactly as predicted so far as I was able to measure - to within, say, 10 seconds or so. (I didn't replicate the calculations for the transit in 2012 - no time and I'd forgotten about how my ghastly mess of code worked - and I wasn't able to observe it either, since it was cloudy where I was at the time.)

More recently, you can calculate Iridium flares and ISS transits. Again, you have to be extremely accurate in calculations to be able to predict where they will occur, and they turn up as promised (except when it's cloudy). And again, there are plenty of websites and apps that will do the calculations for you. With a pair of high-magnification binoculars you can even see that the ISS isn't round.

All this isn't complete and perfect verification. But it's pretty good Bayesian evidence in the direction that all that stuff about orbits and satellites is true.

Comment author: dougclow 01 May 2014 11:03:01AM *  6 points [-]

One thing I should mention where I wasn't able to get a very good match between my own observations and mainstream science.

The Sun and the Moon are very, very close in their apparent diameter in the sky. They are almost exactly the same size. You can measure them yourself and compare, although this is a bit fiddly; I certainly got well within my own measurement errors, although those errors were large. However, you can verify it very easily and directly at the time of solar eclipses. They are so near in size that the wobbliness of the Moon's orbit means that sometimes the Sun is just-smaller than the Moon (when you get a total eclipse) and sometimes it is just-bigger (when you get an annular eclipse).

But they are very, very different in their actual size, and in their distance from the Earth. In Father Ted terms, the Moon is small and close; the Sun is large and far away. In rough terms, the Moon is 400,000 km away and 3,400 km across, and the Sun is 150m km away and 1.4m km across. You don't have to change any one of those four measurements much for them to be quite different apparent sizes from the Earth. Indeed, if you do the calculations (which I can personally attest to), if you go back far enough in time they weren't the same apparent size, and nor are they if you go forward a long way in to the future.

Why? Why this coincidence? And why is it only happening at just the times when humans are around to observe it?

So far as I know, we have no good theories apart from "it just happened to work out that way". This is pretty unsatisfying.

Comment author: Ford 14 July 2014 03:57:12PM 0 points [-]

There are so many possible coincidences, it would be surprising if none of them happened.

I observed 2012 transit of Venus, right on schedule.

Don't know an easy way to prove changing earth-moon distance, but changes in speed of earth's rotation can be seen as changes in number of days per year, visible in growth layers in fossil coral. Taking a magnifying glass to the right museum might allow individual verification.
http://www.nature.com/nature/journal/v197/n4871/abs/197948a0.html

Comment author: Plasmon 01 May 2014 06:21:59PM 0 points [-]

So far as I know, we have no good theories apart from "it just happened to work out that way". This is pretty unsatisfying.

Keep in mind that the earth-moon distance is not constant. The moon appeared larger in the past and will appear smaller in the future.

Comment author: Strilanc 01 May 2014 01:56:38PM 3 points [-]

Wow.

The closest analogue I have to that is grabbing planet positions and velocities from JPL's HORIZONS system, then doing small time steps holding accelerations constant.

That's how I know the (mathematical) solar system behaves as claimed. Except that Mercury's orbit will eventually become so elliptical and gain so much energy that it careens in and out of the solar system until it flies off to infinity (or people are also right about the limitations of the approximation technique I was using).

Comment author: buybuydandavis 01 May 2014 01:52:36AM *  3 points [-]

Is there an easily visible consequence of special relativity that you can see without specialized equipment?

Wasn't one verification of Einstein's theories the bending of starlight as observed in a solar eclipse?

....

Naturally, La Wik has an article on this. http://en.wikipedia.org/wiki/Tests_of_general_relativity#Deflection_of_light_by_the_Sun

Sounds like the light bending requires multiple simultaneously sightings around the world, while the perihelion precession of Mercury could be more easily verified with some diligence and a telescope.

http://en.wikipedia.org/wiki/Tests_of_general_relativity#Deflection_of_light_by_the_Sun

Oh, you wanted Special Relativity.

La Wik saves the day again! http://en.wikipedia.org/wiki/Tests_of_special_relativity

Comment author: Gunnar_Zarncke 30 April 2014 08:46:00PM 3 points [-]

Some genetics can be easily verfied. Some phenotypes are easy to spot: http://www.scienceprofonline.com/genetics/ten-human-genetic-traits-simple-inheritance.html Just sample a few of these and compare with parent-children pairs. This is much easier than trying Mendels pea experiments.

Comment author: christopherj 02 May 2014 12:29:58AM *  2 points [-]

As a general rule, the easiest way to verify a scientific discovery is to find out how the original discoverer did it and replicate their experiment. There are sometimes easier ways, and occasionally the discoverers used some expensive equipment... but mostly the requirement is some math and elbow grease/patience. Another advantage of replicating the original discovery is that you don't accidentally use unverified equipment or discoveries (ie equipment dependent on laws that were unknown at the time).

Comment author: asr 02 May 2014 06:43:43AM *  1 point [-]

Another advantage of replicating the original discovery is that you don't accidentally use unverified equipment or discoveries (ie equipment dependent on laws that were unknown at the time).

I don't consider this an advantage. My goal is to find vivid and direct demonstrations of scientific truths, and so I am happy to use things that are commonplace today, like telephones, computers, cameras, or what-have-you.

That said, I certainly would be interested in hearing about cases where there's something easy to see today that used to be hard -- is there something you have in mind?

Comment author: christopherj 02 May 2014 01:50:09PM 1 point [-]

I don't consider this an advantage. My goal is to find vivid and direct demonstrations of scientific truths, and so I am happy to use things that are commonplace today, like telephones, computers, cameras, or what-have-you.

Well, you could use your smartphone's accelerometer to verify the equations for centrifugal force, or its GPS to verify parts of special and general relativity, or the fact that its chip functions to verify parts of quantum mechanics. But I'm not sure how you can legitimately claim to be verifying anything; if you don't trust those laws how can you trust the phone? It would be like using a laser rangefinder to verify the speed of light. For this sort of thing the fact that your equipment functions is better evidence that the people who made it know the laws of physics, than any test you could do with it.

Comment author: asr 02 May 2014 02:44:20PM 1 point [-]

Well, you could use your smartphone's accelerometer to verify the equations for centrifugal force, or its GPS to verify parts of special and general relativity, or the fact that its chip functions to verify parts of quantum mechanics.

These don't feel like the are quite comparable to each other. I do really trust the accelerometer to measure acceleration. If I take my phone on the merry-go-round and it says "1.2 G", I believe it. I trust my GPS to measure position. But I only take on faith that the GPS had to account for time dilation to work right -- I don't really know anything about the internals of the GPS and so "trust us it works via relativity" isn't really compelling at an emotional level. For somebody who worked with GPS and really knew about the internals of the receiver, this might be a more compelling example.

But I'm not sure how you can legitimately claim to be verifying anything; if you don't trust those laws how can you trust the phone? It would be like using a laser rangefinder to verify the speed of light. For this sort of thing the fact that your equipment functions is better evidence that the people who made it know the laws of physics, than any test you could do with it.

Yes of course. In real life I'm perfectly happy to take on faith that everything in my undergraduate physics textbooks was true. But I want to experience it, not just read about it. And I think "my laser rangefinder works correctly" doesn't feel like experiencing the speed of light. In contrast, building my own rangefinder with a laser and a timing circuit would count as experiencing the speed of light.

I am starting to worry that my criteria for "experience" are idiosyncratic and that different people would find very different science demonstrations compelling.

Comment author: Lumifer 02 May 2014 03:05:15PM 0 points [-]

I am starting to worry that my criteria for "experience" are idiosyncratic and that different people would find very different science demonstrations compelling.

Otherwise known as the Typical Mind Fallacy :-)

But yes, you are correct, as long as your main criterion is something like "compelling at an emotional level", you should expect that different people understand it very differently.

Comment author: asr 02 May 2014 03:31:31PM 0 points [-]

But yes, you are correct, as long as your main criterion is something like "compelling at an emotional level", you should expect that different people understand it very differently.

This actually brings out something I had never thought about before. When I am reading or reviewing papers professionally, mostly the dispute between reviewers is about how interesting the topic is, not about whether the evidence is convincing. Likewise my impression about the history of physics is that mostly the professionals were in agreement about what would constitute evidence.

So it's striking that when I put aside my "working computer scientist" hat and put on my "amateur natural scientist" hat, suddenly that consensus goes away and everybody disagrees about what's convincing.

Comment author: Lumifer 02 May 2014 04:18:30PM 1 point [-]

mostly the dispute between reviewers is about how interesting the topic is, not about whether the evidence is convincing.

That may be a peculiarity of physics (and math). Compare that to biology and medicine, not to mention social sciences.

everybody disagrees about what's convincing

Well, of course, because "compelling at an emotional level" isn't really about evidence. Cute puppies are compelling at an emotional level.

You're basically talking about getting a "proper" gut feeling, and that is very idiosyncratic.

Comment author: Douglas_Knight 02 May 2014 10:04:51PM 0 points [-]

mostly the dispute between reviewers is about how interesting the topic is, not about whether the evidence is convincing

Your observation of little conflict about whether the evidence is convincing could be explained by a consensus about whether it is convincing, but it could also be explained as low priority. That is my experience in math.

Comment author: Douglas_Knight 30 April 2014 10:44:21PM 2 points [-]

It is odd that you highlight the Bedford Level Experiment, rather than other methods that have been used for thousands of years. The new experiment has the advantage that it can be performed by a single person in a single afternoon. It has the disadvantage that it shows that the Earth is flat.

Eratosthenes measured the north-south curvature of the Earth by making observations separated by hundreds of miles. It could be applied east-west with good clocks, or, as you suggest, with the simultaneity of telephones. Since I'd have to travel hundreds of miles anyway to reach the straight canal in Bedford, it has little advantage over Eratosthenes's method. I suppose you could make a similar observation by climbing a mast on a ship the right distance from shore, but the ocean waves add noise not present on the canal. It does have the advantage of requiring less geometry. Since the Bedford experiment used 1/100 the distance, it required 100x the accuracy of angular measurement. This is easy to overlook, since the measurement is not phrased that way, but I think this is why it encounters new sources of error.

Older experiments are generally easier. While everything is easier to measure today, the main advance is in measuring time.

Comment author: dougclow 01 May 2014 10:38:29AM *  2 points [-]

Bedford Level Experiment [...] has the disadvantage that it shows that the Earth is flat.

I love this. As it happens, I live quite near Bedford and am terribly tempted to actually try it one day. (Edit Looking closer, turns out the Bedford Level is in Norfolk, not Bedfordshire, so a little less nearby than I thought.)

There are loads of fun ways of verifying that the Earth isn't flat. Some of these were easily available to the ancients - e.g. the shape of the shadow of the Earth on the Moon during a lunar eclipse (it's always a curve). Others are easier now than they used to be - e.g. the variations in the constellations you can see as you travel north-south (it's much easier to travel far enough to see this than it used to be).

Some, however, simply weren't available.

My favourite explanation for how we know for sure the Earth is round is that we've been up in to space and looked. You can even verify this yourself with a GoPro and a high-altitude balloon, which many hobbyists have done.

Comment author: CellBioGuy 30 April 2014 10:39:39PM 2 points [-]

Is there an easily visible consequence of special relativity that you can see without specialized equipment?

To a point, classical electromagnetism. You can treat the B field as the difference due to special relativity between the E field of a stationary arrangement of particles and the E field of that arrangement in motion. Also when you change the reference frame you view an arrangement of moving charges in, you see the force they feel as having come from different combinations of electric and magnetic fields but always adding up to the same thing.

http://en.wikipedia.org/wiki/Relativistic_electromagnetism

http://en.wikipedia.org/wiki/Classical_electromagnetism_and_special_relativity

Comment author: Douglas_Knight 30 April 2014 10:47:29PM *  2 points [-]

That was Einstein's argument: Maxwell's equations are not compatible with Galilean relativity. But we observe Maxwell's laws to be true in all seasons, so some relativity must apply.

Comment author: Lumifer 30 April 2014 08:35:56PM *  3 points [-]

Is there an easily visible consequence of special relativity that you can see without specialized equipment?

A working GPS receiver.

In general, things like a smartphone "verify" a great deal of modern science.

Just direct observation, by the way, gives you little. Yes, you can observe discontinuous spectra of fluorescent lights. So what? This does not prove quantum mechanics in any way, this is merely consistent with quantum mechanics, just as it is consistent with a large variety of other explanations.

How much can you directly demonstrate in biology or the social sciences?

In biology, it really depends on what do you want demonstrate. For some things a frog and a scalpel will be sufficient :-/ Or maybe just a scalpel X-D

Comment author: Emile 30 April 2014 08:47:57PM 8 points [-]

Is there an easily visible consequence of special relativity that you can see without specialized equipment?

A working GPS receiver.

I only believe that depends on special relativity because I was told so; if I'm so skeptical I suspect that scientist lied to me about special relativity, then I should be equally suspectful of engineers telling me GPSes have to take special relativity into account to work right.

Comment author: dougclow 01 May 2014 09:48:51AM 0 points [-]

If you are at all mathematical, you can verify that relativity affects GPS signals by calculating what difference both special relativity (satellite clock moving faster than clock on Earth, hence slower) and general relativity (satellite clock higher up the gravitational field than clock on Earth) would make to timekeeping and hence accuracy of location. The effects work against each other, but one is larger than the other.

You can verify accuracy of location of a GPS yourself. IME this is almost always considerably less accurate than published estimates by the device manufacturer, but still impressive. However, you need to be careful - most smartphones use multiple technologies to determine their location, not just GPS, so will be more accurate than the GPS signal can possibly be.

Comment author: Emile 04 May 2014 08:08:36AM 0 points [-]

But 1) even if I measure a GPS's accuracy, I can't distinguish errors caused by relativity from other instrument errors, and 2) GPS devices and satellites already try to correct for relativity, so the error I'll be observing is the error in correction.

Comment author: asr 30 April 2014 08:53:56PM 3 points [-]

Is there an easily visible consequence of special relativity that you can see without specialized equipment?

A working GPS receiver.

In general, things like a smartphone "verify" a great deal of modern science.

Yah. Though the immediacy of the verification will vary. When I use my cell phone, I really feel it that information is being carried by radio waves that don't penetrate metal. But I never found the GPS example quite compelling; people assure me "oh yes we needed relativity to get it to work right" and of course I believe them, but I've never seen the details presented and so this doesn't impress me at an emotional level.

I don't know how much my feelings here are idiosyncratic; how similar are different people in what sorts of observations make a big impression on them?

Just direct observation, by the way, gives you little. Yes, you can observe discontinuous spectra of fluorescent lights. So what? This does not prove quantum mechanics in any way, this is merely consistent with quantum mechanics, just as it is consistent with a large variety of other explanations.

I'm not so sure about "consistent with a large variety of other explanations" -- my impression is that nobody was able to come up with a believable theory of spectroscopy before Bohr. Can you point to a non-quantum explanation that ever seemed plausible? Furthermore once you say "okay, spectral lines are due to electron energy-level transitions", you wind up intellectually committed to a whole lot of other things, notably the Pauli exclusion rule.

Comment author: shminux 30 April 2014 08:45:47PM *  2 points [-]

Can you measure the consistency of the velocity of light on your own?

Various ways to measure the speed of light. Many require few modern implements. How to measure constancy of the speed of light -- the original experiment, does not require any complicated or mysterious equipment, only careful design.

Is there an easily visible consequence of special relativity that you can see without specialized equipment?

Off the top of my head, the time dilation effect on muons, which can be seen with a cloud chamber. Less directly, most magnetic fields result from observing electric fields in a moving frame.

Comment author: asr 30 April 2014 09:16:38PM *  3 points [-]

Various ways to measure the speed of light. Many require few modern implements. How to measure constancy of the speed of light -- the original experiment, does not require any complicated or mysterious equipment, only careful design.

The early measurements of the speed of light don't require "modern implements." They do require quite sophisticated engineering or measurement. In particular, the astronomical measurements are not easy at all. Playing the"how would I prove X to myself" game brought home to me just how hard science is. Already by the 18th century and certainly by the 19th, professional astronomers were sophisticated enough to do measurements I couldn't easily match without extensive practice and a real equipment budget.

Suppose you were going to measure the speed of light by astronomy. Stellar aberration seems like the easiest approach, and that's a shift of 20 arcseconds across a time interval of six months. This is probably within my capacities to measure, but it's the sort of thing you would have to work at. It would be a year-long or years-long observation program requiring close attention to detail. In particular, if I wanted a measurement of the speed of light accurate to within 10% I would need my measurement to have error bars of about 2 arcseconds. I suspect an amateur who knew what they were doing could manage it, but it's not something you would just stumble onto as a casual observation.

Comment author: Eugine_Nier 01 May 2014 04:25:50AM 1 point [-]

Suppose you distrusted everything you had ever read about science. How much of modern scientific knowledge could you verify for yourself, using only your own senses and the sort of equipment you could easily obtain? How about if you accept third-party evidence when many thousands of people can easily check the facts?

Interestingly enough, this was the original idea behind science. Hence, the motto of the royal society nullius in verba, or in English "Take no one's word for it".

Comment author: Stabilizer 30 April 2014 08:30:22PM 1 point [-]

This is a very interesting game. At a meta-level though, my belief in a lot of science is grounded in its usefulness. If people who believe in Newtonian physics can make me float in the air in a gigantic metal tube hurtling at 500 miles/hr while I sip my Coke, I suspect their belief is well-justified.

Comment author: Jayson_Virissimo 01 May 2014 01:59:23AM *  6 points [-]

This is a very interesting game. At a meta-level though, my belief in a lot of science is grounded in its usefulness. If people who believe in Newtonian physics can make me float in the air in a gigantic metal tube hurtling at 500 miles/hr while I sip my Coke, I suspect their belief is well-justified.

Yes, and many a medieval could have reasoned thusly:

If these people can contruct such a magnificent thing as Amiens Cathedral, I suspect their beliefs are well-justified.

Comment author: dougclow 01 May 2014 09:41:24AM 8 points [-]

To be fair to the medieval, their theories about how one can build large, beautiful buildings were pretty sound.

Comment author: kokotajlod 08 May 2014 04:09:38PM 0 points [-]

Similarly, modern theories about how to discover the habits of God in governing Creation (the Laws of Nature) are pretty sound as well. Or so theists say.

A better example than Amiens Cathedral would be the Placebo Effect. For most of human history, people with access to lots of data (but no notion of the Placebo Effect) had every reason to believe that e.g. witch doctors, faith healing, etc. was all correct.

Warning: Rampant speculation about a theory of low probability: Consider the corresponding theory about science. Maybe there is a Placebo Effect going on with the laws of nature and even engineering, whereby things work partly because we think they will work. How could this be? Well, we don't understand how the placebo effect could be either. God is a decent explanation--maybe airplanes are his way of rewarding us for spending so much time thinking rationally about the principles of flight. Maybe if we spent enough time thinking rationally about the principles of faster-than-light travel, he would change things behind the scenes so that it became possible.

Comment author: gwern 08 May 2014 11:45:57PM 0 points [-]
Comment author: kokotajlod 09 May 2014 04:07:26AM 0 points [-]

I didn't mean to imply that the placebo effect is a complete mystery. As you say, perhaps it is pretty well understood. But that doesn't touch my overall point which is that before modern medicine (and modern explanations for the placebo effect) people would have had plenty of evidence that e.g. faith healing worked, and that therefore spirits/gods/etc. existed.

Comment author: gwern 09 May 2014 11:04:54PM 0 points [-]

Yes, but they would have been dead wrong about everything they thought about the supernatural, not just the placebo effect. Thus if anyone were to suggest

Consider the corresponding theory about science. Maybe there is a Placebo Effect going on with the laws of nature and even engineering, whereby things work partly because we think they will work. How could this be? Well, we don't understand how the placebo effect could be either. God is a decent explanation--maybe airplanes are his way of rewarding us for spending so much time thinking rationally about the principles of flight. Maybe if we spent enough time thinking rationally about the principles of faster-than-light travel, he would change things behind the scenes so that it became possible.

The example of the placebo effect would work against this theory: "people were completely and totally wrong about beliefs affecting reality before and it turned out to be some artifacts of selection bias / regression to the mean / relaxation / evolutionarily-based allocation of bodily resources, and so I disbelieve in your suggestion even more than I would just on its merits because clearly people are not good at this sort of thinking".

Comment author: kokotajlod 11 May 2014 05:38:06AM -1 points [-]

No, the analogy I had in mind was this:

What People Saw: Acupuncture* being correlated with health, and [building things according to theories developed using the scientific method] being correlated with [having things that work very well]

What People Thought Happened: Acupuncture causing health and [building things according to theories developed using the scientific method] causing [having things that work very well]

What Actually Happened: Placebo effect and Placebo effect (in the former case, involving whatever mechanisms we think cause the placebo effect these days; in the latter case, involving e.g. God.)

people were completely and totally wrong about beliefs affecting reality before

Filtering out all the selection bias etc., the relaxation and evolutionarily-based allocation of bodily resources seem to work fine for my purposes. They are analogous to theism-based allocation of technological power.

Comment author: Stabilizer 01 May 2014 04:07:10PM 2 points [-]

Point taken: useful beliefs are not necessarily true beliefs.

That being said, in this particular case, belief in Jesus Christ wasn't necessary for the cathedral to be built. If you, as a medieval, saw that the Muslims and Hindus too were building magnificent things, then you should conclude that belief in a particular god in inessential (you're still allowed to conclude to that it is well-justified to believe in a god).

With airplanes, the belief in Newtonian physics is essential.

Comment author: Jayson_Virissimo 01 May 2014 05:43:02PM *  5 points [-]

That being said, in this particular case, belief in Jesus Christ wasn't necessary for the cathedral to be built.

Sure, but in order conclude so you'd have to go beyond the people who believe x can make fancy technology y, so I suspect x is a well-justified belief heuristic.

With airplanes, the belief in Newtonian physics is essential.

My understanding of history is that this is not the case. Not too long before some bicycle mechanics were building the first airplane, prominent Newtonian physicists were saying things like "heavier than air flying machines are impossible."

Comment author: satt 02 May 2014 01:26:51AM 2 points [-]

While some bicycle mechanics were building the first airplane, prominent Newtonian physicists were saying things like "heavier than air flying machines are impossible."

Specifically, "I have not the smallest molecule of faith in aerial navigation other than ballooning or of expectation of good results from any of the trials we hear of." (Wikiquote seems to imply the "heavier than air" quotation is a misquotation.) And Kelvin wrote that in 1896, when the Wright brothers were building bicycles rather than flying machines; they didn't start on the latter until 1899.

(I upvoted the parent comment because its basic point is sound, but I don't want to look like I'm upvoting the debatable history.)

Comment author: Jayson_Virissimo 02 May 2014 01:47:45AM 2 points [-]

In case anyone was wondering, I had changed the wording of the part satt quoted before he or she posted this comment, because I thought it sounded kind of misleading (which apparently I was right about). Good catch on the possible misquote, that was from memory.

Comment author: satt 02 May 2014 02:21:32AM 0 points [-]

I need to learn to Google more quickly!

Comment author: CasioTheSane 01 May 2014 11:12:12AM *  0 points [-]

I have been attempting to do this with biology and medicine, seriously for about 5 years now. Not by actually repeating experiments, but in trying to understand the original evidence, and see if I agree that it was interpreted correctly. Of course this is nearly impossible as biology is too broad and complex for one person to understand all of the details.

It's a confusing mess, but I think I am still learning a lot. Even if I come to agree with most of the mainstream ideas, I'd like to think I'd then understand them more deeply, in a way that is more functionally useful.

For much of medicine, there really isn't any biological basis or evidence to review. Much of modern medicine involves covering up symptoms with drugs proven to do this, without understanding the underlying cause of the symptom.

Comment author: dougclow 01 May 2014 03:52:19PM *  7 points [-]

Much of modern medicine involves covering up symptoms with drugs proven to do this, without understanding the underlying cause of the symptom.

What, really? There certainly is a lot of that approach around, but it's not what I think of when I think of modern medicine, as opposed to more traditional forms. Can you give examples?

Most of the ones I can think of are things that have fallen to the modern turn to evidence-based practice. The poster-child one in my head is the story of H. pylori and how a better understanding of the causes of gastritis and gastric ulcers has led to better treatments than the old symptom-relieving approaches. (And I'll tell you what, although Zantac/Ranitidine is only a symptomatic reliever, it was designed to do that job based on a thorough understanding of how that symptom comes about, and it's bloody good at it, as anyone who's had it for bad heartburn or reflux can attest.)

When I think of modern medicine, I think of things like Rituximab, which is a monoclonal antibody designed with a very sophisticated understanding of how the body's immune system works - it targets B cells specifically, and has revolutionised drug treatment for diseases like non-Hodgkin's lymphomas where you want to get rid of B cells. So much so that for some of those lymphomas, we don't have very robust 5 year survival data, because the improvement over traditional chemotherapy alone is so large that the old survival data is no use (we know people will live much longer than that), and Rituximab hasn't been widely used for long enough to get new data. In the last 25 years our understanding of cancer has gone from "it's mutations in the genes, probably these ones" to vast databases of which specific mutations at which specific locations on which specific genes are associated with which specific cancer symptoms, and how those are correlated with prognosis and treatment. And as a result cancer survival rates have improved markedly. We don't have "A Cure For Cancer", and we now know we never will, any more than we can have "A Cure For Infection", but we do have a good enough understanding of how it happens to get much better at reducing its impact.

Even modern medical disasters like Vioxx are hardly a result of a lack of understanding the underlying cause, but more us learning more about other complexities of human biology. Admittedly we don't yet fully understand how pain works, but we do know enough to know that targeting COX-2 exclusively (rather than COX-1 as well, which looks after your gut lining) would be safer for your gut. This is understanding down at the molecular level. It turns out in large scale studies that they are safer for your gut, but of course they're not very safe for your heart, so we've stopped using them. And actually doing the full-scale research on modern rationally-designed drugs like Vioxx suggests that similar old drugs (that we never bothered to test) have the same effect on hearts.

Comment author: Lumifer 01 May 2014 04:42:22PM *  2 points [-]

Can you give examples?

I think that for most autoimmune disorders the "modern medical" approach is to ameliorate the symptoms and that's about it.

CVD, the main killer in the developed world, is rather poorly understood. Oh, sure, we know the details of how the atherosclerotic process works, we just don't quite know what drives it. Or take a look at the metabolic syndrome -- even the name (a syndrome is a collection of symptoms, more or less) gives it away. Can we treat it other than by prescribing a bunch of statins and saying "eat less"? Can we cure diabetes, a VERY widespread ailment?

And that's even for diagnosable diseases. It's hard to find statistics, but it seems that it's not uncommon for people to be... suboptimal and the medicine just doesn't know what's happening inside them.

Comment author: CasioTheSane 01 May 2014 06:50:55PM *  2 points [-]

You're right, we do understand the pathophysiology of many diseases, and those are the ones that have been mostly eradicated. The major chronic diseases that remain are very poorly understood such as type II diabetes, cancer, cardiovascular disease, and alzheimer's.

I spend a lot of time reading about 'alternative' ideas about these diseases, and many seem promising, but aren't taken seriously by the mainstream. It's definitely possible that they're ignored for a good reason, but I haven't been able to find the reasons yet. This is the biggest problem I've found with trying to be 'critical of everything.' In very few instances do I find myself quickly understanding and agreeing with the mainstream view. Instead, the more I read the more my opinion seems to diverge from the mainstream view. I have made an effort to discuss these issues personally with specialized experts, so they could help point out factors I may be missing, or not understanding correctly. I am a PhD candidate in the life sciences, so I have the opportunity to meet with research professors at my university in person to help clarify my understanding.

Here are two example theories, regarding cancer and cardiovascular disease in particular.

1) The idea that cancer isn't initiated by genetic mutations, but that mutations are a downstream phenomena that results after damage to the mitochondria occurs.

This stems from the initial observation by Warburg, that lack of control over glycolysis is part of the cancer cell phenotype. This phenotype can be triggered by a large number of factors which inhibit mitochondrial respiration including hypoxia. Later it was found that the mitochondria in cancer cells undergo a phenotypic change, where the cristae structure is lost. Nuclear transfer experiments have shown that a 'mutated' cancer nucleus placed into a healthy cell cytoplasm does not exhibit a heritable cancer phenotype. Conversely, a healthy nucleus placed into a cancerous cell cytoplasm does exhibit a heritable cancer phenotype.

Here is a review article covering the evidence for this hypothesis:

Cancer as a metabolic disease: implications for novel therapeutics http://carcin.oxfordjournals.org/content/35/3/515

More evidence for this hypothesis includes the observation that active thyroid hormone levels (T3) are inversely correlated with cancer mortality rates in the general population. T3 is a key regulator of mitochondrial respiration:

Thyroid hormones and mortality risk in euthyroid individuals: The Kangbuk Samsung Health Study. http://www.ncbi.nlm.nih.gov/pubmed/24708095

2) The finding that treatment for hypothyroidism drops cholesterol levels significantly, and virtually abolishes cardiovascular disease without the side effects seen from statins. The late Broda O. Barnes was an experimental endocrinologist and a clinical doctor, and he extensively documented this phenomena in his books and publications.

The idea here is that the central mechanism of cardiovascular disese is a low metabolism which inhibits cholesterol clearance from the blood via reduced steroid hormone synthesis, and reduced bile synthesis. The pathophysiology of cardiovascular disease begins with a long residence time of cholesterol particles in the blood, resulting in their oxidation. This can be reversed by any strategy that restores a normal (higher) metabolic rate: a carefully designed diet and/or thyroid hormone supplementation.

Here is a good introduction to this idea:

The Central Role of Thyroid Hormone in Governing LDL Receptor Activity and the Risk of Heart Disease http://blog.cholesterol-and-health.com/2011/08/central-role-of-thyroid-hormone-in.html

I am not insisting that these ideas are correct, or are some sort of 'well proven answer' to these diseases. I'm just pointing out that they seem promising, but are relatively ignored. If they prove accurate, much of the mainstream research on these phenomena would seem to be barking up the wrong tree.

You might notice that both of these examples are essentially the same theory. This is an appealing concept to me: most age-related chronic diseases may be centered around a common process of age related impaired mitochondrial function and/or improper hormonal regulation of mitochondrial function. Insufficient chemical energy (ATP) to fuel normal biological function would have widespread consequences, and could present as a diverse array of seemingly disconnected symptoms. I'll admit, this sounds somewhat like a modern molecular version of vitalism. However, unlike vitalism it makes specific testable predictions, and involves a very specific mechanism. It's also consistent with the 'free radical' and 'tissue peroxidizability index' theories of aging, which involve (among other things) progressive oxidative damage of unsaturated fats (such as cardiolipin) in the mitochondrial inner membrane.

Comment author: Adele_L 03 May 2014 08:42:36PM 1 point [-]

Is there an easily visible consequence of special relativity that you can see without specialized equipment?

If you're willing to accept quantum mechanics/nuclear physics, you can calculate that Gold would be white instead of yellow if it weren't for relativistic effects.

Comment author: Ford 02 May 2014 09:38:30PM *  1 point [-]

Great post!

Evolution of antibiotic resistance is indeed fairly easy, but how about evolving something visibly different? Evolution of simple multicellularity from a unicellular ancestor is easier than you might think: http://www.snowflakeyeastlab.com/

If we can solve the earth-orbits-the-sun problem, we don't need to measure the parallax of stars accurately to show that they're really far away, which seems like an important scientific truth.

Comment author: jkaufman 09 May 2014 06:07:41PM *  0 points [-]

You want books for middle school science teachers.

EDIT: not saying that even most books in this category or what you want, but that many of the books you want are in this category.

Comment author: Nornagest 09 May 2014 06:40:34PM 6 points [-]

What I remember of middle-school science had less to do with reproducing basic results and more to do with memorizing lists of organelles and looking at rotifers under a microscope.

Comment author: asr 10 May 2014 04:06:32AM *  0 points [-]

Yes. Perhaps we might say, this is what middle school or high school science should be.

Likewise direct demonstrations are the sort of thing I wish science museums focused on more clearly. Often they have 75% of it, but the story of "this experiment shows X" gets lost in the "whoa, cool". I'm in favor of neat stuff, but I wish they explained better what insight the viewer should have.

Comment author: CAE_Jones 09 May 2014 09:38:52PM 0 points [-]

Same, here. To get a course that taught replication and experimental design and analysis, I had to go to a residential high school specifically for Math and Science. It was a required first-semester course that spent a lot of time on how to enter data into a calculator and generate graphs/t tests/etc, and I had this nasty habit of spacing out and still completing the assignments. Suffice it to say, I was not prepared for college Physics.

I only ever had one teacher in public school who put emphasis on the science part, but that was primarily in the evaluation I got at the end of the course; meanwhile, I'd been reading Hypephysics and had been commenting excitedly about the particle zoo in the time before the bell, to no good reaction from anyone. Needless to say, rather than getting the point, I applied for the afore-mentioned Math and Science school.

Middle school science was all memorizing lists and labeling diagrams. Hell, College Biology 101 was all memorizing definitions and labeling diagrams and occasionally poking dead animals (in order to label more diagrams).

Comment author: Douglas_Knight 09 May 2014 09:21:51PM 0 points [-]

Have you looked at such books? If so, why not name specific ones?

Do you have such faith in this class of books that you recommend I choose for this class arbitrarily? I'll try that: half of the hits on the first page of google are for this book, but I haven't figured out what it is even about. Amazon then suggests this book which is about easy projects. At least I know what that means.

Comment author: TheMajor 07 May 2014 06:07:52AM *  0 points [-]

For testing Quantum Mechanics a relatively easy thing to test is the Hall Effect.

Comment author: 2ZctE 03 May 2014 08:20:26PM 0 points [-]

This book seems like it could be relevant, but I haven't read it:

http://www.amazon.com/Exploring-Quantum-Physics-through-Projects/dp/1118140664/

Comment author: Gunnar_Zarncke 30 April 2014 09:09:02PM 0 points [-]

If you allow indirect evidence, then the rotation of the earth around the sun follows from the seasons which are easy to observe. Or rather from the earthes tilt. Given that you confirmed a) constant (almost) distance to the sun, b) conservation of angular momentum (via observation of spinning tops), c) changing angle of midday sunlight thru the year the only remaining conclusion is that the earth circles the sun.

Almost. you have to exclude that precession of the eath is causing the changing tilt. You'd have to estimate the amount of precession (http://en.wikipedia.org/wiki/Precession#Classical_.28Newtonian.29) which should be possible given some rough estimates of the mass of the earth.

Comment author: Jayson_Virissimo 01 May 2014 01:49:49AM *  0 points [-]

Heliocentrism isn't the only theory that implies the existence of the seasons:

The motion of the sun eastward along the ecliptic combined with the rotation of the stars westward along the equator to account for seasonal changes in the length of daylight, while moving the circle of the sun's motion slightly off-center toward Gemini adjusted for the inequality of the seasons. The resulting extremes of apogee and perigee of the sun also explained for writers on the sphere why the arctic regions are too cold, and the southern hemisphere is too hot, to be habitable; the intermediate region of habitation was divided into seven climes according to half-hour differences in the length of the solstitial day. Yet another very slow motion of the celestial sphere about the poles of the ecliptic produced the gradual drift, or precession, of the equinoctial and solstitial points eastward along the zodiac; in some accounts, e.g. Robert Grosseteste's (ca. 1215-1230), this Ptolemaic device was supplanted by Thâbit b. Qurra's more intricate mechanism for non-uniform precession, or trepidation.

-- M. S. Mahoney, Dictionary of the Middle Ages

Comment author: Douglas_Knight 01 May 2014 02:11:22AM 1 point [-]

How is that a response? Gunnar didn't say "Heliocentrism, hallelujah!" He emphasized conservation of angular momentum. Maybe one should be skeptical about extrapolating that from Earth to Heaven, but just saying "I made an orrery! Look at me!" is not helpful.

Comment author: Jayson_Virissimo 01 May 2014 02:19:43AM *  2 points [-]

Yeah, it looks as if I may have missed the main point. Sorry about that.

Comment author: Douglas_Knight 01 May 2014 03:06:04AM *  4 points [-]

I'm just happy to get to use the word "orrery."