Showing posts with label science. Show all posts
Showing posts with label science. Show all posts

Wednesday, December 19, 2012

Why You Probably Suck At Science

Let me get right into this post without the whole pointless pre-introduction I often do*: you probably suck at science, even if you think you know about it. I say probably just because there very well could be those out there who do know everything I'm about to say, but your average person will not be. Now, let me say here why I'm doing this post. While I like the fact that science is becoming a buzzword of sorts (think Portal), I also think it's sort of cheapening the concept a little - science encompasses so much that isn't even suggested in the phrase "Look at me still talking // While there's science to do." And while I will recognise that that is a source of the humour - the incongruity - and with my disclaimer that I really enjoy that song, and the series in general, I think that this comes at the expense of reducing the word 'science' to some sort of inherently funny word. I offer this epilepsy-inducing video as a sort of logical conclusion to the whole thing. So consider this post as an antidote of sorts to the whole thing.

First, let me explain why your brain probably sucks at science - we didn't evolve to do science. We evolved to survive. Yes, we're clearly intelligent, and we've had massive scientific technological leaps forward, but that doesn't mean that we don't still contain within us those ideas, biases and limitations that were excellent for surviving in a hunter-gatherer survival-of-the-fittest environment but not so good when figuring out how to get to the moon. And if for some reason you don't think evolution is a thing*, well, I will get to that.

I'm going to start with showing you an example of how your brain can not understand things on any level other than an intellectual one. When you feel yourself starting to fail to grasp what I'm saying, then you will see just one example of what I mean when I say your brain probably sucks at science.

The most simple example is scale. Imagine a single object; let's say an apple for no particular reason. It's pretty easy. Now imagine a second apple. How about a third*? Alright, let's jump to 10. But, that's too easy. Imagine 100 apples. If you're anything like me, it's getting somewhat difficult, but not impossible - you might be imagining a square of 100 apples, 10 by 10 on each side. Alright, we just multiplied by 10. Let's do it again. 1000. No: 10000. Can you imagine 10,000 apples? Can you? It is at about this point that your brain is really starting to give up - you didn't evolve to think of so many apples. Nobody had 10,000 apples back when we were evolving. There just wasn't a point to thinking of so many apples. Now think of this: can you, on a gut level, imagine the difference between one million and ten million apples? How about ten billion? If you can't imagine them (and you almost definitely can't), then you can't really tell the difference properly. You know one is ten times the other. But if someone gave you a truckload of apples, how could you tell how many there were?

As it happens, there are many ways to figure this out. You could weigh the truckload of apples then divide by the weight of one apple. You could put the apples in a pile and do some clever multiplication to estimate how many there are. There's a common theme you'll find when figuring this out: you'll be using maths. I'm going to bold this next sentence, because it's an important one: When dealing with large enough numbers, mathematics is the only way to go.

This is extremely important in science since large numbers are everywhere. Take the number of stars in the Milky Way. There are around 30 billion stars in our galaxy. Except, no, I lied just then, there are actually around 300 billion stars*. You will notice that you don't actually know the difference properly between those figures - your impression of how many stars there are hasn't actually changed. So we need to turn to maths - we can manipulate the number 300 billion far better with equations than we can in our heads.

Let's take, for example, the origin of life, simply because I have an article on hand about it, which you can read here. It says, for all those who don't want to read it, that the simplest theoretical building block of life, had, in the primordial oceans, a one in 1040 chance of coming into being for every trial (mouseover this text for a note on scientific notation). I won't get into the details, but, that means that for every ten thousand trillion trillion trillion events, one building block of life was formed. Your brain can't even begin to process that level of improbability, so we're using maths. Now, you might think that this means that according to science, the odds are incredibly small that life would ever arise on Earth. Well, that's where you're mistaken. According to the article, if you let the volume of the ocean be 1024 litres (which I can't personally speak for the veracity of, but I'm no expert), and let the concentration of ingredients be 10-6 M (roughly on the order of dissolving one grain of salt in a litre of water, apparently a very conservative estimate), then a significant number of building blocks of life. How many you ask? Around 1031, or 10 million trillion trillion building blocks.

Again, huge numbers we're talking about here, and it's all thanks to maths. Your brain by itself couldn't come up with stuff like this. And here's the thing - so many problems in science can be solved with large numbers. The odds that any one planet is suitable for life are small - but with so many planets around so many stars, suddenly the odds that at least one planet become so much larger. Evolution from single-celled organisms to everything we see today through random mutations may seem impossible, but after 4 billion years (again, a number we just can't cope with properly), a heck of a lot of evolution is done. There's even an idea in string theory in which the problem where the universe seems fine-tuned for life because there are so many universes, the odds that one universe is suitable for life becomes pretty damn good.

So that's one example of your brain just not being able to comprehend something because we didn't evolve to comprehend - it wasn't helpful. Another example would be quantum physics*. Take, for example, something called Bell's theorem, which I've picked because it's incredibly fascinating, as well as being something most people don't know about.

This all starts with Einstein - he hated quantum physics. You may have heard his quote "God does not play dice with the universe." Well, he and two other colleagues, Boris Podolsky and Nathan Rosen, found what they thought to be a proof that quantum mechanics was incomplete - a summary may be found here. This incompleteness relied on two things: that the universe had both locality and realism. Locality is pretty simple - if you want to affect one thing, you have to move through space to do it. If you blow on a ball to get it rolling, you move air from your mouth to the ball. Light moves through space. Gravity moves through space*. It makes sense. Realism is slightly trickier, but it just means that no matter if we observe them or not, objects have definite properties - the usual definition being something along the lines of "the moon is always there, even if we don't see it." It doesn't just disappear when we're all not looking at it. Quantum mechanically speaking, it's a little more complicated than that, due to Heisenberg's Uncertainty Principle, but at the time, that was only thought to be an observation problem, in which when we observe something, we change it. But that's roughly what realism is.

Now, about 30 years after this paper, a man named John Stewart Bell came along and found that there was a way to test if this paradox applied. It didn't. In other words: either locality or realism (or both) were wrong. They could not simultaneously be right. The details are a bit technical, but that was the gist of it. So now we have to give up basic principles of the universe that we as humans take for granted: that objects have to move through space to affect other objects, and/or that these objects have definite properties. Welcome to quantum physics, and welcome to your brain being incapable of dealing with it.

So now I believe I have shown you fairly conclusively that our brains are not equipped to deal with a lot of modern concepts in science, as well as the scale at which most of these concepts apply. But humanity's pretty smart, right? We're intelligent - we can work past this, right? We can do precise experiments and analyse them to figure out exactly what secrets nature is hiding. Just because we can't really grasp the difference between one and ten billion (for example) doesn't mean our carefully designed experiments can't. What's stopping us?

Well, out brains, for one. Forgetting the whole aspects of nature we can't understand on any basis other than an intellectual one, we also naturally suck at doing experiments. Essentially, we were not made to be objective, which science demands. This talk by Michael Shermer is simply fantastic, and really sums up much of what I'm going to say in this next paragraph, which is heavily inspired by (read: practically stolen from) this video.

I want you to imagine you're HG from my post about two weeks ago - you're back in hunter-gatherer society, and you're out looking for food. You're walking alongside tall grass, spear in hand, when suddenly you hear a rustle. What could it be? You're not sure - it might be the wind, or it might be a lion ready to leap out and make short work of you. What should you do? You could either get ready to go - fight-or-flight time - or you could ignore it. If you get ready and it's nothing, you live to fight another day! But, if you ignore it and it's a lion, then well, you're lunch.

But what does this mean? Well, pretty much, those who see the false pattern of rustling grass = lion are better at surviving than those who just see the coincidence of rustling grass = wind. So there's already a bias when we do experiments - we tend to see false patterns. Shermer calls this patternicity.

There's also some more problems in doing experiments. One huge problem is called confirmation bias. Essentially, as humans, we expect to see the evidence that fits our theory. Why else would we have the theory, right?

Allow me to tell you a cautionary tale about something called N-rays, which I was introduced to by Eliezer Yudkowsky, who's just fantastic when it comes to this stuff. He's writing "Harry Potter and the Methods of Rationality" (found in the sidebar), and, well, look out for a post soon* on the Sequences.
 
In 1903, a French physicist named Prosper-René Blondlot came across what he thought to be a new type of radiation, which could be observed when it was focused through an aluminium prism in a certain apparatus and you looked really carefully at a certain type of screen, which would glow slightly*. But many physicists, especially in England and Germany, who couldn't see that glow. So Blondlot decided to set up an experiment to demonstrate the existence of these rays. And he did the experiment and everything went as expected - everyone saw the rays, and it was all good.

Except, and here's the kicker, an American physicist named Robert Wood had changed the apparatus without telling anyone - he removed the prism and the object that was to be emitting the N-rays.

So what's the point of this story? Well, remember: there were a lot of physicists who saw the effects of those rays - even though those rays did not exist. And what happened? They thought they saw the rays, they thought they observed them. They went to see the rays, and once they thought they were there, they tended to see them. It also tells us something else: to do good science, we need to be as objective as possible. If you say, "just look a little harder," then you are not being objective. You are trying to convince the observer to see something. Nature cannot be convinced. If someone who doesn't know what they're looking for doesn't see it, then the odds are it does not exist. That's why double-blind studies exist - to get rid of this bias.

As humans, we naturally suck at science. Large numbers just don't work properly in our brains, recent concepts in science go against the grain of what we observe in the world today, we find patterns in the world that aren't there, and once we find an idea, we're not good at being objective about it. There are so many things I haven't gone into - black-and-white thinking, science needing to be falsifiable, how Occam's razor really works - but those are just examples. I am not qualified enough to really go into detail about all these, but, well, I hope this post has shown you how your brain sucks at science, and I hope it inspires you to go read up on it. And, well, if not, I'll be doing a post on the Sequences soon, which explains this sorta stuff much better than I could. As always, thanks for reading.

AB

Friday, February 10, 2012

2nd Rock from the Sun

I was originally going to call this "The Fact Zone: Venus," and have yet another label to use along the lines of "The Plug" and "Opinion Time." But really, I don't feel having another umbrella I can put posts under, if that makes sense (and if it doesn't, I don't particularly care; I can't think of anything better). So we get "2nd Rock from the Sun," which is a sneaky reference to one of my favourite sitcoms, "3rd Rock from the Sun" (where Joseph Gordon-Levitt sorta started out).

Venus. I'm talking about Venus. The planet, not the goddess.

You may be asking why (and it's a fairly reasonable question). Well, I happened to be surfing the net, as I do, when I came across a certain fact - the first one listed below. And I was sad, because I realised I'd forgotten it. Or at least put it in the back of my brain. Reading it gave the reaction of "Ohh, that's right" rather than "I knew that." And I was a tad saddened, because I've been a space nerd ever since I can remember - I brought books about space to school in Kindergarten, for example - and I realised I've been neglecting it recently. So in deference to my younger self, I present awesome facts about the planet Venus, arguably the most interesting planet in the solar system apart from the one that has life on it.

Just a quick disclaimer: I'll be doing the general facts from memory, but may refer to Wikipedia now and then for the specifics. As in, I'd be able to tell you the general idea whenever, but I wouldn't be able to explain the details. But here I can. Anyway. Without further ado, onto the show.

Venus rotates backwards, and pretty damn slowly. There are a couple explanations, my favourite being an asteroid or something hit Venus, messing its rotation up. So it rotates backwards - in other words, the Sun seen from Venus (if you could see it - more of that later) would rise in the west and set in the east. Except it would take a long time to do it.

Before I say exactly how long, I want to briefly mention the difference between sidereal time and solar time. Solar time is the thing we usually measure - when we say a day is 24 hours, we're talking about solar time. Sunrise from sunrise takes 24 hours. However, this is different to sidereal time, which is how long it takes for a planet to make one complete rotation. This is because solar time takes into account orbiting the Sun. Let me try and explain. As the Earth orbits the sun, it moves slightly along in its orbit (duh). So once the Sun goes back to its original position, the Earth has already moved slightly along its orbit, so it takes a different amount of time for the Earth's rotation to compensate for its orbit. This picture explains it better. Short version: I'll be talking about sidereal time for the moment. When I say sunrise to sunrise, that's solar time (if you're interested, Earth's sidereal day is actually slightly less than 24 hours - 23 hours, 56 minutes, 4 seconds to be more precise).

Anyway. Venus's day. It takes Venus 225 days to make one complete orbit around the Sun. It takes Venus 243 days to make one complete rotation (sidereal time, for those keeping score at home). Yes, you read that right - Venus's day is longer than its year. If we talk about solar days, it's 117 days from sunrise to sunrise. Still - pretty damn long. Well, that's enough of days and rotations. Let's move onto temperature.

Venus is the hottest planet in the solar system. It is the second planet in the solar system. This rather odd discrepancy is due to its intense cloud cover - Venus has experienced a runaway greenhouse effect. On the surface, it is pretty much 467 °C at all points on the planet at all times of day. Why? Because the atmosphere is 97% carbon dioxide. And because carbon dioxide is that dense, the pressure on the surface of the planet is over 90 bar. In other words, the pressure is over 90 times stronger on Venus than on Earth. For a frame of reference, that's the pressure you would feel if you were about 900 metres underwater.

That's not all though. Not by a long shot. Venus is thought to have active volcanoes. Yep, active volcanoes. Now, we say "thought to" because there have definitely been lightning strikes, and for Venus, the explanation for that is volcanoes. It can't be the clouds, because for some reason, it's not those. The clouds don't form a huge problem on the surface - when it rains, the raindrops evaporate in the atmosphere, just because it's too hot. I say raindrops instead of water because it's not water. The clouds are made out of sulfur dioxide, so it rains sulfuric acid. Yep, just keeps getting better and better.

There's a lot more awesome things about Venus (it's the third brightest object in the sky, it's the only planet named after a goddess), but I want to end on the exploration of Venus. You have heard all the things about how Venus will kill you, so imagine how difficult it must be to get probes on the surface. So what do you do? You leave it to the Russians*, with their Venera program. The probe that lasted the longest lasted for less than two hours. Now, how do you think they got the photos? If you said glass lenses, you were wrong. If you said diamond lenses, you have probably heard of this before. But well done, you were right*. Diamond lenses had to be used. And, the cool thing, the diamonds are still there. Venus can't destroy them (cause diamonds are a girl's best friend. Get it? Cause Venus was a goddess? The only "feminine" planet?*). So if you're looking for gigantic diamonds, you know where to go - the planet of fiery, acidic death!

Well, that's all the facts I'm going to say about the planet Venus. And in less than two weeks. Slightly less. But less than two weeks. Slightly. Anyway. Next post may be about Sad Sphere. Or Electrode and Diglett. Or Slender Man. Or League of Legends. Or whatever. Remember: Rule #1 of Wayward Letters: There are no rules!*  Yes, I didn't feel like the obvious Fight Club reference. And with that out of the way, I'll end the post.
AB