It evolved over centuries to become the gold standard for conducting scientific inquiry. Yet many people - including some scientists - don't fully understand it. Learn about the basis of how we explore our world in this classic episode.
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Hi, everyone, Happy Saturday. This is Charles W. Chuck Bryant here. I hope you slept well. Hope you're feeling good because you're about to listen to How the Scientific Method Works is from January of two thousand fifteen, and boy, this is a good one. I really loved it because we love science around here and we love the scientific method and proving stuff out. So check it out right now. Welcome to Stuff You Should Know, a production of My Heart Radios How Stuff Works. Hey, and welcome to the podcast. I'm Josh Clark. There's Charles W. Chuck Bryant, there's Jerry Stuffy should Know grinning. It's even a while. I know, it's funny, like those words come pouring out of my mouth and then it's cool. You wake up in the middle of night saying that, and you mean like slugs you in the face. She's sleep She has to dry my brow. Yes, we prerecorded some for December, as we like to do to take a little time off at the end of the year and not explain things for a few weeks in our real lives. Like people ask me things like what happened to that stick of butter? Yeah, I don't know, don't ask. Don't even ask me. I could tell you, but I'm not gonna exactly. That's how it goes in my house. Find your own butter. December was find your own butter Munthy. That's a good that's that's a good one. That should be a T shirt and stuff. You should know. Find your own butter or December is find your own butter mundy. Yeah, that's right. Maybe a stick of butter and some garland on it. Yeah, I like that. So it's good to see you again, man. Good to be back in here. Yeah, it is nice to be back because as much as the break was great, I'm happy to be explaining things again. Well that's good because if we got in here and you're like, I can't do this, I can't do it again, we'll be in trouble. Yeah. Yeah, So I'm glad we're all feeling good. Jerry, you're feeling good. Jerry's got two thumbs up in a big goofy smile, two of her three thumbs. She looks like Bob from that male enhancement pill. I had. Oh see the guy, the old man that's like super buff. I would call him old. He was middle aged. He looked like kind of a Bob Dobbs type dude. I think that's kind of who he was modeled. And I see the guy that's super muscle. Now I'm thinking of someone different. I think you're thinking of Jack La Lane. No, no, no, no, just there's some ad. There's some old man that looks like really creepy because from the next super buff looks like it year old. No. Remember, there was like a male enhancement pill and I'm making air quotes here for erectile dysfunction. Well, there go the air quotes. But yes, and it was like in the early two thousand's, I think maybe late nineties, but I think early two thousands, and these ads were everywhere, and there was Bob and like all these great things happened to him because he started taking this pill. I can't remember the name of the pill. But the company like got into a lot of trouble because it was basically like a subscription service and like you gave him your credit card and you've got this free trial, but then they started sending it to you and it was like next to impossible to cut off service. Interesting They're like, no, we want your mailness to be enhanced. So you you've seen these ads. I was gonna start asking questions, but why why bother? I will? I will YouTube. I will find it on YouTube. I'll be like, oh, Bob, yeah you will. You'll go oh, I won't have to come back in and record an insert the guy that's on the back of all those pill bottles in my bathroom so chucky. I don't even remember how we got Oh yeah, Jerry did that. That was Jerry's fault. But um, you remember we did the Enlightenment episode. Okay, we talked a lot about how there's this kind of um tug of war over the human psyche between rationalism and mysticism. I guess you could you could put it well, I feel like we're talking today about the scientific method. Yeah, great idea. By the way, thank you very much. It's been a long time coming. Um, because I realized, like I, I don't understand as fully as I don't understand science. I understand the scientific method because it's pretty cut and dry, and it's beautiful and elegant and simple. But then you just take this thing and it came out of the birth of rationalism, and when you place it into the world and make it function there's a lot of implications. Is it being used properly? Is it being used responsibly? Like are we putting what constitutes faith into that? You know, like it just raises all this other stuff. And it made me realize, like I don't understand science as much as I want to, So researching this it was awesome. Yeah, and this is a cool episode, I think, because not only are we going to talk about the scientific method, but we're going to talk about just science, like what is science in general? And some of the rock stars along the way who really, you know, laid out the path remarkably and like many many years ago, like coming up with these amazing discoveries that still like hold you know, you can like hold their feet to the fire for a lot this stuff. Yeah, because if you come upon a universal truth, you know it is what it is, like you got to be the person who discovered it because you know, you saw it, you realized it a certain way, but ultimately it was there already. Yeah, like Newton, I mean, we'll talk about all this stuff, but it's not like now we're like, oh, Newton, most of what he said was wrong, But that's understandable because it was a long time ago, like his stuff holds up really really well. I was wondering if he on his deathbed was just like, oh man, I contributed so much to humanity it's mind boggling, but I couldn't enhance my malehood. Well, Bob hadn't come along yet, So Chuck, let's let's just quit stalling and talk about science. Like, what is science? Well, I hate the old elementary school uh defined as but it's a pretty good place to start here to get a base definition of science. Yeah, old William Harris did a great job with this. Yes, William Harris did a great job. Uh. Science the intellectual and practical activity encompassing the structure and behavior of the physical and natural world through observation and experimentation. Boom end of podcast. Uh So, the first part of that is science is practical and it is you know, they make a good he makes. Bill Harris makes a great point in here. It's not just stuff you do in a lab, and it's not just for scientists. It is all about being hands on and active, and it's all about discovery and asking questions about I mean, that's how everything is ultimately solved, is by someone looking at something and having a question about it exactly. And then the scientific method comes in when you say, and this is how you properly get to that answer exactly. Um. And he makes another good point to that the idea that there's a method, a scientific method, makes it seem like it's it's secreted away among the the fraternity of scientists. And like you said, any anybody can use it. It's just kind of part of being a curious human is it's not even anyone can use it. Everyone does use it, you just might not even know that you're using it, like if you I mean, one of the examples that use later is if like your car overheats, when you figure out why and fix it, that's the scientific method, right, playing out exactly based on reasoning. Yeah, okay, in deduction and induction. Man, there's so much to talk about. Okay, So let's let's talk about that definition that you had. So the first part is that science is it's a practical activity. So science is practical, right, It's it's this, Um. The basis of the whole thing is discovery. Right. You see something, you see birds in flight, and you say, where are those birds going? And if you just went and laid down on the ground and went to sleep. After that, then you're not you're not carrying out science. But if you went I want to find out where those birds are going, and you follow them and you start taking notes, that's that is the basis of science, is discovery. Yeah, and that's the observational part as well. Um, sometimes you're using a microscope or a telescope. Sometimes you're using your eyeballs. But no matter what your tool is, uh, you're gonna be watching something and recording what's called data or data, depending on I don't know what kind of person you are. Yeah, what do you say? I think? I say both. I think data. Yeah, I don't think I've I don't think I say data data, I say data data. Yeah, all right, we'll go with data. You say both. I feel like it just comes out of my mouth one way or the other, and I don't really think about it. I think that's like being ambidextrous. Yeah. Yeah, I'm a data data Yeah. Uh. So once you are observing this data, well, there are a couple of kinds. There's quantitative data, which are numbers, like you know, your body temperature is point six, although I think that's changed slightly now, didn't it. Yeah, yeah, there. You used to be like, if you were a human being, your body temperature is point six and they's like, no, there's a little more variation than that. But any kind of just numerical representation is quantitative, whereas qualitative as behavioral, like I'm gonna watch that bird um eat and poop for the next week, right, or what happens if I what will the slug do if I put a bunch of salt on it? You know, I don't do that. No, you really should not do that. No, that's awful. But the reaction of the slug is gathering qualitative data, and depending on who you talk to, there isn't qualitative data and science that it should all just be quantitative, because yeah, because quantitative data is reproducible. Qualitative data is it's not necessarily reproducible. You can observe the same phenomenon, but you're not necessarily controlling it. Okay, well, I guess I get that, But I agree with Bill here and that they are both. They go hand in hand, and neither one is more important than the other. You need to have both. Well, a lot of people do, and we'll talk more about it later. Because without the idea that qualitative data is acceptable and scientific. You don't have the social social sciences, like they don't exist. Yeah, that's a good point, but yes we have quantitative data and qualitative data. I agree with you, they're both useful. Okay. Uh, it is an intellectual pursuit um. So you can make observations on data all day long. But until you bring reason, in this case, inductive reasoning, which is driving a generalization based on your observations, then it's just data sitting there on a piece of paper like it's supposed to lead you somewhere right exactly, And so we should talk about inductive and deductive reasoning and it depending. Again. It's really weird. One of the things that came across is that there's not a universal agreement on how science is carried out. Like No, I saw some places where there's like there's no place for inductive reasoning in science. Then other places they're saying, well, you have to have science using inductive reasoning. Everybody seems to agree that deductive reasoning is the basis of science, but that you also have to have inductive So deductive is basically taking a big broad generalization and saying that it applies to something specific more specific. Yes, Uh, inductive is the opposite where you say, I've noticed these different data points, and uh, that means that this broad generalization is true. So you go from specific, small observations to a broad generalization. And the reason that a lot of people say, well, inductive reasoning doesn't have any place in science is because you're saying, those birds over there are all brown. Therefore all birds of that type are brown. Even though I haven't seen every single bird of that type in the world. I'm saying that all those birds are brown, and a lot of people say there's no place for that in science. Well, if you want to go out and prove that, then that's your business. You know. You can't just say that and be like and I'm done, right exactly, I guess you could, but be much of scientists, right, But the the you can use it to formulate hey hypotheses. Right, So you can say, I've generated all these data points, I'm gonna put them together and see if this broad generalization is right. Okay, so there is a place for inductive reasoning science. But everybody says deductive reasoning is the basis of science. Well, Bill Harris does. He offers a great example for inductive reasoning with Edwin Hubbell of the Hubble Telescope. Uh. He was looking through the Hooker telescope, which at the time at California's Mount Wilson. Is it the one from Rebel Without a Cause? Now that's um Griffith Park Observatory, which has been redesigned, and uh is really cool now, Yeah, I mean it was kind of cool before, but it was definitely like, uh, sort of a bass museum that time forgot. Oh really, so they've updated it. I'll bet that was cool though in its own way. Yeah, it was neat. I used to live near there, so it was kind of But that's like the famous one, at least in the movies. Yeah, that's where they have the big knife fight and there's this James Dean statue there too. Oh I didn't like a bust um. So yes, Edwin Hubble, he's at Mountain Wilson and he's looking through the Hooker telescope, which was the biggest one. And at the time everyone said the Milky Way Galaxy is it? That's what we've got going on? Did you know this? Uh? Yeah, I knew that because we're talking. Yeah, not that long ago did not realize this. And he started looking through this telescope and said, you know what, these nebula that everyone says are part of our galaxy look to me like they're beyond our galaxy. Not only that, they look like they're moving away from us. So he made this, uh, with through inductive reasoning, made this observation that you know what, I think there are many many galaxies out there, and not only that, I think they are expanding. And uh, through technological advancement with telescopes over the years, scientists, you know, it proved to be true. Yeah. Pretty cool. So this is a really good example of him saying, like, I've made some observations and now I'm going to say this broad generalization. Right, So these these galaxies appear to be moving away from another. So the whole universe is expanding. Right. That's inductive reasoning. It's a pretty brave thing, uh, especially back then, because you're really putting your reputation at steak. It really is, you know. So what Hubble was, what Hubble did was what we've come to see as science. He made some observations, he came up with a hypothesis, um, and then it was tested later on. It's not you don't necessarily as a scientist. You're a part of a larger collective of scientists, right, and every scientist needs one another. It's why there's journals and and um conferences and things like that to share information. Right, the party into party, and and Hubble came up with his own observations, and rather than just experimenting, experimenting, experimenting himself, which I'm sure he continued to do, he created this basis of work that he probably realized is going to survive him. Right. And then later on scientists came down the road and they tested his hypothesis and they found it was correct, and so his hypothesis became a theory. It eventually became part of the basis of the Big Bang theory that the universe started as a huge explosion and it's expanding still because we're because it exploded at one point, right. And they did that by carrying out other tests or experiments exactly. So this is how science works. Like some guy back in in n makes some observations in California, he proposes this big broad generally generalization, and over the next like ensuing half a century more and more scientists all around the world start testing his hypothesis and find it to be true, so it becomes a theory. Yeah. Well, well let's finish up here with science. The last part of the definition is that it's systematic, and it's methodical, and it requires testing and experiments, and it requires those experiments and tests to be repeated and verified, and it is is. It's a system, it's a way of working things out. It's a way of working and that is the scientific method. Basically. Yeah, you have your idea, you pose a question, you theorize hyper you put a hypothesis out there, and then you go about trying to either prove it or disprove it. Yeah, exactly. And then the way that you go about proving or disproving it, that's the scientific method. Everything else is just scientific inquiry. The way you go about, the standardized way of going about scientific inquiry is the scientific method. And we, friend, we'll talk about the scientific method right after this. All right, you brought up a point. I think we should go ahead and just get right to my friend, let's do hypotheses and theories. One thing to to stay together. One thing that really chase my hide is, uh, when you hear poop o ers of whatever scientific theory say, well, it's just a theory, and you where was this thing that you found that poop poo that Do you remember what website that was? No? No, Also, I do want to give a shout out now that you mentioned it too Explorables. It's like an online university basically of free courses and uh, there is one on scientific reasoning that is just amazing. It's like a huge rabbit hole. You go down and you start clicking on the embedded links and you end up like understanding all sorts of stuff. So go check that one out if you like understanding stuff. So that's one of the things that bug me if someone says it's just a theory, and this does a great job of kind of throwing that out the window, um, because it's basically mixing up the two definitions of theory. Yeah, there's like a colloquial definition that people use every day that it doesn't really have much to do with the scientific use. Like I got a theory that Jerry and in one hour bathroom breaks every day is really playing words with friends in the lobby. I think your theory is correct. So that's a theory in the colloquial meaning as where science goes. The theory is not just something you postulate. So if this may or may not be true, the theory is b on the hypothesis, and it's something that is strongly supported in many different ways and all there's all kinds of evidence to support something that eventually becomes a theory. Right, So, um, what you your theory about Jerry's bathroom breaks in the scientific world would be a hypothesis. What In fact, yeah, it would be a scientific law, but ultimately would begin as a hypothesis, a hunch based on intuition, based on the data you've collected, observations, that kind of stuff, where like, you know, you've seen that Jerry goes to the bathroom for like an hour to stretch frequently. When she comes back, she's um finishing up a game of words with friends. You've heard that she's been spotted in the lobby during these times. So your hypothesis is that while she is gone for these hour long bathroom breaks, she's actually down the lobby playing words with friends. Right, based on knowledge, observation, and logic. Right, So let's say that you decided to set up an experiment, and you experimented, and you went and you found Jerry playing words with friends five different times, and you told me about it, and I was like, I'm going to run that same experiment exactly the way you did, Right, I would test that same hypothesis. If I found the same results to be true, then what you would have come up with, your hypothesis would move to basically a theory that is, this widely accepted thing. This explanation that Jerry is not actually in the bathroom, she's downstairs playing with friends, would be the Jerry bathroom break theory. Right. And then if it turns out that you find that Jerry spending an hour a day pretending to be in the bathroom but actually being downstairs playing words with friends, if the universe couldn't exist without her doing that every day, you would have a scientific law. That's right. Yeah, I think that was a good example you came up. Well, it's a great example, as it turns out. Uh. I guess the point here is when you hear someone say in an argument, well that's just a theory, just punch him in the head and then tell him what we just said about the bathroom breaks, and they'll say, who's Jerry, or just just queue up that whole bit and stand outside of their window wearing a trench coat and holding a boom box over your head with the smug look on your face. Uh all right, So should we go back in in the old way back machine a little bit and just talk a little bit about how the scientific method came to be? Yes? Man, this this thing? Where are you running this on these days? Straight? Kerosene? The fumes in here killing me? Sorry about that? Trying to go green? You know, kerosene is not cream diesel. Maybe I'm choking bio diesel. How about that? Okay, the way back machine will run French free Greece. That would be fine. I'll get to work on that. I could handle this for you. So you you teach us with the Renaissance, and the reason the Renaissance was so awesome and necessary was because of something else we've talked about, which was the Dark Ages. Uh when, which remember that's the rationalists disparaging term for this era. That's right, Uh? But I think sort of rightfully so, because right before the Dark Ages until about a century after, there was not much advancement at all in the realm of scientific advancement. Uh no, it's it's true. That's hard to argue with that, and and the reason why it is again, science wasn't really born yet and there was a huge struggle between rationalism and mysticism, and ultimately we're living in the age of rationalism now. Yeah, and we should point out too that this was mainly in Europe over in the Islamic world, as I think we had a listener mail point out, there were a lot of advancements being made. Uh, just sort of flying under the European radar at the time, because some say the Catholic Church kind of kept science under its thumb for a while and it's a pretty big threat and said, you know, you can't do this stuff. You can't experiment like this, and don't ask these questions because here are your answers. Yeah. But eventually the Renaissance came about in the twelfth century and people woke up and I saw some of the work in the Islamic world and said, you know what, maybe let's start reading up on Aristotle and told the me and euclid it once again. Yeah, they're like, we forgot about these guys. Yeah, I mean, it literally kind of vanished for a while it did. From the west. Yes, fortunately it was still around, you know, and in its home places. But yes, in the West they were lost. The Roman stuff was almost entirely lost because it was being suppressed by the locals. And I think the Greek knowledge was completely vanished. Yes, somehow, somehow they got there was some um. We got another listener mail after the Enlightenment when they said that it was an Islamic scholar who was the one who translated Aristotle into Latin or something like that, and that without this guy, like, the West wouldn't have had much to start with. Because that's where that birth of rationalism came from from, was this rediscovery of Greek and Roman classical thought. And this was the basis of scientific inquiry of rationalism, of saying, like, okay, there's there's set rules to things, and we need to discover these rules and how the principles of how the universe works, like there has to be principles, and we need to find this in a rational, methodical way. And right out of the gate, Europe said, okay, well whatever you say is right, then, Aristotle. We're used to just believing everything without questioning it. And luckily Albert Magnus, I think is who it was. Um was Albertus Magnus or Roger Bacon, who said, no, it is Bacon. Roger Bacon, who just has this great name, Roger Bacon, the Bacon brothers. Yeah, he said, Roger. They weren't brothers though, but they were they related at all, you know. I looked that up and I don't think people know either way. I don't think there's any proof, but a lot of people think, because of their names and the way things went back then, that they may very well have been red And I mean they were separated by three d or so years. Although Roger was a was a monk, so he would not have had children. So if they were, it's an excellent point. It wasn't necessarily through his line, you know. Yeah, it could have been a nephew or something. Yeah, or his brother Kevin might have had the line that matched. So Roger was the one who said, everybody stopped. Just because Aristotle wrote something doesn't mean it's fact, especially when we find contradictions to it. Yeah, it doesn't. Our cells not automatically right, and this is a huge advancement. Yeah, And Albertus Magnus was the one I believe who said you know this and called revealed truth, which is basically God says this instead of a truth found by experimenting, is maybe we should experiment instead and not take this revealed truth as the truth. Right. And we mentioned in the Enlightenment episode as well about scholasticism about using scientific inquiry to explain theology, which was you know, you're still working from a theological standpoint, right, but you're starting to use scientific inquiry and the the idea that you shouldn't just accept things as truth. That was again a huge, huge breakthrough. Uh. Francis Bacon, the other Bacon brother, he's one of the heroes of this story. Yeah, he was an attorney and philosopher and its possibly Shakespeare. Oh really, I never heard that interesting? So what do you mean like wrote those under the pseudonym huh? And there the Shakespeare sister was the other theory too, right. That was a woman. I've heard that, and she couldn't like you know, women couldn't be the play, right, so's her dumb brother, William. That's good? Was it her brother? I think that was one of the theories. This was a good Smith song too. Uh, Shakespeare sister was that the name of it. Wouldn't it a band too? I think it was? What was it? Maybe? Uh So, anyway, he was a philosopher and a lawyer, and he said, you know what, the Baconian method basically became the scientific method. He was the first dude who really said, this is how the steps that you should take to uh investigate science. There has to be a framework. And the whole point of this that we take this so for granted now because it's so intuitively and on its face right, yeah, as far as scienceific inquiry goes. But this is an enormous breakthrough to say, you follow this step, the up this framework, and if everybody who carries out science follows the same framework, then science will be universal and interchangeable and anyone in the world, and not just now, but anytime, we'll be able to carry out the same experiment and we'll be able to verify or disprove it. Yea, And that is amazing that that happened. That's why Francis Bacon is one of the heroes of the story. And he didn't come up with this entirely on his own, but he was the one who said this is what we're gonna do. I'm going to give it a name. I'm going to spell it out, and from now on you can call me the dad of the scientific method. Yeah. And that's why Newton was such a rock star, because he so rigorously stuck to the scientific method that all these centuries later, his uh, you know, his systems of laws are they have stood the test of time. And uh, I think it's a good point to bring up to that the collaboration of sciences is really the hallmark of advancement and moving forward. It's not working in a vacuum. It's sharing your ideas and working with one another. And the whole h little sidebar here on celth here I thought was pretty cool, which was when science quit. We're not quit, but started looking at small things instead of looking at the universe around them and at the stars. And uh said, basically, you know, through the advancement of lens grinding, Antonio van Leben Hook, specifically a Dutch tradesman, was pretty good at making simple microscopes, and all of a sudden, contemporaries like Robert Hook said, you know what, let's start looking at tiny things because they're in might lie the answer too many many things yeah, and they're right. Robert Hook found cork. He discovered cells by looking at cork through an early microscope. So in this story, science is hastened by technological advance, spent lens grinding to make microscopes, and then this new technology is used to further science, right, Yeah, it's like mutual inspiration between Leavin Hook and Hook. Levin Hook. Yeah, it was neat because Hook heard about Leavin Hooks microscopes, got his hands on one or a microscope, looked at him like cork, and said, oh, there's such thing as cells. Levin Hook said, oh, that's pretty neat. Let me try. And he said, oh, there's such a thing as quote little animals, which we call protozoan bacteria. And one of the Royal Societies. After Leavin Hook presented his findings, turned back to Hook and said, hey, Hook, we know you're pretty handy with the microscope. You confirmed Leavin Hook's findings are their little animals? Hook said, there are, indeed, I can see them with my microscope. That's right. And that inspired a German botanist name Matthias schleiden Uh to look at a lot of plants, and he was the first guy to say, you know what, plants are composed of cells. And he's having dinner one night with his zoologist buddy. Yeah, this is about a hundred years later. Yeah, Theodore schran and said, you know what, dude, Uh, order the wine and order the steak. Trust me, because this place is fantastic. And uh, also, plants are made of cells. Don't tell anyone. And he went, you know what, dude, I have been investigating animals with microscopes and they're made of cells too. And so they figured out at this dinner that everything is made of cells. All living things are made of cells. Boom, Okay, so this is huge. This is a big advancement, right that we're hitting upon right now. Huge, but it laid the further foundation, right, So initial scientific inquiry led to further scientific inquiry and further scientific conclusions and generalizations. All living things are made of cells, and then it was extrapolated elsewhere. Right. Yeah, Like twenty years later, Rudolph Virtual said, you know what, not only is everything made of living cells, but they all come from pre existing cells, which was a huge deal at the time because people believed in spontaneous generation at the time, Like if you left some um wheat seed in a sweaty shirt. It would spawn mice. I think was one of them. There's a lot of weird ones. Press basil between some bricks and you'll get a scorpion. Was one, like they were really out there? Yeah, well the one that is well not true, but the one that you could actually see was rotten meat would eventually uh spawn maggots. How did they possibly get there? Yeah, spontaneous generation. But that's the obvious explanation, and if you think about it, they're working from Okam's razor and Ockham's razor, says, the simplest explanation is usually the right one, all all other things given. Well, the thing is is spontaneous generation has never been shown to be possible. If we've got the cell thing over here, let's investigate that. So this uh what was the guy's name? Virtual? Yes, he's saying, okay, well wait a minute, I get this cell theory I'm working on that's been around for a couple of decades. Hypothesis probably the cell hypothesis at the nice catch. Don't feel bad though, because this article that you sent said that scientists today like still like confuse those terms just and the the house of works. Article makes a good point in saying that science and everything that has to do with it is in the scientific method is very fluid and open to interpretation and experimentation. Obviously, but so he says, um, okay, this cell hypothesis, this is a pretty good explanation for what we now call spontaneous generation. He didn't do anything about it. He just put it out there. Yeah, and then along comes Louis Pastier, who does do something about it. He figures out a great experiment to try to disprove spontaneous generation. Yeah, it's pretty pool to um. He basically took a broth uh, put equal amounts in two different beakers. One had a straight neck and one had an S shaped neck. He boiled it just to make sure everything and it was killed, and then just let it sit there in the same conditions, open to the to the world and are open to the room, like it wasn't corked. In other words, he noticed that the one with the straight neck eventually became cloudy and discolored h meaning there was some junk growing in there, and the one in the S shaped neck did not do anything. It remained the same. So led him to think what well, he thought that germs, that there were such things as germs which m leaving Hoke and Hook had already shown um and that if that in the S shaped flask they had gotten trapped in the neck, in this the open neck, they had been able to just enter unobstructed and had generated there. The reason that the S shaped ask was still sterile was because there is no such thing as spontaneous generation. If there were, then no S shaped neck would impede anything like that, and boom, there you have it. So he disproved that spontaneous generation is a thing, right, that's right through the scientific method. Exactly. Here's the leap that a lot of people make, scientists included that really is a great disservice to science. He didn't prove cell theory right. What he did was take that cell hypothesis and present some really persuasive evidence that it's probably right. Yeah, But like this article you sent points out, disproving something is just as important as proving something. So here's the thing that's the most you can hope for a science is disproving sure with science, unless you're talking about math. With science, there's no such thing as proof a theory, even a law, universal law still has the potential for being undermined by one single experiment, one single observation, and therefore there is no real ultimate proof in science. There's just theories and support for theories, and then ultimately laws aim further and further support for laws, right, but they're not proven. What science does ultimately is disproved things or lend support for existing theories, are existing interpretations of why things happen the way they do. And that's what past true did. So if you look at the experiment, he disproved spontaneous generation, but he lent support to the cell theory, and probably with his experiment it went from the cell hypothesis to the cell theory because it was just so persuasive. And that's what a theory is. It means that a lot of people out there who are reasonable say this explanation is probably the right one. Yeah, it's predictive. If you do it over and over, you're probably going to get the same result. But that's not to say that past year showed that if you do this a million in one times that the S shaped flask won't turn cloudy. He didn't prove that. You can't prove that, which is again science can disprove and when support can't prove. Very good point. So right after this message break, we're going to get into the actual steps of the scientific method. Alright, dude, I guess that long last, we're there. Like you mentioned before, the scientific method is fluid and it's not like when you get your science degree they hand you a little laminated card like the Miranda rights that cop scary that you know, list out all the different steps you have to take. Um. But generally maybe yeah, I would we should carry those around, all right. We should make little wallet cards of the scientific method just to carry the stuff. You should know a logo on it. Oh yeah, I'll make a million bucks a random and sell them. Uh. Generally speaking, though it follows these steps. The first thing you do, like we mentioned earlier, is you observe something. You ask a question. Uh next, Like Darwin was known, I think when we did our podcast on him too, you would spend like a week on three square feet of ground. It was like even longer than that. Remember Remember was wasn't it He said that he didn't he wasn't gonna MOA's lawn for like three years because he wanted to see what what happened? Yeah, so he's the ultimate and qualitative data of just observing, writing things down and asking questions. And the reason you ask your question is so you can narrow something down like that. I think the example they use in here is on galapa ghosts like the beaks of what bird? Was it? Finches? Yeah, the finch bird. He noticed a bunch of different beaks, so he finally posed a question like, um, you know, I think these beaks are different for a very specific reason, and I aim to find out why. Yes, he said, what caused the diversification of finches on Galapagos? Who should have done that with an accent? Well, yeah, he would have had a British accent. Huh yeah, unless he was pretending to be someone else. I think of him as like, um, sounding like Hemingway or something. Oh yeah, just drunken, violent kind of. But he wasn't. He was like the opposite of that. Yeah. Well I saw that the movie. So a picture of his voice as the dude that played him who I can't remember right now, ed Norton. No, I finally saw Birdman though. Did you see that? Yeah? Yeah, great movie? Um, I disagree, Oh you didn't like it? What Wow, that surprises me. Um, we'll get into that off here. So, uh sorry you just threw me with that. Make an observation. Yes, he's on galapagost and he's like, what the hex with all these different finches one small island? Why would there be different species of finch so asking? And and why are they all seeming to survive and coexist so well? What's what makes Yeah, then he leads to the question what's making all of these species of finches so diverse? Right? Or Bill Harris uses a pretty good example that's something everyone can understand, like what car body shape is the best for air resistance? Like one the shape like a box, or one the shape like aerodynamic like a bird. And he carries that out In the next step. You formulate your hypothesis based on your you know, for knowledge and maybe observations like so, you know what, I think that a car shaped like a bird is probably more aerodynamic than one shape like a box. Yeah. If you're thinking, if you're the type of per soon he's sitting around asking questions about aerodynamics, you probably already have some sort of sense that a box is less aerodynamic than a bird. That's right. Boxes rarely fly unless they're carried by one of those delightful Amazon delivery drones. They don't have those yet, right, They're not gonna do that, are they. There's like a pizza delivery drone service. Man. I think where you have pizza are grilled cheese in New York and you go stand on an X after you order and it like comes and drops it. That is the dumbest thing of error. And I can't wait to do it where they're making a lot of money. That's pretty funny. Um, Yet we can't get food to the homeless somehow exactly. We can drop a grilled cheese on someone's head. They're like, you homeless, gut, get off of that x exactly. Um. Alright, So your hypothesis I don't think we ever mentioned is typically represented as an if then statement, Yeah, if you're doing good sciences, Yeah, like if the cars profile. Uh, well, the the example he uses if the body's profile related to the amount of air it produces, which is the more general statement. Yeah, that's like based on a theory. Yeah, and it's gonna get more specific than the car designed, like the body of a bird will be more aerodynamic than one like a box. So that's inductive reasoning, starting with the broad statement and going to something narrow, and it's if. Then at the same time, Yeah, and now you have a test. You have a question that can be answered, you can figure out a way to answer it. Yeah, and he points out to this is pretty important that, uh, your hypothesis, if it's formulated correctly, means it is testable and it's falsifiable, which are often one and the same, you know. Yeah, And that's again we go to the people who say that they're they're soft sciences, aren't real science. There's pseudoscience because a lot of the data that they come up with, a lot of the hypotheses they come up with aren't falsifiable, they're not testable. It's a it's a thing. It's an issue, it's a thing. So next up in the steps, you're gonna experiment. And when you experiment, you can't just go in there willy nilly and do whatever you want. Um, you have to set up specific conditions and they must be controlled, and you want to everything that's supposed to be identical needs to be identical. So basically you have two variables. At least you have an independent variable and you have a dependent variable, and if you're talking about car shape, that is the independent variable in this study, that's the one that's manipulated exactly, it's the one you're controlling. The independent variable is the one you, the researcher, is controlling. So in this case, you're controlling the shape of the car. You have yourself a bird shaped car and you have yourself a box shaped car. So the shape of the car changed because you made it change. Now when you blast a bunch of air over it during your experiment, what your measure ring is the dependent variable. So you're measuring what happens based on the change that you made. That's right, and you want to you you want to study one single variable at a time, basically, Yeah, don't get fancy, just just do good science, step by step, methodical. You also have to have your control group in any experiment. Uh, And an experimental group and then controlled group is what's gonna allow you to compare the test results to that baseline measurement. Yeah, and you need that baseline measurement, so it's not just like chance. Basically exactly like if Pasture had just done the S shaped neck and nothing happen. He wouldn't have necessarily been able to say that he was right even though he was right. He needed that control, which was the open flask. Right. Or with the cars, you need two cars, like you said, one bird shaped and one box shaped, right, Or then maybe in this case, since the bird shape and the box shape both show up in the hypothesis, you need a third like egg shaped one or something like that. I bet that would be pretty streamline. Yeah, yeah, yeah. But the key though, is all of those variables have to be um. All the other variables have to be the same, like you have to have them. They have to be the same weight, they have to be painted the same, the tires, everything, the windows. One can't have an antenna on the other not, They've all they've got to be identical other than the one variable, right, the independent variable that you're that's the one you want different. Everything else you want the same or else it's possible that, oh, well this one had bigger tires, so that actually made it more aerodynamic. Yeah, and you're just doing yourself a favor by doing all that stuff. You know, you want to rule out everything else but that one variable. After that, you want to analyze your data, so you can draw your conclusion, and sometimes it's kind of straightforward and easy. Sometimes takes a lot of work and a lot of various tools draw all that out. Let's say you're just asking a car and a wind tunnel. You're measuring the wind resistance using certain awesome instruments and that kind of stuff, and you're taking that data, and then afterward you're going to analyze. You're going to compare the data that you gathered from the bird shaped car the box shaped car, and then the control the egg shaped car. You're gonna compare them, and you're gonna say, well, the wind resistance was less for the bird shaped car then the box shaped car, which means that my hypothesis was correct. And here all the data points. Whereas Louis paste or could just say, look at the Beaker's exactly, don't be an idiot, I'm a scientist. That one's got gross stuff. You can see it, right. But the other thing about science to chuck ideally is let's say that egg shaped one turned out the control group turned out to have better wind resistance than anything. Well, just by virtue of carrying out this experiment correctly, you would have stumbled upon and even better aerodynamic design, and you would have come up with that little egg shaped Mercedes suv that was so huge, like ten years ago, the Mercedes egg coming to a store near you. So, um, that's a big, big part of the scientific method is carrying out a a an experiment, controlling the variables, analyzing the data. And then there's a step that he missed that is very rarely part of a scientific method list that is to share your data. And this is a huge problem with science right now. Yeah, the article you said, it was really eye opening. Uh, scientific research has changed the world. Now it needs to change itself. It's an economist article. It's up on the internet. Yeah, it was kind of scary that it's I mean, here's some of the data he points out is one rule of thumb among biotech venture capitalists is about half of published research can't even be replicated. And on the biotech firm am Jin found that they could reproduce only six of their fifty three landmark studies in cancer research, So you can't repeat these things. It's like everyone's fighting for dollars in fame, and maybe not fame, but to some our career advancements such that they're kind of not doing that final step any longer. No, and it's not necessarily just them, it's the other scientists aren't going back and saying, well, let me see if your results are reproducible. People are just taking it on faith. We need another Roger Bacon to come along and be like, dude, we can't just blindly accept that one person carried out this one study and then just go do clinical trials on it without anybody reproducing it to see if the results can be verified independently. Yeah. Because uh, and this is a good time to mention bias. There is such a thing as bias, and it still happens. Um. A scientist is usually to prove something or disprove something that they want a specific result. Like, even if you're super open minded, you're probably hoping to disprove or prove something one way or the other, and your confirmation bias might you know, even if you don't think you're doing it, you might nudge out some results that don't support your hypothesis and so you won't make it into that awesome journal. Um, which this author points out that journals need to start uh putting in what he calls uninteresting results and experiments, right, or like the stuff that's not sexy, right, or studies that failed to show that their hypothesis was correct. Yeah, stuff is disproved. Those things still need to well not even disproved. Well, yeah, I guess it is disproved. But yes, like the guy set out to say, like the red balloon uses less helium than a silver balloon, and it turns out that no, they use the same amount if he lium. Well, if that study gets published and put out there into the scientific literature on helium and balloons, then it's going to prevent some other scientists down the road from wasting time, money, and helium, which, as you remember, is an increasingly needed commodity. Um By carrying out the same experiment, whether whether the results are positive or negative or what, the study is meant to be shared. And that's the point of the scientific method, is to to reduce bias. And if you follow it all the way through ideally and do all of the steps, including share your research, whether it's happy or sad, then science benefits. The world benefits, and by not doing that, the world does not benefit. Yeah. He points out that these days only four of published papers are quote unquote negative results and it used to be like or more um And he says, because it's a lot of it has to do with this sort of you know, getting in these journals and you're the rock star scientists and this study is super sexy. Like if they kind of quit going that route and made it what it should be, then research dollars would be better spent and people could you know, he said, the peer reviewed thing isn't even all it's cracked up to be. Know that. He mentioned a study from a medical journal that gave a bunch of peer reviewers some stuff with deliberate errors inserted into the research, into the studies, and even when they were told that they were being tested to find this, they still missed a lot of it. Yeah. So yeah, the science used to kind of re evaluate the way it's carrying out science. It's not science. The problem isn't science itself. The problem isn't the scientific method. It's the way that it's being used or not followed through. And a lot of it has to do with academia and the people funding science. Yeah, and he said, you know, these days there's up seven million researchers, and back in the day, even in like the nineteen fifties there or like a few thousand maybe, right, So there's just a lot of career competition. He calls it careerism. And so you fake a result or two, or you just nudge out some results that don't support your hypothesis. You want the bigger paycheck or the fame or notoriety, and all of a sudden, science is not science. Yeah, you know, it's pseudoscience exactly. And speaking of pseudoscience, I think we've reached the point where, um, we should talk about the limitations of the scientific method, because it does have its limits, right, like the way that the scientific method is set up, especially if you go through um, if you include falsification, which most scientists now say is a thing like falsifiability of your hypothesis means that you have a real scientific hypothesis there if it can be disproven by some observation or some measurement or whatever, then it's falsifiable. And if it's not falsifiable, then it's not really science. So the thing is force something to be falsifiable, and it is actually a philosopher that came up with the concept of falsification, a guy named Carl Popper in the nineteen thirties, and he was the one that said, like, you're you have to be able to falsify something for it to be disproven or supported, and if not, then it's pseudoscience. Well, part and parcel of that is that what you're saying has to be able to be detected empirically. There's some way that it has to the presence of it has to be measured or inferred. And so a lot of people say, well, then with the scientific method it reaches it's the limits of its current usefulness when it tries to explain the supernatural. When somebody says, like, ghosts are real, exactly, you can't prove that, well, you also can't disprove it either, right, And so if you are a scientist who says, uh, because the scientific method can't prove or disprove the existence of ghosts or God, there is no such thing as ghosts or God, you're making a leap of faith just as much as the same person who says science can't prove or disprove the existence of ghosts or God, therefore God's and ghosts are real. They're both leaps of faith. And that really the most scientific approach to the existence of the supernatural, whether it is ghost or god, is that we simply don't know, and that we cannot know scientifically. And but that doesn't mean that it does exist or doesn't exist. And that's saying that science shows that it does or doesn't exist, is by by definition, the opposite of what science shows. Science shows neither. It's not capable of showing or showing that something doesn't exist. That's a good point. Uh. The other place where science can get corrupted is when it blurs the lines, or when people blur the lines between uh, moral judgments and science value judgments. Like you can study global warming, you can study cause and effect, you can report data, but when you make that secondly to say, and this is a scientist, I mean someone can come along and say global warming is bad, shouldn't drive your suv. That's fine, But a scientist can't do a study and say that because that's, uh, that's a value judgment. And that's where science can get corrupted pretty much. Right. You can you can study glow warming and results until the cows come home, but you can't assert that if you use this lightbulb, you're a bad person, right or um ocean acidification is bad. It's not good for humans. But if you're a jelly fits, it's awesome, you know. So yes, and again you made a great point. It's not science, it's people using science to make value judgments. Yeah. So, ultimately, the scientific method, although it does have its limitations and that it needs empirical data, uh to prove or disprove something, it's not that it's not flawed. That's not a flaw. That's a limitation, and it's it's when it's misused then its results become flawed or skewed. And that's the people doing it, man, not science. That's right. It's pretty interesting stuff. Yeah, man, this is a good one. I thought so too. Man. Let it's start out with a bang boom. It's all downhill from here. Uh. If you want to know more about the scientific method, check out that article on the economists, check out explorables uh, and then of course check out the scientific method in the search bar at how stuff works dot com. And since I said that it's time for listener mail, that's right. But quickly before listener mail, uh, we get asked by listeners all the time, what can we do? Since you have a free podcast, we can't pay for it. What can we do to help you, guys? And one thing you can do that we would appreciate is, uh, go to iTunes and leave a rating and a review for us. That makes big, big difference and pen us up there in the rankings, which means more people find stuff you should know. After they listen to Cereal, they'll just say, well, jeez, there's other podcasts in the world, what is this pod cast? So ratings and reviews really help us out and it doesn't cost you anything but a few minutes. Um, be honest, We're not saying go leave us some great review, but go leave us a great review. You said it, Uh, and tell tell one person about stuff you should know. We would appreciate that to turn somebody onto the show. And um, that's it. That's our version of a pledge drive because they wow, we do that what once every three years? No? Not not very obnoxious and at last all right, So onto listener mail. This is from my sister in law. Actually, oh yeah, this is some nepotism. Yeah, Jenny Jenny Bryant, she mentioned in the homeschool episode homeschooled her kids for a little while, and she sort of corrected me Uh love the homeschooling episode. Guys. One very big trend these days in the home schooling community is what Abbey my niece does, which is hybrid homeschooling. So two to three days a week she is at school and then the rest of the time she's a plant. She's not a plant. Uh, the rest of time she's at home. So she says it's a great option with curriculum provided and new topics sought at school and then worked out at home. Many of these schools are accredited making getting into college, including Ivy League schools, Hassle Free and Abbey School has sports teams, homecoming Abbey is actually an excellent volleyball player, Beta club, newspaper staff, all the good stuff. The flexibility is great for families, and we are huge fans of how the hybrid approach prepare students for college by allowing them time outside of class to manage their work and life schedules. So that's from Jenny actually via text first listener mail via text How did you print that out? Did you retype it and print it? Oh? Dude, are you serious? You can part from texts? No, you just copy pasted to an email? Oh yeah, yeah, I forgot about that. Men, then, how in the world did you did you do that with your thoughts? I have a niece who is excellent at volleyball too. Hold, we should get them together. I don't know. It's ten eleven, okay or something like that. Abby just turned thirteen, so there. Oh, maybe they face off against one another. Yeah, is she in Atlanta? Yes, she's up in Canton. You never know where's aving. She's in Roswell. But they think with volleyball they kind of have played all over the state. Bizarre if they play each other. Yeah, we'll just see each other at a match one day on opposite sides of the court with our arms folded. Yeah. Uh, what else? I got nothing else? Well, like Chuck said, go leave us a review. And if you want to get in touch with us, you can tweet to us at s y s K podcast. You can join us on Facebook, dot com, slash Stuff you Should Know. You can email us and we still do that. Yeah, you can't text me at uh stuff podcasts at how Stuff Works dot com and has always joined us at our home on the web. Stuff you Should Know dot Com. Stuff you Should Know is a production of I Heeart Radios how stuff works. 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