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Current time:0:00Total duration:11:49

Video transcript

let's explore the scientific scientific method which at first might seem a little bit intimidating but when we walk through it you'll see that it's actually almost a common-sense way of looking at the world and making progress in our understanding of the world and feeling good about that progress of our understanding of the world so let's just use a tangible example here and we'll walk through what we could consider the steps of the scientific method and you'll see different steps articulated in different ways but they all boil down to the same thing you observe something about reality and you say well let me let me try to come up with a a reason for why that observation happens and then you try to test that explanation it's very important that you come up with explanations that you can test and then you can see if they're true and then based on whether they're true you keep you keep iterating if it's not true you try to come up with another explanation if it is true but it doesn't explain everything well once again you try to explain more of it so as a tangible as a tangible example let's say that you live in in I don't know northern Canada or something and let's say you live near the beach but there's also a pond near your house and you notice that the pond it tends to freeze over sooner in the winter then then the ocean does it does that faster and even does it at higher temperatures than when the ocean seems to freeze over so you could do that as your observation so the first step is you're making an observation observation in our particular case is that the pond freezes over at higher temperatures in the ocean does and it freezes over sooner in the winter well the next question you might want to or the next step you could use a scientific method it doesn't have to be this regimented but this is a structured way of thinking about is well ask yourself a question ask ask a question why does so in this particular question or in this particular scenario why does the pond tend to freeze over faster and at higher temperatures then the ocean does well you then try to answer that question and this is a key part of the scientific method is what you do in this third step is that you try to create an explanation but what's key is that it is a testable explanation so you try to you create a testable explanation testable explanation and this is kind of the core one of the core pillars of the scientific method and this testable explanation is called your hypothesis your hypothesis and so in this particular case a testable explanation could be that well the ocean is made up of salt water and this pond is freshwater so your testable explanation could be salt water salt water has lower freezing point has lower freezing freezing point lower freezing point so it takes colder temperatures to freeze it then then fresh water then fresh water so this right over here this would be a good hypothesis it doesn't matter whether the hypothesis is actually true or not we haven't actually run the experiment but it's a good one because we can construct an experiment that tests this very well now what would be an example of a bad hypothesis or something that you couldn't even necessarily consider as part of the scientific method well you could say that that I there's a there is a fairy fairy that blesses that let's say that performs magic performs performs magic on the pond pond to freeze it faster freeze it faster and the reason why this isn't so good is that this is not so testable because it's depending on this fairy and you don't know how to convince the fairy to try to do it again you haven't seen the fair you haven't observed the fairy it's not based on any observation and so this one right over here this would not be a good a good hypothesis for the scientific method so we would want to rule that one out so let's go back to our testable explanation our hypothesis salt water has a lower freezing point than freshwater well the next step the next step would be to to make a prediction based on that and this is the part where we're really designing an experiment so you could just view all of this is designing let me just in a different color where we want to design an experiment design and experiment and in that experiment let's say and let's see the next two steps I will output as part of this as part of this experimental whoops I messed up let me I did my undo step so the next part that I will do is the experiment experiment and there you go so the first thing is well say I take I you know there's all sorts of things that are going on outside the ocean has waves you know maybe there are boats going by that might potentially break up the ice oh I wanna I just want to isolate that one variable that I care about whether something is saltwater or not and I want to control for everything else so I want to control for whether there's waves or not or whether there's wind or any other possible explanation for why the pond freezes over faster so what I do in a very controlled environment I get I take two cups I take two cups that's one cup and two cups and I put water in those cups I put water in those cups and let's say I start with distilled water but then this one stays the first one right over here stays distilled instilled means that through evaporation I've taken out all of the impurities of that water and in the second one I take I take that distilled water and I throw a bunch of salt in it so this one is fresh very fresh in fact far fresher than what you would find in a pond it's distilled water and then this is this is over here this is saltwater so you wouldn't see the salt but just for our visuals you depict it and then we would make a prediction we'd make a prediction we could even view this as step for our prediction we predict that the fresh water will freeze at a higher temperature than the salt water so what prediction let's say the fresh freezes fresh freezes at zero degrees zero degrees Celsius but salt doesn't salt water doesn't salt whip nuts at salt water doesn't so what you then do is that you test your prediction so then you test it and how would you test it well you could have a very accurate freezer that is exactly at zero degrees Celsius and you put both of these both of these cups into it and you want to make sure that they're identical whatever they were you control for everything else you control for the surface area you control for the material of the glass you control for how much water there is but then you test it and then you see what happened from your test we leave it in overnight and if you see that the fresh water has frozen over so it's frozen over but the salt water hasn't well then that seems to validate that seems to validate your testable explanation that salt water has a lower freezing point than fresh water and if it didn't freeze well it's like okay well that may be that that or if there isn't a difference maybe either both of them didn't freeze or both of them did freeze then you might say well okay that that wasn't a good explanation I have to find another explanation for why the ocean seems to freeze at a lower temperature or you might say well that's part of the explanation but that by itself doesn't explain it or you might now want to ask even further questions well well when does salt water freeze and what else is dependent on do the waves have an impact do the does the wind have an impact and so then you can you can go into the process of iterating and refining so you then refine refine refine and iterate on the process when I'm talking about iterate you're doing it over again but then based on the things that you've learned and so you might come up with a more refined testable explanation or you might come up with more experiments that could get you a better understanding of the difference between fresh and saltwater you might try to come up with experiments for why exactly what is it about the salt that makes this this water harder to freeze so that's essentially the essence of the scientific method and I want to emphasize this isn't some you know bizarre thing this is this is this is logical reasoning make a testable explanation for something that you're observing in the world and then you test it and you see if your explanation seems to hold up based on the data from your tests and then whether or not it holds up you then keep going and you keep refining and you keep learning more about the world and the reason why this is better than just saying oh well look okay I see the pond is frozen over and the ocean has it it must be the salt water and you know I just feel good about that is that you can't feel good about that there's a there's a million different reasons and you shouldn't just go on your gut because at some point your gut might be right 90% of the time but that 10% that it's wrong you're going to be you're going to be passing on knowledge or assumptions about the world that aren't true and then other people are going to build on that and that are all of our knowledge is going to build to be built on kind of a shaky foundation and so the scientific method ensures that our foundation is strong and I'll leave you with the gentleman who is often considered to be the father or one of the fathers of the scientific method he lived in Cairo and in what is now Iraq Oh nearly a thousand or roughly a thousand years ago and he was famous astronomer and and physicist and mathematician and his quote is a pretty powerful one cuz I think it even stands today the duty of the man who investigates the writings of scientists if learning is that if learning the truth is his goal let me start over just so I get the dramatic effect right the duty of the man who investigates the writings of scientists if learning the truth is his goal is to make himself an enemy of all that he reads and attack it from every side he should also suspect himself as he performs his critical examination of it so that he may avoid falling into either prejudice or leniency Hasan even al-haytham and is latinized name is alhazen so he's saying be skeptical and not just skeptical of what other people write and read but even of yourself and another aspect of the scientific method which is super important is if someone says they made a hypothesis and they test it and they got a result in order for that to be a good test and in order for that to be a good hypothesis that experiment has to be reproducible someone can't say oh is only you know a certain time that only happens once every hundred years and not that that's why it happened that day it has to be reproducible and reproducible is key because then another skeptical scientist like yourself could say let me see if I can reproduce it let me see let me not just believe it because that person looks like they're smart and they said that it is true
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