Introduction to Metric System and Science

Hello, 250 Waters. Welcome back. Hi. Remember me? Professor Sylvan? You signed up for my class? Okay. So we... Still in this first chapter of our course, introductory chapter, and I promised you that we would talk about the metric system, which you said, please bring it on, bring it on. And so here we are. We're going to talk about the metric system. We're also going to talk about the scientific method in this video. So hopefully you've seen the metric system before, and this, therefore, will be more of a reminder. not seen the metric system, then this will be an introduction to the metric system. Either way, this is something you need to know because we are going to use it in this course, largely when we're talking about volumes and distances in kilometers from one place in the ocean to the other, as well as distance below the sea surface. So that, in other words, depth, which we will talk about meters. as well as distance below the seafloor, which we might talk about in kilometers when we talk about the structure of the planet. So the metric system is also known as the SI, as SI units. These are easy to use as fractions. The greatest thing about the metric system is the math is easy. They're all multiples related to it. one another by factors of 10. And so meter is 10 centimeters, centimeter is 10 millimeters, and so on down the chain. And the prefixes are used so that So there's a bunch of different units, but those prefixes like Senti and Milli and Micro and all those are universal for the different units, which is really nice. It's used all over the world. I mentioned there were only two countries in the world on the entire planet, besides the United States, that don't use the metric system. They are Liberia and Myanmar, and not that those aren't fine countries. But seriously, the entire rest of the planet uses the metric system. We should really get with it and use it as well. If it makes you feel better, so I am a professional scientist. I use the metric system at work because that's what all of the units that I study are in. When I leave work, excuse me, and I do something like buy milk, I think about gallons. And when I buy gas, I think about gallons. And when I'm going somewhere, I might be able to convert that distance to kilometers, but I'm probably thinking in miles. And so here in the... in the US, if you are American, like most of the people in the class at a state school probably are, that type of thing might happen to you. That's fine. But in terms of science, we use the metric system, so you should become familiar with it. So Benjamin Franklin, one of our original founding fathers, also an atheist, by the way, not all the founding fathers. were super religious. Benjamin Franklin was one of the first to propose the use of the metric system. I think he was also the proponent of the turkey as the national bird, so not all his ideas were good. But this one was a pretty good one. So I throw this up there just to point out that this was actually something that was talked about at the very birth of the country, but it was not used. The metric system is used in global trade and the Trade Act of 1988 to find the metric system as the preferred system awaits and measures for U.S. trade and commerce. So even sectors within the U.S., such as science and trade, use the metric system. Metric units are units of science, as I mentioned. All journals use metric units. I mean, all oceanographers and most other scientists also use the metric system. Okay, so this is from the back of your book, A is for Appendix A1.1, and this gives you some of the common prefixes for basic metric units. units. You don't have to necessarily know all of them, like deca, D-E-K-A. It's not one that I see very often. The most common ones that we see are kilo, centi, milli, and micro, although we might also use nano and pico. I use these because I do some chemistry and think about nanomoles and picomoles, and also I'm a biologist that works with single-celled organisms that are about a micron long, and so I think about nano and pico. quite often. So, and this gives you a few examples. One kilometer, which is about 0.6 miles. One kilometer is a thousand meters, right? And this gives you a kilometer. So that's one kilometer, right? Kilo means a thousand. So one kilometer equals a thousand meters. That just makes sense. Or 100,000 centimeters, right? Because they... there's 10 meters to every centimeter. Oh, I hear, sorry about that, I hear the computer making a lot of noise, but I don't need this particular computer, it just sits there and makes a lot of noise. One kilometer equals 1,000 meters, 100,000 centimeters, a million millimeters, or one billion micrometers. Back in my day, we used to actually call these microns, but micrometers is more appropriate. And so you can see these are all units of 10, so it makes it easy to convert. So in one meter here would equal 100 centimeters, right? Centi means 1 100th, right? millimeters, 100 centimeters, 1,000 millimeters, 1 milli means 1,000th, 1 million microns, and 1 billion nanometers. Or I'm sorry, see, I just did it. 1 million microns. micrometers, or 1 billion nanometers. So I would suggest spending some time with this. Also, if you're not used to seeing scientific notation, this is also something that you'll see throughout the book when we talk about units, because this is how we think about them. And so these are all, you know, 10 to the second is 100, 10 to the third is 1,000. This is 10 times 10 times 10, right? 10 raised to the third. So just get used to seeing these kinds of numbers. It might mean sitting down with them for half an hour. half hour and looking at this table doing a few conversions, but you will need to get used to seeing those types of words. So, and the most common units that we will use, or I'll go over a few of them, so I'll talk about meters in terms of length, we will talk about Celsius. The temperature scale, metric temperature scale, was designed so that freezing point of pure water was set at zero degrees Celsius, and the boiling point of pure water was set at 100 degrees Celsius. So... That liquid temperature, the range of liquid temperature, is divided into 100 units of Celsius. And so that's pretty nice. So in terms of conversions, 0 degrees Celsius is 32 degrees Fahrenheit. This freezing point of water is 32 degrees Fahrenheit, most famously for those of us that grew up. Even just sometimes it snows in College Station. It did snow in College Station in 2017. Um... 32 degrees Celsius, that's around the temperature when you get snow, right? If you live even just a little north of Texas, you'll see snow probably at least once in a while. The further north you go, clearly the more once in a while you see it. So 32 degrees Fahrenheit, freezing point of water, also when we see snow. 37 degrees Celsius is 98.6 degrees Fahrenheit. That is the normal body temperature. So if you ever go into a lab that's growing E. coli, they are usually growing that at 37. degrees Celsius because it can live in our guts. And that's E. coli is a bacteria that's a common lab rat. So grown in a lot of labs that study genetics. And it grows at 37 degrees Celsius. 100 degrees Celsius is the boiling point of water. 200 degrees Fahrenheit, 212 degrees Fahrenheit. I feel like I see that number much less, but 100 degrees Celsius boiling point of water. To convert Fahrenheit to Celsius, the degree of Celsius. equals Fahrenheit minus 32 divided by 1.8. That's not that bad, but a little bit confusing. It's hard to do in your head. I would suggest using an app for these types of conversions. UnitPlus is great. I actually use these apps all the time when I need to make conversions. Usually it's in temperature. Sometimes it's in distance. So there you have it. The metric length unit of... of a metric, the SI unit of length is the meter. This was originally determined as 1 ten millionth of the distance between the North Pole and the equator. Again, we're already in units of 10, or factors of 10. Since 1983, one meter has been defined as the distance of light, I'm sorry, the distance traveled by light in a vacuum during this horrible fraction, 1, 299,792,499,758th of a second. clearly a very tiny fraction of a second. The reason this was defined as that is it will never change ever for the rest of the eternity until the sun comes and swallows the planet earth, which it will when the sun dies eventually, which is why we need to terraform other planets. This is something that remains stable. In the past, it's been that. This actually can change very, very slightly, right? But you want these standards to be very exact. So I think at one point, it might have been like a piece of some stick or something. but again, that can change over time very, very slightly, but it matters. This will never change. One inch is 2.54 centimeters. That's actually a good one to remember. A meter is a little over a yard, 1.1 yards. This is probably the closest one. When we talk about meters, you can almost directly convert to yards. When you're talking about many meters, then it starts to add up and be a big difference, but a meter is a little over a yard, and a kilometer is 0.7. miles. So to help wrap this around your head, help you wrap your head around this, how about that? Ocean covers about 70% of the size of the Earth. Let's think about the size of that in, or one of the aspects of the size of that in metric units. The average water depth of the ocean is 3.8 kilometers, or about, let's say, 4,000 meters. So that's 2.3 kilometers. 3.36 miles. The next question is how far is 3.8 kilometers? I said it right there, so you'll probably get this answer. I'm realizing as I look at the slide, or if you're super smart, you could just look at the next slide since you probably downloaded the slides, but don't do that. Play along with me. This is supposed to be interactive. How far is 3.8 kilometers? The distance from here to Houston, from here to Navasota. If you're not from College Station, Navasota is the next town to... hour south, if you go out on Highway 6, from here to the airport, CLL, whatever CLL stands for. I know the airport code, but that's the College Station Airport, Eastward Airport, is there on the map. Or the distance from here, and when I say here, I mean the O&M building, which is right across from the golf course, right here, right next to the administration building, distance from here to Kyle Field. Which one of these do you think is... 3.8 kilometers, or if you're really not good at telling distances, 2.4, 2.36 miles. George thinks that it's the distance from here to Kyle Field, but George is not very good at distance, it turns out. It's the distance from here to the airport. This is four kilometers. And if you can wrap your head around that, so this... noticing that this arrow doesn't actually point to our building, it should point to there. But so the distance from here to here, right, more or less is the average depth of the ocean. That means that half of the ocean is actually deeper than that, half of the ocean is shallower than that. But this gives you a little bit about, of help thinking about metric units and the size of the ocean. We'll talk about that much more moving forward. Deep breaths. So that's metric units. I'm not going to go into it too much more than that. I'm just going to start using them. So if that's confusing, I suggest that you spend some time with the appendix and any one of probably a bazillion resources online just talking about metric units. units and what they are and familiarize yourself with them. So the last part of this video is going to be talking about the scientific method. So the scientific method is basically the way that scientists perform their work, and the goal is to discover underlying patterns in the natural world and then use this knowledge to make predictions about what will happen under a given set of conditions. This is the biggest thing, right? Scientific method is really taking notice of what's around you and then using that knowledge to try to predict what might happen in a different situation based on what you know about what's happening that you just found out. So an underlying assumption is that the basic laws of physics and all of the rest of science have always operated in the same way within the natural world. If you have better evidence, then please share it with us, but we have to go by that assumption. But this means that when we study things, when we study the way it works now, we're assuming that that worked the same way three billion years ago, if we're trying to extrapolate backwards. And that it will continue to work that way a thousand years in the future. if we're trying to extrapolate forwards. And that it also works that way in China if we're studying something that happens here and trying to extrapolate for a similar system, like maybe a hot spring. Do the things that happen in Yellowstone look the same as hot springs in China? It's a lot of hot springs in China. One can only, we also assume, or know, one can only investigate what we can measure, either directly or indirectly. So if it is not something that... you can actually study and measure, then you can't use the scientific method with it. And the goal of the scientific method is an explanation, a scientific explanation of the natural world is one which best supports the available data. The fun comes in as to what the best available data or what the explanation is that best supports the available data, right? And so there's the data is the data. Those are what we might think of as the facts. But how you interpret the facts sometimes is... up for debate. And this is usually where the fun part of science is, is trying to figure out how you interpret a particular set of data. Okay, so the scientific method at its most basic goes from observation to hypothesis to testing that hypothesis to theory. This is a very linear look at that. I think this is from a few editions ago, 2011, so maybe that's the 9th edition or 10th edition. But an observation, be that as it may, I'll show you another version of it on the next slide. Observation is the collection of scientific facts through observation and measurement. So you just, you look at something, you measure it. A hypothesis is a tentative, testable statement about the natural world that can be used to build more complex influences and explanations. And you see right here, testable is the most important part of that. And you need to, if it's... It's not something that you can go back and test and prove right or wrong. Sometimes your hypothesis turn out to be wrong, and that's part of science. But if you can't prove one way or the other, it's not testable, and therefore it's not science. Testing, development of observations, experiments, and models to test, and if necessary, revise your hypothesis. This is the part where you actually go out and either collect more data, or maybe you run models and see if... if my hypothesis is this, does that remain true after I collect more data or run some simulations? And then if you do a lot of these two things, this says after much testing and experimentation, but basically a lot of hypothesis generation and testing, we will come to theory. So in science, well-substantiated explanation of some aspect of the natural world that can increase. Incorporate facts, laws, logical inferences, and tested hypotheses is a theory. A better way of thinking about this is this version, which is actually the version that occurs in your textbook, where it's more of a circular thing that has repeating parts. And I like that because it really shows you that the hypothesis, testing, collect more observations, come up with another hypothesis, test that, more observations. This part goes around a lot of times before you come out of it. of that with the theory. And that's how science works. And the whole point of a theory is to allow you to make predictions about things that you maybe can't collect enough data for, but have some data and can base it on your theory how that particular system might work. So this brings us to this idea of probably true versus absolutely true. And the fact that we're never certain that we have all observations possible. Sometimes when people are trying to debunk scientists, they'll bring up this like, well, you don't have all of the observations possible. It's true. That's not physically possible. It will never happen. It's kind of a non-serve of an argument because you can't really fight back against that. However, science is continually evolving. continually developing because of new observations. This is the nature of science. There is a potential that everything that I discover and publish might be proven wrong 100 years from now. I hope that's not the case. There's a lot of science that has been around for thousands of years that has remained correct, but sometimes we find out new things and it changes the way we see the Earth or understand the Earth. So, for example, some hypotheses are abandoned because of new conflicting evidence. evidence. A really classic one is that the Earth is the center of the universe. This was believed hundreds of years ago. In the scheme of how long humans have been around, not that long ago. But most of us don't have ancestors that thought that the Earth was the center of the universe. Observations using telescopes showed us that that is actually not true. And so that changed the science. More recently, it used to be when I was growing up, people would tell you that stress causes ulcers, right, when your stomach is bothering you. And that's not technically true. So some theories become increasingly more accurate to the point of no longer being questioned by scientists. For example, the sun is the center of the universe. Nobody would question that because we have observed it in so many different ways at this point over hundreds of years that there's no reason to question that because it is a fact. And so even though we're not sure, we're not sure. We can't collect all of the observations possible to show us that. Nobody has ever actually walked on the sun, right? We've sent satellites very close to it. We have telescopes in space. We have telescopes on this planet and so many observations that show us the sun is the center of the universe. Likewise, we know that new species arise through the process of evolution. We've never been able to watch, you know, one animal magically turn into another animal. This is something that occurs over... longer periods of time than a human life, but there's been so many observations that we know that this is true. And actually, nowadays, using microbes which grow much faster than humans, we actually have gotten really, really close to actually seeing that in action. It just, this takes many, many, many, many generations. And so, but this is something that scientists would not question. So, scientific method in action, I wanted to give you on the last slide for this video an example of what a whole run through the scientific method might look like. actually look like. So it always, notice, it always starts off with curiosity. Curiosity is what turns you into a scientist eventually. It also kills the cat, but curiosity is so crucial if you want to actually be a scientist one day. day. So maybe you walk out into your garden or your backyard one day and you have a pond there and you say, the water in my pond is green and it's not normally green. And so I am curious why that might be. So you start thinking. Maybe the pond is green because of excess algae in the water. If you don't know what algae are, you're going to find out in this course. But those are those phytoplankton. Algae is another word for phytoplankton that people sometimes use. And phytoplankton, because they have chlorophyll, tend to be green. They're not all green, but they tend to be green. So you might say, maybe there's excess algae in the water and that's why it's green. You could say, maybe my son spilled his bucket of green paint into the water. That could also be a hypothesis. But either way, you know, you could say, maybe my son You now have an idea of why you think your pond might be green. You have to now test. You have to collect observations that will help you prove or disprove your hypothesis. I'm going with the algae hypothesis. And so do some experiments. Go collect water from your pond. Look at it under a microscope. You should probably, if you're designing a nice experiment, you should probably also collect water from other ponds that are not green. Or even better yet, from other ponds that are also green and other ponds that are not green. green to help really put into context your experiment, or I should say your experimental data set or your pond, right? And then you perform some measurements. Count algae in those samples. If you think algae is what's making your pond green, one good way to do that would be to see if you have more algae in your pond than you do in other ponds that are not green, as well as similar amounts of algae in your green pond as to other ponds that are also green. and then you analyze your data are these maybe in this case I would use statistics and say not green ponds versus green ponds are there statistically different amounts of algae in the green ponds than there are in the not green ponds statistics are very important um Yes, this looks very important. I'm trying to think of the word for when you tell a story about a single event, which is common in the news and politics. Love using those. Those are not important, unless they represent... statistically significant event or something that's happening. So based on analyzing this data, you will accept anecdote. That's the word, anecdotes. Anecdotes are not statistically relevant. unless they represent something that is. Sometimes you just want to get your idea across and then say, and this story represents 70% of people in whatever situation. So based on your measurements, you will accept or reject your hypothesis. Let's say you counted the algae and you found out there's not more algae in your pond than there are in other green ponds, I'm sorry, other ponds that are not green. Then you would have to refine your hypothesis. You have to find out what the algae is. have disproven your hypothesis in this case I've proven my hypothesis probably I saw a lot of algae and I said maybe the ponds green because it contains a lot of chlorella which is a green algae that I saw in my samples if I hadn't seen Maybe we'll go back to the example I just threw out there. I might say, you know what, I'm going back to that paint hypothesis, and I bet my son spilled a bucket of paint, and now I might go get a robot to swim around my pond. I know, it's totally overkill, right? You probably see right in the pond. But let's over-engineer this experiment. Take a robot out there, put it in the water to swim around, and look for the paint bucket at the bottom of the pond. Or measure the chemistry of the water and see if you can actually measure paint in your samples. and then eventually you will do these a lot of times and lead to a theory right maybe let's go back to the idea on the slide or the example on the slide where we actually found a lot of chlorella and in our pond and we said that's probably the reason that my pond is green okay now i know i'm pond is green and that that got me to solve the initial question i had but why are there so many chlorella in my pond and so that's something that i might go on because if i want to be able to make make predictions in the future, I want to understand the situation that led to so many chlorella. Were there a lot of nutrients in the water? Was there some sort of food that they really liked that made them bloom? And this would require a lot more data collection and hypothesis generation to understand why there are so many chlorella. And then a theory might be, this is how you get a lot of chlorella in your pond. Ta-da! Yeah? Pretty good. We're through two lectures now. That is the end of two? No, we're through three lectures. I can't even count. We're through three lectures. That's the end of this lecture. Thank you. Thank you for joining me. And we will... wrap up this introductory section in the next chapter talking about latitude and longitude, which is kind of the final big, broad introductory topic that you really need to know something about before we start. start moving forward and talking about the planet. Thank you for watching and being part of this course. We started off with my left hand in front of the camera, and we're going to finish with waving goodbye from my left hand, my right hand, and then George will turn off the camera, and I will see you in the next lecture. Bye.

Hello, 250 Waters. Welcome back. Hi. Remember me?

Professor Sylvan? You signed up for my class? Okay.

So we... Still in this first chapter of our course, introductory chapter, and I promised you that we would talk about the metric system, which you said, please bring it on, bring it on. And so here we are. We're going to talk about the metric system. We're also going to talk about the scientific method in this video.

So hopefully you've seen the metric system before, and this, therefore, will be more of a reminder. not seen the metric system, then this will be an introduction to the metric system. Either way, this is something you need to know because we are going to use it in this course, largely when we're talking about volumes and distances in kilometers from one place in the ocean to the other, as well as distance below the sea surface.

So that, in other words, depth, which we will talk about meters. as well as distance below the seafloor, which we might talk about in kilometers when we talk about the structure of the planet. So the metric system is also known as the SI, as SI units.

These are easy to use as fractions. The greatest thing about the metric system is the math is easy. They're all multiples related to it.

one another by factors of 10. And so meter is 10 centimeters, centimeter is 10 millimeters, and so on down the chain. And the prefixes are used so that So there's a bunch of different units, but those prefixes like Senti and Milli and Micro and all those are universal for the different units, which is really nice. It's used all over the world. I mentioned there were only two countries in the world on the entire planet, besides the United States, that don't use the metric system.

They are Liberia and Myanmar, and not that those aren't fine countries. But seriously, the entire rest of the planet uses the metric system. We should really get with it and use it as well. If it makes you feel better, so I am a professional scientist.

I use the metric system at work because that's what all of the units that I study are in. When I leave work, excuse me, and I do something like buy milk, I think about gallons. And when I buy gas, I think about gallons.

And when I'm going somewhere, I might be able to convert that distance to kilometers, but I'm probably thinking in miles. And so here in the... in the US, if you are American, like most of the people in the class at a state school probably are, that type of thing might happen to you. That's fine. But in terms of science, we use the metric system, so you should become familiar with it.

So Benjamin Franklin, one of our original founding fathers, also an atheist, by the way, not all the founding fathers. were super religious. Benjamin Franklin was one of the first to propose the use of the metric system. I think he was also the proponent of the turkey as the national bird, so not all his ideas were good.

But this one was a pretty good one. So I throw this up there just to point out that this was actually something that was talked about at the very birth of the country, but it was not used. The metric system is used in global trade and the Trade Act of 1988 to find the metric system as the preferred system awaits and measures for U.S. trade and commerce. So even sectors within the U.S., such as science and trade, use the metric system. Metric units are units of science, as I mentioned.

All journals use metric units. I mean, all oceanographers and most other scientists also use the metric system. Okay, so this is from the back of your book, A is for Appendix A1.1, and this gives you some of the common prefixes for basic metric units. units. You don't have to necessarily know all of them, like deca, D-E-K-A.

It's not one that I see very often. The most common ones that we see are kilo, centi, milli, and micro, although we might also use nano and pico. I use these because I do some chemistry and think about nanomoles and picomoles, and also I'm a biologist that works with single-celled organisms that are about a micron long, and so I think about nano and pico.

quite often. So, and this gives you a few examples. One kilometer, which is about 0.6 miles. One kilometer is a thousand meters, right?

And this gives you a kilometer. So that's one kilometer, right? Kilo means a thousand. So one kilometer equals a thousand meters. That just makes sense.

Or 100,000 centimeters, right? Because they... there's 10 meters to every centimeter.

Oh, I hear, sorry about that, I hear the computer making a lot of noise, but I don't need this particular computer, it just sits there and makes a lot of noise. One kilometer equals 1,000 meters, 100,000 centimeters, a million millimeters, or one billion micrometers. Back in my day, we used to actually call these microns, but micrometers is more appropriate.

And so you can see these are all units of 10, so it makes it easy to convert. So in one meter here would equal 100 centimeters, right? Centi means 1 100th, right? millimeters, 100 centimeters, 1,000 millimeters, 1 milli means 1,000th, 1 million microns, and 1 billion nanometers.

Or I'm sorry, see, I just did it. 1 million microns. micrometers, or 1 billion nanometers. So I would suggest spending some time with this. Also, if you're not used to seeing scientific notation, this is also something that you'll see throughout the book when we talk about units, because this is how we think about them.

And so these are all, you know, 10 to the second is 100, 10 to the third is 1,000. This is 10 times 10 times 10, right? 10 raised to the third. So just get used to seeing these kinds of numbers.

It might mean sitting down with them for half an hour. half hour and looking at this table doing a few conversions, but you will need to get used to seeing those types of words. So, and the most common units that we will use, or I'll go over a few of them, so I'll talk about meters in terms of length, we will talk about Celsius.

The temperature scale, metric temperature scale, was designed so that freezing point of pure water was set at zero degrees Celsius, and the boiling point of pure water was set at 100 degrees Celsius. So... That liquid temperature, the range of liquid temperature, is divided into 100 units of Celsius. And so that's pretty nice. So in terms of conversions, 0 degrees Celsius is 32 degrees Fahrenheit.

This freezing point of water is 32 degrees Fahrenheit, most famously for those of us that grew up. Even just sometimes it snows in College Station. It did snow in College Station in 2017. Um...

32 degrees Celsius, that's around the temperature when you get snow, right? If you live even just a little north of Texas, you'll see snow probably at least once in a while. The further north you go, clearly the more once in a while you see it.

So 32 degrees Fahrenheit, freezing point of water, also when we see snow. 37 degrees Celsius is 98.6 degrees Fahrenheit. That is the normal body temperature. So if you ever go into a lab that's growing E. coli, they are usually growing that at 37. degrees Celsius because it can live in our guts.

And that's E. coli is a bacteria that's a common lab rat. So grown in a lot of labs that study genetics. And it grows at 37 degrees Celsius.

100 degrees Celsius is the boiling point of water. 200 degrees Fahrenheit, 212 degrees Fahrenheit. I feel like I see that number much less, but 100 degrees Celsius boiling point of water.

To convert Fahrenheit to Celsius, the degree of Celsius. equals Fahrenheit minus 32 divided by 1.8. That's not that bad, but a little bit confusing.

It's hard to do in your head. I would suggest using an app for these types of conversions. UnitPlus is great. I actually use these apps all the time when I need to make conversions.

Usually it's in temperature. Sometimes it's in distance. So there you have it.

The metric length unit of... of a metric, the SI unit of length is the meter. This was originally determined as 1 ten millionth of the distance between the North Pole and the equator. Again, we're already in units of 10, or factors of 10. Since 1983, one meter has been defined as the distance of light, I'm sorry, the distance traveled by light in a vacuum during this horrible fraction, 1, 299,792,499,758th of a second.

clearly a very tiny fraction of a second. The reason this was defined as that is it will never change ever for the rest of the eternity until the sun comes and swallows the planet earth, which it will when the sun dies eventually, which is why we need to terraform other planets. This is something that remains stable. In the past, it's been that.

This actually can change very, very slightly, right? But you want these standards to be very exact. So I think at one point, it might have been like a piece of some stick or something.

but again, that can change over time very, very slightly, but it matters. This will never change. One inch is 2.54 centimeters.

That's actually a good one to remember. A meter is a little over a yard, 1.1 yards. This is probably the closest one. When we talk about meters, you can almost directly convert to yards.

When you're talking about many meters, then it starts to add up and be a big difference, but a meter is a little over a yard, and a kilometer is 0.7. miles. So to help wrap this around your head, help you wrap your head around this, how about that? Ocean covers about 70% of the size of the Earth.

Let's think about the size of that in, or one of the aspects of the size of that in metric units. The average water depth of the ocean is 3.8 kilometers, or about, let's say, 4,000 meters. So that's 2.3 kilometers.

3.36 miles. The next question is how far is 3.8 kilometers? I said it right there, so you'll probably get this answer.

I'm realizing as I look at the slide, or if you're super smart, you could just look at the next slide since you probably downloaded the slides, but don't do that. Play along with me. This is supposed to be interactive. How far is 3.8 kilometers?

The distance from here to Houston, from here to Navasota. If you're not from College Station, Navasota is the next town to... hour south, if you go out on Highway 6, from here to the airport, CLL, whatever CLL stands for.

I know the airport code, but that's the College Station Airport, Eastward Airport, is there on the map. Or the distance from here, and when I say here, I mean the O&M building, which is right across from the golf course, right here, right next to the administration building, distance from here to Kyle Field. Which one of these do you think is...

3.8 kilometers, or if you're really not good at telling distances, 2.4, 2.36 miles. George thinks that it's the distance from here to Kyle Field, but George is not very good at distance, it turns out. It's the distance from here to the airport. This is four kilometers. And if you can wrap your head around that, so this...

noticing that this arrow doesn't actually point to our building, it should point to there. But so the distance from here to here, right, more or less is the average depth of the ocean. That means that half of the ocean is actually deeper than that, half of the ocean is shallower than that.

But this gives you a little bit about, of help thinking about metric units and the size of the ocean. We'll talk about that much more moving forward. Deep breaths.

So that's metric units. I'm not going to go into it too much more than that. I'm just going to start using them. So if that's confusing, I suggest that you spend some time with the appendix and any one of probably a bazillion resources online just talking about metric units.

units and what they are and familiarize yourself with them. So the last part of this video is going to be talking about the scientific method. So the scientific method is basically the way that scientists perform their work, and the goal is to discover underlying patterns in the natural world and then use this knowledge to make predictions about what will happen under a given set of conditions. This is the biggest thing, right?

Scientific method is really taking notice of what's around you and then using that knowledge to try to predict what might happen in a different situation based on what you know about what's happening that you just found out. So an underlying assumption is that the basic laws of physics and all of the rest of science have always operated in the same way within the natural world. If you have better evidence, then please share it with us, but we have to go by that assumption.

But this means that when we study things, when we study the way it works now, we're assuming that that worked the same way three billion years ago, if we're trying to extrapolate backwards. And that it will continue to work that way a thousand years in the future. if we're trying to extrapolate forwards. And that it also works that way in China if we're studying something that happens here and trying to extrapolate for a similar system, like maybe a hot spring. Do the things that happen in Yellowstone look the same as hot springs in China?

It's a lot of hot springs in China. One can only, we also assume, or know, one can only investigate what we can measure, either directly or indirectly. So if it is not something that... you can actually study and measure, then you can't use the scientific method with it.

And the goal of the scientific method is an explanation, a scientific explanation of the natural world is one which best supports the available data. The fun comes in as to what the best available data or what the explanation is that best supports the available data, right? And so there's the data is the data. Those are what we might think of as the facts. But how you interpret the facts sometimes is...

up for debate. And this is usually where the fun part of science is, is trying to figure out how you interpret a particular set of data. Okay, so the scientific method at its most basic goes from observation to hypothesis to testing that hypothesis to theory. This is a very linear look at that.

I think this is from a few editions ago, 2011, so maybe that's the 9th edition or 10th edition. But an observation, be that as it may, I'll show you another version of it on the next slide. Observation is the collection of scientific facts through observation and measurement. So you just, you look at something, you measure it.

A hypothesis is a tentative, testable statement about the natural world that can be used to build more complex influences and explanations. And you see right here, testable is the most important part of that. And you need to, if it's...

It's not something that you can go back and test and prove right or wrong. Sometimes your hypothesis turn out to be wrong, and that's part of science. But if you can't prove one way or the other, it's not testable, and therefore it's not science.

Testing, development of observations, experiments, and models to test, and if necessary, revise your hypothesis. This is the part where you actually go out and either collect more data, or maybe you run models and see if... if my hypothesis is this, does that remain true after I collect more data or run some simulations?

And then if you do a lot of these two things, this says after much testing and experimentation, but basically a lot of hypothesis generation and testing, we will come to theory. So in science, well-substantiated explanation of some aspect of the natural world that can increase. Incorporate facts, laws, logical inferences, and tested hypotheses is a theory. A better way of thinking about this is this version, which is actually the version that occurs in your textbook, where it's more of a circular thing that has repeating parts. And I like that because it really shows you that the hypothesis, testing, collect more observations, come up with another hypothesis, test that, more observations.

This part goes around a lot of times before you come out of it. of that with the theory. And that's how science works. And the whole point of a theory is to allow you to make predictions about things that you maybe can't collect enough data for, but have some data and can base it on your theory how that particular system might work.

So this brings us to this idea of probably true versus absolutely true. And the fact that we're never certain that we have all observations possible. Sometimes when people are trying to debunk scientists, they'll bring up this like, well, you don't have all of the observations possible.

It's true. That's not physically possible. It will never happen.

It's kind of a non-serve of an argument because you can't really fight back against that. However, science is continually evolving. continually developing because of new observations.

This is the nature of science. There is a potential that everything that I discover and publish might be proven wrong 100 years from now. I hope that's not the case. There's a lot of science that has been around for thousands of years that has remained correct, but sometimes we find out new things and it changes the way we see the Earth or understand the Earth.

So, for example, some hypotheses are abandoned because of new conflicting evidence. evidence. A really classic one is that the Earth is the center of the universe.

This was believed hundreds of years ago. In the scheme of how long humans have been around, not that long ago. But most of us don't have ancestors that thought that the Earth was the center of the universe.

Observations using telescopes showed us that that is actually not true. And so that changed the science. More recently, it used to be when I was growing up, people would tell you that stress causes ulcers, right, when your stomach is bothering you. And that's not technically true. So some theories become increasingly more accurate to the point of no longer being questioned by scientists.

For example, the sun is the center of the universe. Nobody would question that because we have observed it in so many different ways at this point over hundreds of years that there's no reason to question that because it is a fact. And so even though we're not sure, we're not sure. We can't collect all of the observations possible to show us that. Nobody has ever actually walked on the sun, right?

We've sent satellites very close to it. We have telescopes in space. We have telescopes on this planet and so many observations that show us the sun is the center of the universe. Likewise, we know that new species arise through the process of evolution. We've never been able to watch, you know, one animal magically turn into another animal.

This is something that occurs over... longer periods of time than a human life, but there's been so many observations that we know that this is true. And actually, nowadays, using microbes which grow much faster than humans, we actually have gotten really, really close to actually seeing that in action. It just, this takes many, many, many, many generations.

And so, but this is something that scientists would not question. So, scientific method in action, I wanted to give you on the last slide for this video an example of what a whole run through the scientific method might look like. actually look like.

So it always, notice, it always starts off with curiosity. Curiosity is what turns you into a scientist eventually. It also kills the cat, but curiosity is so crucial if you want to actually be a scientist one day. day. So maybe you walk out into your garden or your backyard one day and you have a pond there and you say, the water in my pond is green and it's not normally green.

And so I am curious why that might be. So you start thinking. Maybe the pond is green because of excess algae in the water. If you don't know what algae are, you're going to find out in this course. But those are those phytoplankton.

Algae is another word for phytoplankton that people sometimes use. And phytoplankton, because they have chlorophyll, tend to be green. They're not all green, but they tend to be green.

So you might say, maybe there's excess algae in the water and that's why it's green. You could say, maybe my son spilled his bucket of green paint into the water. That could also be a hypothesis. But either way, you know, you could say, maybe my son You now have an idea of why you think your pond might be green. You have to now test.

You have to collect observations that will help you prove or disprove your hypothesis. I'm going with the algae hypothesis. And so do some experiments.

Go collect water from your pond. Look at it under a microscope. You should probably, if you're designing a nice experiment, you should probably also collect water from other ponds that are not green.

Or even better yet, from other ponds that are also green and other ponds that are not green. green to help really put into context your experiment, or I should say your experimental data set or your pond, right? And then you perform some measurements.

Count algae in those samples. If you think algae is what's making your pond green, one good way to do that would be to see if you have more algae in your pond than you do in other ponds that are not green, as well as similar amounts of algae in your green pond as to other ponds that are also green. and then you analyze your data are these maybe in this case I would use statistics and say not green ponds versus green ponds are there statistically different amounts of algae in the green ponds than there are in the not green ponds statistics are very important um Yes, this looks very important.

I'm trying to think of the word for when you tell a story about a single event, which is common in the news and politics. Love using those. Those are not important, unless they represent... statistically significant event or something that's happening. So based on analyzing this data, you will accept anecdote.

That's the word, anecdotes. Anecdotes are not statistically relevant. unless they represent something that is. Sometimes you just want to get your idea across and then say, and this story represents 70% of people in whatever situation.

So based on your measurements, you will accept or reject your hypothesis. Let's say you counted the algae and you found out there's not more algae in your pond than there are in other green ponds, I'm sorry, other ponds that are not green. Then you would have to refine your hypothesis. You have to find out what the algae is. have disproven your hypothesis in this case I've proven my hypothesis probably I saw a lot of algae and I said maybe the ponds green because it contains a lot of chlorella which is a green algae that I saw in my samples if I hadn't seen Maybe we'll go back to the example I just threw out there. I might say, you know what, I'm going back to that paint hypothesis, and I bet my son spilled a bucket of paint, and now I might go get a robot to swim around my pond.

I know, it's totally overkill, right? You probably see right in the pond. But let's over-engineer this experiment.

Take a robot out there, put it in the water to swim around, and look for the paint bucket at the bottom of the pond. Or measure the chemistry of the water and see if you can actually measure paint in your samples. and then eventually you will do these a lot of times and lead to a theory right maybe let's go back to the idea on the slide or the example on the slide where we actually found a lot of chlorella and in our pond and we said that's probably the reason that my pond is green okay now i know i'm pond is green and that that got me to solve the initial question i had but why are there so many chlorella in my pond and so that's something that i might go on because if i want to be able to make make predictions in the future, I want to understand the situation that led to so many chlorella. Were there a lot of nutrients in the water? Was there some sort of food that they really liked that made them bloom?

And this would require a lot more data collection and hypothesis generation to understand why there are so many chlorella. And then a theory might be, this is how you get a lot of chlorella in your pond. Ta-da! Yeah? Pretty good.

We're through two lectures now. That is the end of two? No, we're through three lectures.

I can't even count. We're through three lectures. That's the end of this lecture.

Thank you. Thank you for joining me. And we will... wrap up this introductory section in the next chapter talking about latitude and longitude, which is kind of the final big, broad introductory topic that you really need to know something about before we start.

start moving forward and talking about the planet. Thank you for watching and being part of this course. We started off with my left hand in front of the camera, and we're going to finish with waving goodbye from my left hand, my right hand, and then George will turn off the camera, and I will see you in the next lecture. Bye.

Transcript for:Introduction to Metric System and Science

Transcript for:
Introduction to Metric System and Science