Tag Archives: Science

The Universe is Vast, And Why That Bothers Me

The word “vast” gets tossed around a lot to describe things like the backseat of an SUV, or a big lawn or the open ocean. These things can all be vast, depending on your frame of reference, but if there is anything that can truly be described as “vast” it is the universe.

The size of the universe defies any adequate description or human comprehension. Consider light. Light travels at the cosmic speed limit of 186,000 miles per second.

Chicago satellite image

Satellite view of Chicago

I live in Chicago, and I am often amazed at how big this city is. I could spend my whole life exploring this city and not get to see everything. Google tells me that there are 4300 miles of road in Chicago — longer than the United States is wide — but light could travel every road in the entire city 43 times in one second. One second to travel the entire distance that my first car traveled in its entire lifetime. One second to travel around the Earth’s equator seven times.

Our sun is 93 million miles from where I am sitting. At a steady pace of 3 miles per hour, it would take 3500 years to walk to the sun without any breaks for eating or sleeping. The same light that can circle the whole earth seven times in one second takes 8 whole minutes to get from the sun to our planet. Along the way, there are two planets, one about the same size as earth, and one a bit smaller. Venus has a surface area of 177 million square miles — that’s over 750,000 Chicagos. There are six more planets in our solar system, a handful of dwarf planets, an asteroid belt, an Oort cloud, and more.

The nearest star to our own is Proxima Centauri. Light from our sun takes 4.3 years to get there. 4.3 years going as fast as it is possible for anything to travel.

Our planet is located in a backwater arm of the Milky Way Galaxy. Light takes 100,000 years to travel its diameter. The same light in the same time could circle the earth over 20,000,000,000,000 (20 trillion) times.

You Are Here Milky Way

The nearest galaxy to the Milky Way is the Andromeda Galaxy. It is 220,000 light years across, and 2.5 million light years from Earth. Although it contains somewhere in the order of one trillion stars, the entire galaxy is only visible from Earth as a single point of light.

The observable universe is 93,000,000,000 (93 billion) light years across. Light would take 93 billion years to go from one end of the universe that we know to the other. There is more universe out there, but the light from those parts hasn’t reached us yet because the universe isn’t old enough. The universe is only 13 billion years old.

The observable universe is estimated to have around 100-200 billion galaxies. We don’t know exactly how many there are, because it would take too long for our instruments to count them all. And again, there is more to the universe than what we can see. We don’t know how much more because, well, we can’t see it.

The Hubble "Ultra Deep Field"

The Hubble “Ultra Deep Field” is a view of part of the universe when it was less than a billion years old.

I hope I have given a glimpse of just how big the universe is. It is impossible for me to say exactly how big it is, not just because nobody knows, but because the size is completely incomprehensible. It defies language to describe it, and our brains to understand it. Even if the exact size were known, the number expressing it would be meaningless.

A lot of people hear how big the universe is and it makes them feel small. We are the center of our own lives, and what goes on in our lives is important to us. People used to believe that the Earth was the center of the universe because they couldn’t get their heads around the fact that we are unimportant. But to the universe, we are less than unimportant. For the sake of comparison, a speck of dust is in the order of 100µm (100 nanometers) wide. I am a little shy of 2 meters tall. I am therefore approximately 20 million times the size of a speck of dust (length, not volume).

The Earth has a diameter of about 12,000 miles. Our galaxy has a diameter of about 600,000,000,000,000,000 (600 quadrillion) miles. Our galaxy alone is 50 trillion times bigger than the Earth. People like to give “a speck of dust” as a measure of insignificance, but to our galaxy alone, the earth is far, far less significant than a speck of dust is to a human. And to the universe, our entire galaxy is insignificant. It is perfectly understandable that the universe makes some people feel small.

calvin dust speck

The size of the universe bothers me, too, but not because it makes me feel small. It has never been a problem for me to reconcile my own insignificance in the scheme of things.

I am troubled by the fact that I will spend my life exploring Chicago. I will spend my life getting to know one or two dozen people really well, a have a passing familiarity with maybe one or two hundred more. If I were still a researcher, I would spend my life trying to discover as much about the world as I could. As a non-researcher, I will spend my life learning as much of what others have discovered as I can. But there is so much that I will never know.

For all of the things we know about earth, there is so much more that we don’t know. We are just now starting to discover how common other planets are in our galaxy.

We know that the universe is believed to be about one quarter dark matter, but we don’t even know what dark matter is.

When I look up in the sky and see all that I can see, and understand what I can’t see, it makes me sad that I will never get to know so much of what is out there. So many galaxies. So many stars. So many planets. And I have to spend my life on just this one, with only my short life to see what I can see. There is so much to see on Earth, but the universe holds sights that we cannot possibly fathom.

The "Pillars of Creation"

The “Pillars of Creation”

I am troubled because I am a scientist, and I am greedy. Scientists are driven by the knowledge of the things we do not yet know. We see a hole in our knowledge and we want to fill it in. We are humbled by the knowledge of what we do not yet know, and seeing the vastness of the universe can be crushing.

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Replication in Science

The internet is abuzz with the recent publication of an article in Science which replicated 100 studies in psychology, but only found positive results for a third of them. A lot of people are freaking out over this — both scientists and lay people — and I sure wouldn’t want to be one of those scientists whose study couldn’t be successfully replicated. But for those people, it isn’t the end of the world. Most of them didn’t screw up or do anything fraudulent. This is just how science works. A lot of people have talked about what this means about the state of science, or the state of psychology, or the state of whatever else, and I don’t have much to add to this conversation. But this does make me think about a few things about science in general, and it is those things that I want to say a few words about.

1) The publication of a study is not the end of the conversation. I think the media is guilty of misleading people about this. The truth is that you don’t sell many newspapers with headlines like, “scientists discover that X may be true.” What I see instead are headlines like, “scientists prove X is true,” or, “study disproves theory about X.” This isn’t how scientists think about things. If you have never had the pleasure of being in the presence of scientists when they hear the results of a new paper, it is a wonderful thing. More often than not, they will try to find problems with it. Maybe the author conceptualized their problem in the wrong way. Maybe they didn’t think of a confounding variable in their experiment. Maybe their statistics were misapplied. Maybe their mathematical model didn’t describe reality. To the lay person, this might make scientists sound petty for trying to take away a colleague’s accomplishment, but this is just part of the process.

Replication is not what you do to show that scientists are terrible, it is just a part of the process. When a new study comes out, scientists often say, “This is really interesting, but I’d like to see more work done on it.” What they are calling for, is more studies to see whether the effect can be reproduced in a different way. This is replication and is the process.

A few years ago, one of my own studies was subjected to a replication by another research team. They believed that we had failed to take a particular variable into account, and may have made a type I error as a result. I will admit that I figuratively bit my nails when I heard that this study was coming out. Nobody wants their study to be wrong. But it happened to turn out that even with the new variable included in the analysis, our hypothesis was still supported. It could have gone the other way.

This is part of why science is great — it is self-correcting. If one scientist draws the wrong conclusion, either innocently or maliciously, other scientists will be there to fix it. A scientific publication is not the end of the conversation. It is the beginning. When a scientist publishes a paper, they are saying, “This is what we think is going on, and here is some evidence that we are right. What do you think?”

2) When making conclusions in science, there are two types of possible errors: Type I errors and Type II errors. Type I errors are when you conclude that something is true, but it is not. Maybe your study concludes that watering plants with Brawndo (it’s got what plants crave) makes them grow better, when in reality it does not — type I error. A type II error is when you conclude that something is not true, but in reality it is. Maybe you conclude that monkeys are not actually primates, when they really are — type II error. A lot of the conversation around this replication study is about how scientists might be making too many type I errors. This could be true, but it is not my purpose here to comment on that. But I will point out that when you make it harder to make a type I error, you necessarily make it easier to make a type II error. Conversely, when you make it harder to make a type II error, you make it easier to make a type I error. Both types of errors are still errors, and you don’t want to make either one.

Here’s how it works: In science, we often use p-values as a tool for figuring out what happened. When you analyze your data, the p-value measures how likely it is that whatever trend you found in the data is the result of random chance and not a relationship between your variables. a p-value of 1.0 means that there is a 100% chance that your data is random numbers, and a p-value of 0.0 means that it is impossible for random chance to create those numbers (in reality, p-values are never exactly 0.0 or 1.0, but somewhere in between). Scientists use a cutoff of 0.05 for drawing conclusions — that is, you cannot tell people that you made a discovery unless there is a 5% chance or less of your data being meaningless noise. If the chance is 6% or higher, you cannot make any claims. Ideally, most things you find with a p-value of 0.05 or less are true, and most things that you find with a p-value higher that 0.05 are not true. But sometimes you have a real effect with a p-value higher than 0.05, which leads you to think it’s false (type II error), and sometimes you have an effect that is not real with a p-value that is lower than 0.05, and you think it’s real (type I error). If you lower the cutoff value to, say, 0.01, you will get fewer false positives (type I errors), but more false negatives (type II errors). If you raise the cutoff value to 0.1, the opposite happens — type II errors become less common, but type I errors become more common.

3) Science is hard, and we don’t know all of the answers. When we take science classes in school, there is always a right answer. You know that the substance is supposed to turn blue when you add the right chemicals, and if it doesn’t, you know you made a mistake. When I was a teacher, I would frequently have students come to me with a test tube full of orange fluid and ask, “is this right?” I would resist a straight answer as much as I could, because the purpose of the experiment was not to teach them how to make the fluid change colors, but to think like a scientist. The domain of scientists is the edge of human knowledge. There is no one to whom a scientist can ask, “is this right?” Because if there was, they wouldn’t be doing science. No one knows the answers to the questions that scientists ask, which is why scientists are trying to figure out the answers to those questions. This means that we will sometimes get it wrong. It is for this reason that I praise the scientists who do replication studies, as well as the scientists who did the original research. It is all part of the process.

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Music About Science

I have an opinion that might be unpopular around here: I don’t like music about science. My love of science and scientific knowledge cannot be impugned — my Ph.D. is all the evidence I need to make my case. I never would have made it through my 14 years of biology education if I didn’t love science. I even love boring science lecture — both hearing them and giving them. Music is also very important to me. I have been a casual musician for most of my life, and listening to music and making music are deeply fulfilling for me. There is a bunch of music out there that is about science, and it would be reasonable to guess that I would love this music. But I don’t. There is a time for music, and there is a time for a boring science lecture, but when I’m listening to music, what I want is not a boring science lecture.

Exhibit A:

Symphony of science is pretty popular. But let’s face it — this is literally just a boring science lecture that has been auto-tuned. The words of Carl Sagan, for example, are inspiring in their own right. I don’t think making them musical adds anything to them. If anything, I think his words are cheapened slightly by the gimmick.

Exhibit B:

I have a lot of love for Baba Brinkman, so I feel a little bit bad for listing him here. He is brilliant, great with words, and a good performer. I respect him a lot for using his medium to explain science. I particularly like the way he used this anti-evolution rally song as a base for this song about the science of political values and religion.

I got to see him perform once at an evolutionary psychology conference, and I really have nothing but love for him. For the times that I actually do want to listen to a boring science lecture set to music, I go straight to Baba Brinkman. But this doesn’t change the fact that his work is still essentially a boring science lecture, albeit spoken very rhythmically.

Exhibit C:

Hank Green’s “I Fucking Love Science” is cute. There are some clever lines, but it’s not what I want out of music. It is literal and a little bit lecture-ey at times. What I mean should be clear in a minute.

Please don’t misunderstand me — there is no judgement here. Musicians should write about whatever they want to write about, and people should listen to whatever they want to listen to. My feelings about the music I mention are just my own feelings. I also don’t mean to disparage any of these artists. I’ve tried writing music myself, and I can’t go around calling the kettle black.

This is not about what music I think people should or shouldn’t be writing and listening to, it’s just about what I want out of music. What do I want out of music? Some poetry. Some metaphor. The language of emotion. And would a drum solo kill you?

When I listen to music, I want to be able to identify with the emotions that are conveyed through the medium.

Take this song:

This song is reportedly about Kurt Cobain’s relationship with Tobi Vail, the drummer for Bikini Kill. You may not like this song as much as I do, but you will agree that at no point does this song, which is about a human relationship, sound like an anthropologist talking about the mating behavior of gorillas. The song is about the emotions, not the details. No boring lectures anywhere.

Kurt Cobain talks about his experience in this song without making the context perfectly clear. But it is deeply expressive and poetic, and it is exactly what I want out of a song.

Take another song about a relationship that ended:

Kris Kristofferson’s take on this topic has much more of a narrative style than Kurt Cobain’s. There is no question about what Me and Bobby McGee is about. But there is still poetry. He could have said, “Now she’s gone and I really miss her.” That would have communicated his point effectively, but there is no poetry to it. Instead, he chose to say, “and I’d trade all my tomorrows for one single yesterday.” Give me a minute to catch my breath.

I think the mistake that people make when writing music about science is talking like scientists instead of lyricists. There is a reason why we have scientists write our science, and musicians write our music. It has famously been said that, “Writing about music is like dancing about architecture.” Each of these media have their style, and limits to their application.

Here is what I would like to see: music about the experience of science, rather than the outcome of science. We have beautiful, poetic music about the experience of love, death, happiness, sex, jealousy, war, fatherhood, dissatisfaction, and basically every other human experience one could have. But very little beautiful, poetic music about science.

Consider, for a moment, Leonardo DaVinci. He was both a great scientist and a great artist. Remember that this was the guy who painted the Last Supper, the Mona Lisa, and the Vitruvian Man. If he was going to write a song about science, what would it have sounded like? “If the air passing over the top of a wing is moving faster than the air moving under the wing, it will reduce the pressure above the wing and create lift. La dee dee, la dee dah.” No, probably not.

Through my pursuit of science, I have experienced a wide range of emotions. Scientific discovery can be wonderful, beautiful, painful, emotional, and, at times, even exciting. Where is the music inspired by science that conveys these feelings?

You may disagree, or maybe I just haven’t heard the right music. What’s your favorite song about science?

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The Man Behind the Curtain Turns 1

The Man Behind the Curtain turns 1 today! In the past year, this blog has had over 4800 views from people in 104 nations. This surpassed what expectations I had, and I am looking forward to another good year.

The most popular posts this year were:

Dinosaurs are not Extinct

Hot or Not

Do genes skip generations?

Testing a Claim: Ceramic Knives

The least popular posts were:

Drug-Resistant Diseases

Skipping Generations Part 2

You’re Doing it Wrong, Part 2: Post Hoc Ergo Propter Hoc

A UFO (which was my first post)

And these are my personal favorite posts:

For All Mankind

Dinosaurs are not Extinct

10% of our Brains

The Evolution of Flight

Thanks for reading! I hope 2015 will be even better. (Tomorrow I will go through and fix all of the broken images. Sorry about that.)

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New Science and Math Standards

Education has always been important to me, and I don’t just mean my own education. My parents both started their careers as science teachers and I have been involved in science education education professionally for the past 10 years. In a country where 1 in 4 adults believe that the sun orbits the earth, it’s no secret that we have some serious work to do to improve our education. I could make this entire post about the state of scientific literacy in the United States, but I want to go in another direction. One way we can improve our education is by changing the way we teach. The Next Generation Science Standards (NGSS), which covers only science, and the Common Core State Standards (CCSS), which covers only math and english, are the latest attempt to do just that. The political fallout associated with these standards are very interesting, as they have been attacked for various reasons from people on opposite ends of the political spectrum. Some conservatives believe, for example, that these standards are just another case of government overreach, whereas some liberals believe that the standards are just a way to prioritize corporate profits over the education of our children. Various celebrities have come out against these standards, including Louis CK and Stephen Colbert. However, given that they are neither teachers nor education experts, I care about their opinion on the Common Core about as much as I care about Jenny McCarthy’s opinion about vaccines. I want to know what experts think.

Back in June, I started at C2ST as a volunteer. One of my first tasks was to research potential speakers for a public panel discussion on the NGSS and CCSS-M (the math standards within the common core), which Illinois had just adopted. Not knowing much about these standards myself, I wanted to learn about them as much as everyone else did. My first stop was finding people who knew the most about education. I quickly found researchers who study how people learn math and science.

But I also wanted to know what teachers actually thought — there is sometimes a difference between research and practice, and I didn’t want to get lost in that space. I had heard various opinions from my teacher friends, but none of them actually had any experience in applying the standards. I reached out to some professional organizations for teachers, and they put me in touch with a math teacher and a science teacher who both had experience with the new standards.

The panel still needed a moderator. I wanted to have someone who had very broad experience, who could understand the viewpoints of each of the panelists. We found a guy who had just the experience we needed — he had been a teacher, an administrator, worked for the US Department of Education, and directed an educational institute at a university.

Then in mid-August I was hired as the Director of Programming at C2ST, and I was given the helm on this project. I spoke with each of the people on my list, and I was impressed by how much they all knew about their respective subjects. Collectively, they had the expertise to present the education standards to the public. And we made sure they knew what we wanted: we wanted the truth. We didn’t have an agenda for or against these standards, and we only wanted the best possible information to be given to the public.

I would tell you about each of the panelists, but here they are doing it for themselves. I did not film any of these videos, but I am next to the camera asking questions to the panelists:

And here is the complete program. I don’t care what your opinion is of the new education standards. What I care is that everyone has quality information so that they can decide for themselves.

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What Does It Mean To Be Supernatural?

Image from clipartpanda.com

Halloween is coming up, and popular culture is being filled its annual dose of references to the supernatural (including the recent season premier of the show Supernatural, which is probably not a coincidence). Ghosts, monsters, black magic, vampires, witches, and others all fall under this umbrella of “the supernatural.”

But what does it mean to be supernatural?

My dictionary defines “supernatural” as “(of a manifestation or event) attributed to some force beyond scientific understanding or the laws of nature.”

Being beyond scientific understanding is actually very mundane. Most of the way the brain works is beyond our current scientific understanding, but no serious researcher is throwing up his or her arms and declaring it supernatural. The relationship between mass and energy was beyond scientific understanding until Albert Einstein figured it out. The origin of mitochondria and chloroplasts were beyond scientific understanding until Lynn Margulis figured it out. Every issue of every scientific journal is filled with things that were beyond the understanding of science just a year or so prior. This is not what people mean when they say that something is supernatural. They mean the second thing — beyond the laws of nature. The word supernatural literally means “above nature,” or, more figuratively, outside or separate from nature.

But what is nature and what are its laws?

Consulting my dictionary once again, “nature” is defined as “the phenomena of the physical world collectively, including plants, animals, the landscape, and other features and products of the earth, as opposed to humans or human creations.” And once again, my dictionary fails to provide a completely cogent or useful definition. If humans and our creations are not natural, does that mean that the computer I’m writing on is supernatural? Again, no one would reasonably make this claim. The first part of this definition, “the phenomena of the physical world collectively,” is actually pretty good as it is. Nature, or the physical world, is made up of two things: matter and energy, which Einstein showed us are the same thing. Nature is everything that exists. It is all of the animals, plants, fungi, bacteria and all of the rest of life. It is all of the rocks and minerals and water and air. Even humans, which are animals, are part of nature. Everything beyond our planet is part of the natural world, as well. All of the undiscovered types and forms of matter and energy are part of nature. Every answer to an empirical question is part of nature, and it is the job of scientists to discover nature as it exists.

Are ghosts real? This is an empirical question because the answer is not subject to ideology or personal preference. It’s not possible for ghosts to be real for me but not real for someone else, any more than  the statement “the earth’s atmosphere is 78% nitrogen” can be real for me but not real for someone else. Correct answers to empirical questions are correct whether you like it or not. Likewise, either ghosts are real or they are not. If they are real, they are part of nature, and are therefore natural phenomenon. It may come as a surprise to people that, if ghosts are real, it will be scientists who discover them. This is true of everything else that is commonly labeled as “supernatural.” If everything that exists is part of nature, then what does that mean? If something is truly supernatural, it doesn’t exist.

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Only a Theory

With the recent debate between Bill Nye and Ken Ham, there has been a resurgence of people claiming that “evolution is just a theory.” This is something that really needs to stop. 

In common usage, the word “theory” means a guess. You might have a theory about who will play in the super bowl next year or what will happen later this season on American Horror Story. In this respect, your “theory” is as good as anybody else’s. This is not what we mean when we say “theory” as scientists.

In science, our level of certainty about an idea can be summed up with three words: speculation, hypothesis and theory.

A speculation is the lowest level of certainty. When we suspect that something is true but we haven’t done enough research on the topic to be confident in it, we use this word. This is like having a puzzle that is 10% completed and making a guess about what the missing pieces look like.

When a scientist forms a hypothesis, it means that they have learned everything or nearly everything that humans know about a subject, and they are confident in making a claim about something that is unknown. This is like having a puzzle that is completed but for a couple of pieces and making a claim about what the remaining pieces look like. My students will often define “hypothesis” as “an educated guess.” This is technically true, but it is not a particularly good definition because it implies a larger degree of uncertainty than there really is. While a particular hypothesis may not turn out to be correct, a scientist is confident enough in its accuracy to spend years of their life and tens of thousands of dollars determining whether or not it is true.

In scientific parlance, the word “theory” is synonymous with “fact.” It is an idea for which we have a great deal of evidence. A hypothesis can graduate to a theory once enough evidence is collected in support of it. Having a new theory is like adding a piece to a puzzle. When we know a new piece of information, it give us more insight into the things we do not yet know. It allows us to form new hypotheses that we couldn’t have before. So when someone says “x is only a theory,” they are saying “x is only a fact,” which doesn’t make much sense.

For reference, here are some ideas that are considered theories by scientists: The earth is spherical. The earth orbits the sun. General Relativity. Some diseases are caused by microorganisms. Plate tectonics. Electricity. The diversity of life on earth is the result of evolution by natural selection. Of these, the theory of evolution by natural selection is one of the most strongly supported — about as well-supported as the theory of the heliocentric solar system. It is a benchmark against which we can compare our certainty in other ideas. When something is supported as well as evolutionary theory, we know we’ve got it in the bag.

But when something is a theory, doesn’t that mean it hasn’t been proven? In a sense, yes. Outside of mathematics, scientists do not use the word “proof.” This convention is to constantly remind ourselves that we are not finished learning about things and that there is always a chance, however slim it may be, that we are wrong about something. Within mathematics, a statement can be proven within certain, carefully-established bounds. Some mathematically-proven statements are called “theorems.” Math aside, “theory” means as close to proven as we’re willing to say.

So what is a law? Isn’t a law higher than a theory? Not at all. As it is used, one could define it as a robust and generalizable observation. Unlike with a theory, there is no demand that we understand how it works. For example, Kleiber’s Law is the observation that the body size and metabolic rate of animals are related through the function y = x^3/4. There are hypotheses to explain why this is true, but these explanations are not a part of Kleiber’s law. Despite what many people think, theories do not graduate into laws once we get enough evidence for them. Rather, when we do have laws, we need to develop theories to explain them.

Whenever someone is trying to convince you that a particular scientific idea is wrong by claiming that it is “only a theory,” they are either deliberately trying to mislead you, or they are profoundly ignorant of science. These are the only two options.


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