Someone on Facebook shares a science article. Should you trust the article? I made up a list of things that go through my mind when I read an article. As I write explanations of them, I’ll add links to the numbered items:
- How badly does the story violate established science–and does the evidence warrant the “violation”?
- How reliable is the publisher of the story?
- Are other sites (reliable and unreliable) reporting the story?
- What do the fact-checkers say?
- Is it a press release?
- How much do I trust the author?
- Is the headline sensationalistic?
- Does the story point to the original paper?
- Do the abstract and conclusion of the original paper support the story?
- How robust are the methods?
- What is the agenda of the author?
- What does Phil Plait say?
- What is my agenda as the reader?
- Does it look Photoshopped?
I hope to use examples from real articles to demonstrate each of the points. Next, I’d like to go through an article or two to demonstrate the technique. Finally, I might give some examples and see how the readers do on them.
The idea for this series of articles came from a friend who asked me to evaluate an article I think he found on Facebook. In evaluating the article, I realized I went through a checklist in my head that started with “Is the publisher “The Daily Mail” or “The Daily Caller”? Both are notorious for bad science.
I looked to see if anyone else had written such an article. I found many for people reading science journal articles. There was one BBC audio in my browser that I heard a snippet of in the car while listening to Sirius XM BBC (and still haven’t gotten back to…). But these are the things I think about, although not in such an orderly fashion, nor in so consistent a way. And I may add to this list or modify as I write.
If you’d like to read some of the articles I came across, here’s a list:
The day before the NASA team announced they found 7 planets around the Trappist-1 red dwarf star (three in the habitable zone)1, I went to the Duquesne University Darwin Day lecture by Dr. Nick Lane. If you want, you can watch Dr. Lane’s lecture online.
There are an amazing number of things I want to talk about from that lecture, but with the NASA announcement, I’d like to bring up one: Dr. Lane feels that bacterial-style life may be common, but multicellular life is exceedingly rare.
A quick summary goes like this: Life started on Earth 4.1-3.8 billion years ago. The big argument is whether life bothered to wait for the Late Heavy Bombardment (LHB) to end. The constant bombardment of space rubble doesn’t sound like the best time to start life, but there’s good evidence2 it either started before the LHB end or incredibly shortly thereafter.
A lot of interesting biochemistry went on in cells for the next 2.3 billion years, but it was all single-cell, with maybe a few mats or poorly separated colonies of single cells cooperating–but hardly differentiating into specialized tasks.
Then, something different happened. Multicellular life went hog-wild and became a dominant force. What happened?
According to the endosymbiosis theory of Dr. Dr. Lynn Margulis in 1967, an archaeal cell somehow grabbed a bacteria and didn’t destroy it. The two became symbiotic, and the bacteria became the powerhouse for the new cell–a primitive eukaryote. With this division of labor, the new cell took off, evolved, and became multicellular life.3
It took 2.3 billion years. It only happened once. Dr. Lane thinks that, while the odds are good we will find life somewhere–Mars or Europa or Titan4, or Trappist-1e–it will probably be bacterial or algal.
The step to mitochondria was too hard. It might be “The Great Barrier” that explains why the universe isn’t over-run by aliens. And once the step occurred, it might have been a long, difficult fight to survive it. Mitochondria lost most of their DNA to the cell nucleus, but not all. Reaching that balance must have been incredibly difficult. And mitochondria are dangerous. They’re very tiny, but the energy they produce is tremendous on a cellular scale. They keep those few genes to themselves to keep something “bad” from happening. When cells are programmed to die, the mitochondria are chief players in the destruction. And mitochondria leak out their free radicals, damaging the cell and causing aging. Mitochondria are playing with fire–or at least oxidation!
Dr. Lane may be right. He knows far more than I do. But I’d argue it might not be that bad.
First, life had to invent a lot of biochemistry. Most of the interesting biochemistry in humans and other eukaryotes can be found in yeast. The “last common ancestor” that grabbed a bacteria to become a eukaryote was extremely sophisticated biochemically. There may have been many steps necessary before a cell could even successfully grab the free-living precursor of mitochondria.
Second, a lot of bad things happened during that time. The creation of photosynthesis sucked the carbon dioxide out of the air, causing the Earth to freeze over. There’s a lot of debate as to how many times life was nearly killed off and earth became “Snowball Earth,” but it was at least once and probably a lot more. Any early eukaryotic-like cells with symbiont bacterial energy sources may have died off during those Snowball Earth periods. Survival may have favored the less energetic bacteria and archaeons.
Third, once the primitive eukaryotes got past the “let’s learn to cooperate with this thing I just swallowed” stage, they may have been very difficult to compete against. Mitochondria provide great efficiency and power. Bacteria can still survive as bacteria–and by preying on eukaryotes, but something trying to bridge the gap between them might be in a very precarious position, especially during the time when it’s learning to deal with the engulfed bacteria.
Fourth, it did happen more than once. Some bacterial cell grabbed a cell of algae and, in a process remarkably similar to what happened with the mitochondria, turned it into a chloroplast. So there were two cell lines–those with mitochondria and those with chloroplasts. Yet today, we see plants with chloroplasts and mitochondria. It turns out that mitochondria-containing cells and chloroplast-containing cells merged several times. This process is similar to the one that created chloroplasts and mitochondria. And finally, someone found a bacteria that has engulfed another bacteria. It’s a crude symbiosis, and may have happened “recently,” where “recent” is defined in something between biologically “recent” and geologically “recent.”
Dr. Lane is probably right. Multicellular life is difficult.
But it may not be hopeless.
If Dr. Lane is right, then the “Great Barrier” is behind us. If I’m right, then perhaps there are multiple Great Barriers instead of just one. Examples of these barriers might be, developing intelligence, developing technology, surviving technology, and becoming starfaring.
With the Doomsday Clock two and a half minutes to midnight, it might be more comforting to think the Great Barrier is behind us and statistically, we will survive the coming years.
1.5 billion years ago: Mitochondria
Dr. Lynn Margulis
- https://www.nasa.gov/press-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around [↩]
- http://www.livescience.com/5426-life-survived-earth-early-bombardment.html [↩]
- There’s no way I can footnote this, except to point to the link with Dr. Lane’s lecture or suggest you get his books, which are written for the general public. I’d suggest Power, Sex, Suicide as a good beginning, although you might want to read it on a Kindle or make a book cover if you are reading it on the bus. [↩]
- OK, life on Titan might be weird. Lane, in the lecture, put the odds of something biochemically similar to Earth-life at 995/1000. Titan just might be different, if life exists there [↩]
I’m not entering a 12-Step program for science denial, but I feel that way.
I’m a “facts” person. My natural inclination to go with the data is so strong, I don’t understand when others don’t. “If I give them the facts, they’ll agree with me” is so…logical.
Shortly after I decided to bring the UnSpace blog back, I wrote a post on Facebook with a series of statements. One respondent commented that there were no “facts” anywhere to back up what I said. I posted a point-by-point rebuttal. In researching the rebuttal, I avoided Snopes and tried to use conservative sources like Fox News and the Daily Mail1. I also included video whenever possible. The “respondent” replied that they didn’t believe any news sources and that they had their own special personal sources of information on Benghazi and what the Russians are doing and many, many other “special” things.
Well, that person got blocked pretty quickly. What would the point of further discussion be? I wish I’d gotten a screen capture, but I blocked them too quickly. Oh well.
The irony of the interaction struck me, though. Psychologists have known for years that facts alone won’t change peoples’ minds. If someone’s identity and world view contradicts the facts, more facts will harden their beliefs. Simple fact dumps don’t work.
I know that. If asked, I will tell you all about it. But when someone questions something, I dump facts. I’ll even pull out the math, which probably shuts down people who agree with me. My brain doesn’t “get” the idea that facts might make things worse. How could facts make things work? I love facts! I absorb them like a sponge! I’d sing Data’s “Lifeforms” song right now if “facts” weren’t only one syllable. I know fact dumps don’t work, but my actions deny the facts.
A couple years ago, I tried to take a class called “Making Sense of Climate Denial.” It was a free online class and…I just didn’t get it. I read the words, but the way my brain works, I…I couldn’t connect. I’m not sure I really understood. I gave up. I gave up pretty quickly.
If I’m going to restart this blog, I need to understand that facts alone are not enough. If someone is in denial, I need to approach them in a way that makes things better…not worse. I need to accept the facts aren’t everything.
So I signed up for the 7 week course again and, to make sure I stuck with it, I paid $49 to take the class for a certificate of completion. If I don’t complete the class with at least a 70%, I wasted the $49. It’s surprisingly strong motivation for me.
I suspect the class will generate blog posts, so there’s that. Or…maybe I just dump my homework into blog posts. Either way, it’s going to be interesting.
- Shudder [↩]
Biologists think of swamps (and other wetlands) as wonderful places.1
Swamps control runoff from rain. Here in Pittsburgh, we’re actually working at constructing artificial swamps and wetlands. These swamplets will be far cheaper than the non-biological catch basins that were proposed. In a town focusing on tourism related to our riverlife, eliminating sewage discharge is a must.
Swamps purify water. The plants and microorganisms break down toxins, collect silt, and remove heavy metals from the water. Swamps purify water better than modern water treatment plants–and often cheaper as well.
Swamps protect against hurricanes. Besides acting as a buffer zone between human habitation and the ocean, swamps and other wetlands tend to rapidly suck energy out of hurricanes. Much of the increased hurricane damage costs is attributable to wetland destruction.
Swamps have great biodiversity. That means the environment people depend on for their survival is made stronger. Biodiversity means the web of interactions between organisms are complex–a great place to go “bioprospecting.” Very often, nature has already solved chemistry and biology questions of use to humans. Antibiotics and many drugs are modified versions of biological compounds. Enzymes catalyze reactions, requiring less energy and produce purer products. Swamps and wetlands hold new antibiotics and chemical pathways that, if we don’t kill them off, we might find and make money off of!
“Draining the swamp” is such a strange metaphor. If someone says that they are “draining the swamp,” they are actually saying they’re going to make the problems worse, make solutions harder, and endanger society.
I would be suspicious of that person. Maybe they just don’t know much about swamps.
Or maybe they do, and they’re hoping you don’t.
The National Aviary in Pittsburgh brought the African penguins in from their outdoor exhibit because the weather is too cold.
Normally, that would make me laugh.
But I looked up where African penguins live. They’re from around the part of Africa closest to Antarctica. The weather gets as bad—or even worse—than Pittsburgh.
In the wild, the penguins would ride out that cold. A few, mostly the weak and sick, might die. As Steve Irwin used to say, “That’s nature’s way.”
But at the beginning of the 19th century, nature had about 4 million African penguins. Since then, the numbers have been plunging. There are only 55,000 African penguins left in the wild. At the rate it’s going, there won’t be any African penguins living free in 15 years.
The National Aviary wants to take special care of their African penguins, not only because they want to do their best for the animals, but because zoos are the last realistic hope for their species.
Careful records are kept on the family history of the penguins. They do this to maximize the genetic diversity of the species. Some of the birds are over-represented in the world captive population and aren’t permitted to breed. They are traded between zoos to ensure genetic diversity.
And they’re brought in when it’s too cold.
Because of habitat loss and pollution and even global warming, it’s unlikely that the African penguins will ever be reintroduced if they go extinct in the wild. Reclaiming habitat from industry and beach houses and toxic spills is rare. There’s only so much money for reintroduction, and there are species that might be better to spend that limited money on.
The only examples of these beautiful African penguins will be in zoos. And we’ll bring them inside when it gets too cold, because we don’t dare lose one of these remaining few.
Convergent evolution occurs when two unrelated species evolve similar results. The most famous example of convergent evolution is the eye of the octopus. The octopus, an invertebrate, has a “camera” eye, just like vertebrates do. A “camera eye” has a light-excluding orb like the box of a camera. It has, a lens to focus light, like the lens of a camera. The iris controls the amount of light entering like the iris of a camera controls the aperture. The retina on the far side of the orb from the lens and iris reacts to the light, like film or an image sensor. Shrimp, insects, and other creatures have different eyes that work in different ways. There are many ways to evolve an eye, but two widely separated groups reached similar results.
In “Convergent transcriptional specializations in the brains of humans and song learning birds1,” Pfenning et. al. took the full genetic sequences of several hominids, parrots, songbirds, hummingbirds and non-vocal learning birds and compared them using powerful and complex data analysis on computers. The researchers demonstrate that the area of the brain devoted to learning vocalizations evolved separately in primates and in birds. Among the birds (hummingbirds, songbirds, and parrots), the area for vocal learning evolved two or three separate times. That the same ability—the ability to learn and replicate vocalizations—evolved separately several times was to be expected. The ability to learn new patterns of vocalizations has many evolutionary advantages. But what the researchers found was the 50 or so genes used to control the development in this area were similar across the three groups of birds and primates. The last common ancestor of birds and humans was 310 million years ago. That’s a long time. Dinosaurs evolved about 230 million years ago, so the last common ancestor predates the dinosaurs by about 80 million years.
How did the different groups reach the same biochemical result?
Imagine you purchase a lot in a city. What you can build is determined by the size of the land, the geology, the surroundings, and any applicable zoning regulations. If the lot already has a foundation on it, your choices are more limited. You can destroy the foundation (expensive and time-consuming) or you can build based on the restrictions caused by the foundation. If the first floor has also been built, what you can build is much more limited unless you remove the additional work and start over.
In the same way, the structure of the brain of the last common ancestor of birds and primates imposed limits on how the brain could evolve.
Remember that evolution does not progress from simpler to more complicated or even from less fit to more fit. Evolution is random; it’s stupid, it doesn’t think and it doesn’t plan. The genes of the next generation are determined by chance: chance of mutations, chance in mating, and chance of survival. Even biologists have difficulty understanding this. We think of the first cells and then think of humans and mistakenly conclude evolution had a goal of creating intelligent creatures like us, but that isn’t a correct view of evolution. I find myself having to fight the incorrect urge to speak as if evolution had a goal. Anthropomorphizing evolution is an easy mistake to make, but very, very wrong.
If a bunch of organisms with a brain happen to evolve into creatures that can learn vocalizations, what’s the most likely way it can happen? Is it more probable that structures already in place will be used by chance, or is it more likely that those structures will be lost and then a new structure will happen to evolve? Now, actually calculating the odds on those possibilities is impossible, but you don’t have to run a Monte Carlo simulation to realize that more times than not, the existing brain structures will be used.
In the case of the vocal learning areas of the brains, apparently using certain genes is the most probable way to do it.
The finding that convergent neural circuits for vocal learning are accompanied by convergent molecular changes of multiple genes in species separated by millions of years from a common ancestor indicates that brain circuits for complex traits may have limited ways in which they could have evolved from that ancestor.2
Is it the only way to produce vocal learning? No one knows, but I doubt it. There could be some creature out there that evolved vocal learning a different way. If different gene patterns for vocal learning exist, one of the four groups examined (mammals, parrots, hummingbirds and songbirds) might have used it instead. That the four groups all used a similar genes to perform the same function shows that alternate methods are likely rare.
Going back to the octopus, some species are capable of learning to mimic other creatures or their surroundings visually. Is this “display learning” a similar form of data analysis to vocal learning or is it hardwired mimicry? Do both systems use similar genes? The last common ancestor between vertebrates and invertebrates date back at least to the Cambrian. so that’s a very long time ago and in a totally different system in the brain. If the genes for display learning and vocal learning have similar properties (let alone similar genetic sequences), it would tell us there are severe restrictions on how brains learn.
Note to the adult helper:
Please look over the following material. You might want to cut some things out. Remember, you want this to be a pleasant experience for the child. If the child asks questions, maybe you’ll think of some things to add on your own. In this series, I’m giving what I’m wishing I had been given when I was in grade school starting with aquariums, but 8 year old me is not the child you’re working with.
- Matter has mass and, in a gravity field, weight.
- Mathematics has practical uses.
- The aquarium will be heavy. What are the consequences?
- Estimation allows us to think about and check the answer.
For this lesson, you will need your notebook and something with which to write.
If there’s a place on the cover, write “Aquarium Notebook #1.” Beneath it, write your proper name. This is your notebook. If there’s no place on the cover, there might be on the inside. If not, write it on the first page. On the next page, write the date.
There are many different types of aquariums. An aquarium can be a lush freshwater tank with plants and fish; it can be a crystal clear saltwater tank filled with animals. Some people keep aquariums with only plants. If a fish is ill, the “hospital tank” might only contain water, medicine, and the sick fish.
There are two things that all aquariums have: the tank and the water. You need both: without the water, it’s not an aquarium. Without the tank…it’s a mess!
Let’s look at the water first.
Write this question down in your notebook: “What is water?” What are the things you think of when you think of water? Write down as many as you can before you read my suggestions.
When I think of water, some of the things that I think of are that it’s wet, it’s heavy, it can be hot or cold, it’s transparent, and it’s necessary for life. You can freeze it into a solid, you can boil it into a gas, and when you have a leak in your house, it’s a mess to clean up. You can dissolve things in water—including air!
Many of those properties of water are what make an aquarium possible. Imagine water with no weight—the water would float away, which would make keeping an aquarium very difficult. Imagine water that you couldn’t see through. You might have fish in your aquarium, but it wouldn’t be any fun.
Water is a form of matter. In very advanced science, what matter “is” can get very strange, but for everyday use, you can think of matter as being something that has mass, volume and temperature.
What is mass?
Mass is how much an unattached object resists being moved. If something is just sitting there, you have to work to move it. Once something’s moving, you have to work to stop it from moving. How much you have to work is its mass.
On everyday Earth, we treat mass and weight as the same thing. Weight is the force of an object produced by gravity pulling on it. If you’re on Earth, you can get away with saying mass and weight are the same. But if you were on the International Space Station, where things are weightless, nothing has weight but it still has mass!
There have been aquariums on space stations, but I doubt you’re creating your aquarium on a space station or on the moon. So we’ll treat mass and weight as the same. But whenever someone treats mass and weight the same, I want you to think “Yeah, but they’re not the same!” Just don’t say it out loud, because people will look at you funny.
Water, being a form of matter, has mass—and on Earth, it has weight. Milk is mostly water, and if you pick up a gallon jug of milk, you’ll realize it’s pretty heavy. A gallon of milk weighs 8.6 lbs. Now, water, which doesn’t have all the extra things of milk dissolved in it, weights 8.3 lbs.
Estimation is when you want an answer that’s “good enough.” Everyone estimates, because it makes life easier. If you want to play catch with a friend, and you say “Go about 10 yards away,” your friend doesn’t take out a tape measure and measure 10 yards exactly. Your friend might go 9 yards away or 10.1 yards away or even 15 yards away. Your friend estimates the distance. The answer is “good enough.”
We said that water is 8.3 lbs. per gallon. If you have a 20 gallon aquarium, how much does the water weigh? Can you multiply 8.3 * 20 in your head? 20 is 10 * 2, so 8.3 * 20 is the same as 8.3 * 10 * 2, which is 83 *2. 2 *3 is 6, 80 * 2 is 160, so 8.3 * 20 is 166.
What if you’d estimated by saying water is 8 lbs. per gallon? 8 * 20 is 160 and you’re done. It’s not the correct answer, but it’s only wrong by 6 / 166 which is about .036. That’s pretty small. For what we’re doing, we can estimate by saying water is 8 lbs. per gallon.
When your teacher at school asks for an answer, assume she wants an exact answer. But when you’re trying to work things out for yourself to see about how much something is, you can estimate.
Here are some other estimating tricks. In English units, we use pounds (lbs.) for weight and gallons for volume. In the metric system, we use kilograms for mass (and we’re going to use mass as if it were weight, but we know that’s not quite right, right?). 1 liter is .264 gallons, which is a little bit more than 1/4th. There are .454 kilograms in a pound, which is almost ½.
So we can estimate the number of liters in a gallon by saying there are 4 liters in a gallon and ¼ a gallon is a liter. We can estimate number of kilograms by saying it’s a half a pound and half a pound is 2 kilograms.
So how many liters are in a 20 gallon aquarium? There’s about 80 liters. Now, the fun thing about the Metric system is, water weighs 1 kilogram per liter. So how much does an 80 liter aquarium weigh? It weighs 80 kilograms.
Your friend bought a 5 gallon aquarium. What does it weigh in lbs? How many liters is it? How much does it mass in kilograms? Write down in your notebook “A 5 gallon aquarium is approximately”. Below that, write down approximately how many pounds it is, how many liters and how many kilograms. Try to do the calculations in your head. Don’t move on until you do.
What did you get for the answers? Did you write “40 lbs, 20 liters and 20 kilograms”?
Now, write down A 5 gallon aquarium is exactly”. Below that, multiply 5 by 8.3 to get the exact number of pounds. Divide the number of gallons by .264 to get the exact number of liters. Once you have the number of liters, you’ll know how many kilograms it is. You can do these calculations with a calculator, or, if you’re feeling adventurous, do it using a pencil and paper. Write those answers down.
Again, what were your answers? Did you get 41.5 lbs? 18.9 liters and 18.9 kilograms?
Which way was easier to solve the problem?
Let’s say another friend bought a 55 gallon aquarium. Write down “A 55 gallon aquarium is approximately” and below it write down how many lbs., liters and kilograms. See if you can do the calculations in your head. Then write down “A 55 gallon aquarium is exactly” and below it write down how many lbs., liters and kilograms.
Did you get 440 lbs, 220 liters and 220 kilograms for the approximation? Did you get 456 lbs., 208 liters and 208 kilograms?
Now, let’s think about our results a little bit. Is 160 lbs and 80 kilograms—the weight of the water in a 20 gallon aquarium—a lot? Scientists estimate the mass of an adult man at 75 kilograms. 80 is a bit more than 75 kilograms. 80 kilograms not a tremendous amount, but it’s more than a gallon of milk. What do you think would happen if you put a 160 lb. aquarium on one end of a table? Have you ever seen someone sit on a table and the table move or even get tipped over? Would you put an 80 liter aquarium on top of a cardboard box? It might be possible to make a stand out of cardboard that would safely hold 80 kilograms. But what happens to cardboard when it gets wet? Do you think working on an aquarium might get the cardboard wet? Even if you were careful, the aquarium could leak. A leak would be a problem by itself, but imagine what would happen if the cardboard stand got soggy!
You have to put your aquarium on a piece of furniture so you can see it easily. What do you think that piece of furniture should be like?
With permission of an adult, jump up and down in the middle of a room. Does it make a lot of noise and do things vibrate a bit? Now, go jump near a wall. What kind of noise does it make and how do things vibrate? Finally, go jump up and down in a corner. What happens? Write down in your notebook what you did and what you observed.
Next, stand in the middle of the room on one foot. How easy is it to stand on one foot? Go over to the wall, lean slightly on it, and see if you can stand longer on one foot than you could in the middle of a room. Finally, lean in the corner and stand on one foot. Where is it easiest to stand? Write down in your notebook what you did and what you observed.
You want the aquarium to be stable. You don’t want it to vibrate, you don’t want it to fall over, and you don’t want it to fall through the floor. There’s not much danger of a 20 gallon aquarium falling through the floor, but what if you had a 100 gallon aquarium? About how much would that weigh? Could it cause problems in the middle of a room?
Where do you think the best place to put an aquarium is based on your jumping up and down and trying to stand on one leg? Write down in your notebook how you would rank places to put your aquarium.
Next, what if you had to put the aquarium in the worst place in the room? What can you think of doing to give your aquarium the best chance to survive if you put it there. Write that down in the notebook. Drawing pictures will help explain what you’re saying. You can also talk to the person helping you. Can they think of other things that could be done to make the aquarium safe? If you don’t have to, would you want to do these things? Do you think they would be more or less expensive?
By estimating, you were able to figure out how much different size aquariums would weigh (or mass). Estimation lets you think about things without investing effort you don’t need to make. If you had done the exact calculations, would it have made any difference in the answer as to where you’d put an aquarium? If you had a 5 gallon aquarium, do you think you could get away with putting the aquarium in the worst possible place? What if it were a 55 gallon aquarium? Would you be worried if you had to put it in the worst possible place?
Estimation lets you know if it’s worth doing the full calculations!
When I was writing this, I did the multiplication in my head and got an answer for the weight of a 20 gallon aquarium of 8.3 * 20 as “246 lbs.” I multiplied the 8 by 30, not 20. Because I estimated the weight at 160 lbs., I knew something was wrong. Now, I didn’t know whether my estimation was wrong or my full calculation was wrong, so I pulled out a piece of paper and did the calculation carefully. I got the correct answer of 166. Because I had estimated, I avoided a significant mistake.
When you’re done with a test, go back through and look to see if your answers are reasonable. Where appropriate, estimate the answer—does the estimate match the answer you put? Estimating is a way to check your work!
Finally, draw a line under the last thing you wrote in your notebook. That’s all for today, and the line lets you know where that day’s data ends!
How big will your aquarium be?
You will have your child work out how big an aquarium to get, but you will want to direct the conversation. There are several considerations.
- The larger the aquarium, the easier it is to care for—up to a point. The smaller the tank, the easier it is for something to go wrong. Things can go wrong quickly with a 5 gallon tank that will take longer to develop for a 55 gallon tank. But there are maintenance issues. A 20% water change on a 20 gallon tank is 4 gallons. A 20% water change on a 150 gallon tank is 30 gallons.
- Where the aquarium will go will be an issue. Aquariums are heavy. A liter of water is a kilogram. A liter is about a quart, so a gallon is about 4 kilograms, or about 8 lbs. A 20 gallon aquarium is 80 kg. Or 160 lbs., and that’s not including the weight of the aquarium itself. Generally, aquariums go away from direct light to control temperature and algae, away from drafts to control temperature, and along a wall (to prevent problems with the floor). You want the aquarium away from fumes that be absorbed into the water and kill the fish, so the kitchen is probably out.The result is usually either the child’s room or the family room, which may limit the size.
- Finally, there’s the cost of the aquarium. I put together a spreadsheet and listed everything I purchased for my 20 gallon aquarium. I’m up to $525 dollars as I write this. Please realize that I went with the best available equipment and supplies, and I probably won’t need to buy anything for a year.There are ways to cut the costs. I purchased from a local store that charges more but can give me advice when I need it. The costs in the graph below are from online, and are cheaper than what I paid. I’ve seen aquariums for sale at estate sales, Craigslist, and at aquarium club meetings. Making friends with someone who has aquariums may be a way to get a deal on someone’s spare tank! There are a number of ways to get less expensive aquariums, but you must also ask what happens if the tank leaks. Stores have sales. If you wait a couple months, you may find a deal on an aquarium kit.
I hope this post helps you think about the important points before you begin this project.
I named this series “Science in 80 Liters” because an 80 liter (20 gallon) aquarium is a nice compromise between size, ease of maintenance and cost.
You may wish to go smaller or larger, depending upon your situation. You may guide your child or children through the decision, or you may simply choose a size and go on from there.
Some advances in science happen accidentally. We all know the stories of radioactive samples left on top of photographic plates, mold getting into your bacterial colonies, etc. It’s great when it happens. And you should take advantage of random opportunities to present science, technology, engineering and/or mathematics (STEM) to your child.
But that’s not how most science happens, and that’s not how an aquarium should happen.
Most science happens while going through a set of steps. Now, most people don’t think of these steps as steps, and they may rearrange the steps, combine them, or just do it subconsciously. But the steps look approximately like this:
- Calculating costs
- Performing experiments & taking data
At this point, I’m supposed to put “Evaluating “ as #7. In real life, evaluating happens all the time. During the “thinking” phase, evaluation happens naturally. That’s part of thinking. The same goes for planning. Unlike comic books where Reed Richards (Mr. Fantastic) and Tony Stark (Iron Man) have unlimited funds, a lot of evaluating can happen during the “Calculating costs” and “Purchasing” parts of the experiment. A researcher might ask herself questions like these:
- Can we afford this?
- Is there a cheaper way to do this?
- Does someone else have this piece of equipment that I can borrow?
- Do I want to look for another topic to research?
Evaluation can occur during “Assembling,” especially when the researcher finds out things don’t go together like the instructions say. Think “Ikea furniture.” I know of one case where it really was Ikea furniture that didn’t go together like the drawings showed and changed the experiment.
Some of the most important evaluation occurs during the first couple runs of the experiment. Even when doing a double blind study, a researcher will check to make sure things are running smoothly. Most of the time, they don’t. The researcher may not have ever done this particular experiment before. Perhaps no one has done it. The first couple times, researchers check to make sure everything works as planned. Often it doesn’t, and the researcher goes back to the beginning and work through the steps again with the new knowledge.
Sometimes things don’t work as planned. And, if you look at all those serendipitous discoveries, you’ll find that those wonderful accidents were found during the evaluation phase of going through these steps.
What’s the one thing common to all of these steps?
Seriously. Everyone knows that scientists record data. there are even cute aphorisms about data collection like “Document or it didn’t happen” and “Collect data; it makes it look like you’ve been doing something.”
But think about it even in your own life. Ever come up with a great idea and forget it during lunch? If you’d kept notes, that wouldn’t have happened. Think of something when planning a party but forget about it until the first guest knocks at the door?
So your first homework assignment is to go out and buy lab notebooks: one for you and one for each child with whom you’re working.1
You don’t need to get the big expensive professional lab books. Composition notebooks are wonderful, especially if they happen to have the numbered pages. Everyone keeps their own data. The adult will keep the adult version, but each child should keep his or her own. Yes, there should be words and numbers in the book, but there should also be drawings of things observed. If you take a picture of the aquarium or the supplies, printing out the picture and taping or gluing it in the book is wonderful. Scientists use drawings, photographs and more to record things–as well as words and numbers.
By keeping a notebook yourself, you’re modelling the behavior for your child or children. The children are practicing important skills like writing and drawing.
Also, when something goes wrong, that notebook might help you figure out what it was or keep you from making that mistake again!
- I’m keeping my notebook on a computer. The first time the data files get corrupted, you can laugh at me. Lab notebooks are things the child can touch and hold and look back on years from now. It’s a simple thing, but your child will benefit. [↩]
In 1967, I was in third grade and got a book by Beverly Cleary titled “Henry Huggins.” In the book, Henry goes to a pet store and buys a pair of guppies. The two guppies had babies. Soon Henry’s room and life are over-run with jars of fish. This story disaster inspired me to ask my parents to let me have an aquarium. My parents agreed, and soon there were three aquariums in our new house.
Recently, I looked back on those experiences with tropical fish and realized just how much science I learned from them. Making the water safe for the fish taught me a lot of chemistry. Learning about the fish, keeping a balanced tank the fish could live in, and breeding them introduced me to topics in biology long before I had them in my classes. Even mathematics, physics and a touch of engineering came into play.
Today, scientists and educators are making a deliberate attempt to interest children in science, technology, engineering and mathematics—it’s abreviated STEM. In the past, such activities tended to be aimed mostly at boys. Now, the goal is to interest everyone, no matter their gender.
I learned through books. My first book on aquariums taught me how to set up a small 5 gallon tank. As I got bigger books, I got bigger tanks. My Dad was an engineer, but for the most part, he stuck to lifting heavy objects, curbing some of my excesses, and suggesting how to look up an answer. It worked for me.
Part of me would love to write a book for third through fifth graders explaining the science as they set up a modern aquarium. Unfortunately, my wife and I weren’t blessed with children. I’m not sure if I’d know how to write for third to fifth graders.
As I thought about it, I realized I don’t want to write for those third to fifth graders. I want to write for their parents. The parents can guide their children, pick and choose the topics that are appropriate, and interpret the lessons for their children’s level of understanding. With any luck, the parents and children have fun together with the tank.
And who knows? Maybe the parents will gain a little more understanding and appreciation for science.
As I see it now, I’ll write a lesson about once a week, focusing on the particular topic involved with that stage of the aquarium setup. That might seem slow, and, as I get a feel for it, perhaps the frequency of the posts will increase. But one of the tricks to setting up an aquarium is to take it slowly. If, in a single day, you purchase an aquarium, set it up, and put the fish in, there’s a high probability that you’ll waste a lot of money and kill the fish.
If anyone is going to follow along, I would appreciate getting feedback. What was clear? What wasn’t clear? What was too difficult for your child to understand? What was too simple? What was too expensive? What better ways are there to do this? A comment section is available at the end of each article. I’ll make every effort to answer questions and learn from any suggestions.