Not long ago my 7 year old son looked up from a picture he was drawing.
“Mom,” he said, “if atoms had eyes, could they see subatomic particles?”
His question was inspired by a certain type of video that recently piqued his interest and captured it with an iron grip.
Size comparison videos are animated short films that use special effects to show the scale of things, usually from smallest to largest. Most are done with no narration, just 3D renderings of objects that are scaled in size and then move like an assembly line. They are widely available on YouTube and are free to watch, although some have ads. You can find videos that compare planets, animals, bones in the human body, and even fictional spaceships.
That day my son had painted tiny things on a whiteboard in the living room: an atom, a dust mite, protons. The day before, there were enormous things: galaxies, black holes, supergiant stars.
At first I assumed these videos were just another in a long line of YouTube sensations that are popular with children and confusing for parents. Think of disembodied hands opening gift boxes or Thomas trains repeatedly crashing on a loop. Similarly, size comparisons are simple and hypnotic, a dopamine rush on a 7-year-old brain. In our house they were all my son wanted to see and ditched Pokémon and the entire Marvel franchise.
He is not alone. A size comparison video entitled “Universe Size Comparison 3D” has been viewed more than 77 million times. Alvaro Gracia, an animator from Spain, has created nearly 100 size comparison videos that are often used by teachers who incorporate them into lesson plans. Matthew Lawrence, who does size comparisons for children on his Kids Learning Tube channel, said his views had risen 40 percent during the pandemic.
How should parents understand this? What explains the attraction? Do they have any educational value or is this just pointless screen time?
Simple patterns help young children understand the world.
The ability to organize things according to size or quantity has a name in cognitive development: seriation. In the 1940s, developmental psychologist Jean Piaget noted that while adults can sort a row of jumbled sticks by size almost pointlessly, children under the age of 5 often fail at this task. And only around the age of 7 can they do it with ease.
Maggie McGonigle, a retired lecturer at the University of Edinburgh and author of the textbook Understanding Cognitive Development, repeated Piaget’s observations in a series of experiments that tested children’s ability to sort five or more squares or bars on a touch screen . She also found that 5-year-olds, while having problems initially, can be trained to sort objects successfully.
Her colleague Iain Kusel developed a computer model that simulated her learning process during this sorting exercise. They concluded that the 5-year-olds go through a trial and error ranking process that ends up looking for the slightest difference between objects. Increased working memory capacity, which develops by ages 5 to 7, enables 7-year-olds to use this smallest difference information to solve the problem on the fly.
Dr. Kusel said he wasn’t surprised that kids would be using this type of video at this stage of developmental growth.
“I suspect the videos are opening up something,” he said. “It’s a way of enabling them to find a new engine, a new muscle to express,” he said.
People are exceptional at seeing patterns and they enjoy analogies from a young age, said Dedre Gentner, professor of psychology at Northwestern University. In fact, she believes that this is the key to our success as a species. Patterns are also of great value in a child’s intellectual development and are vital to science and math.
Both size comparison videos and sorting tasks contain more than just the objects, but also the relationship between the objects.
“That’s part of what I consider to be the thrill for kids,” said Dr. Gentner. “You get this constant shift from the object into a relational pattern. It makes sense to the world in a way that is extremely satisfying. “
The concept of scaling is mind-boggling.
It’s not just the relationship between objects in these videos: they show scaling, too. Look at the solar system. Almost every image of the sun and planets that a child sees, be it in a textbook, storybook, or puzzle, is severely distorted. Planets often appear close together and of similar size. Because of this, children (and adults) of all ages develop inappropriately sized notions. And it takes creativity to unravel these misunderstandings.
One reason children develop misconceptions about size, height, and distance, said Matthew Schneps, former chief scientist at the Harvard-Smithsonian Center for Astrophysics, “is because they try to understand things they can’t understand. Confused, they try to build an understanding of every experience they have, whether or not the experience is true. “
Dr. Schneps has spent much of his career helping students understand science more fully. And he studied video as a learning tool. He was the lead author of a study that found that even brief exposure to 3D virtual simulations of the solar system improved students’ understanding of spatial scaling and helped clear up deep-seated misconceptions. His work indicates that unimaginably large and small scale comparisons are common in science, such as geological time, the size and age of the universe, biological evolution, and the size and speed of atomic and subatomic particles.
Some of these scales are so big or so small that they confuse the brain. For example, to convey a sense of grandeur, in 2015 a group of friends built a full-scale solar system over seven miles of arid seabed in Nevada’s Black Rock Desert. Neptune, on the outer limit of the system, was more than three miles from Earth, the size of a marble. Neptune was the size of a tennis ball.
Like the simulations in Dr. Schneps’ study, size comparison videos can be an example of screens that succeed where school books fail. Many of these videos are created by animators, not necessarily scientists or educators, and they are generally not independently verified for accuracy. Dr. However, Schneps said he likes size comparison videos because they “provide enough enriching information, expressed about the details in the pictures, for learners of all levels to take away something useful”.
How to teach kids to scale.
There are screen-free ways to teach kids to scale that require a little creativity – and lots of space. David Jackson, Associate Professor of Science Education at the University of Georgia, suggests such an activity for middle school science teachers. It places important events in geological history on a 30 meter long hallway and demonstrates a geological timescale of solid earth history that goes back 4 billion years. The earliest bacteria appear 16 feet from the wall, and the first evidence of multicellular life is 96 feet later, nearly seven-eighths of the way down the hallway.
The students are always surprised to see how new modern people have emerged, he said: only an inch away from the present. That’s the length of a peppercorn from the finish line.
The use of everyday objects to represent yardsticks is memorable for all children, said Dr. Jackson. For example, if the earth were the size of a standard globe, the moon would be a softball and Jupiter would fill the average bedroom.
Promote active thinking.
If kids really like this way of thinking, encourage them, said Dr. Schneps. Give them the tools to explore – even if it’s a YouTube video.
“Children are brilliant thinkers, they formulate a lot of ideas. And we have to do this active thinking process if they want to learn, ”he said.
That brings me back to my son’s question: could atoms see subatomic particles with eyes? I had no idea and my husband was at a loss too.
Fortunately, a scientifically minded friend came up with a calculation. He compared the size of the average 7-year-old to the smallest thing a child could see – that’s about a tenth of a millimeter, or about the size of a pollen grain. Then he applied the same resolution to a nitrogen atom. And he concluded that no, even the largest protons and neutrons, which are fantastically small, were too small for this atom to see.
I said to my son, who thought about it for a second, nodded and then said, “Now ask him what boogers are for.”
Jenny Marder is a senior science writer at NASA and a freelance journalist. Previously, she was an editor for digital management at PBS NewsHour.