Big Course: Year 4
Another whirlwind adventure
Welcome to Year 4 of our Big Course.
Live classes (seminars and webinars) will begin the week of September 14th, 2026.
Or, you can start streaming recordings for Year 4 on September 20th.
To catch up on Years 1, 2 and 3, check out our past recorded topics.
From our inbox
“We so appreciate your approach and your work and time that you put into these incredible lessons!
We talk about Brandon often in our house, and my kids feel like they know you and they trust you. I firmly believe education is best achieved in relationship, so that is very important to me.
In addition, I appreciate that you don’t shy away from tough topics and you don’t see anything as off limits within developmentally appropriate reason...this is how we operate in our home, and I think it’s the best way for kids to learn that nothing is bad or wrong unless we designate it as such. So thank you for all your work and everything you do!”
The six topics
Topic 19:
The Sun is Weird
In which we see everything in light of the big glowing ball in the sky
Ah, the Sun! We see nothing without it… but we don’t really see it at all. And what it is is much weirder than you might think: what’s going on in there is so strange that physicists had to invent new ideas to explain it. We’ll peer inside the Sun to talk how it was born, how it will die, and how, in the meantime, using its light might save us all.
-
This is the ninety-first lesson of our Big Course — the inaugural lesson of Year 4, and the first day of the SECOND HALF OF THE BIG COURSE.
And, hey hey, we're stepping things up!
Along the way to the answer, you'll get a reminder on whether "up" and "the sky" are real, get "embiggened" up to Gigaworld to see how big the Sun (and the planets, and the other stars) really are, and see what happens when you punch the Sun. By the end, you'll have drawn the first-ever accurate picture of what the Sun fundamentally is.
-
This is the ninety-second lesson of our Big Course. Along the way to the answer, you'll understand how four seemingly-unrelated facts about the world (the sky is blue, the Sun is yellow, mountains are blue, and the sunset is red) are ACTUALLY THE SAME THING.
That's just chapter 1. You'll also take a close look at the rainbow and see some things in it you may have missed before. Finally, you'll learn why the Sun actually shines... and learn something rather disquieting about how it looks.
-
This is the ninety-third lesson of our Big Course. Along the way to the answer, you'll learn why you might not want to buy a solar-powered car, how much of the world you would need to cover in solar panels to give us the electricity we need, and what the single biggest problem is with solar energy.
-
This is the ninety-fourth lesson of our Big Course. Along the way to the answer, you'll learn why "atoms" are overrated, how you should understand "plasma", where the Sun's heat comes from, and where FIRE'S heat comes from.
(We won't spoil it, but this lesson culminates with one of the Big Ideas in all physics.)
-
This is the ninety-fifth lesson of our Big Course. Along the way to the answer, you'll learn what an "astronomic unit" is, the (stupid, not-very-useful-for-your-understanding) layers of the Sun are... and then you'll learn some GOOD stuff. Like what sunspots really are, and what the texture of the Sun is, and what the heck those LOOPS are, and that weird HAZE around the Sun, and HOW SOMETHING KEEPS SHOOTING BULLETS GOING NEARLY THE SPEED OF LIGHT AT US (and what keeps saving us).
Topic 20:
Soaps are Weird
In which we get down and dirty with cleaners and chemistry
Soap, bleach, alcohol, ammonia… we’ve got a whole arsenal of cleaners under your sink, but most of the time, we grab the wrong one! Each destroys gunk in a completely different way. This month, you’ll learn the (surprisingly ancient) stories of human cleanliness so you can take on the stickiest messes. Most of all, we’ll use cleansers to explore one of the most important questions in chemistry: what is a chemical bond, really?
-
This is the ninety-sixth lesson of our Big Course. Along the way to the answer, you'll learn what we really mean when we say "clean", why you might not want a "universal solvent" (even if it could cure illness), and why a certain common kitchen substance is ridiculously good at dissolving stuff.
-
This is the ninety-seventh lesson of our Big Course. Along the way to the answer, you'll learn what a soap molecule looks like, why oil and water don't mix, and what, precisely, soap DOES when you use it to clean stuff up.
-
-
-
Topic 21:
Guts are Weird
In which we digest a bunch of intestinal information
You are — and we mean this respectfully — a tube with legs. Food comes in one end, poop comes out the other, and in between is what you call “being alive”. How’s it all work? We’ll trace the journey food makes through your basic gastro-intestinal tract. You’ll learn to read your excrement, and come to terms with the trillions of tiny creatures who call you “home”. By the end, you’ll understand the fundamentals of nutrition, and have earned an opinion on some actually controversial questions, like “is high-fructose corn syrup bad?”
Topic 22:
Dirt is Weird
In which we dig deep and unearth the secrets of the soil
“Dirt” is almost a dirty word. It gets no respect. And yet without, most life on land couldn’t exist. Why’s it so special? You’ll learn what plants actually need from it, and whether organic fruit is actually worth the money. You’ll shrink down tiny to discover different worlds in different soils. You’ll see how misunderstanding dirt has led to disasters, and how one man’s insight literally saved billions of people from a slow death. Along the way, you might even learn a few things that will help you become a better gardener!
-
-
-
-
Coming soon!
-
Topic 23:
Onions are Weird
In which we peel back the layers… and the layers fight back
An onion isn’t “a plant”! Here, we’ll bring together physiology, chemistry, and evolution to understand what an onion really is, and how the whole plant family tree hangs together. We’ll find what “spicy” actually means (it’s probably not what you think), and what happens the instant your knife slices through an onion’s skin.
Topic 24:
Mosquitoes are Weird
In which we see through the compound eyes of Earth’s deadliest animal
We all feel like we understand mosquitoes, and we’re all wrong. This month, you’ll shrink down to see what one actually looks like, and how she experiences the world — how she sees, hears, smells, tastes, and feels. You’ll trace her ancestry through the invertebrate “half” of animals — that is, the 97% of animals without bones. You’ll find out why mosquito bites itch, and how to cure them instantly. Finally, we’ll all wrestle with a genuinely hard moral question: as we gain the power to drive them extinct, should we?
Watch an open house
Year 4 FAQ
-
Probably! We design our lessons to link up together. That said, you could do the live lessons of this year AND blast through Year 1's recordings on your own.
-
Somewhere in between ages 8–18. But we have some kids older and younger than that, too. (Sometimes adults sign up for themselves!)
Year 3 builds on the earlier years and is intended to grow with the students from Year 1 all the way to Year 6.
Returning students never age out of our live science classes.
-
Usually a bit more than 90 minutes in total, broken up into 20–30 minute chunks.
-
For as long as your subscription lasts, or permanently if you purchase a topic outright.
-
Usually just a notebook — we recommended a dotted one, like this or this. We'll let you know when you'll need additional materials (usually it's stuff lying around the house).
-
Actually, these are the same thing as the live webinar — just lightly edited for your viewing pleasure.
-
Quite a few: see our Discounts page.
-
Yes, in quite a few places. Check our Approved Vendor page to see the programs and networks we currently work with.
-
Loads of people! See “Why You Might Hate Us.” (But remember our Ridiculous Guarantee.)
-
Feel free to use it with everyone in your family! (You don’t need to purchase it multiple times.)