Bunsen Bites is a short-form educational podcast that tackles big questions in bite-sized episodes. Two young presenters, Tess and Rui, talk through topics from science and maths to history, technology and the world around us. Each episode breaks a subject down into clear explanations, relatable examples and open questions worth thinking about. It is aimed at middle-school listeners who want to understand how things work. The show is created with the help of AI and spoken by AI voices.
Episodes
Who's Holding the Other Two-Thirds? (Physics Level 8)
We're going to find the one rule that makes that possible, and it fits in three words: force times distance. Then we'll find out what that rule secretly charges you, because nothing comes free, not even in physics.No machine gives you something for nothing. Every one of them obeys moment = force × distance, and the units, newton metres, tell you why. A small force at a big distance equals a big fo
The Horse Watt Rounded Up (Physics Level 8)
We're going to follow Watt as he tries to put a price on a horse's effort, and that will show us exactly what work and power are. Then we'll open your electricity bill and see that you're paying for the thing Watt was trying to measure.The listener can explain why the highest-wattage appliance in the house might not be the one that costs the most. They can also say the three formulas in order: wor
The Flask That Doesn't Know Anything (Physics Level 8)
It doesn't know anything. It just blocks every road heat can travel, and there turn out to be two kinds of road: one you can block by taking stuff away, and one that doesn't need any stuff at all.The flask is a heat-blocking checklist. The vacuum stops the two particle routes, and the shiny walls fight the route that needs no particles. That is why it works both ways: it doesn't care which directi
Where Your Phone Battery Actually Goes (Physics Level 8)
Here's the deal: we're going to follow every single joule out of a dying phone and find out where it actually goes. Then we'll hit a weirder question: if all that energy is sitting in your room right now, why isn't your room roasting?Your phone didn't destroy its energy. It smeared it across the whole room, adding loads of joules but almost no degrees, until everything reached the same temperature
The Mars Bar and the Power Station (Physics Level 8)
We'll follow one Mars bar from the wrapper into you, then follow the same idea into a power station. By the end you'll know why some energy runs out forever and some never does, and it comes down to whether you're spending today's sunlight or sunlight from millions of years ago.You and a power station are both sunlight-spenders. The Mars bar is this year's sunlight, caught by plants. Coal is ancie
The Magnet That Never Arrives (Physics Level 8)
This episode chases one idea: a magnet with an off switch. First we'll see what you can do by switching it on and off, then what happens when you flip it back and forth fast enough to make sound and spin a motor.The motor is the bell's trick grown up. The bell interrupts itself to keep ringing, and the motor reverses itself to keep spinning. A magnet that never gets where it's going is what makes
Why the North Pole Is Secretly South (Physics Level 8)
We're going to work out why the North Pole is secretly a south pole, using nothing but the rules of magnets. Then we'll find out that the Earth isn't really a magnet like the one on your fridge at all. It's something you can build on a kitchen table.The 'wrong' pole name is the rules working correctly. The planet's magnet isn't a lump of magnetised rock but moving metal, the same idea as the coil
The Night a Prankster Rewired Your House (Physics Level 8)
We're going to run your house wired the wrong way, watch it fall apart, then rewire it the right way. Along the way you'll get the two rules electricians live by.Houses are wired in parallel so every device gets full voltage and works on its own. The price is that the currents add up in the wire feeding them. The listener leaves able to state both rules with symbols and units. In series, current i
Why the Pigeon Doesn't Fry (Physics Level 8)
The bird's secret is that a volt isn't something a wire has. It's a difference between two points. We'll chase that idea until it gives us one equation, and by the end you'll be able to work out exactly why the bird lives.The bird isn't tough. The maths protects it. Small V over big R means almost no I. The listener leaves able to say what potential difference is and how to measure it, state R = V
Stuck Charge, Moving Charge (Physics Level 8)
We're hunting for the one difference between those two. First we'll make charge pile up and stay put, then we'll let it go and count it as it moves, and by the end you'll know exactly what an amp is counting.The spark and the glow differ in one thing only: whether the charge keeps moving. A zap is a pile that empties all at once. A light is charge passing steadily, and amps are just the count of h
The Flash You've Never Seen (Physics Level 8)
That invisible flash is a cousin of the light you read by, and of your microwave, your dentist's X-ray and sunburn. They're all one family. By the end you'll know the family in order, why they all travel at the same speed, and how a thing's place in the line tells you whether it heats your dinner or damages your cells.The listener can recite the spectrum in order. They can state that all of it mov
Why Your Red Shirt Goes Black (Physics Level 8)
By the end you'll know why that shirt goes black. First we take white light apart to see what's inside it. Then we see that every coloured thing you've ever looked at is really throwing light away.Back to the shirt, and now the listener can explain it themselves. A red object only reflects red. Green light contains no red. So nothing bounces back to your eye, and you see black. Colour was never in
The Mirror Nobody Can See (Physics Level 8)
So today's question is: how do you steer something moving at 300,000 kilometres every second? It turns out light only lets you do two things to it, bounce it or slow it down, and by the end you'll know the exact rule for each.Two rules, one invisible line. Reflection: the angle of incidence equals the angle of reflection, measured in degrees from the normal. Refraction: when light crosses into a n
The Screams Over Your Head (Physics Level 8)
We're going to work out exactly what a sound has to be for your ears to catch it, and then why bats deliberately make the ones you can't. By the end you'll be able to calculate how small a bat's sound waves are, using one short formula.The scream you can't hear is the bat's whole strategy. Push the frequency up past the edge of human hearing and the wavelength shrinks to the size of dinner. You ca
Seventy Miles an Hour and Zero Newtons (Physics Level 8)
We're going to find out why a thing can be moving fast and still have its forces add up to exactly nothing. Then we'll take that idea somewhere much scarier: a person falling out of a plane.The listener can now say: resultant force = the forces in one direction minus the forces in the opposite direction, measured in newtons. If it's zero, the object stays still or keeps a steady speed. If it isn't
The Getaway Car That Was Parked and Speeding (Physics Level 8)
We're going to solve this case. To do it, we need to learn to read one kind of motion graph, then catch the detective nearly arresting the wrong person because she read the second one the same way.The case is solved by one habit: read the up-axis before the line. The listener leaves able to say speed = distance/time (m/s) and acceleration = change in speed/time (m/s²), and to explain why a flat li
Your Bathroom Scale Is Lying (Physics Level 8)
We're going to work out what a scale actually feels when you stand on it, and what number it should really show. Then we'll take that scale somewhere else and watch the number change, even though you haven't changed at all.The listener works out their own real weight. Take your kilograms and times by 10: forty kilos means 400 newtons. Then comes the twist. The scale was only ever guessing your kil
The Fittest Might Be Squishy (Biology Level 8)
Today we're finding out what 'fittest' really means, and it isn't strongest or fastest. First we'll see what every living thing is actually fighting over. Then we'll see what happens when the rules of that fight change, and why scientists are freezing seeds just in case.Survival of the fittest really means survival of whoever happens to fit. You can't train for it or choose it. That's why variety
The Forest That Needs an Otter (Biology Level 8)
We're going to work out who that animal is and why a forest needs it. To do that we'll zoom out step by step, from one animal to the whole forest, and then find out what happened when people took that animal away.If you wanted to save the forest, your first instinct would be to protect the kelp, and that's the wrong answer. The right answer is to protect a furry animal that eats urchins. The liste
Which Way Does the Arrow Point? (Biology Level 8)
We're going to work out what that arrow really means. Then we'll follow it to the top of the food chain and find out why the animal everyone thinks is in charge is the one most likely to be in trouble.The listener comes back to the opening question and now answers it correctly: the arrow points to the eater, because energy flows into it. They can explain why that same direction makes the top preda
The Leaf That Can't Stop Leaking (Biology Level 8)
Because a leaf is trying to make food out of thin air, and the doors it has to open to get that air are the same doors its water escapes through. First we work out the recipe the leaf is cooking. Then we find out what that recipe costs.The listener realises the oxygen they are breathing right now came out of the same tiny holes a tree loses its water through. A tree on a hot, sunny, windy day is m
Why Your Blood Goes Through Your Heart Twice (Biology Level 8)
We're going to follow one red blood cell on one full lap of your body, and find out why its route has two loops instead of one. Then we'll look at what it's carrying and who's riding with it, because the road is dangerous.The listener can trace one complete lap of the body: right side, lungs, left side, body, back. They can say why each of the three vessels is built the way it is, and name what ea
You Are Breathing Out Your Breakfast (Biology Level 8)
We're going to follow that breakfast out of you. First we find the door it leaves by, which is your lungs. Then we find where it was turned into gas in the first place, and that's a different process with a different name from breathing.Puffing after PE isn't you 'needing air'. It's your cells turning food into carbon dioxide faster, and your lungs racing to throw it out. The listener can now say
The Cracker That Turns Sweet (Biology Level 8)
That sugar was made inside your mouth, just now, by a chemical tool you carry around. Today we follow that cracker all the way through you. First, how your body cuts food into tiny pieces. Then, how those pieces get into you, and who deals with the bits you can't cut.You don't digest alone, and you don't digest in one place. You're a scissor factory that leads into a folded tennis court, with a cr
The Plant That Robs an Empty Wallet (Biology Level 8)
To see why that's impossible, we first need the rule that moves almost everything in and out of your cells for free. Then we'll watch the plant break it and find out what that costs.Back to the plant: it isn't breaking the rule, it's paying to beat it. The listener can now state both definitions. Diffusion is movement from high to low concentration down a gradient, with no energy needed. Active tr
The Cells That Threw Away Their DNA (Biology Level 8)
So why would your body build cells that are missing parts? We'll find out what each specialist cell gives up to be brilliant at one job. Then we'll see why giving things up means no cell can survive alone, and that forces your body into five levels of teamwork.The listener can say what a specialised cell is: a cell whose shape matches its function, usually by giving something up. They can name the
The Cell With a Wall That Isn't a Plant (Biology Level 8)
So today we're cell detectives. First we learn the clues that tell a plant cell from an animal cell. Then a suspect turns up that breaks those clues, and the only way to catch it is to work out how big it really is, with one simple sum.Case closed. A cell wall alone proves nothing. The nucleus decides the case (plant or animal if it has one, bacterium if it doesn't), and the size sum backs up the
The Plate That Survives the Oven but Not the Floor (Chemistry Level 8)
That's what we're chasing: first, what makes ceramics so tough and so fragile at the same time. Then, how people beat that weakness by joining two materials so each one covers for the other.Composites solve the dropped-plate problem without inventing a new substance. You keep one material's strength and borrow another's to cover its weak spot. The listener can now say that ceramics are hard, britt
Why Your Lunchbox Will Outlive Your Sandwich (Chemistry Level 8)
We're going to find out what bread, wool and a plastic box have in common: they're all giant chains. Then we'll see how we learned to build our own chains on purpose, and why the thing that makes plastic so useful is exactly the thing that makes it a problem.Go back to the lunchbox. It lasts because someone designed it to last. The listener can now say what a polymer is (a long chain of repeating
Why Nobody Ever Found a Lump of Sodium ready (Chemistry Level 8)
That one question is the whole episode. First we work out which metals are the bullies that grab other things and won't let go, and how we know. Then we see how humans steal them back out of rocks, and why the biggest bullies need something stronger than fire.The listener can now answer the opening question in one sentence: sodium is too grabby ever to be found alone, and gold is too lazy ever to
The Case of the Vanishing Metal (Chemistry Level 8)
We're tracking down missing metal. First we find out where it disappears to in acid. Then we catch metal doing the opposite in plain air, getting heavier, and work out what it stole.The case is solved: metal is never lost or created, it just swaps partners. You can now say both word equations, name the salt from the acid, describe the pop test, and explain why a dry iron nail doesn't rust.Sources:
The Rigged Race in your Teacup (Chemistry Level 8)
Here's the secret behind every way of pulling a mixture apart: find the one way its bits are different, then turn that difference into a race only some of them can win. We'll start with the most beautiful race in chemistry, paper chromatography, then go back to your kitchen, where you've been running these races for years without knowing it.Back to the tea bag: it's a race where the leaves are dis
Why Salt Slips Through the Filter (Chemistry Level 8)
We're going to chase that question. First we'll see what a filter can actually catch, then why salt slips straight through it, and what you have to do instead.The sieve couldn't tell salt from water, but boiling can. With that, the listener can rescue either half of salt water: evaporate to keep the salt, distil to keep the water. They can also explain why a filter alone never could.Source: Episod
The Sugar That Never Left (Chemistry Level 8)
In the next few minutes we're going to track that sugar down. First we prove it never actually left. Then we find out that water can only hide so much, and what happens when it runs out of room.The crystals that appear on cooling are the hidden stuff coming back, and that answers both opening questions. It never left, because mass is conserved, and you get it back by shrinking the water's hiding r
Why the Juice Carton Is Lying (Chemistry Level 8)
So we're going to find out what 'pure' really means to a chemist, and why the juice fails the test. Then we'll see what the juice actually is, and why that turns out to be useful rather than a let-down.The listener can now catch the word 'pure' lying. Pure means one substance, and you can check it because the substance melts sharply at one fixed temperature. Anything else is a mixture, where the p
Why You Can't Breathe Water (Chemistry Level 8)
The answer is the difference between atoms that are just hanging around together and atoms that are actually locked together. Once you get that difference, you can read a chemical formula, and you'll see how a deadly gas and a dangerous metal end up on your chips.The listener can now answer the opening question. You can't breathe the oxygen in water because it isn't oxygen gas any more. It is bond
What Every Atom Wants (Chemistry Level 8)
So we're chasing one question: what does an atom actually want? First we'll work out exactly what 'full' means for an atom. Then we'll find the two ways atoms get there: one grabs, one shares.The listener can now predict the bond without memorising a list. Is it a metal meeting a non-metal? Something gets handed over and ions form. Two non-metals? They share and a molecule forms. Both follow from
The Salt Shaker Periodic Table (Chemistry Level 8)
We're going to find out what sodium and chlorine actually are, why one counts as a metal and the other doesn't. Then we'll see why those two in particular grab each other so hard, and why some elements refuse to grab anything at all.Back to the salt shaker. It holds one element from the metal side and one from the non-metal side, a Group 1 metal and a Group 7 halogen, and they've cancelled each ot
The Empty Seat: How Mendeleev Described an Element Before It Existed (Chemistry Level 8)
So how do you describe something before it exists? We'll follow Mendeleev's trick first, then crack open an atom and find that the clue he was sorting by wasn't what really makes an element itself.Gallium's real address isn't 'weighs about 68'. It's 'has 31 protons'. The listener can now say what atomic number is (number of protons) and what mass number is (protons + neutrons, a plain count with n
The Invisible Kickers: Particles, Substances and States (Chemistry Level 8)
We're going to track down the invisible thing that was shoving that pollen around. Then we'll use it to solve a harder case: two liquids that look exactly the same. How do you prove which is which?The mystery Brown couldn't solve becomes a tool. The same particle picture that explains the dancing pollen lets the listener name a substance by its fingerprint. They can say what density is (mass ÷ vol
Ice, Water, Steam: One Substance or Three? (Chemistry Level 8)
We're going to find out what actually makes something the same stuff, even when it looks, feels and behaves completely differently. First we'll work out how scientists identify a substance. Then we'll see why the same substance can act like three different things, and how we know the invisible particles are really there.The listener can now say that a substance is one type of particle. They can na
