Quiz: animals, inventions and brainteasers!

It's quiz time! Chris Smith got the panel ready for some devious questions...

Chris - This is the competition that leads to a prize beyond price: it is the Naked Scientists Big Brain of the Month award. Have you won this before, Tim? Have you been on...

Tim - Two out of two!

Chris - Have you? What a track record! That's like on the Apprentice when they say I've been in the winning team X number of times, you've got a reputation to defend. You're in good hands here Ella. You've got Tim with a strong track record. Alright. Now the way this works is they've got two teams. Ella and Tim are Team 1, and Jess and Hannah, you're going to be Team 2. There are three rounds, and it's whoever's got the highest score by the end of it. Okay, so let's start Round 1. Round 1 is called 'New Year's Evolutions'. Did you see what I did there? Echidnas and bees, Tim and Ella, are the only known land animals that have evolved what special sense? And to give you a clue, lots of fish have it and so do sharks. What do you think?

Ella - That weird electrical one that sharks can do? I don't know.

Tim - Yeah. Sense electric fields?

Ella - Yeah, I'm going to go with that.

Tim - Yeah. Shall we try that?

Chris - On fire! Yes, absolutely, electricity. Lots of fish do have electroreception but it's very rare on land, because probably how poorly air conducts electricity. But some echidnas, like their semi-aquatic cousins the platypuses - because they're both monotremes, they're related - have electric receptors in their bills. And also bumblebees and honeybees also seem to be able to detect electric fields around flowers, which is very handy for them. So there you go. Well done. Plus one to Team 1. Question 2. So this is over to Jess and Hannah. The process called carcinisation, which has happened many times independently in the different groups of animals on earth, has been described as "one of the many attempts of nature to evolve" what?

Jess - Does it have anything to do with carbon?

Chris - I suppose in some respects it does, yeah.

Hannah - Bones... carbon....

Chris - It's a creature. It's an animal. We want an animal.

Jess - What it's an... carcinisation is some animal that's been trying to form?

Chris - An attempt to... Yes. In a nutshell, yes. That's what you want. So what's the animal?

Jess - Okay.

Hannah - What's your favourite animal?

Chris - I really have no idea what this is trying to even get at. I'm so sorry.

Chris - It's actually a crab. The phrase comes from the 20th Century zoologist LA Borrodaile, and trying to evolve crabs has happened at least 10 times independently in different groups of crustaceans. Creatures that have a hard exoskeleton like a crab.

Jess - Okay, well I'll keep that fact.

Chris - Sorry, no points on that one. You've got plenty to play for, don't worry. Here we go. Onto Round 2. This is called 'First to Market'. So back to Tim and Ella. Which of these inventions came first: the smoke detector, the metal detector, or the particle detector?

Tim - Oh, I have no idea. Do you?

Ella - Oh, no. It depends on what you consider each of these things. Are they in their current form?

Tim - Well I don't know!

Ella - I mean, I bet there's a really old smoke detector...

Tim - Yeah.

Ella - Fire's been around a while.

Chris - It's called a nose!

Tim - Smoke detectors are sort of particle detectors...

Ella - Ooh, careful.

Tim - What was the other one?

Chris - Smoke detector, metal detector, or particle detector.

Tim - I think we should go particle detector. I think that's the one they don't want us to pick.

Ella - Okay. I'm willing to go with you, with your 100% track record.

Chris - No! Surprising this one, it's the metal detector. The appropriately-named Frenchman Gustave Trouvé - get it - invented a handheld metal detector in 1874, and that was to find bullets in people's bodies. CTR Wilson invented a cloud chamber, which was the particle detector, in 1911. The first smoke detector, apart from your nose, which it was right for you to point that out, didn't come until the 1930s when Swiss physicist Walter Jaeger tried to invent a sensor for poison gas. He failed, but his instruments did manage to detect his cigarette smoke. So he could tell if you were smoking or not. But then you'd kind of know that, wouldn't you? So sorry Tim and Ella, on this case, zero. So Jess and Hannah, here's your chance. Which of these inventions came first? Was it the sewing machine, the vending machine, or the machine gun?

Jess - Oh gosh, okay. Sewing machine, again, what is it? The current iteration of the product or are we thinking way back?

Hannah - Not the middle one, not... ooh. Maybe there's a really old vending machine.

Jess - I don't know if there would have been a need for a really old vending machine. I don't know if people in Victorian times were like, "I'm going to go and get a Kit Kat." And maybe because sewing was largely women's work it wasn't something that they'd... you know, we learn about looms and things like that, that was probably the first generation of that.

Chris - So are you going for that then?

Jess - No, no. Hold your horses.

Chris - I'm going to have to hurry you.

Jess - Should we go for machine gun?

Hannah - Okay!

Chris - You want to go machine gun? Ah, no. The answer will surprise you. The vending machine was the oldest of the inventions. The first machine gun was the Gatling gun, that was 1861, and the Maxim gun was 1884. The Englishman Thomas Saint. Invented the sewing machine. The very first vending machine though dates back to the first century AD! The inventor was Hero in Alexandria, and in his book Mechanics and Optics he has a device with a slot at the top, and if you drop in a coin, it dispenses holy water. There's a thing. When the coin deposits, it falls on a pan. That's attached to a lever. The lever opens a valve, some water flows out, and the pan continues to tilt with the weight of the coin 'til it falls off, and at that point the counterweight snaps the lever back up and it shuts off the valve. So it dispenses a vended portion of holy water.

Jess - I'm so sorry, Hannah.

Chris - Right, Round 3. And it's... you could equalise. So you're still in the game you two. So keep your chin up. Here we go. Round 3: Brainteasers. Now this is quite hard, you're going to have to listen carefully for this one, okay. You're in a locked dungeon, Tim and Ella. By the door are three boxes, a red one, a white one, and a black one. On the black box it says "the key is in this box". On the white box it says "the key is not in this box". On the red box it says "the key is not in the black box". A sign says "of these three statements, at most one is true". You're only allowed to open one box. So which one are you going to open to find the key? Right, I'll park you two looking at that one while I give the other two theirs, okay. So Hannah and Jess. Now let's say that those are right and they get out of the dungeon and they reach... or you get out of the dungeon and you come to another door, and surprise, surprise, there's another three boxes. And on the black box, this one says "the key is not in the white box". On the white box it says "the key is not in this box". And on the red box it says "the key is in this box". A sign says "of these three statements, at least one is true and at least one is false". You're only allowed to open one box. Which one's got the key in it?

Ella - Solid reasoning.

Chris - Okay, you ready to go, you two?

Tim - We've got an answer.

Chris - Okay, right. So while Jess and Hannah are still thinking, so your question: on the black box it says the key's in this box, the white box says the key's not in this box, the red box says the key is not in the black box. The sign says "of these three statements, at most one is true". So what box do you want to open?

Tim - I mean before saying this, I must say in previous times, my partner has saved me every time and that's why my record is good. We think the answer is that the key is in the white box.

Chris - Yes, you're absolutely right. You have scored a correct answer. So what that means is that Hannah and Jess, you can't catch up I'm afraid. But did you have an answer anyway for us?

Jess - I'm going to let Hannah go for it.

Chris - Because unfortunately they have pipped you to the post, but we'd love to hear the answer anyway. So I told you that on the black box it says the key's not in the white box, on the white box it says the key is not in this box, and on the red box it says the key is in this box. Of the three statements, at least one's true and at least one is false. So what do you think? Just to salvage your reputation.

Jess - Oh, I think that's gone already.

Chris - Any thoughts? What are you going for?

Hannah - I actually threw away my brainteaser book over Christmas.

Ella - Decluttering for 2020!

Chris - Alright then. Well look, we have to give you a big round of applause, Tim and Ella; you're this week's Naked Scientists Big Brains of the Week. Well done. A score of two out of three, that's very good. And you got that very hard brainteaser right which was very impressive.