Quiz: What kills more, sharks or selfies?

13 June 2017

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Chris: But before we have any more questions, as promised we have a little quiz for our panel and for you at home…We’re going to have two teams so what we’ll do is we’ll have Dani and Stuart who are sitting next to each other - you'll be one team. And we’ll have Carolin and Duncan as the other team. So I read you a question and you have to decide it it’s right or if it’s wrong.

Chris - Duncan and Carolin, this is your first question.

Q1. What has more eyes, a dragonfly or a box jellyfish?

Carolin - A dragonfly’s only got two eyes but they’re really sort of compound eyes aren’t they? Do they count as individual?

Duncan - I don’t know. My knowledge of eyes is limited.

Carolin - This is very embarrassing because I do have a son who actually works in insect eyes, so I should know the answer to this. Do jellyfish have eyes?

Duncan - I think dragonfly.

Carolin - OK. If you can count all those little compound bits as eyes, I’ll go with dragonfly as well.

Chris - A box jellyfish is the answer! Dragonflies have two eyes, these are compound eyes, so they’re built from tens of thousands of miniature units, but the box jellyfish actually has 24.

Did you know that Dani?

Dani - I might have been thrown by the complex eyes as well. I could have been a little bit thrown, but yeah, I would have erred on the side of the jellyfish.

Chris - Discovered in 1955, Chironex fleckeri after the doctor who fished one out of the water because a young boy unfortunately died of the sting. He was found to have found a new species of jellyfish, and it was named Chironex fleckeri in his honour.

Zero for that so you’re doing well so far [giggles]

Let’s go over to Dani and Stuart

Q2. Who holds the record for smallest vertebrate (animal with a backbone) in the world... a fish or a frog?

Stuart - I’m looking at you here Dani.

Dani - I’d be tempted to go fish. I don’t know.

Stuart - I can imagine a fish being smaller than the smallest frog I can imagine. What do you reckon?

Dani - Let’s go fish.

Stuart - OK. We’re going to go fish.

Chris - It’s a frog! But only recently. The record holder until 2012 was an Indonesian fish (Paedocypris progenetica) at just under a centimetre, but then a frog (Paedophryne amanuensis) was found in Papua new Guinea  that was only 7mm - tiny! There might be smaller vertebrates to find, but unfortunately they’re harder to spot.

We’re level pegging. Very high scoring round so far - zero/zero.

Back to our first team Duncan and Caroline.

Q3: Next then, what would take longer – walking once around the equator, or getting a spaceship to Mars?

Carolin - Well, it depends how fast you travel through space, doesn’t it? If you could travel at the speed of light you’d get to Mars a lot quicker than it would take you to walk round the the Earth.

Duncan - Do you mean with standard space travel methods?

Chris - Yeah.

Carolin - In a rocket it takes you six to nine months to get to Mars. You could also say it depends whether we’re on the same side of the Sun as Mars at the time.

Duncan - Oh gosh - it’s complicated.

Carolin - Yeah, it’s a kind of three dimensional problem isn’t it?

Duncan - Let’s say six to nine months to Mars from here.

Carolin - By conventional spacecraft.

Duncan - Exactly. I don’t know that I could walk round the equator of the Earth in six to nine months!

Carolin - I think it would be a challenge yes.

Chris - So what are you going for?

Carolin - Shall we say it’s longer to walk round the equator?

Duncan - Yeah.

Carolin - Especially , it would be difficult over the sea wouldn’t it?

Duncan - Yeah.

Chris - You're going for taking longer to walk round the equator.

Duncan - Yeah

Chris - Yep! Well, we’ve done some back of the envelope calculations. The equator is around 25000 miles around, if the average walking speed is 3mph that’s 8,300 hours. Assuming whoever it is doesn’t need any breaks (and can walk through water) that would take about 345 days. On the other hand, spaceships have reached Mars in 156 days.  So it’s quicker to get to Mars!

Very well done. One point to Duncan and Carolin.

Dani and Stuart - here we go.

Q4: Which is the larger: number of germs in a sneeze, or trees on Earth?

Stuart - There’s a lot of trees.

Dani - But microbes are really small aren’t they? You know all about size don’t you - you're the size man!

Stuart - Cells are in the order of about 2 microns, so two thousandths of a millimetre.

Cani - And the volume of a sneeze… A litre - is it that much?

Stuart - A litre of sneeze. That’s horrible!

Dani - I’ve got hayfever. It feels like a litre today.

Stuart - But there’s all that business, if you sneeze in a tube carriage it kind of hits the back end of the tube carriage - it will go all through the train carriage.

Chris - On that pleasant thought, would you like to give me an answer? Are you going more germs or more trees?

Stuart - More germs.

Dani - We’ll go germs.

Chris - I’m afraid not it’s trees! There are thousands to millions of virus particles in an infected person’s sneeze, but a recent estimate by researchers at Yale University put the number of trees on earth at about three trillion. Although the number is going down they caution - we’re losing trees.

We might as well carry on. We might as well have the last one.

What releases more carbon dioxide, one human breath, or running a Google search?

Carolin - A google search doesn’t last very long.

Stuart - I’m just trying to think of how to quantify the amount of carbon released from a google search.

Carolin - Well, presumably the computers that are running or what you need to have..

Stuart - Electricity.

Carolin - … electricity and what you may have needed to manufacture to enable that google search. Shall we be controversial and go for the google search?

Stuart - I’ll trust you.

Carolin - Oh don’t.

Chris - So you’re going for google search releases more CO2?

Duncan - Yeah.

Chris - GOOGLE! According to Google’s own numbers, a typical search amounts to 0.0003 kWh of energy - and you’d need to emit about 0.2g of CO2 to generate that as electrical power to run their data centre. The average human, on the other hand, exhales around 1kg of carbon dioxide a day, so - at 12 breaths per minute - that works out at roughly 0.05 grams of CO2 per breath. So Google searches cost more C02 than a breath. The figure is slightly controversial because Google’s figures don’t include the carbon cost of running your own computer…

Could be a tie - are you ready. Dani and Stuart...

Q6: What kills more people – sharks… or selfies?

Dani - I want to go selfies on that. Just people of people off the side of cliffs and things isn’t it?

Stuart - A big thing recently… governments have started warning people to stop taking selfies off dangerous ledges and things.

Dani - Like a person with a selfie stick and it has a red thing through it. There’s signs telling people not to in dangerous places.

Stuart - It’s got to be selfies.

Dani - Yeah. Let’s go selfies.

Chris - Selfies. Sharks kill around 5 people a year, but in 2016 over 50 people were killed-off trying to take photos of themselves on their phones.

The winners this week beyond price - the prestige of winning the Naked Scientists fact or fiction quiz this week is Duncan and Carolin. Very well done.

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