What's the limit of human thinking power?

Why are yawns contagious? How did butter come about? What’s the limit of our brain capacity?
02 March 2018
Presented by Chris Smith


In a world of self drive cars would they have indicators? Why do you put sugar in before milk? Why are yawns contagious? How did butter come about? What’s the limit of our  brain capacity? Eusebius McKaiser and Chris Smith take on questions from the 702 and Cape Talk audience...

EUSEBIUS - Good morning to you Chris I hope you’re well?

CHRIS - Oh I certainly am yes and I hope you are too. Good morning.

EUSEBIUS - I am most definitely! We've already got lots of people have called in and that's fantastic - and Twitter questions. But before we do so we of course always start with a side story of the week and this week it is dark matter.

CHRIS – Yes, I thought I'd push the boundaries of physics a bit because we often end up talking about things like medicine and biology so I thought we'd go out there into the deep unknown and the origins of the universe this week because there's a pair of papers in the journal Nature which suggest that there might be some new physics for us to find.

Now the two papers have actually been commented on by a chap called Lincoln Greenhill who's written a very nice what we call “News and Views” article which brings together the key elements of both and it's a good read.

Now what the story is all about is that researchers used a very simple radio antenna but very well-built; very accurate; it was looking at the same sorts of frequencies that FM radio and television transmitters operate at; they were actually looking at various aspects of the deep dark sky out in out in the universe and they were retrieving signals which are effectively echoes left over from the Big Bang. So they're looking at radio signals that date back to when the universe first formed.

Now what's interesting is that they can look at one particular range of frequencies which correspond to hydrogen gas because one of the main things that formed when the universe formed was a large amount of hydrogen gas and you can work out by looking at how that gas absorbs radiation how hot it must be. So, effectively, you've got a way of giving the universe a temperature measurement at this point in its lifetime.

But when they make that temperature measurement, they find that the gas is colder by quite a considerable margin than it should be. Now the only place that the heat could have gone is into other hydrogen, which doesn't make sense, or into one of the other things that was around at the time of the Big Bang and that was Dark Matter.

So what they think has happened is that the dark matter has in some way stolen this heat away from the hydrogen, and this flies completely in the face of our current understanding of Dark Matter which is this stuff we call “dark” because we can't see it and we can't measure it. We can only infer its presence because we know it has a lot of mass and it has gravity and it makes things move in a certain way so we can see its influence.

It makes up 25 percent of the mass of the universe but we've no idea what it is. Now we have an insight into how it was behaving right at the beginning of the universe and evidence that maybe it can interact albeit very weakly with matter like hydrogen. So this is a new beginning of our understanding of one of the major constituents of our universe that previously we had no idea what it was.

EUSEBIUS - Amazing; Albert, you’re our first caller; what is your question for Chris?

ALBERT - Thank you. Good morning Chris. Chris I'm sure you are familiar with that little question that people like to ask, which is did Adam and Eve have belly buttons? So I'd like to instead of looking in the past I'd like to look into the future and I'd like to I'd like to pose a similar question and say in a world where all roads are driven on only by self-drive God well those guys in your opinion need brake lights and indicators.

CHRIS - What a wonderful question. I did wonder where that was going for a minute. Yeah.

Well the great virtue of using technology is that unlike humans technology does not make mistakes. And a really good stat I have on this is we were talking to the engineering giant Rolls Royce recently. This is the company based in Derby England who make about a third of the world's jet engines. So they are some of the world's best engineers. Another project that Rolls Royce have is an autonomous shipping programme. They are pioneering a driverless ship project, which is already underway and they are aiming to remove all the humans from ships so that, actually, ships will drive themselves.

The chances of ships having accidents is actually a lot lower than cars having accidents. But the point that the engineers at Rolls-Royce made to me is, if you look at what's gone wrong in shipping in recent history then roughly 100 per cent of the problems have been attributable to humans making mistakes. Now if you write your software properly, and you build your machines properly, they're not flawed like humans are: they don’t make human mistakes. Things can still go wrong, but they don’t make the kinds of mistakes that humans do: they don’t have lapses of attention; they don’t get disturbed and distracted by the phone ringing and take their eyes off where they should be going and answer the phone - you shouldn’t be doing that anyway, but this is what happens.

So, in answer to your question, the reason we have brake lights is to try to warn flaky humans who are flawed and make those mistakes that the car in front is probably going to be stopping so you should do the same. We will be able to streamline that process. We won’t need brake lights I wouldn’t have thought but we will need ways of warning people because there will still be people wandering around and most of the accidents that happen are because people step out into the road in front of approaching vehicles and so making them more visible is important.

The other thing that driverless vehicles are going to enable us to do is - because they’re all segued together, because the vehicle in front is talking to the vehicle behind and so on and so on - actually the timing can be very precise; you can run these things really close together and you just apply the brakes to the whole train of cars - and you do it do automatically - and it means that that you can have very very small gaps between them, which is good from an air resistance point of view; it's good from a road efficiency use point of view, and it means there are virtually no delays at traffic lights compared with the current situation where there’s about half an hour's delay while one person drives off and then the person who was in the traffic jam behind stops applying their makeup, or picking their nose or whatever they had been doing and then they think “oh, better drive off now!” and this introduces huge delays. That could be solved!

EUSEBIUS - We've got a lot of fun questions on Twitter as one of them. Someone wants to know from you Chris, why do babies “emote”. I suppose, more precisely, gesticulate when they are “emoting” with their legs?

CHRIS – Well, you know, if you've got kids we've all had the experience where you put them down on a mat, or in a baby bouncer or something, and they kick furiously and shake their limbs all over the place. Why are they doing that? Well the answer is that, unlike some animals, if you take animals that are born, like a zebra or a horse, these animals have to be very active from the minute they're born, whereas humans are not very well developed when they're born. And the reason is that an animal like a zebra has got to be able to be almost autonomous; it's going to feed from its mother, but it's got about to look after itself because otherwise it will be eaten. Humans are a social species; we have evolved to look after our young and, because we have a huge head and a big brain which is going to get even bigger, there’s a limit on how developed our nervous system can be at the time we are born.

So, we compromise: we give birth to a baby which is less developed than it is going to have to be. But we spend more time looking after it so that means babies brains and the motor pathways in their brains are not very well developed at the time of birth. Some are some pathways some nerve systems are better developed but many are not.

And what the baby is doing when its kicking and moving is that its actually training its nervous system it's developing the motor pathways and the feedback loops in its nervous system. So it “knows” - and I say “knows” in inverted commas - how one particular action begets another reaction. So it’s effectively training its nervous system and you are therefore getting this conversation going between nerves and muscles; you’re building up muscles; you’re strengthening muscles and you’re strengthening your ability to coordinate those muscles. And this reflects an underlying developmental process in the nervous system; it’s a consequence of the fact that we are born being absolutely useless and, were it not for our parents, we wouldn't survive five minutes!

EUSEBIUS - Sherrie thank you so much for holding on. Go ahead.

SHERRIE - I'm delighted to be able to speak to Chris in person about the key experiment. I'm retired now but I did physics and chemistry at university to practise as a physicist all my working life. I was fascinated by that as an abject - as an avid – tea drinker yes, I concurred with the person who originally phoned in his views on how the tea floats; the milk flowed slightly below the surface of the tea. If one pours it in, being careful to use a clean cup each time, if you put the sugar in first, the milk then sort of it doesn't rise immediately to the surface but you've got the little strings of it gradually with the sugar finding their way to the top and creating turbulence. So I went one further and I actually made the tea with sugar so that it completely dissolved and then poured the milk in, but then I noticed that the milk still sat on the top; so I'd love to know what Chris has come up with!

EUSEBIUS - Chris I think our callers are going to eventually force you to write a paper or three on tea!

CHRIS - This is looking that way isn't it. Well, look, I'll let the cat out of the bag a little bit because we're about about a nanometre away from actually saying what we're going to do in South Africa this Easter. And one of the things we're going to be doing is going to be with 702. So I'm thinking that what we're going to do is we're doing that we come and do the experiment properly and we'll do it on every appliance and like we will do this and then we'll actually come up with both the experiment the data test it properly and we'll come up with some explanations and we'll do it live in front of people so that everyone can see what we're doing and we can then hopefully nail this one and then maybe we can write a big science paper which has the entire 702 and Cape Talk audience involved – one with the biggest authorship in history - 30000 people!

EUSEBIUS - Let's take another fun one from Twitter this month I'm sure you've been asked this before I would imagine yawning appears to be contagious is it. And why yes.

CHRIS - Yawning is most certainly contagious. We've talked about this a little bit in the past and the evidence is that humans have evolved to yawn to improve arousal and alertness.

EUSEBIUS - Now the suggestion is that yawning occurs to cool your brain because a tired brain is a hotter brain and a tired brain that's potentially losing its vigilance means that you're more likely to be eaten by something in our evolutionary past whereas if you yawn and you make the person next door to you who's probably also nodding off. Yawn both of you become more alert less likely to get eaten.

Evidence for this is there was a paper published by Gordon gallop at the State University of New York in the mid “noughties” and he got a bunch of students showed them videos of people yawning didn't tell them why they were watching these films and counted how many times they yawned in sympathy with the video proving yes that yawning appears to be contagious because people were catching yawns off the video.

Then what he did was to ask the students randomly either to breathe through their mouths or to hold a cold compress onto their forehead. The breathing through the mouth bypasses any cold air going up through the nose which could call the head call the blood vessels in the head and cool your brain. Breathing through your nose, or holding a cold compress onto your head, obviously has the effect of cooling the brain.

When he did this, he found that the rate of yawning in the people breathing through their mouth rose and became even higher. In the people holding the cold compresses on their heads the rate of yawning dramatically dropped. And this strongly suggests that yawning - and contagious yawning in sympathy with other people yawning - is a brain cooling manoeuvre to increase your alertness so you are less likely to be eaten and that's why we have evolved to catch yawns.

EUSEBIUS - Janine is our next caller. Janine thanks for your patience. What is your question for the Naked Scientist?

JANINE -  Hi Chris. Hi Eusebius; I’m 19 weeks pregnant and my gynaecologist found high of antibodies in my bloodstream and asked if it was positive twice already and this is a big concern and it never came across something that is so selective unnatural I'd be worried what should I do?

CHRIS - Hello Janine; Congratulations! There’s a few other follow up questions that I would like to ask but just talking generically for a second. The most reassuring thing is that someone has been testing things and has checked something and they've found something that they want to investigate further which means that it's being followed up and that's the most important thing because following up things you find is important because if you overlook something or ignore something then bad things can happen much better to be in a position knowledge.

Now you don’t say what these antibodies are, and there are lots of different things that you could be being tested for. There are lots of things that we screen for when women are pregnant to make sure that we minimise any risks to the child. So, without further information of what these antibodies are, it's very difficult for me to say any more than other than I'm reassured by the fact that someone has found something and that they're going to check you out.

I haven't heard many people come to me and say well, you know “I've had antibodies detected in pregnancy”. Everyone's got antibodies; the blood is full of antibodies; if we didn't have antibodies we'd be covered with infections and things would be punishing us all the time. So everyone's got antibodies.

It may well be that these particular antibodies can do something under certain circumstances and so they want to make sure that you're not at any risk; but do make sure that you ask the right questions next week when you see your specialist in terms of: the impacts of this? Is any treatment going to be necessary? And feel free to drop me an email to Chris at Naked Scientist dot com and I’ll see if I can follow up with any more information or questions for you, if I have the chance.

EUSEBIUS - Thank you, Chris. Tessa, good morning!

TESSA - Hi. I've got a very strange question. I've always wondered how butter came about?

CHRIS - Fair enough. Well, of course the way we make butter is you get butter from milk, and milk is very fatty. And the reason milk is very fatty is that a cow is big and it has to pass a lot of calories into the young baby calf so the calf can grow, build muscle, build body mass and become a big cow. Because, when it's small it's vulnerable. If it can grow big quickly, it's got more chances of surviving and reproducing itself.

So the way you get lots of calories very quickly into your offspring is you make your milk very, very fatty because oil has an extremely high embodied energy. In other words the amount of energy in the bonds the chemical bonds in oil is very high and when the baby breaks those bonds and makes new bonds with them it can release a lot of energy. So it's a good way to get lots of calories very efficiently into your offspring.

Now when we therefore shake up milk what you can do is to separate the oily bits from the watery bits and so when you when you sort of beat up milk and churn it, you can form globules of oil which turn into bigger globules and bigger globules and eventually all the oil joins together and forms this pat of butter with the butter milk - the watery stuff – sits on top and you separate that off.

Now, I dont know exactly how someone first invented butter but they were probably looking for a way to store energy and calories efficiently just like you know we do in the fridge these days. Or how how do we do that how do we stop milk going off. They made cheese along the way by accident as well but probably by carting milk around and sort of vibrating it and shaking it by just physically moving it around. They probably did what a churn does and make all the little dissolved globules of fat merge into big globules and then big insoluble blobs of fat. And that's how butter came about. I'm speculating but that's basically what butter is it's the it's the fat out of the milk which is all the little globules have joined together to make one big pat of butter...

EUSEBIUS - Someone asked earlier on Twitter “Is there a limit to how smart an individual can be?” And I'd like to tag on my own curiosity to that question Chris: sometimes we hear things like I don't know the average human uses 5 percent of their brain capacity. How do we know what that upper limit is of our intellectual capacity all brain capacity?

CHRIS - Well actually we don't and this is the extraordinary thing and you think there are geniuses in history and there are geniuses who make amazing music there are geniuses with mathematics there are geniuses in many aspects of life and the human brain is an amazing thing because he's got a 100 billion nerve cells in it and those 100 billion nerve cells each make about 5000 connections or more to other nerve cells and those connections can all be refined or shaped or changed.

But our brain wires itself up and builds itself from first principles using a vague instruction manual but with a bit of “noise” thrown in - by “noise” I mean that there's some variation or randomness to the way the brain wires itself. So everyone's brain is unique and everyone's brain is like a sponge it has the ability to be shaped and moulded and adjusted and adapted by your day to day and week to week year to year experience.

So we are the product of the life we live and therefore the realms of possibility and the degrees of freedom are absolutely huge with hundreds of billions of nerve cells making thousands and thousands of connections multiplied by billions of people on earth. All we need is for people and I say all we need is for people to have a good education and a rich environment to grow in because then they have the best prospects of realizing the potential of what their brain is capable of.

But, basically, with this huge degree of diversity on Earth you're going to find people who are really, really good in particular areas, because their brain has - by chance - wired itself and been moulded and shaped to do certain things extremely well and those are the people who are the supreme musicians, the supreme artists, the supreme physicists, the supreme mathematicians; people who are really really good at sports for example, because sporting ability is also all about how your nervous system interacts with the environment around you and makes your body move in the most optimal way to win at that sport.

Now just to pick up on your last point, Eusebius, you said there are these reports that people only use five or 10 percent of their brain all the time. There are some of those people: we know than they go on Twitter quite a lot and one of them's running a big country on the other side of the Atlantic. But, on the whole, this is a complete myth, okay! There’s no evidence that people only use 10 percent of their brain.

Nature and evolution wouldn’t let you do that because the brain is so metabolically hungry it uses so much energy. Nature would not let you have such a wasteful organ and it would not compromise your ability to pop out from your mum by having such a big head so you need all your brain it's there for a reason and we use all of it all the time what we do do is to use some parts of it more at certain moments in time because different parts of the brain are highly specialised for doing different tasks so when you’re reading you’re using visual areas language areas and you’re increasing, relatively speaking, the activity of those areas over other areas. But you need 100 percent of your brain...


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