How can we keep our homes cool in a changing climate?

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Hello, delightful, curious-minded listeners.

Welcome to BBC Inside Science, a program first broadcast on the 17th of July, 2025.

I'm Victoria Gill.

And as many of us have spent this week sweltering and sheltering in this extreme summer weather, we will be looking at the science science behind keeping the buildings we live and work in cool as the world heats up.

And the rise of the robotic taxi will be getting under the bonnet of driverless car design.

And in the week that the UK Space Conference has come to Manchester, just down the road, I am joined by Professor of Astrophysics and friend of Inside Science, Tim O'Brien.

Hello, Tim.

Hello.

It's lovely to have you in the studio again.

And what have you been up to?

As you say, with the Space Conference being here this week, we actually hosted a visit just the other day by John McFaul.

Ah, Isa astronaut, John McFall.

Yeah, European Space Agency astronaut in reserve at the moment.

But

he came to Jodrell and we got to show him around the place.

But he also did a bunch of schools, talks, and a public event in the evening as well, which was very popular.

Exciting.

Yeah, I mean, Issa had been looking at the possibility of having people with physical disabilities in space.

And so he volunteered on that basis.

And he's been through a whole sort of process of checking the city.

He He lost his lower leg in a bike accident when he was a teenager, and now he has a prosthetic limb.

Is that right?

Yeah, from above the knee, yeah.

So he's got quite a fancy prosthetic leg, actually.

This sort of mechatronic thing with lots of sensors and things.

And so that needed to be, you know, checked out for going into space for safety, like any other piece of equipment.

But there's sort of interesting sort of little wrinkles with it, really.

With, for example, in that environment, it can

off-gas, they call it.

So gases from within the prosthesis prosthesis can get into the environment

through the polymers or the glues or whatever that are in this.

So, you don't want that in the International Space Station?

Exactly.

Well, it turns out that the rate they come off, it's okay in the body of the space station.

Right.

But he couldn't wear it in a space suit where it's a much smaller volume.

How ancient,

yeah.

The amazing visitors and the interesting things you get up to at Jodrell Bank.

Well, you'll have more science and space news for us a little bit later.

So, stick around and we will be back with you shortly.

Now, though, our homes are where we go to escape the weather, but many of us have been struggling to keep the heat out recently as the hot conditions across the country have continued.

And the extremes in temperature and rainfall that we're experiencing this year are set to be our new normal in a warming climate.

That's what the Met Office announced this week.

So we want to know how we adapt, how we can make our buildings cooler, more comfortable, and most importantly, safer in this new normal.

Joining me on the line is Professor of Zero Carbon Design, David Coley from the University of Bath.

Hello, David.

Hello.

Hello.

Thank you so much for joining us.

A lot of us have been struggling to sleep, been pretty uncomfortable, but this is something you look into from a research perspective.

Why is it so much more significant than that?

And such a big issue of our buildings are getting hot?

Well, we only have to look at the heat wave that hit Paris in 2003.

There, Paris suffered 14,000 mainly vulnerable people dying due to the heat.

And almost all of them died within buildings.

Strangely enough, even though you have health complications typically if you live on the street, if you lived on the street, you were more likely to survive as an elderly person than you lived in buildings.

So in a sense, the people were killed by architecture.

That's extraordinary.

And is that architecture changing?

You know, we know we've felt the effects of the climate changing, and that's such a significant issue for our health.

So, is the way that we design those buildings changing?

I'd love to say yes, but the answer is no.

We still don't have the requirement to calculate the typical temperatures that you'll have in a heat wave in your home, a new home built in the UK.

You know, what's problematic?

What makes a building not suitable or even kind of dangerous in that extreme heat?

So, buildings overheat for a reason.

Everything happens for a reason.

So, examples would be sunlight coming through the windows at the same time as you've got hot air.

Not being able to cool the building at night because it's not safe to leave windows open is a real classic example.

So trying to get the elderly in central London to leave windows open at night is problematic.

So pathways for air to flow at night are critical.

What about when we look at cities more broadly?

Because, you know, you mentioned there, London and Paris, but there are cities big cities in the tropics and in very hot countries that have been building these buildings and designing these spaces for for many people to occupy in high densities for centuries in very hot climates can we learn more from that architecture and from that city design we can certainly learn something and we might have to augment that with air conditioning for example.

But we keep building highly glazed buildings, which are little more than greenhouses.

They have very clever glass systems on them.

But a much simpler way of dealing with that is to go back to a more traditional design.

And if you've been to the Lambra or somewhere like that in southern Spain, you'll have seen this, where windows are real things that punctuate the facade rather than just being continuous glazing.

So if we can go back to a building which really isn't designed to overheat, but one that's designed to not overheat, then a lot of the problems would be solved.

Is that a challenge in terms of the economics of building?

Like, why are we building all of these highly glazed?

You know, I'm sitting in a studio in Salford and I can see the sort of skyline going up and up and being developed in Manchester.

And it is, as you say, these highly glazed buildings.

Why are we doing that?

Why not go back to these more traditional methods?

Is there a big cost difference?

No, if you look at the panels that you're looking at, those glazed panels, they could actually be just virtually the same material, but opaque.

It's not hard to achieve.

So it's an artistic statement.

And if you look at those 14,000 people dying in Paris, and we don't know when we're going to get hit by such a heat wave, but all the predictions are we are going to get hit by such a heat wave.

The fact that people may die or have just a torrid time at work, but art, because that's what architecture is at this level, it's a rather strange thing to be doing.

We have these buildings that people are living and working in now.

So what technologies are being developed that might be able to be used to make them safer, to make them cooler?

Well, I think the first thing is to try and work out where you live, how much of a problem this is, because it's different than in the southeast of the UK than it would be up in the Shetlands.

So one thing we've done is developed a website called Kobe at the university where you can put in your postcode and look at a historic heat wave.

and then what that heat wave is going to look like in the future.

Depending on where you live, the uplifts will be more or less extreme.

But in the southeast, for example, it'll be, say, eight to 10 degrees Celsius, which is huge, absolutely vast.

And the most frightening thing about that is that you may find that in your location,

the predicted nighttime minimum temperature

is at the same value in Celsius as the daytime maximum temperature of a heat wave when I was young, which is phenomenal.

To actually deal with that scale of event, we've not only got to introduce maybe some technologies, the simplest one is just shading over our windows and providing secure airflows and how we use our buildings.

So for example, if it's hotter outside than it is inside, around about midday, maybe during a heat wave, you don't want a huge airflow.

through your building.

In fact, you want to seal it more up.

And that's how we see buildings being used in southern Europe, for example, traditionally.

And then at night, we may well want to have very large airflows to try and cool the mass of the building down.

Then we want to make sure our building has some mass to store that cool inside rather than just being lightweight materials.

Shutters, shading, airflow, you know, all these things are sort of simple, traditional techniques.

They're not high-tech.

Are there other things that are being developed?

You know, I'm thinking of super-reflective paints, for example, that would reflect the heat back from roofs or from the outer walls of buildings.

Are there any technologies that you're particularly interested in that you think could be applied at a bigger urban scale?

Yes, I mean, things like reflective paints are quite useful.

More planting within cities, so what we call green space, more blue space, i.e.

water within cities, be an absolute...

brilliant idea.

Or another very simple technology is underneath windows where air is going to enter the building, don't have dark tarmac driveways.

Have some planting in that first meter or two to make sure you don't superheat the air before it flows into your home.

Well, thank you very much, David Coley from the University of Bath.

It's been great having you on the programme.

Thank you.

And you are listening to Inside Science.

And now to the surprising science behind one of our most familiar flowers and a project that we were particularly enchanted by at the Royal Society's recent Summer Science exhibition.

It was unpicking the genetic code of the humble daffodil.

This was a special part of the exhibition that that was run by school children who've been spending their lunch breaks and weekends extracting and analysing daffodil DNA.

We met a group of students and one of their teachers who travelled down to London from Angus in Scotland to take part.

I'm Lewis Coole.

I'm a science teacher from Kinemuer at Webster's High School.

You're actually Mr.

Cool.

Yeah, Mr.

Cool.

Amazing.

And yeah, can we just ask each of you to introduce yourselves?

Yes, I'm Joshua Hainowski and I'm a sixth-year student at Webster's High.

I'm Kenzie Mill and I'm also a sixth year student at Webster's High.

I'm Daria Ersoy and I'm also a sixth-year student at Webster's High School.

And I'm Michael Ross and I'm also also a sixth year student at Webster's High School.

Also, also.

Can I just start with what's brought you here?

Just tell me about this project and how it got started.

Yeah, so it started

a year or two ago.

We've got a sort of teacher email group and there was a post about this project called the Data Project.

And I thought, not done anything like that before, sounds really interesting.

So I went to a meeting for it, signed up, put my application to Royal Society, thankfully got the funding,

got this group of pupils to be involved and that's sort of where it began.

Then we've been working since November meeting weekly, lunch times more or less and then we had a whole lab day where we did all the practical work.

Explain to me what you've been doing then.

What's giving you an insight?

Taking DNA out from daffodils and sequencing the different DNA of some

types we had.

There were three types of daffodils, and we sequenced it all, or we extracted it in the lab from the daffodils themselves.

And then, through a complicated process, we managed to isolate it and then put it into a thing called a DNA gel electrophoresis, which is like a gel you put it in, which shows the DNA.

And then we sent that to the James Houghton Institute to be sequenced.

So, you've been DNA fingerprinting these different daffodils

to identify the genes.

And what's that been like, sort of being quite hands-on with the science?

What's the experience of doing those extractions and getting your results been like for you?

Well it's quite challenging.

We had to have like lots of practices using all the different scientific equipment because a lot of it you don't use in normal like biology lessons.

So that's what we were doing at lunchtime.

We were using practicing with like the micropipets and with the vortex and electrophoresis.

But yeah it was just practicing making sure we all were able to do it and then so when we were actually doing the big investigation we're all like ready to go.

And yeah it's been interesting to see what actually happens inside all the daffodil plants because you don't really think about it.

And it's really good because it brings together what we've learned in class and it shows us how it's used practically.

And it's like an example, so we can learn about PCR, but we never do it.

So this was an opportunity to do this and learn how it's used in real world.

Because there's a big website with all the daftils that people have sequenced, the DNA of them.

So we're actually able to see how closely related our DNA is to other daffodils as well, which is really cool.

So apart from kind of just learning,

getting under the kind of genetic skin of these plants that might be really familiar to you, right?

We see daffodils kind of growing everywhere in the spring, but how have they surprised you?

What would you say you've learned?

Is there anything that's really stuck in your mind?

So, yeah, we have loads of daffodils in our area, and it's amazing to see how many different varieties there are.

And when you look at them, how different their DNA is.

Like, they may look the same, but their DNA is so different.

And the project just really shows that.

Also, how they've like adapted, because they don't originate in Scotland, they're from Morocco.

And it's like the ones in Morocco look so different from the ones here, and it's how they've totally, I mean, it's like two completely opposite climates as well, so how they've adapted to live in Scotland,

but they're from like a desert, so that was quite cool as well.

And all like the genes of them,

this is never

done before research.

So we're compiling these into a database with millions of our schools, not millions of our schools, but a lot of them.

And us finding out the genetic component of them will allow us to develop technology which will let them be better suited to climate change, etc., and adapt and not die out, and us to understand how they work, which is just an important thing to know in general.

And there's also something in daffodils that can be really important for medicine that's to help Alzheimer's.

What's it called?

Like galthymine or something?

Galthyme?

I don't know, something

long name.

What is that?

What is a different thing?

The pronunciation I'm not 100% sure.

I think it's going to be Galatamine.

Galatamine?

Yeah, it's an Alzheimer's medication

done pre-sequencing, so it wasn't using that technology.

But the idea is that you wouldn't think you would get a chemical from daffodils that would help slow the progression of Alzheimer's, but you did.

And it just goes to show that it can be the most unlikely things that do help.

And so by doing this sort of research, the application might not be immediately apparent, but one day you've got this genetic material, you know, it's all been sequenced, we've uploaded it, someone might find a use for it.

You just don't know.

You're a proud science teacher, Mr.

Cool.

Oh, very.

They've done a phenomenal job

setting everything up, handling the younger pupils.

So, no, they've done a great job.

Thank you to the students and to Mr.

Cool, the science teacher from Webster's High School.

And that compound that we were talking about at the end and trying to pronounce is galantamine.

It helps prevent the breakdown of a chemical that sends signals in the brain.

And I had no idea that it was in daffodils.

Now, Tim, you are a teacher, you are a sharer of science.

Tim O'Brien, how important is it to get young people doing science, kind of getting hands-on with science early on?

Well, I think it's fundamental, really.

I mean, it's that hands-on experience of,

you know, as those kids were saying, you know,

actually learning how to use the equipment, learning how to go about a particular study, that things go wrong, not everything always works,

that that's not a problem, that's just normal.

That rang true.

Yeah, Yeah, absolutely.

I had a very brief scientific career and mostly it went wrong.

Yeah, yeah.

And that null results are important as well, you know, that not everything's going to behave the way you expected or hoped it would.

All these things are, you know, crucial things to learn, I think.

So, and I, and I think with

getting kids sort of, particularly, I mean, that was amazing, you know, doing that DNA sequencing with, you know, with the with that, and particularly with something as simple as a daffodil.

Well, it seems as simple as a daffodil with a plant and understanding the wider implications.

So, yeah, getting kids to be curious

but hands-on.

Yeah.

And it's not all just theory, it's not just what the teacher's telling them in the class or what they're reading in a book or whatever.

That it's actually a practical and interesting job is I think is crucial, actually.

Yeah, yeah.

And the enthusiasm was just infectious.

Now, whether the idea of riding in a driverless robotic taxi fills you with dread or gives you a technophilic thrill, these vehicles are starting to arrive in cities all over the world.

But with reports of autonomous taxis breaking traffic laws and going awry in some strange ways, are they safe?

How can a series of sensors and an advanced algorithm be as proficient of a driver as a human being?

We asked technology journalist Gareth Mitchell to investigate.

On a blustery day, a plastic bag in the road flutters and dives in the breeze.

It's an annoyance at worst for most of us.

We just feel cross about whoever's been so careless with their litter.

But for engineers working on tomorrow's autonomous vehicles, this is a problem that's been keeping them up at night.

Nothing confuses vehicle guidance systems quite like an object moving unpredictably, changing its shape, and blending in against the background.

A vehicle may confuse the plastic bag for a more harmful, solid object and needlessly slam the brakes on.

Or, even worse, the car might dismiss an actual hazard as just a plastic bag and underreact

though seemingly trivial the plastic bag problem is one big reason why it's proven to be quite so hard to take the driver out of the driving seat It also helps us understand the systems operating under the bonnet in driverless cars, all of them flummoxed by plastic bags in their own way.

System number one, computer vision, cameras bolted onto machine learning basically.

Cameras tend to prefer solid objects with defined edges.

They don't do transparent plastic very well and cameras are susceptible to shadows and glare.

Driverless cars also use a technology called LIDAR where lasers build up 3D images or point clouds of the surroundings.

Flimsy plastic doesn't show up very well in a LIDAR point cloud.

Then there's radar to sense how far away things are and to help the car judge its speed.

It's a bit like echo location in bats.

The car sends out millimeter wave radio frequencies and times how long it takes the echoes to return as they bounce off objects.

In radar rangefinding, plastic isn't really your friend, often giving weak or sporadic echo returns.

But it's not all bad news.

The car manufacturers have actually become very good at combining data from all three systems, cameras, LIDAR and radar.

That gives computers a better crack at telling a bag from a bolting dog, say, especially when you throw in some machine learning built on masses of training data from real-world driving.

All of which explains why progress continues and driverless taxis are now on the actual road carrying fare-paying passengers.

In China, the company Baidu operates more than 500 of its Apollo Go driverless cars in Wuhan and other cities.

In the US, Waymo Ride Hailing is on the road in San Francisco, LA and one or two other places.

Amazon plans to launch its Zooks service in Las Vegas later this year.

And Tesla is currently test running its Robo taxis in Austin, Texas.

Now, all of the driverless taxi operators have had their problems.

A Waymo passenger found his cab going around in circles in an airport car park.

An Amazon Zooks test vehicle had a minor collision with an e-scooter.

And in Tesla's Robo Taxi public tests, cars made driving mistakes and stopped abruptly, even when there weren't any obstacles.

It's also worth saying that, unlike the other driverless cars, Tesla's guidance system is camera-only, no LIDAR or radar.

Meanwhile back here in the UK the government wants to play catch-up with the US and China.

Our Automated Vehicles Act gained royal assent in May last year and the government is fast-tracking commercial trials.

Self-driving taxis and even buses could be with some of us around spring 2026.

Plenty of technical and regulatory challenges lie ahead, of course, not least of all public acceptance.

I'm quite a taxi driver fan to be honest.

So persuading us all to entrust our lives to taxis without taxi drivers, solving the plastic bag problem, may turn out to have been the easy bit.

Thank you, Gareth Mitchell.

Now, Tim O'Brien is still with me in the studio.

And Tim, you have been looking at some of the most significant science stories that have been published over the last couple of weeks.

And it's been a big two weeks for space, hasn't it?

Yeah, I mean, we mentioned it's the UK Space Conference in Manchester this week, but last week it was the National Astronomy Week,

National Astronomy meeting, in fact, in Durham, at the University of Durham.

So it's where all the or many of the astronomers in the UK come together and sort of, you know, discuss the latest science.

I was looking through some of the stories that have come out of that and I've just picked a few of those to talk about.

Excellent.

So what have you brought us?

So starting off really with a project that's sort of a bit close to home in fact because it uses some of the telescopes we operate from Jodrell Bank, which is the e-Merlin array of radio telescopes.

Okay, so this is a large array of lots of telescopes all over the world working together to yeah.

Well, e-Merlin are seven telescopes in the UK, right?

Um, so they're spread across about 200 kilometres.

Um, the signals are brought together and they allow us to produce much sharper images at radio wavelengths.

So, we sort of see the invisible sky with the sort of same sharpness of view as, say, the Hubble Space Telescope would do, for which it has to get above the atmosphere.

So, that's that's why we spread these telescopes apart.

But this particular project was looking at nearby stars and looking at the formation of planets around those stars.

About how planetary systems form.

Yeah, exactly.

So, we know, and obviously, we know that stars and their planets form from interstellar clouds of gas and dust, and they sort of collapse under their own weight.

And they form this sort of disk of gas and dust that gradually stick together, and then gravity sort of pulls them together.

So, they go from being like a few micron-sized grains to pebble-size, to boulders, to mountain-size, to planets.

That's the theory.

And we see

one end of that story we've known about for many years, which is the clouds of dust grain sort of size things.

We see that with infrared telescopes in particular.

And we see the other end of the story.

We've now, amazingly enough, found planets,

formed planets orbiting other stars.

But there's sort of gaps in the middle where we really need to understand it.

And this project was

the latest results on looking at the pebble-sized objects.

And the next story I see is about life on Venus.

I'm going to say life on Venus.

That's sort of a shorthand and a little bit of stretch, isn't it?

But it's something we've discussed before.

What's this about?

The story that we've talked about before is this possibility of whether there might actually be life in the sort of clouds of Venus.

Pretty extreme environment for life, to be frank, and quite a controversial topic.

But yeah, the proposal is to planning a spacecraft that will actually travel.

Well, in fact, it'll piggyback on another spacecraft.

There's a European Space Agency mission called Envision, Envision, which is scheduled for 2031.

And here, the proposal was to put a CubeSat, so one of these quite small micro-satellites on board this spacecraft, piggyback out to Venus, and then that would be specifically designed to look for these trace elements called phosphine and ammonia as well, which could be produced by life that might exist in the atmosphere of Venus.

Right.

So it's these, we've seen the signal of phosphine in almost from the colour, from signals that we can actually see in the atmosphere of Venus.

This CubeSat, this satellite that could be dropped off at Venus, would study that a bit more.

Would it be able to sniff at the atmosphere and actually detect it?

Well, yeah, it's not quite diving in there and grabbing it yet, but it's more close at hand with instruments that are specifically designed for that study.

So we've learnt more about these things over the years since this was announced a few years ago now, that this seems to rise and fall with the daytime temperatures.

So it's produced and then the sunlight sort of destroys it.

We've learned certain things about it, but I think a close-at-hand observation would certainly be helpful in this case.

So, more news about possible life on Venus in 2031, perhaps.

And finally, we have another interstellar, a very, very old interstellar visitor.

Tell me about this.

Yeah, I mean, this is just a discovery from just a couple of weeks ago, actually.

It was first noticed by a telescope called ATLAS, which is a survey telescope in Chile that's basically looking for points of light moving relative to the stars.

This telescope discovered this new thing not previously known before.

You measure its speed, the speed at which it's moving, and if that's greater than the escape velocity of the solar system, you know it's not sort of gravitationally bound to the solar system.

So it's come from outside the solar system, it's an interstellar visitor, it's going to fly through the solar system, whip around the sun and then head back out again.

And it's the third one of these we've found, only the third one of these we've found, yeah.

Wow.

So they're quite, you know, they're quite rare.

The more regularly and the deeper the observations, the fainter things we look at with our telescopes, the more of these we expect to see.

But this particular one looks like it may be because you can work out where it came from, in which part of the Milky Way, roughly, you know.

And so, from that, you can get an idea of its age.

And the suggestion here is that it was maybe the oldest comet we've ever found because it came from outs, it's older than our solar system.

It's seven billion years old rather than a sort of four and a half billion years.

How do we know that it's older than our solar system?

How can we put an age on that?

So it's it's just basically looking at the origin of where it where it came from in terms of the population of stars from which that trajectory sort of came from.

And just finding

when will it pass closest to us?

What do we what's this comet been named?

I'm sure it's got a really catchy name, they always do.

It's it's yeah, it's called three Eye

slash Atlas.

Three eye slash Atlas.

Three Eyes the third interstellar and the slash Atlas is who discovered it, so it's the Atlas Atlas telescope.

It'll come closest to the

Sun in October of 2025.

It's not coming close to Earth.

It's going to be about one and a half times farther away from the Sun than the Earth is.

It would be, if you've got a reasonably sized sort of amateur telescope at home, you might be able to see it in late 2025, early 2026 when it's nearer the Sun, so it'll be a bit brighter.

And I would just warn you, in case you see any stories coming up in the near future, it's almost certainly not got anything to do with aliens.

Right.

Despite some rather wild speculation I've seen online.

Well, that's disappointing,

but also good to get the evidence-based truth on that from an astrophysicist.

So, yeah, so amateur astronomists keep an eye out in October.

Well, thank you very much indeed, Tim O'Brien.

It is a pleasure having you on the programme.

And that is all we have time for this week.

Thank you to Tim O'Brien and to all of our guests.

You've been listening to BBC Inside Science with me, Victoria Gill.

The producers were Dan Welsh, Claire Salisbury, and Jonathan Blackwell.

Technical production was by Joe Stickler and Diffanne Rose, and the show was made in Cardiff by BBC Wales and West.

Next week, we have a special programme recorded with a live audience at the Hay Festival, where we explored what we can learn about language, culture, kindness, and conflict from the animal kingdom.

Until then, thanks for listening and bye-bye.

Sucks!

The new musical has made Tony award-winning history on Broadway.

We demand to be hosted!

Winner, best score!

We demand to be seen.

Winner, best book.

It's a theatrical masterpiece that's thrilling, inspiring, dazzlingly entertaining, and unquestionably the most emotionally stirring musical this season.

Suffs!

Playing the Orpheum Theater October 22nd through November 9th.

Tickets at BroadwaySF.com.