Sunlight Matters

Surviving Winter with Sunlight – A Conversation on Light, Health, and Infrared Science with Glen Jeffery, Bob Fosbury and Scott Zimmerman

• Dave Wallace • Season 1 • Episode 15

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In this companion episode to the Roger Seheult episode, Dave is joined by three experts—Prof. Glen Jeffery, Scott Zimmerman, and Dr. Bob Fosbury—to explore how sunlight and infrared light influence human health, particularly in the darker months when Seasonal Affective Disorder (SAD) becomes more prevalent.

Dave opens up about his own experience with SAD, leading to a wide-ranging discussion of how modern indoor lighting, architecture, and urban planning fail to meet the biological needs shaped by our evolution under the sun.

☀️ Key Topics Covered:

🌤️ 1. Sunlight, Metabolism & Infrared Light

  • Sunlight isn’t just about visible light; it’s packed with near and mid-infrared radiation that helps us metabolize food more efficiently.
  • Buildings and LED lighting systems block this critical part of the light spectrum, leaving our bodies in a state of "metabolic darkness."
  • Even on cloudy days and in indirect light, infrared exposure still provides meaningful benefits.

🧬 2. The Mitochondrial Connection

  • Mitochondria, our cells' energy centers, thrive in infrared-rich environments.
  • There’s compelling evidence suggesting that light exposure, especially infrared, directly influences aging, energy levels, and immunity.

🏡 3. Indoor Light vs Outdoor Light

  • Modern architecture prioritizes energy efficiency (e.g., LED lighting and infrared-reflective glass), but at a steep cost to human health.
  • Real estate sun studies and shadow mapping in urban design must now account for solar exposure and infrared access, especially in northern latitudes.

💡 4. Incandescent vs. LED Light Debate

  • All three experts agree: incandescent bulbs are far superior to modern LEDs in terms of health benefits because they emit full-spectrum, thermal light—including infrared.
  • LEDs emit light for vision, not for life. This has triggered a global metabolic health crisis, especially in developed nations.

🔥 5. Practical Tips to Survive Winter

  • Use incandescent bulbs indoors with dimmers (e.g., oven or heat lamp bulbs).
  • Spend time outside daily, even if it's cloudy—clouds reflect valuable infrared.
  • Install a small outdoor sun shelter or plastic greenhouse to maximize sun exposure.
  • Use a fireplace or candles to reintroduce thermal light into the home.
  • Saunas also provide therapeutic benefits through infrared exposure and vasodilation.
  • Reconsider the window design, indoor layout, and lighting strategy to optimize natural light orientation.

🌎 Broader Implications:

The discussion highlights how our evolutionary biology is deeply tied to the solar spectrum, yet modern society is stripping us of this essential relationship. There’s a pressing need for policy changes around building codes, indoor lighting regulations, and environmental design to restore sunlight accessibility in our daily lives.

Bob Fosbury:

We find the concept of infrared very difficult to deal with because you can't see it. We think of chlorophyll as being green, but if our eyes saw a little bit further into the infrared, the the chlorophyll would be brilliant red. In the summer, when we're surrounded by vegetation, we're bathed in huge amounts of near infrared radiation from the plants around us. Infrared radiation, which is uh extremely good for metabolic health.

Glen Jeffery:

We know mitochondria talk to one another across the body. They're very, very underestimated. They're doing it all the time. I don't know what they're saying, but they're doing it all the time. Most of the things that are consumed in your cell are going to be consumed by mitochondria. They've got unbelievable appetites. Your body temperature is partly because the heat that mitochondria run hot.

Scott Zimmerman:

The problem is that the government is getting involved in this process of science and they're putting restrictions in place. In 2028, this light bulb will not be uh able to be sold in the United States because the DOE is putting certain restrictions on. We're we're trying to do the science to convince the government to do something that they shouldn't be involved in in the first place.

Bob Fosbury:

We we've been told to improve energy efficiency in lighting, and incandescent bulbs are a waste of energy because they just radiate everything in the infrared, and that's of no value to the fish. And so we've introduced white LEDs. Now, that wasn't to make lighting more efficient and and spend less less energy, less money on lighting. White LEDs were so energy efficient that people put them everywhere on the planet all the time. We're using much more energy on lighting now than we were using when we had incandescence in in people's buildings and houses. Because everybody's gone crazy lighting the outside and shining all this energy off into space. We're we're not saving energy with white LEDs, we're doing quite the opposite.

Glen Jeffery:

We're all saying get an incandescent light bulb or the equivalent.

Speaker:

Welcome to Sunlight Matters, the podcast that reconnects us with the sun. Join us as we explore the power and influence of our star, the force at the heart of everything. Each episode, we speak with leading experts to uncover the ways sunlight shapes our world.

Dave Wallace:

Welcome to today's episode. Today I'm joined by three incredible guests, and we are gonna tackle a topic which is very personal to me, and that's how do you survive winter? So I suffer from sad or seasonal affective disorder, and it is one of the reasons that I've ended up doing uh the work I'm doing and investigating more about sunlight. So I'd like to welcome Professor Glenn Jeffrey, Scott Zimmerman, and Bob Fosbury to the show. So welcome, gentlemen. Um I'm not sure we need massive introductions, but maybe we could have sort of a word or two from each of you, and then we'll get started.

Glen Jeffery:

I'm Glenn, I'm Professor of Visual Neuroscience at University College London.

Scott Zimmerman:

I'm Scott Zimmerman, I'm an optical engineer. I've been working with uh two great guys for a while there.

Bob Fosbury:

And I'm Bob Fosbury, I'm actually an astrophysicist, but I've been working with Glenn Jeffrey at UCL for nearly a decade now. Uh so I have an honorary position at UCL for this work.

Dave Wallace:

So I guess I guess the background to this is you you, the three of you, have been really looking quite deeply at the impact of light and sunlight in particular on the way life functions. And, you know, obviously for us who live in the northern hemisphere, there is a difference between the summer and the winter. So, you know, in the UK, we've been blessed with a fantastic spring and summer, and I think we've had wall-to-wall sunshine. But as we head into shorter days, I can already feel my my sort of mood um getting worse, to be honest with you. And I can actually feel almost a kind of pain inside me when I think about those those long kind of winter days. So what can you sort of give any thoughts as to what might be going on in terms of um I guess the physiology and the psychology as we sort of head towards the winter months and those shorter days? So uh yeah, um any of you just uh just jump in.

Glen Jeffery:

Well, I I I definitely suffer from uh suffer from uh feeling just generally under the weather as as as we approach this period. Yesterday I was doing some calculations for a manuscript we were about to submit, and I I just had to go over the weather scenarios in London, and in last year in December, it was about 92% cloud cover. 92% of the time it was grey, and even worse, 100% of the time I was cycling home and it was dark. Right. So it's it's not surprising for an animal that has evolved on the equator in Africa, um, that this is not the right place to be. Definitely. Um, and um it makes it worse probably when we what we then we huddle into buildings, you know, we huddle into buildings where lit whatever little daylight there is outside is is locked away. So I think it's very, very common. I don't know what you you you two guys feel about this time of year.

Scott Zimmerman:

Well, I guess one of the things I'd bring up is I did a paper a long time uh quite a while ago on seasonality, and I think that there is the sad part of the the whole equation, but it has a bigger impact, even bigger impact on the fact that we get sick more. We have all these problems associated with during the winter. And there was this really interesting statement right before COVID that I found when I was working on some of the COVID stuff, is is that uh uh they the head of the CDC, one of the CDC uh researchers said that if we ever understood why flu season, why flu disappears in the summer, it'd be more effective than any uh influenza vaccine that we could ever develop. So it's a big issue, you know, wrapped around. I understand the sad part, but it's also a big issue uh associated with mortality. You know, the all-cause mortalities always spike at the in the northern hemispheres. And so when you start looking at that optically, there's a lot of things that we can do. And, you know, for us, my wife has SADs just like you do, and we have a little enclosure that has thin plastic, clear plastic walls that you just go to watch a football game or whatever in. And we'll take and set that out there with a sheepskin in the bottom and a rocker, and she'll sit out there and read a book for on a on a sunny day, and she doesn't do it every day. Whether when the sun comes out, she goes out there, and I always say my grandsons will come to the visit and they'll curl up in the corner under on the sheepskin and fall asleep. You see the same thing with animal behavior. There's always this intent to get as much of the sun into that time period as possible. And my concern is that we've created these indoor spaces that are exactly the opposite. We're blocking all the infrared content, the light sources have no infrared, we're spending our time exposed to things like this, you know, to a TV, watching TV at night. We also always have a fire going in our fireplace when during the winter, because it's a great thing. So that's my perspective, that it's kind of like, well, you want to f under have pay people be happy, you also need to do it to keep from getting sick.

Bob Fosbury:

So yeah, I think that that evidence for getting sick in the winter is absolutely overwhelming. And you know, one of our collaborators, uh Roger Schwelt in the US, has uh has a lot of evidence, along with Glenn with his studies of lighting in in in in in in in buildings, in offices, and so on. So I'm I'm very aware of this as a um as a person having to survive the winter. So I'm I I'm now very, very strongly convinced we understand pretty much why this is the case and why the absence of uh outdoor light is always important, but it's especially important in the winter. And that is because we're we're realizing that the way um the way your body your body energetics works, the way you metabolize food into energy to keep you keep you alive, um if you're in the darkness or in in in a in a building which doesn't have infrared transmitting glass and only has white LEDs, as far as the body is concerned, you're in essentially complete darkness. And in darkness, you can live, you can survive for probably quite a long time, but you won't have very much energy. You you you you have what's called the basal metabolic rate, which means the food you eat only goes towards keeping you alive, and it doesn't actually allow you to generate energy, much energy to do anything like think or walk around or run around. And um we realize by by by calculating this stuff that in sunlight there's always extra energy going into your metabolic process that will allow you to rise your raise your metabolic rate above its base level. Because the energy from the sunlight is allowing you to speed up your metabolic process and just metabolize your food more efficiently and faster. The sunlight is not directly giving you energy in this case, it's actually allowing you to m metabolize. The energy is still coming from the food, uh, but you metabolize it much more efficiently. And so, you know, if you're not getting any sunlight in the winter, if you're not getting any daylight, it doesn't have to be direct sunlight. I mean, there's a lot of infrared coming down in from the clouds and so on. A clear blue sky is quite dark, but clouds are still bright in the infrared in in in the daytime in the winter. In fact, clouds are your best bet because as you mentioned uh a while ago, the uh the the tree leaves uh can't give you very much infrared because there are few tree leaves around in the winter. So the the the infrared you get is often coming from the clouds. And that's much, much, much more than you would ever get inside in an LED lit room.

Scott Zimmerman:

I mean I think the other thing you don't understand is that um the ground itself is about 50% reflective throughout from the infrared clear out to almost five microns. So you get you do are even though it's not the same as the leaves, it's got there's there's a a component in the ground reflectance that you can't ignore either.

Glen Jeffery:

So So wrapping this wrapping these bits together, one point that people should perhaps pay attention to is even though it's pretty inclement out there and you don't it's not very appealing, walking outside in winter is a positive event. You know, you you may have to wrap up fairly well for it, but if we think that um a lot of our metabolism may be regulated by infrared light, well, don't think just because it's overcast there's no infrared there. There's actually a lot of infrared out there, and you should just go for a walk, even though it's not quite as appealing.

Dave Wallace:

So and and that's I mean, to me is fascinating because you know, I I guess I would have thought that going out on a clear blue sky day, you know, where the sun's out, you you would probably be getting more infrared or more sort of from the sun. But it sounds like because of what happens from a cloud cover point of view, that that that you're you're gonna be getting plenty, well, not plenty, but you're gonna be getting uh from the clouds as well, which is sort of to me is kind of a new insight. Um, because I think you know it kind of goes against what people would probably generally have in their head. Um but uh again, one of the things I'm learning is that you know we have to probably unlearn an awful lot of what we've learned anyway, um, in in order to kind of make sense of all of this.

Glen Jeffery:

Yeah. You know, the other thing to the the we we we we find the concept of infrared very difficult to deal with because you can't see it. Yeah, it's very important. The other thing about infrared, which is you know really quite unusual, is that uh okay, when it comes down from the sky, um, where does it go? Well, in actual fact, there's very little that's actually absorbing infrared. One of my biggest problems in some of the science I do is it's bouncing round everywhere. So, you know, it might be a cloudy day and you might have your nose stuck up against a brick wall, but there will be infrared light bouncing off that brick wall. And I've said this a number of times before. In some of my experiments where I need to control the amount of light in a room, I've actually had to wrap people's bodies in in aluminium foil. Because it's all over the place. It's it's if we if we could have an eye that saw infrared looking out there, it would be very, very bright. And so because there are no absorbers, even if you're walking along um and the grass has gone and the trees have got no leaves on them, the infrared is bouncing around you.

Bob Fosbury:

There's a very good reason for this, which is well known to astronomers, and we call it the chlorophyll red edge. And uh this became very fashionable after uh Carl Sagan um got the uh the Galileo spacecraft to look at the Earth from a distance. Um quite a long time ago now. There was a paper in Nature about it, uh more than a decade ago. Um and uh it was clear that the earth is covered in bright infrared patches, really bright infrared patches when seen from space. And those are the forests. Because because chlorophyll is transparent uh in the near infrared, and we think of chlorophyll as being green, but if our eyes saw a little bit further into the infrared, the the chlorophyll would be brilliant red because uh it uh it it lets the red light scatter around inside leaves and come out again, and uh that's a that's an incredibly powerful reflector. We call it a reflector, we should really call it a scatterer of infrared light. So in the summer, when we're surrounded by vegetation, we're bathed in huge amounts of near-infrared radiation from the plants around us. And in a way, this is a kind of collaboration between the plants and the animals because the plants don't need that infrared. It would be damaging to them because it would heat their leaves up and make them lose water. Uh so they they export their infrared as quickly and efficiently as they can. And when they do this in a forest, they bathe the forest floor in large quantities of infrared radiation, which they uh let through their canopy and then scatter down onto all the life forms living in the forest. And we know that in a rainforest, for instance, the the life is incredibly rich and diverse. And that's because they're continuously bathed in infrared radiation, which is for extremely good for metabolic health. So, you know, we are, under certain circumstances, in a very, very positive uh beneficial environment. And, you know, you think about forest bathing in in Japan. They know this is beneficial. They possibly don't realize why, but it's beneficial because you are bathed in large quantities of uh infrared radiation. And if you look at a tree, Glenn mentioned looking at the walls around him, the walls are relatively poor infrared reflectors compared to a tree and compared to grass.

Dave Wallace:

I mean, it's it it's interesting because I mean I guess leaves drop in the summer in the northern hemisphere and southern hemisphere. Mainly, yeah, the northern hemisphere. Um because the trees there there isn't the UV that they need, so there's excess energy there. I mean, uh and I could be talking out tern, but I guess um so they drop the leaves, therefore you don't get that infrared um effect from the leaves. But I guess the the plus side is without the leaves there, you know, living creatures then have more access directly to to the UV because they're not being shielded by the trees. Um so I I just sort of wonder if there's a sort of slightly different thing going on in terms of our relationship as as sort of uh creatures in in in the winter because of the way that the trees have changed because they've well, yeah.

Bob Fosbury:

The I mean the the reason that is good is because if you're living outside and all the leaves have gone, and leaves are very good at giving you infrared, but the sun is even better at giving you in infrared. So if you see the sky and especially if the sky's got clouds in it, you'll see a lot of infrared coming from the sun uh via the clouds. And so yes, just being outside in the winter is a an advantage in in some way, losing the leaves in some way compensates for their beneficial effects in the summer.

Scott Zimmerman:

Yeah, and and again, like I said, dirt itself is not uh absorb a hundred percent absorbing. And in fact, you know, ourselves, we ourselves are reflective like leaves. We have about diffuse reflectance on the order of uh, you know, somewhere up eight even to fifty percent. That is the skin, our skin itself. And yet what's been interesting is we've been going through this process where people looked at light, sunlight, and first said, Well, it's here what I can see with my eye. That was our first detector, basically. Now we're starting to get people are starting to get detectors that go out uh readily available that go out to a thousand nanometers. Well, that lets you see a little bit of the near infrared. Now we're finding that if all of us here, even though we're very white-skinned, we have very beyond a thousand nanometers out to six thousand nanometers, which sun provides, we are dark skinned with white hair. There's no difference because it's all water absorption. So as you go through that, we're kind of almost going through a process of expanding our view of the world, or at least sunlight. And the farther out we go, we're finding all these different things. And eventually we're radiating, we're setting our the body up to radiate into the back into space. So, as Bob's shown very well, is that you have sunlight coming in, you eventually have to get it back out. If you don't get it back out, it's just as bad as if you don't get it in. So it's a kind of complex interaction. But we're like I say, I had my two-year-old grandson out yesterday, and I had took the meter and I looked at him, and he was white as white. I mean, he was uh a child is uh like a a white, he he's whiter than a leaf is. It's uh in the near infrared. But if you go out in longer wavelengths, he's black as black. So it's it's not so simple sometimes, I guess, is what I'd say.

Bob Fosbury:

I think I'd I'd make the point, um, Dave, that you know, the reason we're all studying this is the fact that the lighting changed uh over the last few decades from the mid mid-20th century to the beginning of this century when we all had uh white LEDs for indoor lighting. And you know, that gradual erosion, well, very rapid erosion of access to the full spectrum of sunlight, uh has caused uh a crisis in metabolic health. And it's this crisis which has actually triggered all of us to do this research. And it's become very obvious to us that you know the life has evolved on Earth over four four and a half billion years, which is a long time. It's a third of the age of the universe. And all that time, the origin of life and the and the flourishing of life has all happened under a source like the sun, which we call a thermal source, it radiates because it's hot, and that has a broad spectrum, which is well understood by by physicists, it's a Planck spectrum, and uh the sun spectrum extends from all the way from the ultraviolet through to the mid and far infrared. And it it it's strongest in the in the visible near-infrared region in the middle. And uh that means that life has evolved to use all of this radiation for a whole range of functions. I mean, not just metabolism. Metabolism may be the really um important core one, but you know, we use the UV for synthesizing vitamin D. Uh we probably use the longer wavelength infrared for protecting our body against pathogens. And all of these things in between. I mean, they're too too numerous to list, but we're focusing on the metabolism. But um, so we're we're all accustomed to having to being illuminated what we call thermal sources. Well, you can list thermal sources. It's the sun, it's the moon reflecting sunlight, it's the fires, camp fires, forest fires, burning wood in your grate. That's a thermal source. A gas mantle is a thermal source, an oil lamp is a thermal source, a candle is a thermal source, a tungsten filament light bulb is a is a thermal source. An LED is not a thermal source. It's what we call a non-thermal source. And they've have been developed to only emit visible light. I mean, that's the whole raison d'etre for for LEDs to fit to emit only visible light for maximum efficiency at emitting visible light, which is great if you're just interested in seeing. But if you haven't, unusually to be interested in living as well, it's a disaster.

Dave Wallace:

If you're enjoying Sunlight Matters, make sure to subscribe and leave us a review on your favourite podcast platform. You can also search Sunlight Matters on Google to find more episodes, guest information, and further insights about sunlight analysis, solar exposure, and the way light shapes our spaces. It's quite frankly a disaster. Which is it it's so like I I I've I hear this and I understand it myself, but it seems so like a LED light seems so innocuous. Like the whole thing seems so innocuous. And I think this is why what you're doing, the all of you from a research point of view is so important, because it's sort of reconnecting us. So I guess one of the questions I've got is if we go back a hundred years, was there SAD because we had these thermal light sources, i you know, we had fires and oil lamps and candles. You know, I I don't know, I haven't looked, but I probably asked Chat GPT after this.

Bob Fosbury:

Did all you have to do, Dave, is look at pictures of people, you know, just at the public in the in the early part of the 20th century. They're all walking around and doing stuff, and then ask yourself the question how many of them had type 2 diabetes? How many of them were obese? And a whole list of questions. And Glenn can describe, you know, these diseases of aging that that that are dependent on the way you metabolize.

Glen Jeffery:

Very very dependent on light. I mean, quite simply. Most disease, most metabolic diseases kick off in winter. You know, it's it's it's the data are all out there, the stories are all there. Um that it is an absence of light that is associated with uh initiation of disease and other diseases may actually suddenly turn up in spring, and you think, oh well, hang on, this is this this disease has turned up in spring. No, it was initiated it it was initiated in winter. And a fundamental kind of point which I grumble about continually is we shouldn't be here. You know, we should be back on the equator. Why, in God's name, do I live in Archway in North London? I shouldn't be here. I should be somewhere with a 12, 12 light, dark cycle, and it'd be relatively warm all the time. Our migration patterns have just taken us to inappropriate places, and we think, well, you know, we've been here for a long time. Well, in terms of human evolution, whether it's four or three or whatever million years, my move to archway in North London is a very, very small percentage of that. And in many senses, my the evolution of my body has not got ready for archway. Nice. You know, it's still it still thinks it's somewhere in Ethiopia.

Dave Wallace:

I and you you know, I guess it's even shorter the time from sort of incandescent to LEDs. So we're talking about the last 10, 10, 20 years and I sorry, sorry.

Scott Zimmerman:

And I guess I'd put make the point that based on Glenn's work, it doesn't take a lot of change based on the amount of energy that we need to input in on a regular basis. The problem is how do you get it in there on a regular basis? You know, it the body seems to be able to adapt to a higher light environment, and for a couple days it's okay, maybe five days, sometimes longer. We have this problem of inconsistency of getting the right spectrum. It's and I think there's a lot of people will poo foo what we're doing from the standpoint of saying that, well, you're never going to bring the intensity level of outdoors indoors. Well, that's true, but we are literally, and Glenn's literally showing that very low levels of exposure, if done improperly, throws off the balance of the body. The body is adapted, assuming that it is exposed, as Bob says, to a broadband thermal emitter that covers it. And every time we look at a different part of the solar spectrum that's been ignored, it's doing something and affecting our ability to essentially thrive.

Speaker 6:

Yeah.

Glen Jeffery:

I think the important point there is you don't need much to have a significant improvement. You know.

Scott Zimmerman:

I don't want Glenn to have to move to Ethiopia right now. Come on.

Dave Wallace:

It's a very beautiful country, I have to say.

Bob Fosbury:

So um You don't need much because zero is very little. And if you're starting from zero, a liturgy is a lot. Well, Glenn is a lot.

Dave Wallace:

You'll you'll be pleased to know that um I packed off after our last chat, I packed off my son to university, and my parting gift was uh an incandescent bulb, which uh and I said, look, you're probably not gonna see the sun for the next three years, but you know, at least get this. So he's dutifully put that into his uh his Angle Poise lamp.

Glen Jeffery:

So I give I I gave a load away last Christmas to my relatives. I gave them, you know, presents. Everyone got an incandescent light bulb.

Scott Zimmerman:

That's really interesting. And I and I and I have a company that uh that does incandescent light bulbs and LEDs combined for exactly this reason.

Bob Fosbury:

So if you if you can't find one of these, because you can't buy incandescent bulbs easily these days, this is a lamp that goes in your oven. And you can't put an LED in an oven because it gets too hot. So you still have to have an incandescent bulb in an oven. So you can buy these, they're 40 watts. They cost about two pounds. And I use this all the time. I use it for my bedside lighting, I use it for my study lighting. It's 40 watts, and I run it dimmed uh to make the filament last longer. If you if you dim it slightly with a with a rear stat, the filament will last forever. And it costs nothing. And the the beneficial effects of these are enormous. I use them to heal sores on my legs. Just You know, the total cost of the whole system is two pounds for the lamp, nine pounds for a dimmer, and an old angle poise lamp, and that's all it costs. You don't have to spend six thousand pounds on some fancy LED light, red light, in order to to survive. You know, I the the important principle here is we use energy for environmental purposes in buildings. We use energy for heating buildings and we use energy for lighting buildings. Now heating is a complex problem because if you you know if you've got a glass building in the summer, you get too much heat in it, and you have to keep the heat out in order to keep the environment in the building reasonable. And this is why glass manufacturers uh produce infrared rejecting glass. It both heat keeps the heat in in the winter and keeps it out in the summer, which is the these are laudable design goals. But the trouble is if you keep the infrared out of the buildings, the the buildings are infrared dark. And what if you're if you're trying to maintain the environment in a building, I think the the the protocol is very simple. If you fill it with incandescent light bulbs, people are going to complain that you're using too much energy for lighting, and that's true in a sense. So use perfectly okay to use white LEDs in in places where you just need to walk through, like corridors, stairwells, um, freezer, freezer compartments in in buildings and so on. Uh, anywhere where you don't have people residing for long periods of time, using these white LEDs is fine for vision, just to enable you to see. If you're working in a building or living a long time in in a space, then you need infrared uh an infrared component. And the point is, people will complain that the infrared component is using is wasting energy. If you use an incandescent light bulb, it's wasting energy because it produces very little visible light and lots of infrared light. But it's keeping you alive. So it's not a waste of energy. And take the money, goodness sake, take the money out of the heating budget. Use the incandescent bulb to heat the building. Not completely heat the building, but it's a heat input to the building. So any heat you're using to drive an incandescent bulb is serving the positive function of keeping people healthy. It's also contributing to the heating of the building. So in the winter, especially, use incandescent bulbs wherever you can where you have people. So you shine the light through the people, the people will excrete the heat back into the building and heat the building. So but you're passing part of your heating through the body. And when that infrared light progresses through your body, it dissipates and it keeps you alive. That's what keeps you alive. So always always associate, always associate the infrared emitters in a building with the people. Don't bother where there are no people, but get the lights to follow the people.

Dave Wallace:

So I guess if you're in an open plan, oh sorry, Bob, I was just gonna say you're in an cost out of the heating budget. It's very simple, straightforward. But if you're in an open plan office, like, you know, and they don't have incandescence, then just buy a cheap and you're worried, just buy a cheap angle poise lamp, take an incandescent bulb in with you, and pop it on your desk, you know. Yeah.

Glen Jeffery:

You know, you got three guys here who you introduced us as experts. Um my mum says things like that. Not many other people do. But you've got three people here who spend a lot of time probably not agreeing with one another. I you know I you know, I kind of find something out about metabolism, and Bob comes in and says, Oh, that's because there's a pulsar somewhere in a distant planet, and that's doing everything, and and and even worse, he walks out of the room and said, We all knew that. But you've got three people here who are all actually singing the same tune, as far as anyone that listens to us. We're all saying, get an incandescent light bulb or the equivalent. Okay? Scott's manufacturing something which does that. The light, this light is coming from a window. This light coming from this side is from an incandescent light bulb turned down incredibly low with a dimmer switch, exactly what Bob said. So if you've got people listening to this podcast, and these we've got these those three experts, they they are all actually saying the same thing. Go and buy, go and get a light bulb. Certainly in the UK, you can get them very easily. And Bob's got a mega one that's been on steel.

Bob Fosbury:

Well, the thing is, that this is interesting as well. This is an old-fashioned heat lamp. You know, you used to be able to buy these. You still can actually in the market. You can still buy these. So they're an incandescent bulb, which have a red filter over the front to make them look red. But forget the red filter, it doesn't matter. I use this in my study in the winter, struck or or clamped onto my my desk over here, and I run it at very low voltage. I mean, if you turn this thing on full, it'll it'll it'll fry you because, you know, it uses a it uses a couple of hundred watts and it will fry you. But you don't need all that. You just turn it right down with a rear stat. So it just glows slightly, and it heats my room. I have the radiator off in my office because it's on the back of my thermostat. If I have my radiator on, the rest of the house freezes, so I have to turn my radiator off. So in the winter I use this in my office, just shining on my body from behind. It doesn't glow very bright, it just looks at uh a red filament. And there's heaps and heaps of infrared radiation coming from this, and it's perfect for uh Yeah.

Dave Wallace:

Well, when you said you don't need the red filter on top. It's the more the the incandescent well, the temperature. Yeah, yeah.

Bob Fosbury:

I mean I mean the red the red filter on there is just for show. Right, okay. It serves no purpose other than warming warming the bulb up because you're absorbing the visible light. But it's it it's no function there. It's a heat lamp. And and you, you know, it's a it's a very powerful filament, but you don't have to run it anything like full power. You just run, you know, trickle, trickle the energy into it. It's probably uh I probably only use it for 40 or 50 watts or something like that. Still more than an LED, but it's keeping me alive, yeah. If that's an advantage.

Scott Zimmerman:

So still one of the frustrations about this whole thing is that you know, I'm in the in the lighting industry. The lighting industry has all the technology necessary to solve this problem. But what's getting in the way is things like they pass this rule change that you have to have X number of lumens for watt, that, and so that and take it all away. You know, so like in our particular case, there's our incandescents and there's our LEDs, because in reality, if I truly want to match sunlight, an incandescent has too much infrared and not enough visible, and an LED has too much visible and not enough infrared. So you do a hybrid, so that way you know what you're getting when you have the thing. It doesn't mean that any of the other approaches aren't good to do. You go get an incandescent. The problem is that the government is getting involved in this process of science and they're putting restrictions in place. In 2028, this light bulb will not be able to be sold in the United States because the DOE is putting certain restrictions on. And I think the real problem is that there's these silos in the governments that all we care about is doing it this way with the hybrid approach, it's a closer match to sunlight, and it gets five times more efficiency in lumens per watt than just an incandescent. But it works just as well to put an incandescent in. You'll get a variation, but it'll bounce around and all that other stuff. But you know, unfortunately, the science, we're we're trying to do the science to convince the government to do something that they shouldn't be involved in in the first place. So yeah.

Dave Wallace:

Yeah, so and they I mean again, we've got, like I guess in the UK, this whole thing around net zero, wars, LED light here.

Scott Zimmerman:

You know, I mean, it's it's it's not just the UK, it's across Europe and you know, well, literally every and Glenn and Bob have been talking to architects left and right from the standpoint of the architects understand this, but they're stuck because of lead requirements and all these energy requirements. That near infrared blocking glass is part and parcel of how they get the efficiency numbers they want. But they don't ever include the health negative health benefit costs associated with what they're forcing the the architects and the uh the industry to do.

Bob Fosbury:

Dave, just a point about the um the energy efficiency thing. We we've been told to improve energy efficiency in lighting, and incandescent bulbs are a waste of energy because they just radiate everything in the in the infrared, and that's of no value for vision. And so we've introduced white LEDs. Now, that was a the idea of introducing white LEDs was to make lighting more efficient and and spend less less energy, less money on lighting. What did we do? White LEDs were so energy efficient that people put them everywhere on the planet all the time. And so we're lighting the outside of the planet, outside buildings, incredibly brightly all the time. We're using much more energy on lighting now than we were using when we had incandescence in in people's buildings and houses. Because everybody's gone crazy, lighting the outside and shining all this energy off into space. All you have to do is to control outdoor lighting, use outdoor outdoor lighting sensibly. You're much better off for security if you have low-level lighting outside. Because if you blind everyone with these bright uh white LEDs, enormous power, you create these huge shadows that, you know, people, bad people can can can move around in. It's been well demonstrated in many cases that the security is better under low-level outdoor lighting. So, you know, we're we're not saving energy with white LEDs, we're doing quite the opposite.

Dave Wallace:

And I guess going back to the you know, I'm trying to kind of close this off because, you know, I guess we could go on and on about this because it I mean it fascinates, the whole thing is fascinating. But I I shared some research yesterday that they did um using Apple Watch detectors. So basically people the Apple Watch can say how much daylight you've been exposed to. They looked at 53,000 people in the US. And I think the average time in sort of January that people were outside was like 20 minutes or something like that. So that means the rest of the time they were inside probably under LED light. So to your point around all of the the the mitochondrial and metabolic, I mean, this is why this is so problematic, isn't it? So you know, I mean, again, listening to you today, like I I genuinely had no understanding that it was cloudy, that you can get access to infrared. Um, you know, I was puzzled why my mum and dad were saying, you know, let's go for a Sunday walk or something like that. But, you know, intuitively they they knew that was the right thing to be doing in winter. So, you know, just getting people outside a lot more in winter is is kind of super critical. But if you are inside, it's that you know, thinking about mixing up your lighting with incandescence.

Bob Fosbury:

I'd make another remark about the winter. It's often thought that, you know, we we have to take vitamin D supplements in the winter because we don't get any from the sky, from the sun. Now I mean in in a sense that's true, but not for the reasons people think. Uh in the winter we don't get very much the ultraviolet for uh the vitamin D wavelengths in the winter when the because the sun never gets high enough in the sky. So the direct path from the sun to you doesn't give you ultraviolet. But on the other hand, the path of sunlight to the higher atmosphere and the clouds, the high clouds and so on, and the upper atmosphere can scatter UV radiation down on you from above, which is a supplementary path for getting UV to you in the winter. And you do get significant amounts that way in the winter. Right. In fact, you get something like it with with a with a normal sun high enough to give you some UV, you're getting about half the UV directly from the sun, and you're getting the other half from the sky, mostly directly above you. So the fact that you need vitamin D supplements in the winter is not so much that you don't get ultraviolet in the winter, it's the fact you cover set cover yourself up in the winter, obviously, with clothes. And the clothes are opaque to ultraviolet. And I should mention, having said that, that clothes are transparent to the infrared. Right. So if you want to get infrared from the sky, you don't have to disrobe, uh, you know, wearing normal light clothing. You get the you get the infrared going straight through. So infrared, clothes are nothing to infrared. In fact, Sony stopped selling infrared cameras in the early 2000s because they realized that clothes were transparent and it didn't do much for their reputation. They were afraid of being sued.

Scott Zimmerman:

Yeah, but I think you have to start separating out somewhat what you're getting from the benefits of outdoors and what you're getting from uh what we're putting people into now in their indoor environment. You know, what is it, five minutes a month outdoors for someone in a nursing home or whatever. But what you're taking them into is something that's not good. You know, it takes very little exposure to LEDs to start seeing some negative effects, just like Lens showing, add a little bit of infrared back in, and all of a sudden the ATP process increases its efficiency, CO2 levels increase. So part of the problem has been that there's been this isolation of what are the downsides to LED because it's not just sitting there that you know it's passive, it's actually creating a problem because it's throwing off this imbalance. Because every one of the processes in the body are essentially under the understanding that you're exposed to something that emits from 280 nanometers out to six microns. And you start playing games with that, you start messing, you can have a negative impact on on what uh you know our health. And that's what I think Glenn shows so well with some of his tests that he's been running.

Dave Wallace:

I mean, it feels like there's a there's an urgency around this from a message point of view, because our older people are going into homes. You know, I've I've seen it with uh you know my parents and uh my grandparents, you know, going in. You know, so there's that, then you know, I guess there's things like schools as well. So schools are you know, you go into a school and they're gonna be lit by LED, you know, maybe that's impacting people's ability to learn. You know, I think Glenn, we talked about hospitals are particularly um terrible places for kind of uh for for LED lighting as well. So the very place where you want people to be finding sort of therapeutic uh benefits from light are the very places where where they're kind of not getting it. So, you know, I think again there's an urgency, and I if winter can kind of help focus that, because as you uh Bob, you said that the higher case mortality in winter is the the stats are there, then that's kind of a uh it's a good thing that we're kind of really looking to get this this promoted out.

Bob Fosbury:

There are there are two I think there are two metabolic problems facing the planet at the moment, and they're both serious. One is ultra-processed foods, and there's a lot of discussion about this. This is very much in the public eye, you know, the the disbenefits of uh of ultra-processed food. And I think, you know, while that's a complex problem, the the the the what it's doing is very simple, uh, and that is, you know, your food, you're eating food to keep yourself alive. I mean, the fact that you're using the food to give you energy to do stuff is is is true as well, but that's incidental. The process of eating is to keep you alive, it's to keep you from uh becoming the same temperature as your surroundings, and I uh uh in other words, being dead. And uh and and so if you're eating food which you cannot metabolize, you're not keeping yourself alive. And the problems with ultra-processed foods, I I mean I I'm wary of saying this in public, but I I think it uh it's absolutely true. Ultra-processed foods don't contain what you need to stay alive, and that's highly ordered foods. You're you you you you have to eat high-quality foods that are highly structured and also have a high energy content, but are structured in such a way that you metabolize them at the right place in your gut. And ultra-processed food is almost completely disordered. It doesn't have any order in it at all. All the order's been taken. We call them maximum entropy food. They're maximally disordered. And so ultra-processed foods on their own are essentially of no nutritional value. They're not what you need to keep your body working properly and alive. And, you know, the the consequence of doing this is you, of course, you you run into type 2 diabetes, obesity, and all of these things. Now, the other aspect is what we've been talking about, is the light. And this is very closely related to the food. It's not unrelated to the food. These two factors, they're working together as a perfect storm. Because the light, the absence of the light does not allow us to metabolize properly. Well, I mean, in a way And the food will not metabolized the ultra-processed food will not metabolize properly. So we're we're giving ourselves a double whammy. We're stopping ourselves uh metabolizing properly in two different ways simultaneously.

Dave Wallace:

I mean, in a in a way, we're using ultra-processed light, aren't we? That's the problem. So you've got food and light, which are both ultra-processed, and the the the the two of them together are a heady combination, but you know, nothing good comes of it, does it?

Bob Fosbury:

Exactly, exactly. And I think that's the point to make. Because if you if you look at the ultra-processed food issue, it's in the public eye all the time, especially in this country. I don't know so much about other countries. It's in the public eye. All the nutritionists talk about ultra-processed food. As far as I'm aware, none of the nutritionists talk about light. Light is the more fundamental of these two things, I think. It's you know, it's the thing which is is really designed to drive our metabolism. It's it we've evolved to use light to metabolize. And so, in a sense, this this metabolic pathway using light to metabolize is sits right there alongside photosynthesis. Photosynthesis uses photons of sunlight to make the food that we eat. The food that we eat is metabolized properly using uh infrared radiation from sunlight. The photosynthesis uses the visible spectrum, the metabolism uses the infrared spectrum. And these are parallel paths, they're in some sense mirrors of one another. And so if we don't have both these paths working properly, we're in bad shape.

Dave Wallace:

No, it's it's very interesting. Very interesting. So Glenn, I had a question which is, I mean, you may or may not be able to answer it, but it's just something which I I've been pondering. Well I was born in the tropics. Uh so you know, my first experiences as a child were sort of equatorial, basically. So I was born pretty much bang smack on the equator, and then lived for a time in the tropics in Fiji when I was growing up as well. So my early years were all very much dominated by uh 12 hours of sunshine, 12 hours of dark. And I do sometimes wonder whether that early experience sort of tuned my body up. So when I get sad, it's a very profound, very, you know, really visceral experience. I I sort of wonder if my mitochondria might re remember that. So I, you know, I don't know, maybe that's just a daft question, but because you're here, I it it is it's not daft at all.

Glen Jeffery:

I'm beginning to think quite seriously that mitochondria have got really good memories. We know mitochondria talk to one another across the body, they're very, very underestimated. Now, the one bit of science that I bring to that situation is a very unusual piece of science, and that's that children that are born in the Arctic in winter months grow up with very different colour vision than those that are born at other times of the year. Now, colour vision is highly dependent on mitochondria. A vision uses more mitochondria than any other part of our body, it's got the highest metabolic rate, ages fast, etc. And that paper came out, I don't know, maybe 10 years ago. We all sat down and we read it, and we went, God, this is this is a solid bit of science. It's a really solid bit of science. What the hell's going on? Okay, what is going on? So I would say to you that that is a bit of evidence that is very solid that is saying to you something is remembering where you were born. Okay, so Arctic in winter, extreme reductions in light. Okay, and also it's not just dark, it's very, very deep blue. Right? So maybe mitochondria have got memories. You know? I think it's an absolutely fascinating idea. The more we find out about mitochondria, the more we realise that they're running circles around us intellectually.

Dave Wallace:

No, I I I mean it I and so the other the other one was my my mother was half Italian, um, my father was sort of English-Scottish, but my mother was half Italian. And I I I believe you inherit your mitochondria from your mother, don't you?

Speaker 6:

Yeah.

Dave Wallace:

So, you know, my my my mitochondria are sort of half Italian, where the the rest of me, you know. So I I wonder if there's a sort of genetic imprint into mitochondria as well, which is so but you you know, you're you're a highly complex individual born in Fiji with an Italian mother, a British father.

Glen Jeffery:

I mean, you know I mean, born in Fiji, fantastic for you. Um but humans, I mean they're they're so diverse, they're so different. It's why people work on mice that are all the same. Um, I don't know, but the idea that mitochondria have got memories, yeah, you know, but there's a lot of people that are gonna are gonna really dislike that idea. But there again, there'll be lots of people not very long ago that would say to you, mitochondria never talk to one another. And they're doing it all the time. I don't know what they're saying, but they're doing it all the time. I thought upset them in your finger here, your toe knows about it the following morning.

Dave Wallace:

Yeah, no. I I'm um way as well as reading scale that Bob suggested, I'm also reading uh quantum biology by by Jeffrey Guy, which I'm finding fascinating, but you know, the more I read it, the more I think we really do live in a magical world, you know. I don't even know how you would describe it. So, you know, to me, mitochondria having memory is, you know, perfectly would make perfect sense. So I I love the fact, and I'll look up that paper around uh the coloured eyes, because I it's sort of that's fascinating.

Bob Fosbury:

Of course, the the of course the mitochondria were at least the the mechanisms in the mitochondria, the the things that produce the energy evolved very early in life, much earlier than people thought before. The recent understanding is that these uh these this enzyme that produces uh ATP, the energy uh the energy for the cells, was around long before multicellular life started. They were around during uh the very early um unicellular uh uh population of the earth. Probably going right back to very close to the beginning. I mean, I had no idea how something so exquisitely complicated to have evolved so early, but it's it's an amazing, it's an amazing story. So this is all, I I have to say, all of what we're talking about, offices and lighting and incandescence and so on, is much more locate uh much more um concerned with um the much bigger picture of how the universe has evolved. My recent talk, but I I've I've learned this very recently, but there's a much closer connection between the whole uh history of the universe and the role of life within that. And life is not a freak occurrence, I don't think. Life is an an inbuilt potential in in in throughout the universe through a very straightforward, simple physical process.

Dave Wallace:

So there's a I've found a really interesting new card before I'll forward it on to you, which sort of builds on that idea. So I I wanted to go back to surviving winter because um what one uh one way that I cope is with saunas. I I'm sort of fascinated by saunas in in their own right. So, you know, I do a lot of swimming and I'm lucky because the local Lido has a nice sauna, and I found saunas are a really good way of kind of improving my mood in winter. Um is that because of the infrared that you get from a sauna? Is that sort of helping with things? Um, I just wondered if you've got any thoughts about what's going on. And then the other thing is culturally, I guess in northern the northern hemisphere, uh saunas have been things which are very popular and particularly sort of used in winter. So I just wondered if there's any thoughts that you uh any of you may have around the idea of saunas at all.

Glen Jeffery:

They um well, they say uh that's there's there's a a very interesting chap called Jonathan Stone in Australia. Uh he's very eminent and he always comes out with ideas that are different from anybody else, and you find out they're true afterwards. And he said um, you know, that the killer in life is the pulse, the pulse of your heart as you get older, because your blood vessels are stiff, and and um one of the things that you know he points out is saunas, which dilate your blood vessels. You know, why is it that, you know, people that take saunas on a regular basis actually tend to have rather good outcomes in terms of life? So we can think about mitochondria, but also when you dilate your blood vessels, you're getting more nutrients to the cell, and most of the things that are consumed in your cell are going to be consumed by mitochondria. They've got unbelievable appetites. You know, you you your body temperature is partly because the heat that my mitochondria run hot. Well, now we don't know how hot they run, but they're certainly more than 37 degrees, and some people out there are saying it could be close to 50 degrees. They are Yeah, yeah, they are hot. So the pulse, the dilation of blood vessels, saunas certainly seem to be s associated with longevity. Um and keeping your blood vessels flexible so that they can contract and expand.

Dave Wallace:

So I mean, going back to the whole point of that Bob made around lubrication of the metabolic process from light, it sounds like something the sauna themselves because of sort of vasodilation, sort of forcing things into Yeah, and then and then jumping naked into ice pools.

Glen Jeffery:

You know, it sounds it sounds absolutely bloody horrendous. However, from a term from your physiology, I'm sure it's doing you a lot of good. I I'm not going to do it myself, but it sounds, it sounds that they probably are.

Scott Zimmerman:

Well, I think also that you have to understand that when you look at a sauna, when you go into a sauna, you're getting, you know, we have sunlight that's 58,800 Kelvin. You got a sauna that's at least some part of it is heating up and providing infrared component into this whole equation, too. So that I I'm working on a paper where sunlight and saunas meet. Um, because it's in the longer wavelengths, you know. If you look at it, uh so one of the arguments is or one of the things I found was that for every one degree of fever that your body uh generates, it's a 10% increase in your metabolic rate. So when you go into a sauna, you're essentially providing a high level of not only uh of these longer wavelengths in the infrared where you're clearly absorbing. And so I would argue that that the optically there is a benefit associated with extending or bringing that extra longer wavelength component into. And like I say, I keep on we keep on moving further and further into our understanding of what wavelength range sunlight provides. You know, for a long time people just said, oh, there's nothing going on beyond a thousand nanometers. And if you look at a standard spectrum that's used in watts per meter squared per nanometer, you see everything peaks up, and then you see this little tail. What Bob and I have been working on is basically saying, but wait a minute, if we truly are a solar collector, you need to put it in terms of electron volts. When you do that, all of a sudden these longer wavelengths become much more important looking. And, you know, we're catching a lot of flack because of saying that this is a way to look at it. But the reality is that those longer wavelengths, the highest density of photons in the body occur in those longer wavelengths because of the way they're absorbed in the outer part of the skin. I told you the skin is black from 1,000 out to 6,000 nanometers. So there's a lot of things going on optically, and when you're going into a sauna, you're essentially doing exactly the opposite of what you're doing when you're walking into a room with near infrared blocking glass and uh LED lighting. So I think there's a real reason that saunas have a benefit. And the other thing you have to take into account, you were talking about your your background with uh where you grew up. Imagine the people that had moved with dark skin up to higher latitudes. You know, during COVID, a black African American was 40 times more likely to die of COVID than a sub-Saharan African. So these are big issues that we're trying to deal with and understand because it's affecting basic health. I mean, Glenn does his experiments. It's absolutely mind-boggling to me that it took Glenn after all these years, as far as I know, he's the first that actually compared an LED to an incandescent on anything. You know, as far as the biological markers. And that's why I think they're so important what he's showing. And it's clear that the longer wavelengths that we got rid of, because we got rid of 90% of the spectrum, as such, it's having a negative effect on our health, is my opinion.

Dave Wallace:

I think it's I mean, it is mind-boggling that you know this is this is uh a new area of research. I mean, it is absolutely I can't quite get my head round it. Um but I think you know, so often in in sort of history, people have been looking the wrong way when things have been going on. So you know, like the the the story of Scurvy's fat, you know, it took them they kind of knew what was going on, but it took them a long time with scurvy.

Bob Fosbury:

Hundred years. Hundred years before the Navy fixed it. Yeah.

Dave Wallace:

So I I I mean again, I've this is a another uh sort of crazy thing to ponder. But one one of the other things about being in northern latitudes is snow cover. And you know, Bob Scott, I don't I don't know have you sort of thought about snow cover at all in terms of you know what it does from a from a a kind of light point of view? And I guess the reason uh like it's a slightly tongue-in-cheek, but I I've I've sort of often wondered why one of the reasons that that the British set sail in the first place is our weather's so lousy here, because it's like neither one thing or the other. So, you know, why not go off and find other places in the world where the sun shines brightly? Um but if you go north and you get snow cover, and you know, do you do you see any difference in things like all cause mortality as you go further north? Or you you know doesn't matter.

Scott Zimmerman:

It definitely changes the spectrum. It does change the spectrum because uh snow tends not to be as reflective as uh it's more reflective in the visible than it is in the the infrared. But again, we're also still talking about a narrow band. There's longer wavelengths that we actually don't really have much information on. That's been one of the big problems for this whole thing. Most people can't measure, most labs can't measure. You know, when we did our bulb, we measured out to 3,000 nanometers. There was only one lab in the entire country that we could find that could measure out there. And it cost us like three grand to measure that spectrum. Now, you know, the astronomers, they know all this stuff left and right, but the lighting industry is kind of doesn't have the capability to even measure out in some of those places. So, you know, a lot of the questions that you're talking about are kind of fundamental that we don't have the answer to all of them.

Dave Wallace:

So interesting.

Bob Fosbury:

Interesting. So I think I don't know how much longer you have, but there is one aspect about going to high latitudes, which I think is often overlooked. And uh I think um uh Glenn went on about this a moment ago, about not wanting to be in high latitudes. But actually, high latitudes offer do offer an advantage to animals which are metabolizing to produce energy. And that's purely a thermodynamic advantage. I mean, you're some of your audience will have heard of heat engines and the Carnot engine. And there's uh something which is well known Nicano efficiency. I mean, how how efficient a steam engine is or a heat engine and uh another kind of heat engine is. If you move to high latitude from the equator, you're exposing your body to a much colder environment. And the amount of useful energy you can produce by metabolizing your food is firmly limited by the temperature difference between your body, 37 degrees, and your surroundings. You, I suspect, are sitting in a room which has a a a wall temperature of probably 21 or 22 degrees centigrade, and your body is at 37. That's a relatively small difference. And that means you cannot produce more than 5% of your metabolized food. You cannot convert that into useful energy. It's thermodynamically, it's the second law of thermodynamics, it's thermodynamically impossible for you to produce more than 5% of your of your 2,000 calories in terms of energy. This is why it's so hard to get slim by doing exercise, because, you know, you you're using almost all of your metabolized food to stay alive, and you're using a tiny fraction of it uh to think and move around. And if you go to high latitudes, you can expose at least the inside of your lungs, uh, breathing cold air, and the inside of your lung is what? It's a surface area, roughly that of a tennis court. So you're transferring an enormous amount of energy through uh inhaling and exhaling, even though you're wearing warm clothes. And if you the Fuegian Indians who lived in Tierra del Fuego, they were running around naked in temperatures of ambient temperatures, say five degrees centigrade on average. And they were, they had huge amounts of energy because they could metabolize more than twice as efficiently uh than we can sitting inside inside an office. So there's a thermodynamic issue here, as well as the photon-driven metabolic issue we've been talking about, pure thermodynamics, very simple thermodynamics of human bodies. This is why when you walk outside in the summer and you sit in the shadow of a tree surrounded by blue sky, which you can see, you've you've hidden the sun under the tree, behind the tree, but you're sitting surrounded by blue sky. That blue sky is at minus 50 centigrade. And it allows you to export your your waste heat much more efficiently, and it means you can produce more than twice as much useful energy in that environment than you can sitting inside an office at 20 degrees. This is a huge effect, and this is why you feel so good when you go outside under a clear sky in the summer and you're in the shade. Best place you can be.

Dave Wallace:

Very, very sorry, I I I spoke with someone last week who said that in winter, one of the things to do, he said, if you don't like the idea of coal plunging, which I'm I'm with Glenn, I can't stand the thought of it. Although I have been just been invited to do an ice swim in in Finland in 25 metres in which I I don't think I'll be doing. But he was saying just you know, if you can go outside in a t-shirt and shorts on a cold day and spend sort of five, ten minutes outside, um, you know, because he said that sort of will get your metabolism kind of kicked off and stuff like that. So look, it I mean, I don't but that's sort of a bit try, but it sounds almost along the lines of what you're talking about in terms of it is exactly exactly, and it's very, very simple.

Bob Fosbury:

It's a f it's the simplest mathematical equation you can think of. It's one minus the temperature of your surroundings over the temperature of your body. But you have to express those temperatures in absolute temperatures. So your body is not 37 degrees, it's 310 Kelvins. And similarly, the temperature of the surroundings is 200, uh 300 and whatever it is, 300 degrees. So um now this is this is the simplest possible uh uh mathematics of thermodynamics, and it tells you this profound thing that you have much more useful energy available if you're in a cold environment. So if you're an office worker, you should be in a cold office and wear a warm jacket. You get much more work out of you.

Scott Zimmerman:

Well one of the one of the things that was has always been fascinating about this area of work is that you'd have thought that we'd have thought through this a little bit and we'd understand how light propagates into the body and you know where where it's going, where it's localized. And you know, when I first got involved with this stuff, it it was just amazed me that 99% of the literature says that infrared only goes a millimeter into the body or less. And what Bob shows is with his picture that it's going three inches, four inches, and then then you start looking at it a little further and you go to the longer wavelengths, and all of a sudden you see that the body's absorbing. You know, if you're wanting to, how many solar cells are white? They're not, they're black. So now it looks like that from a thousand nanometers out to six six thousand nanometers, the body is doing everything possible to absorb every photon it could get a hold of, and that happens to coincide with the metabolic with the electron volt characteristics of most of the activation processes in metabolism. So there's so much here to understand, and how and every time you turn around, the body is doing not only something biochemically, but it's doing something optically to localize more infrared in your retina, to get uh certain wavelengths to the baby as it's developing, you know, and then as the pregnancy goes on, the skin stretches and expands the spectrum. And so there's all these things that we don't know anything about that is causing that I believe is causing everything from affecting our test. I'm doing a lot of work with these biosensors looking at sweat. And literally, you walk outdoors, your hormone levels shift, you start doing exercise, melatonin goes up just as much as cortisol goes up on very short timescales. So we're not only don't understand the processes, we're not even measuring on the right timescales for some of this stuff. So I think that's what's so cool about, you know, especially some of the stuff Glenn's doing, is that you're starting to see that literally exposing the uh some a body to changes of the metabolic rate in a matter of minutes, and that we don't take it, that transient response is kind of ignored by the all the circadian guys and all this other stuff. So there's a lot to learn. It's a great area.

Bob Fosbury:

If you if people here are having trouble understanding all this stuff, I think the only message that you really have to get to the to people who are trying to get their heads around this, if you are exposed to daylight and a proper dose of infrared radiation regularly, uh, it doesn't have to be very much, but regularly, you age more slowly.

Dave Wallace:

Very cool. Very cool. It's as simple, it's as simple as that.

Bob Fosbury:

They age rapidly. And they when they get back to Earth, they rage. This is not Einstein's relativity, it's the fact that their metabolism has not been working properly. Look, if you if you want to if you want to age slowly, go and sit in the sun.

Dave Wallace:

I think it's amazing. Well look, I I think you you know we've we've we've covered a lot of ground. I'm walking away actually feel my sad lifting as as we sp as we've spoken, because I'm going to embrace cloudy days and not see them as as depressing because I know that I'm they're doing me good. So I think that's a real positive, but it means that I've got to get outside. You know, one of the things that I I have done, I think, is listen a lot more to myself and my natural rhythm. So, you know, I've started getting up a lot earlier. So it I thought that would kind of drop off in winter, like as the the mornings got darker, but it doesn't seem to be. So getting up, being productive, and then you know, finding I've got time in the morning to get the dogs out, which I never had before. So, you know, just a few like an hour in the morning just with the dogs, that's I've changed all our bowls for incandescent. Uh, we've got a fire, so we've had a fire going. You know, I I've sort of started trying to invest in um in the odd candle or two, non-scented, because I think scented things drive me mad, but you know, you can still occasionally buy church candles which are unscented. Um saunas, you know, it sounds like that's a good thing to be doing. Scott, I love your suggestion of you know, using a simple plastic tent in the garden. I think that that could work extremely well. You know, I I mean I've got a conservatory which has actually got very thin glass, so I'm I'm wondering if I'm getting quite a lot of infrared through that because I warm up very quickly in that. So, you know, and then obviously I I guess the final question is is is heading off to uh lovely places as well for a couple of weeks.

Bob Fosbury:

So if you go on if you if you're not careful, Dave, you'll outlive the hell out of the rest of us.

Dave Wallace:

But if if if I go on holiday to a sunny place for a couple of weeks in winter, is that you you know, is that a band-aid or does that help your uh metabol? I mean, it certainly helps my mood to be.

Scott Zimmerman:

When just ran the experiment. Yeah, well, there you go.

Bob Fosbury:

It's good for you, but it's bad for the planet.

Dave Wallace:

Yeah, exactly. Well there's a balance to be had, isn't there? So no. But I think, you know, I think people will be sort of wondering if I go away for a couple of weeks and it does that do you get long-term impacts from m metabolism, or is the the sort of infrared relationship with metabolism a lot more kind of short-lived, or you you know, maybe that's an area that you don't know and or haven't thought about.

Bob Fosbury:

So uh I think you have to be careful there. If you send people out to a really sunny place and they lie on a sunbed all day for a week and then come back home, their metabolism probably will not benefit enough to uh counteract the uh damages of lying in the sun unprotected for a long time.

Dave Wallace:

Okay.

Glen Jeffery:

To be honest, I don't care if I go to us to go. I would I've just come back from the Aegean, and you know, to be honest, I really don't care if my metabolism's upset or not. I I had a very good time, and I'm gonna try and squeeze as much of that in as I possibly can.

Dave Wallace:

Very cool. Very cool advice. Well, listen, thank you so much, all of you. I don't know if there's any sort of final words of wisdom that you've got, but I've thoroughly enjoyed it. What about one word? Incandescent. Incandescent, yeah.

Scott Zimmerman:

So uh my family are gonna be over the moon when they all get light bulbs this Christmas, but I think it's um it's I think it it one of the things that has to happen is we have to find some way to get enough momentum to get the government out of the the pri picture from the standpoint of what they're literally doing. There it's banned to have an incandescent in the US, other than the oven one that you're talking about. And uh that has rippling effects on everything because uh you know all those people are uh essentially exposed to what I consider harmful lighting. And uh, you know but the government the government makes it almost impossible for you to solve the problem, you know, in in the least in the long term.

Dave Wallace:

Yeah, no well I think I think to be honest with you, again, my I've been doing campaigning on clean water and actually the whole the whole involving government and things does slow things down, but it's a very necessary process. So you you know, one of the things I was gonna start asking Bob and Glenn about in the UK is how do I tackle my MP on lighting, you know. So uh are there letters that we can write? Um, you know, so I I guess it it i in the in the US you have a kind of bottom-up process that this can kind of all work to. But you know, it's a very important thing that this gets put back on the political agenda, isn't it?

Scott Zimmerman:

Well, we're we put in a petition to try and revoke some of the Biden-air uh rules rules in the DOE. But uh, you know, we've got the DLC, which is a non-governmental but monitoring process uh uh entity, and they're trying to force it even higher than what the EOE is doing. So what uh it's it's a very difficult process because everybody considers LEDs to be the green uh solution and they can see energy savings. That's why, practically speaking, it's gonna be very hard to get incandescence to come back. But if you do the hybrids approaches and get a little bit of, you know, we're doing 60, 70 lumens per watt compared to 10 lumens per watt on incandescent. But it's very even that will get banned in another three years.

Dave Wallace:

So something needs to change in in our understanding, and that's why I think it's so important what Glenn's been doing here lately, uh, especially you know, and I think it's important, you know, Glenn was uh I on the Huberman um he did a podcast with Rick Rubin and he talked about your work, Glenn, almost up front, and that has a big impact on people like Huberman talking about this and the work Roger's doing in terms of promoting it, the work you're all doing in terms or we're all doing it in terms of promoting it. But I think when when Andrew Huberman talks about it, then people will start listening. And I he's a route into government around all of this stuff. So, you know, Glenn, get on the Huberman show as fast as you can, because I think it's a is a great way of sort of short circuiting all of this stuff.

Glen Jeffery:

Well, hey, you know, let's forget about going on the Glenn getting Glenn on the Huberman uh program. To get on the Huberman program, you've got to get to California, and I'm looking forward to some warmth in California, I can tell you.

Dave Wallace:

There you go. There you go. That's the main thing. Anyway, listen, thank you so much, all of you. I've really enjoyed it, and um I I look forward to uh spending time outside this winter. I'll let you know how I get on. Thanks for listening to Sunlight Matters, brought to you by Shadow Man, where we explore how sunlight influences the way we build, design, and live each day. If you like what you heard today, be sure to subscribe, follow, and leave a review on your preferred streaming platform. You can also search Sunlight Matters on Google to find all our episodes, guest information and resources about sunlight analysis, solar exposure, and the best home orientation for natural light. You can also head over to shadowmat.org where you can download our iOS app for free today to visualize how Sun is currently impacting your life. We appreciate you being part of the conversation, and we'll see you next time, where you can keep exploring the world through the lens of light.