Episode Transcript
[00:00:07] Speaker A: Welcome to ID the Future, a podcast about intelligent design and evolution.
Welcome to ID the Future. My name is Sarah Chaffee. We're talking about a new book, Children of Light, the Astonishing Properties of Sunlight that Make Us Possible, by Michael Denton. Dr. Denton is a Senior Fellow with Discovery Institute center for Science and Culture. He holds an MD from Bristol University University and a PhD in biochemistry from King's College in London. Dr. Denton has published his work in journals such as Nature, Biochemical Journal, Nature Genetics, Biosystems, Human Genetics, Clinical Genetics, the Journal of Theoretical Biology and Biology and Philosophy. His previous books include A Theory and Crisis, Nature's how the Laws of Biology Reveal Purpose in the Universe, and Evolution Still A Theory in Crisis.
In Children of Light, Denton elucidates the miraculous convergence of properties on the tiny band of the electromagnetic spectrum that allows intelligent life to flourish on Earth.
Today we have Dr. Denton on the show to discuss light and our atmosphere. Welcome.
[00:01:18] Speaker B: It's a pleasure to be here, Sarah. Thank you.
[00:01:20] Speaker A: Carl Sagan notes that even if life were to somehow develop on Venus, it could not invent science as humans have done on Earth. Why?
[00:01:31] Speaker B: Well, according to Carl Sagan, Venus is completely cloud covered and nothing of the astronomical universe would be visible. If you looked up into the night sky of Venus, even the sun would be invisible in the daytime. Its light would be scattered and diffused over the whole sky, just as scuba divers see only a uniform enveloping radiance beneath the sea.
And what Sagan claims is, and I think he's probably right, that if we couldn't see out beyond the atmosphere, we'd never have seen the regularities of the movements of the moon, the stars and the planets and such like. And it was the realization of the regularity of those movements, which, according to one line of thinking, and I think it's probably correct that it was the discovery of the regularities of the movements of the lights in the sky, as it were, which led to the idea that the regularities of nature, and that's led onto the idea of the regularities of natural law. So basically, and as far as modern science is concerned, our knowledge of the universe would be virtually zero if we couldn't see through the atmosphere. I mean, Sagan is talking about the impression that primitive humans, when they first started investigating, looking at the universe around them, they saw these regularities in the sky and which suggested that somehow there was some deep order to the nature of things. And I think that's probably correct. I think that did play a role as far as modern science is concerned, as Far as our current understanding of stars and the Big Bang and things like this, we'd know nothing about this. If we lived on a planet with a thick atmosphere like Venus. How could we ever have worked out where atoms were made if we never saw a star, we never saw the sun.
So, yes, we're fortunate to have an atmosphere which lets through light so that we can peer out into the greater universe around us, understand how stars are formed, how planetary systems are formed, how the Earth was formed, what happened in the milliseconds following the Big Bang and so forth. All this vast, vast inventory of sort of scientific knowledge would just simply not be possible if we lived on a planet like Venus with a completely cloud covered sort of atmosphere, very thick, opaque atmosphere.
[00:03:48] Speaker A: So it sounds like our atmosphere is rather special.
Moving to Earth, what kind of electromagnetic radiation is essential for life here? And what role does our atmosphere play in bringing us essential life?
[00:04:04] Speaker B: Well, as far as advanced life forms on the surface of the planet are concerned, we are absolutely dependent on the radiation of the sun, which happen to be concentrated in the visual band and in the adjacent band, the heat band, or the infrared band. That's why, in fact, William Broad described us as light eaters. We live by oxidizing reduced carbon compounds like sugars, starch and so forth. And we get the oxygen from photosynthesis and we get the reduced sugars ultimately from photosynthesis, because ultimately everything eats plants.
The wildebeest eats grass, and the lion eats the wildebeest. But in the end, the lion and ourselves are light eaters, because the ultimate source of oxygen and the reduced carbons we need comes from the work of the plants generated in the leaves of plants. And the plants use solar energy to generate reduced carbons and let out the oxygen we need.
So what's essential for life like us? It's not essential for all forms of life. There are forms of life which are not light eaters, like the complex life on the surface of the planet, like ourselves. There are forms of life around the hydrothermal vents in the depths of the sea. They get by without the light of the sun. They're not light eaters, they are rock eaters. And they get their energy from all sorts of chemical reactions which are completely independent of the sun. But forms of light advanced life on the surface of the Earth. We're all light eaters. You ask, what role does the atmosphere play in bringing us the essential light?
The atmosphere, amazingly, lets through the light of the sun and it absorbs all the other dangerous radiations on either side of the Right band on either side of the visual band. And the infrared X radiation, gamma radiation, the far uv, all that dangerous radiation is absorbed by the atmosphere and the atmosphere lets through miraculously, just the light we need, which is of course, also corresponds to the light put out by the sun.
Once again, there's an extraordinary fact about this and that the actual light put out by the sun on the infrared occupies a tiny fraction of the electromagnetic spectrum, which extends from high energy gamma rays all the way to low energy radio waves. Gamma rays have a wavelength of down in the order of 10 to the -16 meters, basically. Long wave radio waves have wavelengths up to 100,000 meters. So there's a vast range of different wavelengths. And the only band that's useful for life is a tiny visual band on the adjacent infrared. The atmosphere lets through just the light you need, and the sun puts out just the light you need. It's a remarkable coincidence. It's as if the sun was conspiring with the atmosphere. It's very, very remarkable. The atmosphere does just what is needed for life on Earth.
[00:07:11] Speaker A: Yeah, I enjoyed what you were talking about, you know, regarding how much is powered by photosynthesis. It's amazing to me to think that over 150 billion metric tons of carbohydrates are produced by photosynthesis each year.
It's just this amazing ability of light to sustain us.
[00:07:30] Speaker B: Yes, it's extraordinary. Yeah. It's hard to imagine any complex, advanced carbon based life on the surface of a planet remotely like ourselves if it wasn't for photosynthesis, if it wasn't for the sun putting out just the light you need, and if it wasn't for the atmosphere letting through just the light you need. And a very, very remarkable aspect of this is that if you ask, well, which, which chemical compounds take part in the chemical process of photosynthesis?
Well, photosynthesis involves carbon dioxide, it involves water, it involves sunlight. And the energy of the sun is utilized ultimately to produce reduced carbons and let our oxygen. So there are three atmospheric gases involved in the actual chemical process of photosynthesis.
And the amazing thing about it is that these gases have just the right physical absorption properties to let through the light.
And so in a way, they have the right chemical characteristics for the actual chemical reactions of photosynthesis which occur in the leaf. And they have just the right physical characteristics to let through just the light you need to enable their incorporation and involvement in the actual chemical process of photosynthesis. That's just simply magic.
An astonishing fact.
Yeah.
[00:08:52] Speaker A: What would happen if Our atmosphere absorbed a slightly different part of the electromagnetic spectrum.
[00:08:58] Speaker B: Well, it would be a catastrophe. If you take the atmospheric absorption in the infrared, which is the heat region. If there were slightly more absorbent bands, the Earth would be a hellish hot house like Venus.
But if there were no absorption bands, there would be in the infrared region, as there are no absorption bands, very, very few in the visual area. Suppose there's no absorption of heat.
Well, then in sunlight, the Earth's temperature would be terrifically hot.
And as soon as the sun went behind a cloud or disappeared, temperature would drop tens, hundreds of degrees immediately. Because, in fact, the blanket of the atmosphere which absorbs some of the heat would not be there.
So that in fact, if there was no absorption, we'd be like a frozen world like Mars, much colder than Mars, like something like Pluto or something.
So more absorption would be like a hellish hothouse like Venus. If there was no absorption, it would be like some frozen sterile world like Pluto or one of the outer planets.
So, yes, you imagine changing the absorption pattern slightly. Supposing, for instance, that the visual light had been absorbed. Then there would be no light with the right energy to raise atoms and molecules for chemical reactions.
You might have the right heat on the Earth if you kept the absorption pattern in the ir the same, you might have an Earth you could live in. But there'd be no photosynthesis and there'd be no complex life on the surface of the planet. So even slight changes in the pattern of absorption of the atmosphere would lead to catastrophe. The pattern of absorption has to be exactly as it is for advanced life on the planet's surface.
[00:10:40] Speaker A: So what do you conclude from your study of light?
[00:10:45] Speaker B: Well, my conclusion is that in fact we exist because of an extraordinary degree of fine tuning in nature for beings like ourselves.
And a common sense interpretation of the evidence, and I really should quote perhaps Fred Hoyle in this, the common sense interpretation would be that he said, it looks as if, in fact, an intelligence is fiddled with the laws of physics.
And that's what it looks like. It looks as if, in fact, things were arranged for the end of life on Earth. And one of the obvious explanations for that is that there is indeed a divine mind behind the world that prefigured things for our existence. And that's the view I'm inclined to take. Of course, you can say, well, yes, the universe is fine tuned for life. It looks as if it's prefigured by some sort of intelligence.
But it's all a massive coincidence. It's All a huge fluke. There's multiverses and things like this. But one thing's for sure, modern science has discovered the fine tuning. The fine tuning is a fact and it certainly looks as if on a common sense interpretation of the evidence, again to quote Hoyth, this is the result of some intelligence fiddling with the laws of nature.
[00:11:56] Speaker A: It certainly seems to go beyond surprising to perhaps bewildering.
[00:12:02] Speaker B: Well it's very, very remarkable indeed.
Descriptive terms fail me when I think about it. I'm blown away by this evidence. I mean it's not just the evidence of the fine tuning of sunlight, the atmosphere and so forth for photosynthesis. There's so much more. I mean there's the, there's the sort of fine tuning of the properties of water for beings like ourselves, fine tuning the properties of the crystal rocks for plate tectonics, the fine tuning of the universe to generate the periodic table of elements which have just the properties to make the carbon based cell. The fine tuning of atmospheric conditions for fire making and for advanced technology and it goes on and on and on. Yes, it's certainly bewildering. You can call it bewildering. The important thing is that this fine tuning is a discovery of science. So the fine tuning is not really in doubt.
In the same way that in fact cosmologists and astronomers will talk about the fine tuning of the constants of physics which allow the generation of stars, stable planetary systems and of course the nuclear synthesis of the atoms in the center of stars. An amazing story in itself which links our body, the atoms of our body, with the properties of stars. And it's always amazed me to think the atoms in my body were once cooked in the nuclear furnace inside a star.
It's sort of recalling the alchemy and astrology of the medieval scholars who envisaged all sorts of deep connections between human beings and the greater macrocosm, the stars and so forth. It's totally bewildering. The fine tuning can't be got rid of. It's there now, it's been discovered by science and the common sense interpretation of it is that it looks as if some intelligence has ordered things for the existence of beings like ourselves on a planet like the Earth.
[00:13:58] Speaker A: Well thank you so much for coming on today Dr. Denton to talk about your new book, Children of Light.
[00:14:03] Speaker B: Thank you very much. It's a pleasure Sarah, thank you.
[00:14:07] Speaker A: To learn more about these properties of sunlight that make human life possible, get your own copy of Children of Light that is available at Amazon now for id the future. I'm Sarah Chaffee.
Thank you for listening.
This program was recorded by Discovery Institute's center for Science and Culture. ID the future is copyright Discovery Institute.
For more information, visit IntelligentDesign.org and IDTheFuture.com SAM.
