The Ashen Light

was a lot of fun. I really enjoyed it. And the thing about things like the Will of the Wisp is you have so many sightings of it over the years. People claim they see a light over the marsh or a light in the swamp or something like that. Um that you have to assume it's not just people making stuff up. Somebody at some point really did see something.

But obviously we don't think it's a ghost or a spirit or a malevolent blacksmith who died in the swamp and now wants to lead people off of cliffs and to quicksand uh, those stories are pretty great, but you have to assume something is there, right, well, something is there that the woods. The woods are filled with various

some things. I always come back to the star jelly example, right, Uh, the the idea that there's a shooting star and someone says, hey, I think there's a meteorite out there in the woods. I'm going to go find it. And then they start going out and they start looking around, poking around in a place that they have passing familiarity with but have

no real expertise. And then as they're poking around, they find something strange to them, some sort of gooey substance, and it's it's probably, I mean, it certainly is some sort of natural occurring is you know, maybe it's Yeah, there's a lot of oozy stuff in the woods if you poke around enough, and that's what they find. But then they think this is the thing, this is the goo that fell from the sky, and and so I think there there's there's certainly a case to be made.

I imagine. I discussed this in the Will of the Whisp episode, and we both discussed this that we noticed something, we have no immediate explanation for it. But then if we have some sort of predominant theory to tie into it, or some bit of a myth or folklore, then it can take on a life of its own. Yeah. Yeah, exactly.

But then with a lot of this stuff, you do actually have to wonder about it in ways that you you feel disinclined to, because, like with the Will of the Whisp, there are so many reports over the years, you think, well, people had to be seeing some kind of light. We don't know what it was. We think there was a materialistic explanation for it, but we don't know what it was, but there must have been something. Then again, how often are people seeing Will of the

Whisp today? What where did all the sightings go? Yeah, that's kind of a strange question. If people really were seeing something, how come they don't seem to be seeing it with nearly the same frequency anymore? And if you're if you're intrigued by that question, you should check out our Will of the Whisp episode. Will include a link to it on the landing page for this episode is

Stuff to your Mind dot Com. Today we want to focus on a totally different type of ghost light, one of the most interesting elusive lights in the history of science. And this is not something that you would see in the Mars shore. This fickle, unexplained light in the swamp. This is a fickle, unexplained light that astronomers have claimed to see through the vast reaches of outer space on the surface of another planet. Now, to be clear, we're not talking about seeing it, just gazing up into the

sky and seeing it. We're talking about using a telescope, right, because obviously planets other than I don't know if you call the Moon a planet, things out there other than the Moon and the Sun resolved to a kind of point like light source for the naked eye, right. And and of course we're all familiar with the various strange lights one can observe in the sky. Uh, and then attribute to any number of of natural or appearing normal or causes. Yeah, we're not talking about UFOs or anything

like that. We're gonna be looking at a planet in our Solar system. So I want to start off this mystery hunt by introducing you to a seventeenth century Italian astronomer, and his name was Giovanni Batista Riccioli. He lived fIF to sixteen seventy one. And Riccioli was a Catholic priest and an astronomer working in the generation after Galileo. So

this was a great time of innovation and progress in astronomy. Right, So you've had Galileo's strong case made for the Copernican cosmology, right, and you've had Galileo improving telescope optics and and so the people working at this time to appear into the night sky had a lot of new ideas and a lot of new technology available to them, better able to see and model observable universe exactly. Riccioli was also a very important lunar astronomer, and he made detailed maps of

the Earth facing side of our moon. As we know, the Moon is tidally locked with planet Earth, so we always see the same side of the Moon, and that side has a bunch of topographical features like seas and craters, and so a lot of the names of the features on the surface of the Moon come from Riccioli's original nomenclature, like the Sea of Tranquility and so forth. But on January nine three, richili was examining the planet Venus through

a telescope when it was in its crescent phase. So what does it mean for Venus to be in a crescent phase. The easiest point of comparison for this would be our moon, right, which goes through phases of its own.

You've got full moon, give us crescent new moon. Uh. And of course the moon orbits around the Earth, and as it does, it's always day on the side of the moon facing the Sun and night on the side of the moon facing away from the Sun. And so the type of moon we see depends on how much of the day versus night side of the moon we see facing the Earth. So when the moon is between the Earth and the Sun, we're looking at the dark nighttime side of the moon, and we get a new moon.

And when the moon is on the opposite side of the Earth from the Sun, we're seeing the bright daytime side of the moon, so we get a full moon. We're always looking at the same side of the moon, but it but sometimes it's day, sometimes it's night on that side that we can see. Uh. And then of course in between those phases there there are crescents and

stuff like that. So a crescent moon happens when the half of the moon facing us contains mostly the moon's night side and then a little sliver of the lid up day side. Now, of course, Venus isn't orbiting Earth, right, so the timing of these phases is somewhat different, but the same basic principles apply Venus orbits the Sun on a different schedule than we do. So when Venus is visible, sometimes the side facing Us is mostly the bright daytime side which reflects a lot of sunlight and looks very

bright in the sky. And other times when Venus comes sort of between the Earth and the Sun. As you can imagine if you picture this, the Venus orbits inside the Earth's orbit, so it sort of comes between the Earth and the Sun. The side facing Us is mostly or entirely the darkened night time side of Venus that's facing away from the Sun. And Robert, I bet you've

heard about this before. But of course the phases of Venus play a role in the history of establishing how the Solar system works, right like this was a point of contention for Galileo and and his critics during during

the time he was alive. Yeah, I mean, this is this, this all it makes for a major advancement just celestial mechanics, just understanding how the planets in our Solar system are moving exactly because the first time we actually know of that the phases of Venus that seeing it as so sort of more darkened or more or more bright and

more daytime side. Uh. The first time these phases were observed through a telescope and described was by Galileo, and this was in the early sixteen hundreds, and at the time the phases of Venus were more than a curiosity. They were a kind of brutal line of evidence against the Ptolemaic geocentric model of the universe. And the reason for this is that Galileo showed with the telescope you could look at Venus and that it had phases just

like our moon. But he observed the unlike our moon, Venus had a full phase when it was roughly in the same direction in the sky as the Sun. So think about that. You're looking toward Venus and it's in pretty much the same direction as the Sun, but the side we can see of it is all lit up and bright. The Moon's never like that. When the moon's in the same direction as the Sun, the side of

it we can see as dark. So if all of the planets in the Sun went around the Earth, how would it be possible for Venus to appear full to us, lit up in daytime side when it's in the same direction as the Sun. It couldn't were forced to to

reevaluate the entire structure of our our solar system. Exactly. Yeah, So what this showed was that Venus, because it showed a full phase at the same time that it was in the same direction as the Sun, it couldn't be between the Earth and the Sun. It had to be on the other side of the Sun from Us, which meant that Venus was not orbiting Earth, it was opening the Sun. And so Galileo first published this argument in his sixteen thirteen Letters on Sun Spots, which was a

sort of a series of letters that he turned into a pamphlet, and which turned out to be the first place Galileo actually officially endorsed the Copernican model of the solar system, in which the planets go around the Sun instead of everything going around the Earth. And of course we all know that this was kind of a this was rather a controversial theory at the time. It it was not well received by by some powerful individuals. Yeah, exactly. I mean this put Galileo on course to have extreme

conflicts with both the scientific and religious hierarchies of the day. Uh. People, people forget that it wasn't just the church that was persecuting Galileo. I mean a lot of his scientific colleagues, I just thought he was wrong for reasoning, you know, for reasons of their own. Yeah, and there were a lot of people that were very invested in the previous model. He's really changed everything, whether you were looking up at the stars with a with a more of a scientific

mindset or or a purely religious one exactly. But anyway, so when an astronomer looks at Venus in its crescent phase, they're seeing mostly the night side of Venus, right, and so you've got this sliver of daytime that's separated by what's known as the terminator line. The terminator line is the boundary between the night side and the day side

on the surface of a planet. And if you've never seen this, it can be very haunting, Like if you view the terminator line on Earth from the International Space Station. There are videos of this you can look up online where the station is rapidly orbiting the Earth. You see the ground beneath passing along and it's the daytime side of the planet and suddenly this curtain of dark just sweeps over the face of the planet. Uh. It's it's kind of terrifying to see actually but also very beautiful.

It's it's worth looking up alright. So so we're looking up at the night side of Venus here gazing into the dark, just into the dark on another planet, right, What is the curious incident of the Venus in the night So on that j Your evening sixteen forty three, Richie Ali's looking at Venus through his telescope in this crescent phase where there's a small crescent limb of light and there's the terminator line, and most of Venus should be dark. The crescent portion was at roughly thirty percent

of the planet when when Richieli was looking at it. Now, when you look at Venus in a crescent phase like this, the nighttime side of the planet is supposed to be completely invisible. It's so dark compared to the brightly lit up crescent of the daytime side that you shouldn't be able to see it at all. The daytime sliver of the planet should be like a bright melanrind floating in space by itself with nothing else there. But when Richili looked at it that January evening in sixty three, something

was not right. Instead of a bright crescent and an invisible nighttime side, Richie Eli believed he saw something startling, a very faint glow coming from the dark side of Venus. The side of Venus where it was currently night time appeared to be ever so faintly shining gray light into space. And Richie Eli gave this glow a name. He called it the ashen Light of Venus. Spooky. Huh, yeah, it has it has it certainly has an anonymous ring to it. Yeah,

it's It's funny. How if you just give something a really good name, it'll end up getting a lot more attention than something that doesn't have a good name. Uh And and I think that's probably the case here. The ashen light, I think maybe gets more attention from amateur astronomers trying to find it and stuff like that than a similar observation would be if it was just called

something very mundane. It sounds like a like like a new metal album from from the early two thousands, so people were like, yeah, let's look for that ashen light. I'm pretty sure there is a is a metal band called Ash and Light. You just know it happens, right, It's like there's nothing left. The metal bands have scoured the earth. It's like going through a post apocalyptic wasteland has been picked clean of every bit of canned food

and ammunition and everything you think you might want. If there's an idea or an ordering of words that sounds cool, it has been scavenged by a metal band in Ohio somewhere. I don't know. I have a feeling that before we make it through this this episode will have found something that some fledgling metal band can latch onto and embraces

their name. But anyway, the Action Light itself. So Ever, since Riccioli's original sighting, other astronomers, both professional and amateur, have been looking for the Action Light, and a lot have claimed to see it, but many others have looked when it should be visible and found nothing. So this controversy exists. Does the Action Light really exist? And if it does exist, what is it? What is making the

night time side of Venus glow? On that note, we're going to take a quick break, and when we come back we will discuss subsequent sightings or claims of sightings of the Action Light and some ideas about just what it could be. Alright, we're back. So we've been discussing Giovanni Batista Riccioli's original sighting of what he thought was the action light on the night side of Venus in

sixty three, and here's how he described it. So he said, it appears to be a dull, faint glow, some sort of gray, somewhat like earth shine on the dark side of the moon. Now what is earth shine. That's when the moon is in a crescent phase, meaning most of the moon's sunlit day side is facing away from Earth and most of the moon's darkened night side is facing towards Earth, and light from the Earth shines on the night time side of the Moon to produce a soft, gray,

glowing reflection. But the action light is allegedly even fainter than the earth shine on the moon. Because we know the earth shine on the moon exists, we've got evidence of that that the action light is still controversial. So you've got all these claims of sighting this of this dull brownish or copper or gray light on the other side of Venus. Now where do some of these sightings come from? One of them was by William Durham in seventeen fourteen, so that was apparently the next sighting after

richie Oli. Uh seventeen fourteen, the English natural philosopher William Durham was observing Venus through a telescope and he called the light a dull, rusty color. Then you had actually a big name in the history of astronomy, the German born British astronomer Sir William Herschel. Oh yeah, yeah, nature name there. So he lives seventeen thirty eight to eighteen

twenty two. And Herschel was the discoverer of Uranus in seventeen eighty one, which was extremely significant because I think a lot of people don't really It's got a mythological name, right like the other planet. So a lot of times I think people assume that Uranus was known about by the people who believed in the god Uranus or Uranus like I guess, however you say it, both both are correct, just once more funny solistic with Uranus. But yeah, the

Uranus was actually discovered in sev one. It was. This was extremely significant because it was the first discovery of

a new Solar System planet since ancient times. The ancients had been able even before telescopes, to see planets like Jupiter with the naked eye, so to be clear at this point, we've we've already established there's not just one individual who saw it, and it's not just uh, and and and and Also we're talking about like noted astronomers of of their day here, not near amateurs who just happened to pick up a telescope and and gaze hopefully up at Venus to see what they could see. No,

these were respected astronomers and observers of the sky. These are people who we can talk about this more in a minute. But there are people who you wouldn't expect to be hoaxing. You know. It's not like somebody is just like, oh, yeah, yeah, yeah, I saw a willow, the whisp and the swamp. Yeah it was great. But then to be clear too, whereas the willow will of the whisp already has like supernatural connotations to it, this was more of a purely scientific observation without getting into

some of the possible reasons that could be attached to it. Uh, just gazing at another planetary body and and and seeing some sort of illumination or seeing just anything, any kind of phenomena that they could not be easily explained. I mean, that's kind of part for the course of gazing up at other planets. I mean, I would be shocked if over the years, somebody at some point didn't claim that the ashen light was caused by I don't know, the fires of hell burning on the surface of Venus where

all the damned and heretics went. I mean, just think of Herschel for example, here like which is the crazier thing, Which is the bigger moment in his life? Yeah, I saw some of this light that this other guy was talking about. I saw it on on the dark side of Venus, versus I've discovered a new planet. Yeah, he don't planet exactly. That's a good point. He didn't need

to be like a tension seeking or anything. There's no reason really for Herschel to claim to see this without actually seeing it, though of course he could be mistaken about seeing right, And when we're discussing it in hindsight, the action light is more of a mystery, yeah, versus the the the awe that would have been associated with discovering a new planet. Because, like you say, we've known

of of Uranus our entire lives. It's just it's one of the planets to memorize, and we often fall into the traffic, just thinking that humans have known about it for ages. Yeah, exactly. Uh so. Another observer in the nineteenth century Thomas William Webb in eighteen seventy eight. He was a British astronomer. He was a reverend, and he claimed he saw the light in eighteen seventy eight on January thirty one, with a two hundred and thirty eight

millimeter reflector, so you know, mirror based telescope. And he writes quote on January thirty feet after having many times looked for it in Vain in former years, I saw it without specially thinking about it, with powers of about ninety and two twelve on my nine point three at inch or two hundred two hundred and thirty eight millimeter mirror, coming out at intervals rather paler and browner than the twilight sky, and equally visible when the bright crescent was

hidden by a field bar. Now, this field bar, or sometimes called an occulting bar, would be a device that essentially blocks something bright so that you can see dimmer things better. In this case, it would block out the crescent on Venus, because that's the daytime side is very bright, and that would allow you to see whether there's something

visible on the nighttime side by eliminating the glare. And I also want to point out for anyone who lacked unto the fact that this guy was a reverend um a number of these sort of gentlemen scientists of the of the day. Uh, we're also religious individuals as well, so that's not really that uncommon. Oh yeah, Especially in the history of astronomy, you see tons of astronomers who were affiliated with, for example, the Catholic Church, or with

the Church of England or something like that. Another astronomer named C. V. Zinger of Prague said he observed the ghost slide of Venus in January eight eighty three and that the disc of the planet was quote splendidly visible. The most important feature of the observation was the ring that I could detect all around the disk dark part and crescent of brownish red color more pronounced on the illuminated side than on the dark part of the limb, but of a peculiar coppery hue. And then of course

there were many reported sightings in the twentieth century. A bunch of sightings in nineteen fifty three with independent observers claiming to see the light at the same time in different locations. Uh. There were also a number of alleged sightings in nineteen fifty six and fifty seven. Also, I think I read about sightings in nineteen forty and I think on all in all these years I mentioned there were sightings on consecutive nights reported to the British Astronomical Association.

But already we can see that if something is occurring, if there actually is a light there, it's not it's not there all the time, right, Yeah, So this is something that's going to contribute to the mystery and maybe help us reason about if it really exists what it is. Um, Now you may be noticing so far that we're all talking about visual sightings, not about capturing images of it.

Now that that'll that will play into our discussion. In a minute, just to mention a couple more sightings real quick. Um and Dale Crookshank, a planetary scientist at NASA Ames Research Center, and William K. Hartman, another planetary scientists, they observed Venus at inferior conjunction. Now that conjunction is when planets line up in a line, So inferior conjunction would be when the Earth Venus and the Sun line up together, with Venus on the same side of the Sun as

the Earth. I guess obviously it would have to be on the same side of the Sun as the Earth if we're observing it now. The thing here that I'm sure it's jumping out at everyone though, as we mentioned these dates, is that none of these dates are particularly recent, and it's it's easy to just assume that. Okay, as as as our technology increases, is our ability to view and capture images of venous increases. If sightings go down, then that's that's a huge red flag. It absolutely is.

That's a very good point in something that other astronomers uh we we will talk about later in the episode, have pointed out. But yeah, it seems that while there have been all these numbers of sightings, sightings apparently get more rare as our ability to capture faint images with astronomical equipment becomes better. Uh So, uh Dale, Dale Crookshank, and William Hartman that I mentioned a minute ago, they did not capture an image of it. They drew an

image of it based on their visual observations. Um. They said that the circle of the disk within the ring of light glowed to kind of dull brown color, and they said that this was a different color from the blue sky behind the planet, and that the color difference seemed to be the strongest near the crescent. And so

I added an illustration of what they think they saw. Robert, Now, it looks kind of like if there's a bright ring and then inside it there's just a slight, slight hue of brown, right right, And now trying to include this image on the landing page for this episode of Stuff to Plow your Mind dot Com so that people can can see what we're talking about as well. Just one more alleged siding, the English astronomer Sir Patrick Moore, who

passed away unfortunately in two thousand twelve. He claimed to have seen the ash and light many times throughout his career, including a siding in nineteen eighty that he regarded as sort of unmistakable, in which he described as looking like

earth shine on the moon. Now, despite all of these claims of observations, as we've been discussing, there is emerging a pattern of like questions that somebody skeptical of this phenomenon should should be asking, right, the British astronomers Dr Paul Abel and Pete Lawrence, writing for BBC Sky at Night magazine right about how part of the problem with the ash and light is that all the claimed sidings over the years have just been people claiming to see

it directly with their eyes through the eyepiece of the telescope, and no one has ever captured a good, really unmistakable photo or digital image of the glow. And they discuss how lots of astronomers have searched for the low over the years and never been able to see it, despite

earnest attempts many many years in a row. For example, the famous American astronomer Edward Emerson Barnard tried to see it, but he never could And the authors themselves at the time of writing claimed they've never been able to see the ash and light. Yeah, all you have here is observation data. You have no like like hard measurements of it based I mean, besides what can be made with the human eye and then recorded, which opens it up to a number of different errors in cognition and memory

encoding that can occur. And really you have to realize to here, that's like most people that are looking at venus do not see it. Only some people are seeing it. Some people are arguably good at seeing it, whereas others are are less skilled at seeing the ash and light. Now, to be fair to proponents of the ash and light, it's it seems to be part of the phenomenon. If it is real, that it is infrequent, like it only appears at certain times, and we could discuss later what

could cause that. If it really is a is an actual glow coming from the planet and not just a trick of the eye. Uh So, I guess before we get into explaining what it could be if it is real, we should explain what could cause all these sightings if it is not real. One of the things you always have to consider, of course, is the possibility of a hoax. But that really doesn't seem very likely to me in this case, because you've got so many reports from very

apparently serious people over the years. Um, like, this wasn't a ghost reported by some drunk high schoolers in a in a swamp or something. No, But but I think it is important to realize that seeing a UFO whilst drunk in the swamp is exactly the kind of thing that a that a that a that a non scientist might see, but seeing an astronomical detail that other experts

have reported over the years. I mean, that's the kind of thing that an astronomical observer might uh want to see, right, Oh yeah, yeah, I I certainly think that they could the people seeing it could be mistaken. Well, I was going to mention that in a second, but I'm trying to rule I don't think it's deliberate hoax. That that seems like it doesn't fit. Uh, you know, why would William Herschel be participating in a deliberate hoax and all

these different people over the years. It just doesn't does not seem like a good explanation to call this wilful misrepresentation. Now, on the other hand, observer error is a very strong candidate. As as you're talking about Able and Lawrence right in their article quote, it's reasonable to suppose that under certain conditions, the brilliant crescent of Venus, combined with poor seeing tricks the human eye into thinking it can see the night

side of Venus when in reality it is not visible. Now, we've talked before about different kinds of optical illusions on the show, and a very common kind of optical illusion is a kind of completion effect of the eye. Right, you see part of a figure, and the brain knows what the rest of the figure should look like and kind of seese it. Because our brain, our vision is not a camera or a video recording device. No, our

vision is cognitive. It is a cognitive process. And and therefore it's not just our brains are not just seeing what we're seeing. Our brains are forming the picture of the world that our eyes are helping us to to take in. Yeah, so you see with your eyes, but you also see with your emotions, and you see with your memory, and you see with your biases. These these actually affect what you see. Like you say, Robert, it's not just a totally neutral device taking pictures of things

and recording different light levels at each pixel spot. Yeah. I'm instantly reminded of times that I've looked at, say, you know, a three D image one of these of what were they called? They they had whole books off them, and you had to sort of stare magic I have the magic Eye books, and uh, some of those I could see fairly easily, but others that would just stare at and stare at, and then you reach a point where you're like, do I see it? I think maybe I see it. I kind of want to stop staring

at it, but maybe I see it. Um maybe this means there's something wrong with my brain. But I was never able to see those things. Well, this could be something we explore in a future episode, like why why do some people see the Magic Eye things more more readily than others? Um Or is it? Maybe it's all a hoax. Maybe there's there's nothing there. But if you stare at it long enough and people were expecting you and priming you to see these images, then you eventually say, yes,

it's a tiger. Clearly, the Emperor has no clothes. The magic Eye is fake. There is no tiger. It's all just gibberish. Everybody's like, oh, yes, yes, I see the fleas. I mean, I've also had that situation with I mean and being a little glimp here about the magic Eye.

But I've had that situation with the attempt to observe something supernatural, the like the the desire to say, see a spaceship, you know, as a kid, like look up at the stars and and maybe you know you're afraid to see something, but you also you just want to see something staring into the woods and hoping to see a ghost, that kind of thing. And I never did see anything of that nature, um in either case. But there's this you can feel the straining at time, like

like do I see something? Do I see something? Like it almost like you're pushing yourself up to that line of telling yourself you see something. Uh you know whether you're willing to actually cross that line, uh you know or not. But it's not. But I don't think that line is necessarily a situation of today. I shall make something up today, I will will create the story of how I saw a UFO. I feel like that's a

line that we that we sometimes creep up to. Oh and then suddenly you're standing on the other side of it.

I know exactly what you're talking about. Yeah, yeah, yeah, I mean it's like, uh, it's like listening for the sounds of ghosts whispering in an echoeek cathedral, Like you know your you might not be likely to hear that if you just stand there listening, But if you're trying to hear a ghost speaking in a cathedral, you might not think that you're making it up, but you will be sensitive to kind of anomalous and m pops and sounds that you can apply your cognitive filters too and

make something out of. Yeah, and we've discussed before in the show how you know, we've already talked how the brain is sort of filling in the blanks of vision, and when we are presented with limited stimuli, be it auditory or visual, the brain can kind of create, uh, patterns where there are no patterns. It can create a voice where there is no voice, a sound where there is no voice. And and ultimately you're talking about astronomical

data that is limited visual stimuli. That's right, But then again, I I also don't want to go over the edge and be too dismissive because you've got a lot of

reports over the year. There's a lot of undeniable And again getting back to that that very important point that whatever it is, we're just if we were just to assume, yes, there is was an action light on venus, like you said, it is clearly not observable all the time, so it's not something that can be is regorously tested, as say, the the idea of canals on Mars, which we'll get to in a bit, right, So if it does cist, I think we should transition to talk about, if it

does exist, what could explain it? What would match the descriptions people see, what kind of light could be shining off of the night time side of venus uh And I think clearly, clearly the best explanation for the ashen light comes to us from the Bavarian astronomer and physician Franz Vonpaala Growthhausand uh from who he lived from seventeen eighteen fifty two. And he was you know, it seems to me he wasn't a dummy, but he was obsessed with space aliens. Oh yeah, he was. He was the

real deal. He was a major contributor of the day to fields of urology and lithotrity, which is the treatment and removal of gall stones, bezors, and kidney stones. We we discussed all three of these on our Stone of Madness episode did a few years back. Uh So he developed key technologies that helped make bladderstone removal safer and less likely to result in the horror rible death of

the patient. As we discussed in that Stone of Madness episode, not only were kidney stones painful ordeals, but the methods of treating and removing them, but they had the other days were just barbaric. Uh. So there was a very high mortality rate for surgical intervention and growth thousand helped change that. He helped establish the technologies that allowed the uh these fields to evolve and for people to uh to to engage in the treatment of of of various

stones without without facing down death quite as often. So so real physician, not a dummy, Yeah, not a dummy. He was highly influential in his field. During his life. He went on to write hundreds of scientific articles and a number of books that covered various topics in the field of natural sciences. So he was, you know, he was something of a renaissance man in that regard, and he was he was a legit astronomer. Yeah. He became professor of astronomy at the University of Munich in eighteen

twenty six. So again, very bright guy. Uh, No mere amateur. He didn't just pick up a telescope and say, hey, I see the ash and light. I'm going to write a book about it. Uh. He knew what he was talking about. But at the same time, I think it could definitely be argued that he he engaged with uh, with astronomy, with a certain imagination. Uh, nothing wrong with imagination, but you should remember the difference between imagination and good theory. Yeah.

So for starters, he believed Earth's moon was habitable, which is not a crazy thing to to think. There are people today who think that that, yes, given appropriate technology, we could live on the moon. And and it certainly wasn't all that unusual back then a lot of people thought stuff like this. But what's more, he also identified what he took to be structures on the moon. He thought he observed a vast city. And even when it had called it Volver, wasn't that a craft ferk album?

It could be. It could also be a great name for a metal bands. There you go, We've already had another possible suggestion there. So again he's he's he's not a nobody. He's making this this uh, this this claim. So if he says there are cities on the moon, even one called Velver, people people take the sea, they took, they took notice that there's a certain amount of sensation ensued. Uh,

I mean cities on the moon. Right, So the notion resonated through the media of the day, through the culture of the day, influencing the literary world, and and not just early sci fi. It laid the seeds for the nineteenth and twentieth century telescope sightings of canals on Mars, which will discuss more in a bit, which you know greatly influenced our perception of the red planet and continues to sort of color our our perception and expectations of

the planet Mars. Yeah. It also, uh again, influenced literature. Alfred Lord Tennyson wrote of of these lunar cities in his poem tim Buck two. He wrote, I saw the smallest grain that dappled the dark Earth, the indistinctist atom in deep air, the Moon's white cities, and the opal width of her small glowing lakes, her silver heights unvisited with dew of vagrant cloud, and the unsounded, undescended depth

of her black hollows. That's good stuff, man. Yeah. Tennyson is not usually one of my favorite poets, but I like that. Well, yeah, you you inject a little sci fi and uh it's a it's a whole different kettle of fish, right. I should also point out the growth thousand Uh you know, it wasn't all just cities on

the Moon. Uh In terms of his astronomical contributions, he also suggested that lunar craters were caused by meteorite strikes, which is reasonable, right, uh So, but we should get to his explanation for the ashen light, which is fantastic. So this is quoted and discussed in the book Atlas of Venus by Peter Cattermole and Patrick Moore from Cambridge

University Press. And so they're writing about growth thousand. I'm sure I'm saying his name wrong, but that that's the closest I can do growth thausand his opinions on the action light of Venus. And so apparently Growthausand noticed that astronomers had claimed to see the light in seventeen fifty nine and then again in eighteen o six, which means that the main previous sightings in his lifetime were separated by forty seven Earth years, which is seventy six Venus years.

And Growthausand wrote, quote, we can assume that some Venusian Alexander or Napoleon then attained universal power if we estimate that the ordinary life of an inhabitant of Venus lasts a hundred and thirty Venusian years, which amounts to eighty Earth years. The reign of an emperor of Venus might well last for seventy six Venusian years. The observed appearance is evidently the result of a general festival illumination in honor of the ascension of a new emperor to the

throne of the planet. What do you think, Thumbs up? Thumbs down. I'm gonna have to give a thumbs down to that. Why, I mean, assuming he wasn't just joking around, if if he's presenting this is uh, is anything close to a possible explanation that it is a bit ridiculous. It's there's so many, so many leaps of faith one has to take there. I think that's that's a terrible explanation, even if you think there's life on the surface of Venus,

because how would you be timing out the coronation process later. Yeah, you're making so many assumptions about about life on Venus. Uh. He also later suggested that the ashen light might be due to Venutian slash and burn agriculture, in which farmers of Venus would burn down these huge stretches of jungle in order to clear the land for tilling and planting. Quote, large migrations of people would be prevented so that possible wars would be avoided by abolishing the reason for them.

Thus the race would be kept united. Well, I don't know that feels a little more reasonable. I mean, really, I guess in both cases what he's essentially doing is reasonable. He's saying, how would I explain this light on venus? And on both cases he's assuming that there is some sort of intelligent life form. What do we do on our planet? And then how might I model behavior on the other side. Yeah, if if the dark side of Earth is shining, what causes that? Well, it's probably some

huge illumination for some festival or its agricultural burning. Right, it can't be just the light of cities, because then it would be more stationary, wouldn't be this, wouldn't have this this frequency to it, right, Uh, And so all this stuff it's it sounds cookie to us, but it's not in principle as cookie as it sounds. Because Robert, as you mentioned a minute ago, lots of people used to believe that there were visible civilizations on the surfaces

of other rocky planets in the Solar System. We've talked before about the American author and astronomer Percival Lowell. You know, he comes to mind who Around the turn of the twentieth century he was writing about the supposed canals of Mars, which we talked about. I thought that the canals of Mars were evidence of the handiwork of Martian civilization. Now, of course, later it was discovered that the observations that people thought were canals on the surface of Mars were illusions,

and Mars does not have canals. Yeah, they were actually first observed in eighteen seventy seven and then confirmed, uh if you will, by various dedicated astronomers around the world. So this is something that Carl Sagan actually wrote a little bit about in The Demon Haunted World, his his book that essentially about science communication and the struggle between uh, you know, scientific literacy and uh uh and our susceptibility

to everything from conspiracy theory to pseudoscience. He wrote A network of single and double straight lines was reported criss crossing the Martian surface, and with such uncanny geometrical regularity that they could only be of intelligent origin. Evocative conclusions were drawn about a parched and dying planet populated by an older and wiser technical civilization dedicated to conservation of water resources. So hundreds of canals were actually mapped and

named um. But but just as with the action light, there were no photos. This was all based on observation through telescopes. Most astronomers did not see them, but some did, and says Sagan suggests that, you know, it might have even been more of a you know, perceptual delusion. But but one of the key differences here is that canals on Mars, that's something that you can keep looking for.

Unless you're rolling out some elaborate explanation about canals disappearing or being hidden by secretive Martians, They're going to remain there and you can look for them. Yeah, it should be a fixed feature of the surface. Right, So as our observation abilities improved, we found that they did not exist. When Marin or nine orbited the planet in nine UM and Sagan was an experiment er for that mission, he said, there were, of course no canals at all, and nobody

was surprised by this by that point. But but again, this was a perfectly testable situation in the science corrected our expectations and understanding of the surface of Mars. And now we understand, as we've discussed in the past, we understand more about the surface of Mars than we do about the the bottom of earth oceans. Yeah, uh yeah, And so that's a fortunate situation where this misconception could

be cleared up. Like you say, but as you implied, the problem with the light on Venus is that it is observed to be infrequent and difficult to detect, very faint, and it's not always there. So this makes it harder to verify or disconfirm through experimentation. Right now, as far as as the idea of life on Venus, we actually just did a recent episode on the possible existence of life on Venus. But of course, as we know, if it were to exist, it would not take the form

of a surface dwelling agricultural civilization. The surface of Venus has an average temperature of over four hundred and fifty degrees celsius or over eight hundred and fifty degrees fahrenheit. Then that makes complex life totty much impossible. If if life were to exist on Venus, astrobiologists generally think that it would consist of micro organisms living dispersed in vapor droplets in the clouds of the upper Venusian atmosphere, higher up where it's cooler. So I guess we should get

back to the question of the action light. It is the action light like the canals of Mars. Is it just an observer illusion? And if not, what is the real cause? What could really make the nighttime side of Venus glow? All right, We're gonna take a quick break and then when we come back we will continue. Thank you,

thank you. All right, we're back. So I think it's time to turn to a paper by William Sheehan, Klaus brosch, Dale Crookshank, and Richard Baum from the Journal of the British Astronomical Association, and the papers called the Ashen Light of Venus the oldest unsolved solar system Mystery, and this paper tried to take a look at the action light to determine if it's real, and if it is real,

what could explain it. So they point out that many of the observations of the action light are very likely illusory, based on optical illusions or inadequate equipment, poor telescopes, all that stuff. But really the question is not are some of the observations of the action light illusory obviously some of them are, but are all of them illusory? Or is there there's something real to it? And there's a problem.

The identify in the term action light apparently appears to refer to at least three different kinds of observation scenarios. So one of them is you've got the dark side of Venus and it appears paler or the same brightness but a different color or darker against a bright twilight or daylight background. And then another type of observation is

the planet is observed near inferior conjunction. Remember that's when Venus, Earth and the Sun line up, with Venus and Earth on the same side of the sun, so we're near that, and they see the planet against a bright sky or in daylight, and the extent shin of the horns of the crescent planet seemed to go all the way around the planet and form a bright ring, and they say this is probably due to scattering of sunlight from the

planet's atmosphere. And then third, finally there's the true ashen light, in which the dark side of the planet appears as a brighter glow against a darker background sky, and it's that third category we're going to be most interested in here, right, because that is that is the true action light. Yes, though all three categories are met by various observations around the years, so so they take a look at all of them, but that the third one is considered the

true ash and light. And given the different uses for the term, obviously it can be hard to nail down an explanation that fits them all perfectly. I mean this goes back to our Will of the Wisp episode. Like if you're trying to say, Okay, if people really did see something, what's the best material explanation for it? You've got a problem in that the sightings are so different

in the way they're described. Yeah, they range from the original ashtion lie to these descriptions of something that's more rusty and uh and sort of like the color of dried blood. But there have been plenty of explanations proposed over the years. So for example, how about the idea of earth shine, Like is light reflecting off of Earth and then bouncing to Venus so that we can occasionally occasionally see the light bouncing off of Earth reflected from

the surface of Venus at night. Uh, The authors say no. Many calculations have been done and found earth shine to be much much too weak to explain the observations, but

people have tried to reason this way. One explanation along these lines was offered by a guy named god Free Sykes, who apparently worked for Personal Lowell, uh you know Personal Lowell of the Canals of Mars fame and god Free Sykes thought that Venus was tidally locked with the Sun, which would mean that one the same side of it was always facing inward towards the Sun, and that it's dark side, which always faced away from the Sun, would

be completely covered in a hemisphere year of ice. And this ice, being highly reflective, would reflect light from the Earth and other planets and stars and all all that all that light coming into the dark side of Venus would reflect off of the ice, the ice sheet on that side of the planet back out into space, and thus we would see that kind of shine. Obviously this is wrong for you know, clear reasons, because we now know that Venus is too hot for liquid water, let

alone ice. Alright, what else do we have? People have proposed lightning? How about lightning? Well, that makes sense, So we have lightning in our world, and it certainly can light up the sky. Yeah, there's actually long been a question of whether there's lightning in the clouds of Venus

and if so, how much. And there does appear to be some evidence for lightning on Venus, including these what are called low frequency quote whistler waves that are detected in the Venusian atmosphere, like for example, they were detected by the Venus Express vehicle. But astronomers have also largely ruled out the lightning explanation because the lightning would just

be too faint to be seen on Earth. So the authors of this paper right quote, the auroral and lightning theories have both been eliminated because though visible spectrum night side air glow on Venus was discovered by the veneera nine intent spacecraft, and lightning has also been confirmed from spacecraft observations, the illumination they produce is orders of magnitude too faint to be detectable with the eye from Earth. So it's not just a little bit too faint, it

would be way too faint. And it likewise that means that whatever is occurring, if it's occurring, is uh is substantial enough that it is it is orders of magnitude beyond what near lightning activity or rural activity would consist of right for us to be seeing it with the eye and telescopes from Earth. Now, you've got a couple of remaining hypotheses. One of them is infrared thermal emission from the night side. We know that the surface and lower atmosphere of Venus are red hot, and she had

at all right quote. Since the absorption and light scattering by sulfuric acid aerosols in venous atmosphere are weak at visible and near infrared wavelengths, a number of authors have proposed that at least in principle, the lower atmosphere from fifty kilometers down to the surface might produce a glow that for a suitably dark adapted observer under the right atmospheric conditions both on Venus and the Earth, may be

dimly perceived at visual wavelengths. So maybe the planet is so hot it's glowing in a way that the atmosphere does not appropriately scatter the light, and the light comes through to us. And in their article Able and Lawrence right about this idea, uh they write that apparently the thick atmosphere occasionally thins in places, allowing the hot surface

to be seen. Quote. The problem is that this would only be visible in the infrared part of the spectrum, well beyond the threshold of the human eye, So infrared heat is below the frequency of the visual band of the the electromagnetic spectra. And she Han and co authors

right quote. Thermal emission of a body at venus temperature reaches its peak value at about three point nine five micrometers wavelength, which is invisible to the eye, and decreases very rapidly towards shorter wavelengths that the eye can detect. The longest wavelength visible to the human eyes about zero point seven micrometers. Using Planks law, we calculate that wind venus is very near inferior conjunction when it just a

few degrees of separation from the sun. The intensity of the heat emission at zero point seven micrometers is some thirty thousand times weaker than the brightness of the sunlit sky, So the lowest possible frequency of light that could feasibly be seen by the human eye, that the lowest frequency that's visible to us is produced at far too weak an intensity. On an object of the temperature of venus,

compared to the sky around it. So, yes, Venus is very hot, but not hot enough to glow in a way that we could see from Earth with the naked eye through a telescope lens. Alright, so it has to be something else, right, Yeah, So it can't be the planet glowing from heat. So what's left pretty much just

one hypothesis, and that's the hypothesis of oxygen emission. So in nineteen sixty seven, the Mirrorner five spacecraft did an early fly by Venus and detected what was believed to be an ultra violet quote night air glow on the dark lamb of the planet. So there was a nighttime

on the night side of the planet. The atmosphere was glowing slightly and scientists at the time thought that this night glow on the dark side of the Venus might be due to chemical reactions in the atmosphere or possibly due to the atmosphere being bombarded by charged particles from the Sun. And then later the Mirrorner ten vehicle did another Venus fly by in nineteen seventy four and it also found both a daytime and nighttime air glow around Venus, and it was found to be ten times brighter than

had been predicted. So this sounds really promising, right, Yeah, and this is this is a perfectly reasonable scientific explanation for what could be occurring. Yeah, exactly. So at the time people thought that the problem of the ashen light maybe was solved. So one version of the chemistry explanation from oxygen emission goes like this, You've got UV radiation from the Sun also ions charge particles flying out from the Sun, and this UV radiation and other stuff hits

particles in the upper atmosphere of Venus. And the atmosphere of Venus is made made up mostly of carbon dioxide, which contains one carbon atom and two oxygen atoms. And when the solar bombardment hits these carbon dioxide molecules, it splits them into and what it leaves in their wake when when they get split up is you get a carbon monoxide molecule which has one oxygen atom one carbon atom, and then you get a single isolated oxygen atom. And

single isolated oxygen atoms are not happy. They're lonely, they don't want to be out on their own, and they tend to recombine into other molecules. In this case, combining with other free oxygen atoms to orm O two, two oxygen atoms together in a molecule, and when this combination happens, the atoms emit photons of light in the visible spectrum,

and it's often described as a green light. And apparently this has been observed with instruments like apparently the Keeck one telescope in Hawaii has previously spotted green light in the atmosphere of Venus, which is consistent with the light that would be emitted by free oxygen atoms combining to form O two in the in the Venusian atmosphere. And that light was apparently also observed by the Soviet spacecraft

Vanera nine and Vanera tin. And what's more, this theory could help explain why there are some years when so many observers claim to see the light and other years in which nobody can find it, because this would depend on the atmosphere of Venus being bombarded by the Sun. So variations in solar activity could explain variations in the emissions due to atmospheric chemistry on Venus, like when the Sun is hitting the planet hardest, the oxygen mission becomes

the strongest, well it sounds like a pretty strong theory. Yeah, it does. It's so far at least so, but is it is it accepted? Is this is anywhere you're accepted? Unfortunately not. The authors conclude that while this this theory probably has the best chance of being correct, ultimately they

decided probably is not the correct explanation. So they decided to investigate the validity of the oxygen emission hypothesis in the spring of two thousand twelve, and they used visual observation and cc D or charge couple device recorded imagery of with different telescopes and different filters and observing visually. There were occasions where they thought maybe they saw the ashen light when they looked at Venus in two thousand twelve.

The authors actually quote Johann Shredder saying it had the texture of thought, Oh well, that's that's a that sounds a lot like I'm making it up. Yeah, well no, I mean I think that's what they're saying. It's like they're sitting there looking at it and they think maybe they can see it, but they get the sensation that maybe they're seeing with with their minds as much as seeing with their eye. This is this is staring at the magic eye image. This is staring into the woods

and trying to convince yourself you see something. Yeah. But of course the authors here aren't aren't just trying to go by their own perceptions. They want to use neutral imagery to see if they can capture this somehow. So they used a special filter for green light, and with that special filter they were able to detect a glow that could be imaged. I've actually got an image here with a very creepy looking crescent and and some green light. I don't know if you can see that, Robert, it's

yeah on here. Yeah, that that that is. That is creepy looking. But the authors also used some planet simulation comparisons to establish that the red and green ashen light perceptions that they thought they saw and that were imaged, we're probably due two scattered light from the illuminated to the unilluminated side, and there was no actual ashen light detected.

Another big problem I'm thinking about here. Most of the astronomers who have reported seeing the ash and light over the past three centuries have not had this kind of equipment, you know, with with the equipment available in the past, it seems highly possible that observers would not likely have been able to see this emission for moto formation. So it's not that there is no light coming off of venus from from the chemistry of the atmosphere, that it

does appear to be coming off of venus. The question is would it have ever been bright enough for people with telescopes hundreds of years ago to see And the answer looks like probably not. It's kind of like staring across a great lake, right, and maybe you can distantly

see the distantly see the other side. And then if you if you're trying to figure out if you can see people or not, you know, and then if you if you investigate, you can later find out, oh, yeah, there are people on the other side, but it's it's a far different thing than being able to actually see them from your shore. Yeah. So ultimately the authors conclude

that they don't know for sure. The most sensible explanation at this point is, unfortunately, the illusion hypothesis that despite the many reports over the years by by very respected astronomers, the phenomenon is most likely due to observer error and sort of optical artifacts from imperfect telescopes. And there's an

example they give and in their paper. In the early es, there's a there was a German astronomy writer named Daniel Fisher who produced an example of what he thought at the time was a directly captured digital image of the action light with a charge coupled device, you know, like

a digital camera. Unfortunately, it now seems clear that the image is actually just a case of what's known as filter leakage, and Fisher himself has accepted the fact that the image is is not a real image of the action light and has actually come to strongly doubt the existence of the action light. So the reasons he gives are there are no good direct images of it captured by a neutral device. And then he he says, quote just as amateur planetary imagers have started getting really good

reports have dwindled. This is what we talked about earlier. It's kind of like, you notice how as soon as cell phone cameras are everywhere, suddenly bigfoot sightings and UFO sightings drastically drop off. It seems like, just as people should be really having the ability to capture this image but on a neutral recording device, suddenly people aren't seeing it nearly as much as they used to uh, and so Fisher actually now thinks that the phenomenon is fringe

science and calls it quote the locknest monster of astronomy. Now, I don't think it's that bad because it's it's not a monster. There's no reason that you you shouldn't expect to find some kind of strange, chemically produced light on the dark side of a planet, right, that's perfectly plausible. The question is just we're people really seeing it or was it all tricks of the eye and tricks of

the mind. And certainly the more it became a mystery to write it has this appeal, Like you the near fact that we're talking about it is is evidence of this, you know, and the action light of Venus. Who who doesn't want that to be real? Who doesn't want to to glimpse that and partake of the mystery as well? Yeah? Exactly so. Ultimately, the authors of the paper conclude quote none of the putative images of the actual action light

can be regarded as convincing. They appear to be due to filter leakage, crescent glare, and excessive image processing used to bring out dark side detail. And yet despite their doubts, they say it's still possible that the action light does

exist despite their inability to detect it. One possible explanation could be that maybe it's only during extraordinary solar events, such as like coronal mass ejections, because that would provide extra bombardment of the planet Venus enough that its atmosphere really has a lot of oxygen emission going on, and that oxygen emission spectrum can be seen from Earth only during those times when the planet is hit with really

strong solar radiation. Well, that that makes sense, and it's in as in a sense, it would be the echo of a may your solar anomaly. Yeah, exactly. They don't mention whether what because we know about we know about solar activity in the past, so they don't mention trying to line up observations of it in the past with

what the Sun was doing at the time. I wonder if somebody tried to do a correlation analysis there if they would find anything that seems like the logical next step, doesn't it, But they right at the end quote for the time being, we can say no more. The action light cannot yet be laid to rest, though inevitably it

becomes a little harder to believe in. With each passing elongation, it might finally transpire that the longest standing mystery and Solar System astronomy is nothing more than a stubborn illusion. But in the meantime, the observer who enjoys a challenge is encouraged to remain on the key viv or on the alert. So here's my By the way, I had a crazy idea float here's my crazy question linking our

two venous episodes. So, first of all, I do want to say I accept their their conclusion that by far the most reasonable explanation of the point seems to be observer error. But if it is real, what if there is microbial life in the clouds of Venus, And if there is, what if it's bioluminescent. How do you like that? Yeah? So like if the ashen light is real and it's the glowing equivalent of periodic algal blooms and the clouds on the hot house planet, So uh yeah, I wonder

about that. Astrobiologists, astronomers, planetary scientists tell me why this is wrong? Well, I mean, the the one idea that comes to mind here is that it would have to be pretty intense during these flare apps. They would have to be again an order of orders of magnitude above what mere lightning or a rural activity would consist of. Correct, And it's I mean it's difficult to I mean, we've

all seen terrific lightning storms. We've seen uh, you know, the Aurora borealis at least in you know, images of it, and it's uh, it's it's on inspiring and also challenging to imagine some sort of biological phenomena occurring of the same caliber, you know. But but then again, I mean it's a long shot, but maybe yeah, somebody at least if you if you know what kind of spectra that a big luminescent organism in a cloud could produce, Uh,

do the math? What does that? Is it possible? I mean it kind of matches up really with the ideas of like coronations and wars and slash and burn agriculture, because what are these but um, but the infrequent bursts of activity that line up with biological activity on our planet. So this could be, yeah, the case of an intense season of mating or even some sort of essentially a war.

You know, I'm thinking about the way that that different varieties of coral wage wars against each other for dominance, and it's just um the and the you know, the death that takes place at the borders between the two. Uh. Maybe the action light is that sort of phenomenon, the you know, two different rival species of bioluminescent organisms clashing, you know, micro microbial war in the venus and clouds. That's a good that's a good story. I like that one. Well,

here's another thing I want to know. Do we have any astronomers out there among you all in the audience who have seen the action Light? Do you think you've seen it? If you've seen it, Uh, do you think it's likely you could have been mistaken or there are reasons you have for thinking you were not mistaken? We

would like to hear about this. Yeah, anybody else who has any stories about attempting to see something and that that curious mindset that we're talking about, where you're you're sort of screening to see something you don't see or hear something you can't hear, and what it's like to sort of creep your way up towards that line. Yeah, it's always shocking what our brands are capable of can't trust them. You can't, you can't. But it's all we have. I mean, it's not all we have. We have science.

That's the one of the the key r D mints here is that we do have scientific inquiry. We have uh, the ability to observe and record data. That should be it. That's a great pro science slogan. Science better than your brain, that's right, I mean created by our brain. But uh, but but so much better at tackling problems like this. Agreed. Well, uh, I think that does it for today. But this has been fun, Robert, Yeah. Yeah. Perhaps we'll return to Venus in the future. For the time being, head on over

to stuff to Blow your Mind dot com. That's where we'll find all the episodes of the podcast, including those past episodes on Venus, including that Will of the Whisp episode, and social media links. If you want to find out what we're doing on Facebook, Twitter, Tumblo, you want to see if we have some sort of revide live tour in the works, there will be a tab up there for that. Huge thank you as always to our excellent

audio producers Alex Williams and Tarry Harrison. If you would like to get in touch with us directly, to let us know feedback on this episode during the other to let us know if you've seen the ashen light or looked forward and not seen it. To let us know uh topic you think maybe we should cover in the future, or just to say hi, let us know where you listen from, tell us who you are. You can email us at blow the Mind at how stuff works dot com for more on this and thousands of other topics.

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