Where There's Intelligent Life, There's Mythology - Gliese 581g

[champu 1]

No doubt some of you read about the newest planet found in the Gliese 581 system. One of the things in the article made me think...

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The planet is tidally locked to the star, meaning that one side is always facing the star and basking in perpetual daylight, while the side facing away from the star is in perpetual darkness. One effect of this is to stabilize the planet's surface climates, according to Vogt. The most habitable zone on the planet's surface would be the line between shadow and light (known as the "terminator"), with surface temperatures decreasing toward the dark side and increasing toward the light side.

"Any emerging life forms would have a wide range of stable climates to choose from and to evolve around, depending on their longitude," Vogt said.

Forgetting for a moment the ramifications tidal lock and the resulting wildly different ground temperatures would have on the development and behavior of the atmosphere, imagine language-capable life's first round of mythological explanations for a light that hung in one spot in the sky for all time, and if you travelled too far in the direction towards it you'd fry and if you travelled too far away you'd freeze.

[GeorgiaDon 380]

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Forgetting for a moment the ramifications tidal lock and the resulting wildly different ground temperatures would have on the development and behavior of the atmosphere, imagine language-capable life's first round of mythological explanations for a light that hung in one spot in the sky for all time, and if you travelled too far in the direction towards it you'd fry and if you travelled too far away you'd freeze.

Sounds like an interesting premise for a science fiction story. I can't recall any that use this idea, does anyone know of one?

Don

_____________________________________
Tolerance is the cost we must pay for our adventure in liberty. (Dworkin, 1996)
“Education is not filling a bucket, but lighting a fire.” (Yeats)

[Remster 30]

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Forgetting for a moment the ramifications tidal lock and the resulting wildly different ground temperatures would have on the development and behavior of the atmosphere, imagine language-capable life's first round of mythological explanations for a light that hung in one spot in the sky for all time, and if you travelled too far in the direction towards it you'd fry and if you travelled too far away you'd freeze.

Sounds like an interesting premise for a science fiction story. I can't recall any that use this idea, does anyone know of one?

Don

'
I dont recall an specific story, but I had thought of that a while ago as a possibility (a sci fi possibility that is) and since I'm not THAT imaginative lol, I probably saw it somewhere before.

Remster

[turtlespeed 226]

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Forgetting for a moment the ramifications tidal lock and the resulting wildly different ground temperatures would have on the development and behavior of the atmosphere, imagine language-capable life's first round of mythological explanations for a light that hung in one spot in the sky for all time, and if you travelled too far in the direction towards it you'd fry and if you travelled too far away you'd freeze.

Sounds like an interesting premise for a science fiction story. I can't recall any that use this idea, does anyone know of one?

Don

Chronicles of Riddic had something Similar

I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama
BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun

[wmw999 2,589]

Nightfall by Isaac Asimov postulated a world with constant light and the mythology surrounding the (rare) time when both suns were obscured.

Wendy P.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[nanook 1]

I would imagine that they would live in a world of perpetual sunset. I wonder about tales that would be made up. It would be different from ours: No concept of day and night periods. Realization of the planet's orbit may take longer for civilization to realize. No seasons. Their periods of measuring time would be based on some other phenomena. . .very odd calendars, different concept of time. ect.

_____________________________

"The trouble with quotes on the internet is that you can never know if they are genuine" - Abraham Lincoln

[champu 1]

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I would imagine that they would live in a world of perpetual sunset. I wonder about tales that would be made up. It would be different from ours: No concept of day and night periods. Realization of the planet's orbit may take longer for civilization to realize. No seasons. Their periods of measuring time would be based on some other phenomena. . .very odd calendars, different concept of time. ect.

Yup, and again depending on how the atmosphere behaved, astronomy would be very bizarre. But if you could sneak off to the dark side of the terminator without freezing to death you could set up an observatory, watch constellations constantly, and see them move ever so slowly until your view repeated. That would probably be their first knowledge of a changing cyclic environment beyond their planet.

/edited to add: Communication satellites would be an interesting challenge. A synchronous orbit at L1 or L2 would result in terrible elevation angles, latencies, and the L1 would have the "sun" in the field of view at all times. I suppose you could put a plane of satellites into an orbit with an inclination and LAN of 90 degrees and they would just run around the habitable ring and never go into eclipse, that would be kinda cool.

[billvon 3,120]

>No seasons. Their periods of measuring time would be based on some
>other phenomena. . .

Well, if the orbit is at all elliptical, they'd have seasons (over the course of 30 days.) That would probably be their primary means of telling time.

In addition, while a tidal lock prevents rotation in two axes, it could still be spinning along its long axis. This would result in visible motion in stars over the course of a few hours to a few days. If it has a moon, the moon may be seen orbiting the planet, and may result in tides.

The winds would be incredible. The atmosphere would be constantly moving to the warm side, rising, then circulating back at high altitudes to descend again on the cold side.

[wmw999 2,589]

I got a PM saying that the book we're looking for is Jack of Shadows by Roger Zelazny.

Wendy P.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[champu 1]

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Well, if the orbit is at all elliptical, they'd have seasons (over the course of 30 days.) That would probably be their primary means of telling time.

The article didn't mention eccentricity and I have no idea about the prevelance of particular eccentricities, but yes an orbit like Mars (E = 0.09) or Mercury (E = 0.21) could generate significant seasons without taking the planet outside the habitable zone.

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The winds would be incredible. The atmosphere would be constantly moving to the warm side, rising, then circulating back at high altitudes to descend again on the cold side.

This is what I was alluding to in my previous two atmosphere comments. It's hard to say what that would mean in terms of haze, dust storms, etc. Don't know how easy creatures that were all that tall (bipeds) would have it. Flying creatures would also be hilarious.

[pirana 0]

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Well, if the orbit is at all elliptical, they'd have seasons (over the course of 30 days.) That would probably be their primary means of telling time.

In addition, while a tidal lock prevents rotation in two axes, it could still be spinning along its long axis.

The seasons are due to the tilt of the Earth's axis and the resultant variation in sun angle and length of day; not the elipticity of the orbit. The difference between close approach (perihelion) and farthest distance (aphelion) would have to be much greater than they are for it to significantly alter weather/climate patterns.

In other words, the orbit could be perfectly round and we would still have seasons based on axial tilt; but without axial tilt, we would need a dramtically elongated eliptical orbit to have seasons.

In more other words, the seasons are caused by the poles pointing away from perpendicular to the solar plane. When the pole you live closest to points directly toward the Sun, it is midsummer - and vice versa. (Not accounting for annual heat lag that causes the warmest and coldest days to be a month or 2 later then the solstices).

The only rotation for a body in tidal lock is on it's axis that is perpendicular to the rotational plane of the 2nd body; and it's rotational speed on that axis matches it's speed of revolution around the larger body (such as the Earth and Moon). There are examples of 2 bodies in 'dual lock' (can't think of the proper term) in which both bodies show each other one hemisphere at all times.

And then there is the freak Uranus.

" . . . the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging them and kicking them into obedience." -- Aldous Huxley

[billvon 3,120]

>The seasons are due to the tilt of the Earth's axis and the resultant
>variation in sun angle and length of day; not the elipticity of the orbit.

Right. But if they're tide-locked, either there's no spin whatsoever (one side always faces the sun) or the axis of spin is pointed right at the sun. So axial tilt won't give them seasons - but their orbit might.

>we would need a dramtically elongated eliptical orbit to have seasons.

Not so dramatic. Insolation falls off by the square of distance, so a little change causes a more significant change in energy. A 10% change in distance would give them a 21% change in insolation.

>In other words, the orbit could be perfectly round and we would still have
> seasons based on axial tilt;

Useless trivia - we're actually closer to the Sun in winter (in the Northern hemisphere) but the effects of our tilt predominate.

[pirana 0]

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But if they're tide-locked, either there's no spin whatsoever (one side always faces the sun) or the axis of spin is pointed right at the sun. So axial tilt won't give them seasons - but their orbit might.

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It is true that elipticity of the Earth's orbit provides some impact on seasonality; but it is very small and far less than that caused by minor factors such as ocean currents, albedo, wind, etc.; and trivial compared to axial tilt. In fact, the Earth as a whole is warmer at aphelion than at perihelion because of the orientation of land masses at that part of the orbit, further demonstrating the extreme dominace of tilt over elipticity (at least given the Earth's degrees of tilt and elipticity).

Tidal locked bodies ALWAYS have spin. (Do you think that because the Moon is tidally locked to Earth that it has no rotational spin along the plane of it's revolution around the Earth?) Tidal locking does not erase or eliminate spin, it's just that the rate of spin along the axis perpendicular to the 2nd body is the same speed as the revolution around the 2nd body. Rotation and revolution are in 1:1 resonance, but rotation is definitely not eliminated. In the case of a dual locked system, the spin of both bodies and the revolution around the center of the sytem are all in a 1:1 resonance.

A tidal locked body could have spin as described above; and also spin around a 2nd axis. If Uranus was tidally locked with the Sun, with it's pole always pointed to the Sun, it would have spin perpendicular to the solar plane in a 1:1 resonance to it's revolution around the Sun, as well as spin around it's poles. In that case it's seasonality would be based strictly on elipticity; but that would be an extreme case (and it's not tidally locked anyway).

A tidally locked planet with a rotational spin axis pointed directly at the Sun will not have axial tilt - along any axis.

" . . . the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging them and kicking them into obedience." -- Aldous Huxley

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[billvon 3,120]

>Tidal locked bodies ALWAYS have spin.

Right, just not relative to the body they're locked to. (Other than axial spin.)

[pirana 0]

OK, had to look it up. Aphelion is only 2.5% farther than average distance, or 3.4% farther than preihelion. Also came across several references confirming elipticity as a relatively trivial component of Earth's seasonality. It's not that it can not matter, just that in the case of Earth it matters very little.

" . . . the lust for power can be just as completely satisfied by suggesting people into loving their servitude as by flogging them and kicking them into obedience." -- Aldous Huxley

[champu 1]

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It's not that it can not matter, just that in the case of Earth it matters very little.

Correct. See my post #10.

To look at it another way, recall the fact that a "habitable zone" exists and how small it is. If the semi-major axis of the planet's orbit was roughly in the middle of the habitable zone but the eccentricity got up to around 0.25 or 0.30 (which isn't that eccentric) the planet would be scraping both edges of the habitable zone every orbit.

[Erroll 80]

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....imagine language-capable life's first round of mythological explanations for a light that hung in one spot in the sky for all time, and if you travelled too far in the direction towards it you'd fry and if you travelled too far away you'd freeze.

It would be interesting to consider the evolution of 'language-capable life' in the various niches of that environment.

[kallend 2,150]

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>The seasons are due to the tilt of the Earth's axis and the resultant
>variation in sun angle and length of day; not the elipticity of the orbit.

Right. But if they're tide-locked, either there's no spin whatsoever (one side always faces the sun) or the axis of spin is pointed right at the sun. So axial tilt won't give them seasons - but their orbit might.

>we would need a dramtically elongated eliptical orbit to have seasons.

Not so dramatic. Insolation falls off by the square of distance, so a little change causes a more significant change in energy. A 10% change in distance would give them a 21% change in insolation.

>In other words, the orbit could be perfectly round and we would still have
> seasons based on axial tilt;

Useless trivia - we're actually closer to the Sun in winter (in the Northern hemisphere) but the effects of our tilt predominate.

And that also explains why the analemma is not a symmetrical figure 8.

...

The only sure way to survive a canopy collision is not to have one.

[champu 1]

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....imagine language-capable life's first round of mythological explanations for a light that hung in one spot in the sky for all time, and if you travelled too far in the direction towards it you'd fry and if you travelled too far away you'd freeze.

It would be interesting to consider the evolution of 'language-capable life' in the various niches of that environment.

Absolutely. For starters, if the winds were howling constantly their language might not be acoustic.

[wolfriverjoe 1,523]

So we'd need BillyV to interperet for us?

Oh great, there go interplanetary relations down the tubes

"There are NO situations which do not call for a French Maid outfit." Lucky McSwervy

"~ya don't GET old by being weak & stupid!" - Airtwardo

[champu 1]

Gestures, pheromones, bioluminescence (in and out of our visible spectrum), there's all kinds of things that could develop.

[billvon 3,120]

>For starters, if the winds were howling constantly their language might
>not be acoustic.

Or it might not be based on _generating_ acoustic signals; it could be based on modulating the pervasive white noise. That would have the advantage of taking even less energy than talking.

[Guest]

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Well, if the orbit is at all elliptical, they'd have seasons (over the course of 30 days.) That would probably be their primary means of telling time.

In addition, while a tidal lock prevents rotation in two axes, it could still be spinning along its long axis.

The seasons are due to the tilt of the Earth's axis and the resultant variation in sun angle and length of day; not the ellipticity of the orbit. The difference between close approach (perihelion) and farthest distance (aphelion) would have to be much greater than they are for it to significantly alter weather/climate patterns.

In other words, the orbit could be perfectly round and we would still have seasons based on axial tilt; but without axial tilt, we would need a dramatically elongated elliptical orbit to have seasons.

In more other words, the seasons are caused by the poles pointing away from perpendicular to the solar plane. When the pole you live closest to points directly toward the Sun, it is midsummer - and vice versa. (Not accounting for annual heat lag that causes the warmest and coldest days to be a month or 2 later then the solstices).

The only rotation for a body in tidal lock is on it's its axis that is perpendicular to the rotational plane of the 2nd body; and it's its rotational speed on that axis matches it's its speed of revolution around the larger body (such as the Earth and Moon). There are examples of 2 bodies in 'dual lock' (can't think of the proper term [it's called "Tidal Lock") in which both bodies show each other one hemisphere at all times.

And then there is the freak Uranus.

I agree that the planet Uranus is arguably the most eccentric body in the solar system - it is just plain wacky and its behavior defies much of what we think we know about Keplerian mechanics. It is always the exception that somehow proves the rule, but we haven't seen all the answers yet. The planet may yet surprise us with some tricks. Too bad there's no long-term orbital mission to study the outermost planets the way Jupiter and Saturn have been (the New Horizons Pluto flyby is just that - a flyby).

The other Really Freaky Thing [TM] is the phenomenon of orbital resonance. Not even Kepler's brilliant math can explain that one. Last month's Astronomy Magazine discussed the subject. Truly amazing. It will be mind-boggling if systems like Gliese 581 exhibit the same characteristics as ours in this respect.

Good stuff, except for your overkill with apostrophes. Corrected, and I left the other spelling alone. You also abused semicolons.

mh
.

"The mouse does not know life until it is in the mouth of the cat."