Larger planet supporting life?

[hawkinator]

Sounds good, I like it, consider me your first fan. Oh, and have a rep point while your at it.

Also. are Humanity Humans from Earth, or an alien from another place that resembles Humans?

Edited December 2, 2013 by hawkinator

[Ralathon]

Hmm... Food for thought.

We are trying to follow real physics as much as possible, the only major exception being how I have solved the speed of light barrier.(Basically, ripping a hole into another dimension and back again, but in a different relative location. I know that sounds OP, but it is balanced out by requiring an immense amount of power, and the further away the destination is, the more power it requires, so with even the biggest ships you can usually only jump 10 to 100 Light years at a time. Also the size of the ship doesn't matter, the portal consumes a marginal amount less if you were to open one a micrometre across than one a kilometre across, limiting smaller ships to jumping between a couple of star systems at a time, and waiting for a recharge to optimal power levels before jumping again.) Either way, I do want to see whether the major alien's homeworld can be physically possible.

Don't laugh at me for this but the main aliens in the series are person sized and looking(ish) two tailed squirrels. (These aliens also gifted humanity with the afore mentioned warp tech, known as a Sabier Drive) Their moon (Tallifrae) Is rich in resources, along with being inhabited by the imaginatively named Tallifraeans. (Think blue half person half shrimp marine aliens.)

EDIT: The planet is known as Gaia, to all races including Humanity, the Wagshee (The two-tailed squirrel people[Pronounced Wog-she]), and the Tallifraeans.

EDIT EDIT: I was thinking that it would be option two, but the planet/moon would be just far enough away that tides n both would be comparable to earth. Also, the atmosphere on both should be hospitable to humans on both the moon and the planet, if a slight reduction in life expectancy from a slightly higher content of noble gasses, such as xenon and argon on the moon.

The light speed bypass sounds good. I don't see any immediate loopholes for it. Just be sure to add some significant cooldown period for it as the ship dissipates heat and charges for the next jump. Else space battles would be a boring game of cat and mouse.

The only things I'd reconsider is the slight reduction in life expectancy and the alien appearance. Noble gasses do not interact chemically and are perfectly okay to breathe. I could replace all the nitrogen on this planet with Neon and nobody would notice a thing (Until the nitrogen cycle starts to break down). Just chalk up the lower life expectancy to the higher gravity if it is a major plot point. Increased gravity means people will have a much higher risk of cardiovascular diseases etc. As for the aliens, it sounds like they're alien for the sake of being alien. But I don't really see any advantage to a giant squirrel on a high gravity world, heat dissipation becomes very difficult if you are as big as a human yet as furry as a squirrel for example. Try to build up some ecological niche and fill that instead: Are they carnivorous? How does their biosphere look? What adaptations would they need to succeed in such an environment? Why did they evolve intelligence?

[lajoswinkler]

Life can exist anywhere, even on our Jupiter.... the gravity there just means WE cannot survive there, but any life that started on that planet, could, in theory survive, because it would have evolved *IN* those harsh conditions.

Same with atmosphere... we cannot breathe in arsenic gas... but life that evolved on that planet could breathe it....

What I am saying is, in Sci Fi, it doesn't matter it life can or cannot exist, write your story, people will either love it or hate it. the "Fi" in that statement means FICTION, ie, not real... this is why people write stories like Star Wars even though none of the tech exists for us... but so what.... most of the science is also bogus, but so what....

Sci Fi writers have never been to other worlds, they make the science FIT their story. Who is going to argue with them? The Aliens of BORRUS IV?

Arsenic sublimes at 615°C. There are no liquids supporting any possible notion of life (including the one we know) that could exist at those temperatures.

If you knew the basics of what life is, you'd know very well that life can not exist everywhere.

SF and fantasy are two different things, and he wants to make a very realistic SF.

0 chance? you can not do these kind of asseverations without prove it.

Even scientists said that is possible cross a wall walking without touch it if you try an infinite number of times.

You can said that is highly improbable. then I will be agree.

One time that I leave out needy vocabulary and I'm immediately criticized.

Yes, of course there is no absolute, mathematically zero probability. Let's say it's "practical zero".

But what about material structure that we dont know? What about different quarks structures? What about electromagnetism or other forces.

I am glad that you use the concept of entropy to describe life. But when you said that life require low entropy, this is in the case of life as we know it.

In fact what life do is take energy from outside, produce work and reduce its internal entropy, all this would increase the total universe entropy. So I dont find any logic rule to demonstrate that life can not exist.

And "I guess" that the light that plants absorb is in a higher entropy state that the elements inside a star.

I can said that in the center of the star there is a black hole, and inside the black hole there is life. And you can not refute becouse we dont know how a black hole looks from inside.

What quark structures? If there is no proof of something, and the proposition fails to be in coordinance with the stuff we already know, we can dismiss it.

Electromagnetism? Well we are here because of electromagnetism. Our whole structure is a bunch of EM forces.

No, not life as we know it. Life itself. Life as we know it is RNA/DNA-based. Life as a concept, that has "order" built in just like water has "wet" and circle has "round".

I'm not sure what you mean by the part with entropy. There's nothing weird about life, nothing against thermodynamic laws.

If there was a black hole in the center of a star, the star would be eaten because such system is unstable.

[AngelLestat]

Hmm... Food for thought.

Yes. Like hawkinator and other people said, a planet with those characteristics can support life similar to us.

More taking into account that they evolve in that world.

But there is still some plots that you can use to improve your story with this scenary.

A original scenary is not only the background landscape that your characters see through the window.

Is an oportunity to generate extra content.

For example, a planet with 1.5 g and 1.1 in radius can not have a normal space program like us.

Chemical rockets can not reach orbit. Their only hope is beam propulsion or advanced methods.

On the contrary their local moon would develop and conquerer the star system with ease.

I read every month news discovers that increases the habitable zone in differents concept systems.

For example in tidal looking planets orbiting stars at close distance is possible..

You can have a zone that is very hot, a zone that is really cold and a zone where the conditions are ok.

Also in your story the planets can orbit each other at close distances to allow some benefic to reach orbit at that direction.

They can be in a far orbit from their star, but they keep warm for the tidal forces. With a lot of volcanos in some planet points if their are face locked like moon with earth. It can be thousands of examples where these problems can be balanced to support life.

[Galane]

If you want to read some stories with giant planets, Hal Clement did a few. Most notably the novels "Close to Critical" (1968), "Mission of gravity" (1954) and its sequel "Star Light". (1971)

Close to Critical is set on a giant planet with a very deep, very thick atmosphere where the rain comes in boulder sized drops that slowly drift towards the ground, and that's just a small part of the weirdness, including a surface temperature of just over 374C.

Mission of Gravity is set on a giant planet that rotates very quickly, so quickly its shape is distorted into a very oblate spheroid. Centrifugal force reduces the apparent gravity at the equator to merely 2.5 G while at the poles it's hundreds of G. The author's calculations when he wrote it estimated the polar G would be around 700, but other people in later years, with computers capable of attempting the complex calculations for such a planet come up with a somewhat lower number.

The plot for that book is an experimental probe for studying the high gravity landed at one of the poles, then shortly stopped transmitting. Intelligent natives were discovered and their aid enlisted to recover data from the probe. The natives develop their own plans for the knowledge the humans are sharing to help them on their journey to the pole.

Star Light casts some of the same crew of Mesklinites from the previous book. Since they're from a world of high gravity, extreme cold and atmospheric pressure, they're the ideal explorers for the giant planet Dhrawn. It doesn't spin fast so it's a proper round world, but it's covered in ice and has an atmosphere with a lot of ammonia and poisonous oxygen instead of the methane of their home planet. Once again the Mesklinites have plans of their own for Dhrawn.

Harry Clement Stubbs was an astronomer and chemist, flew 35 B-24 Liberator combat missions in WW2, taught astronomy and chemistry for many years, and amongst all that wrote hard SciFi, usually involving very out of the norm worlds and odd quirks of chemical reactions on a giant scale.

He also tried to start a shared SF universe. With Mission of Gravity he opened Mesklin to other authors to write stories, but AFAIK, nobody did.

[Deathsoul097]

The wagshee were thought up because I thought a slightly larger world mostly covered in trees would be easy for a squirrel resembling race to navigate(Jumping between trees etc). The planet also has about a 45:55 ratio of land to water. Originally Gaia was going to be the size of Jupiter, but that has (Obviously) since changed, what can I say, I thought this stuff up when I was thirteen, two and a half years ago. (When you think about that it makes sense that between me and my friends we created this stuff, and then it just got ridiculous, to the point where one guy claimed that his planet's moons held all of the extinct species fro earth, like the dinosaurs, and another said that his creatures' fur was fire and electricity proof.) Also the reduction in life expectancy was just something I thought would happen to humans, having not evolved in an environment containing such materials.

Thank you hawkinator, I'll be sure to send you a copy of the prologue and chapters as we complete them.

Also, the series is called Forces at War, and the first book is Forces at War: Oblivion. (Sets the scene for the rest of the series and also develops both major human factions, the New Britannic Empire, and the Polar Federation, and is set in our galaxy, but the planets and stars are our own creations, excluding earth and sol etc. General storyline is that humanity all but wipes itself out in world war three (started by north korea launching nukes at america), and eventually only two nations remain; The cruel and marginally evil New Britannic Empire, based in the remenants of my homeland, England, and the Polar Federation, originally a large group of refugee nations in the war that sought asylum in Antarctica, and eventually develop to be slightly the NBE's superior technologically, until the wagshee decide to intervene an give both factions equal access to higher level technology. Eventually the two begin to encroach on eacothers territory as earth is slowly reclaimed from a smouldering nuclear wasteland, and anoher war begins, forcing the NBE to permanently leave earth.)

I will probably end up reducing the gravity to 1.3 or 1.2 Gs.

And no matter how much people ask, I will not change the aliens. (They are my pride and joy of creation in my bleak existence)

EDIT: This does seem to be getting slightly off topic now, doesn't it?

Edited December 2, 2013 by Deathsoul097

[brdavis]

Noble gasses do not interact chemically and are perfectly okay to breathe.

Well… yeah, you'd think that. Gaseous nitrogen is pretty close to a nobel gas, but humans have problems with nitrogen narcosis. Xenon is an excellent anesthetic. Helium has effects on the nervous system at high pressures. I don't think any of that is a problem is you evolved there… but for visiting humans, well, we have a rather narrow tolerance on a whole host of gases (oxygen is toxic, nitrogen is toxic, etc.)

As for the aliens, it sounds like they're alien for the sake of being alien. But I don't really see any advantage to a giant squirrel on a high gravity world, heat dissipation becomes very difficult if you are as big as a human yet as furry as a squirrel for example.

True, but depends on the climate and metabolism. If they have a slightly lower metabolism, or a slightly higher internal temperature, they will have greater heat loss… and even with terrestrial life there's a wide range (tigers and lions are roughly human-sized, and live in hot climate… and certainly aren't naked). Humans are rather uniquely good at heat dissipation, and so might not be the ideal model here.

Try to build up some ecological niche and fill that instead: Are they carnivorous? How does their biosphere look? What adaptations would they need to succeed in such an environment? Why did they evolve intelligence?

But I couldn't agree more with this

[DonLorenzo]

I dive and oh my god I get so high when deeper than about 30-35 meters (4 - 4.5 bar breathing air pressure). It's thought to be due to the gases dissolving in the fatty acids of cell walls, altering their conductivity. Most of your cells don't care, but neurons do and you use those to think.

edit: forgot to make my point, that it's not necesarilly chemical effects that mess you up

[brdavis]

You're right, we've gotten off-topic… but it was a fun direction to take it

Would it be possible for a slightly larger planet than earth (Say 1.5 G, and 1.1xEq radius) to support life? Theories, anyone? And could it have a water covered habitable moon?

Well… work the numbers. If it has the same composition as Earth (5520 [kg/m^3]) and was 10% larger, the mass would be 7.98e+24 [kg], or 1.33 [Me]. But surface gravity scales nicely with the mean density: g = (4 pi / 3) G rho R. So if it's the same density, the best you've got is about 1.1 [G's] for a surface gravity. To push that up to 1.5 [G's] on a planet with a radius of 1.1 [Re] would require a density 36% larger than Earth's bulk density, or about 7,527 [kg/m^3].

That's a problem.

Self-compression means things are denser than you would normally think, but from what we know that's a really high density for a terrestrial planet. You're inventing a big moon here, and maybe you could explain the high density for the planet as due to a Moon-forming impact leaving the planet with a larger than average core… but Earth already had that going for it. Could you get there, yes… but it's going to take a really really large core of metal.

Well, shoot… I did just say you could figure this out, right? OK… assume the mantle averages 5000 [kg/m^3], and the core 11000 [kg/m^3]. To get the bulk density around 7,530 [kg/m^3], the core will have to stretch 75% of the way to the surface (as near as I can tell)

Possible? Well, perhaps… but the moment I saw "1.5 G and 1.1 Radius" my suspension of disbelief radar went off on high. I may have a much lower tolerance than your readership, but I suspect that's the critical thing here. If I was reading it, I'd start questioning it… if a Star Wars fan was reading it, they would likely happily continue and not realize anything was amiss. So… who are you writing for?

Note I'd also say this object would likely be more volcanically active than Earth (given the same age). If they are in a mutual tidal lock there's no additional tidal input of energy, but if they are not yet in such a lock, tidal dissipation might be significant (it still is with Earth, for example). And in terms of internal radioactivity, an object 1.1 [Re] would have a heat flow about 1.1x the Earth, per square meter (the square-cube law is your friend). So the planet will have potentially plate tectonics, crustal recycling, and something called the carbonate-silicate feedback. It's in good shape.

The moon is a harder case. Smaller, almost certainly tidally locked, it's not going to have much in the way of internal heat… so unlikely to have plate tectonics even with extensive oceans (yeah, Venus is telling us you apparently need those). So no CO2 feedback, no (known) way to adjust for the star getting brighter, far less likely to remain habitable though out the life history of the star. Without crustal recycling, you aren't going to have mountains… especially not with an active hydrosphere. So, this is going to look a lot like Epona I suspect… not great for the inhabitants, aquatic or otherwise.

Have you figured out the atmospheric pressure and composition of these two worlds? Scale hight should be interesting… and atmospheric loss is something you'll need to be concerned on for at least the moon. Not to mention day length…

Yeah, I'm a geek. But I'm a geek with a PhD in physics who assigns world building projects to his college classes, so… yeah, this is my thing

[lajoswinkler]

Well… yeah, you'd think that. Gaseous nitrogen is pretty close to a nobel gas, but humans have problems with nitrogen narcosis. Xenon is an excellent anesthetic. Helium has effects on the nervous system at high pressures. I don't think any of that is a problem is you evolved there… but for visiting humans, well, we have a rather narrow tolerance on a whole host of gases (oxygen is toxic, nitrogen is toxic, etc.)

True, but depends on the climate and metabolism. If they have a slightly lower metabolism, or a slightly higher internal temperature, they will have greater heat loss… and even with terrestrial life there's a wide range (tigers and lions are roughly human-sized, and live in hot climate… and certainly aren't naked). Humans are rather uniquely good at heat dissipation, and so might not be the ideal model here.

But I couldn't agree more with this

You make a good point, though it's a bit of a semantic problem here. Nitrogen and noble gas narcosis is not due to chemical reaction. It's just that their molecules or atoms are overcrowding the body, so the highest functions of our biochemical machinery (high order parts of central nervous system) fail first. But there is no actual chemical reaction going on.

[AngelLestat]

One time that I leave out needy vocabulary and I'm immediately criticized.

Yes, of course there is no absolute, mathematically zero probability. Let's say it's "practical zero".

Sorry, but we are in the science section But well. I am agree then.

What quark structures? If there is no proof of something, and the proposition fails to be in coordinance with the stuff we already know, we can dismiss it.

http://www.sci-news.com/physics/science-particle-four-quark-matter-01538.html

Electromagnetism? Well we are here because of electromagnetism. Our whole structure is a bunch of EM forces.

No, not life as we know it. Life itself. Life as we know it is RNA/DNA-based. Life as a concept, that has "order" built in just like water has "wet" and circle has "round".

You answer me in base the definition that I choose (replicants that can evolve), so I dont know why you make an example based in us about elecromagnetism or why you are using different words to the life definition.

I need to remember you that we dont have a good definition about life yet. So there is not right or wrong. We choose one to keep the frame of the discussion.

I can give you some examples about replicants with the posibility to evolve.

-digital software in a virtual enviroment.

-memes in a brain-brain "cultural" enviroment.

-etc.

So is clear that it does not need to be matter to become a replicant.

All depends on the replicant and the enviroment. With some errors in the replicant process and natural selection, complex structures can emerge if the enviroment alow it. And when you have something really complex, a conscience can be found.

I'm not sure what you mean by the part with entropy. There's nothing weird about life, nothing against thermodynamic laws.

I am agree, but I had the feeling that you use the entropy example to try to prove that life can not be possible inside a star. But well, my english is really bad and maybe I misunderstudd.

If there was a black hole in the center of a star, the star would be eaten because such system is unstable.

for sure, but the only that matters is how long this process take..

If you have a tiny black hole, it can be in the center of earth, and it can take billons of years to absorb earth. All depends on the size.

Also maybe you have a big black hole that would consume the star in just some minutes. But we dont know nothing about the time inside a black hole. Maybe from inside that process takes billons of years.

The only that we know about a black hole is that there is an event horizon. We can calculate the entropy. but that's all. After that point, all our known physsics stops working.

From the entropy and information view point, there are amazing similarities with our universe.

I will probably end up reducing the gravity to 1.3 or 1.2 Gs.

Still with those values (in case you want to explain in some moment part of their history) chemicals rockets would not be able to reach orbit. Maybe with zero in payload they could, but with more efficient rockets that ours.

But all the adaptation problems or difference against human culture that you can find, it will only enhance the history and engiroment of your novel.

You're right, we've gotten off-topic… but it was a fun direction to take it

Agree. I can not discuss these topics with my friends

In your opinion, how close can be 2 planets one from the other tidal locked were life as we know it would be possible?

[brdavis]

it's a bit of a semantic problem here. Nitrogen and noble gas narcosis is not due to chemical reaction. It's just that their molecules or atoms are overcrowding the body… there is no actual chemical reaction going on.

There's no covalent bonding going on… but there are plenty of chemical effects. After all, the lipid membranes of the cell aren't kept together by covalent bonding (but weaker VanDerWalls forces), and even isotopic difference, which are *very* much "non-chemical", can kill you (don't drink the heavy water, it's a great way to screw up relative reaction rates… and *that's* certainly chemistry).

[lajoswinkler]

Sorry, but we are in the science section But well. I am agree then.

http://www.sci-news.com/physics/science-particle-four-quark-matter-01538.html

That's an unstable particle that probably decays extremely quickly. We honestly don't have any confirmation that actual matter that makes up the visible universe which interacts chemically is anything other than systems of protons, neutrons and electrons.

You answer me in base the definition that I choose (replicants that can evolve), so I dont know why you make an example based in us about elecromagnetism or why you are using different words to the life definition.

I need to remember you that we dont have a good definition about life yet. So there is not right or wrong. We choose one to keep the frame of the discussion.

I can give you some examples about replicants with the posibility to evolve.

-digital software in a virtual enviroment.

-memes in a brain-brain "cultural" enviroment.

-etc.

So is clear that it does not need to be matter to become a replicant.

All depends on the replicant and the enviroment. With some errors in the replicant process and natural selection, complex structures can emerge if the enviroment alow it. And when you have something really complex, a conscience can be found.

I'm talking about life in the form of organized matter, not information. Conscience is hardly relevant here. Tapeworm is alive, yet has no conscience.

There are some things which are on the border of live matter and chemicals. Viruses, viroids, prions, as separate objects, and various strands of foreign DNA which are embedded in our genome and are passed on as cells divide.

If you really want to discuss life in the form of information, that information needs a substrate. Again, ordered matter.

Memes are certainly not considered alive. Neither are selfish genes. They appear alive in some aspects, but that's it.

I am agree, but I had the feeling that you use the entropy example to try to prove that life can not be possible inside a star. But well, my english is really bad and maybe I misunderstudd.

I wanted to say that stars are sterile, because they're composed of matter which can not form organized units. Besides various ionic molecules above Sun's surface, our star gets progressively more disordered with depth. Few hundred kilometres below the photosphere there are no molecules of anything.

for sure, but the only that matters is how long this process take..

If you have a tiny black hole, it can be in the center of earth, and it can take billons of years to absorb earth. All depends on the size.

Also maybe you have a big black hole that would consume the star in just some minutes. But we dont know nothing about the time inside a black hole. Maybe from inside that process takes billons of years.

The only that we know about a black hole is that there is an event horizon. We can calculate the entropy. but that's all. After that point, all our known physsics stops working.

From the entropy and information view point, there are amazing similarities with our universe.

Actually our physics works inside black holes. It does not work in their centers. Passing the event horizon is visually interesting, but that's about it.

There might be stable orbits inside certain black holes but chances are extremely slim for anything other than subatomic particles trapped in those orbits.

Here's a paper on those orbits. http://arxiv.org/abs/1103.6140

[lajoswinkler]

There's no covalent bonding going on… but there are plenty of chemical effects. After all, the lipid membranes of the cell aren't kept together by covalent bonding (but weaker VanDerWalls forces), and even isotopic difference, which are *very* much "non-chemical", can kill you (don't drink the heavy water, it's a great way to screw up relative reaction rates… and *that's* certainly chemistry).

Well, you need to draw the line somewhere. Any atom or molecule interacts with others at least by London forces, but we can not call such interactions chemical reactions. Xenon has a fairly huge atom, but its narcotic effects are more due to overcrowding effects.

It is chemistry, but it is not a chemical reaction.

[brdavis]

Well, you need to draw the line somewhere.

True. I was drawing the line at "interfere with the water-based chemistry of life". And given the context of the discussion… I thought that was a reasonable line to draw. Especially when you consider how much of "biochemistry" has to deal with things like conformal changes in protein structure (not a chemical change at all).

[brdavis]

In your opinion, how close can be 2 planets one from the other tidal locked were life as we know it would be possible?

Hmm. Tricky.

First I think you can have life in tidally locked worlds (even once-faced worlds tidally locked to their stars it seem are OK if they have even an Earth-normal style atmosphere for heat transfer). I'm mostly pointing out that for a tidally locked satellite the solar day can be fairly long, which is something to consider… and something you can change (for story purposes). Move it into a lower orbit, and it orbits faster, and even if tidally locked has a shorter solar day. The limit there is probably that you shouldn't have a moon (especially a large one) below synchronous orbit (moons above synchronous orbit tidally evolve outward, which is probably OK... below synchronous orbit they tidally evolve inwards, which can result in serious consequences for anyone on the planet below ). But even there you have a lot of flexibility… if you need a fast moon orbit, put it just outside synchronous orbit, and make synchronous orbit low by having a rapidly spinning primary*.

Secondly, you can work out, roughly, the tidal locking limits at a given time… but before I want to do all that, there are a bunch of things to consider. Masses and radii of both bodies, how far apart they are, and the "Q factor" (how good they are at dissipating tidal energy). If you have advanced life here, the system needs to be… well, we're not sure how old. Life seems to kick off almost as soon as a planet has liquid oceans (it seems to have taken at most a 100 million years or so for Earth - which is a very short time, geologically speaking). Complex life, multicellular life, seems to have taken a good deal longer, possibly waiting until you started having some oxygen in the atmosphere… billions of years. So I'd guess the system in question might be at least 3 billion years old, based on Earth and "optimistically" shifting things around… but could be at least 5-6 billion (more than that… the biosphere is likely to run into other problems, like carbon starvation due to the carbonate-silicate cycle, etc., etc.).

While we're at it, what type of star is this planet orbiting? There's a maximum distance you can have a moon at (related to the SOI, but a little bit different - research Hill Radius).

*Yes, there are limits there - spin it too fast and it comes apart. I can work the numbers, when there are firmer numbers to work with, but for discussion let's assume a day length no shorter then 3-4 hours or so.

[Deathsoul097]

Well, I was planning on having the moon tidally locked to the planet, but not the planet to the moon, so the planet would have tides but the moon wouldn't. Also, the planet's day is about 30 earth hours, due to a larger radius and slightly slower rotation. I will reduce the gravity to 1.1G as well, and (AFAIK) having an increase by 0.1G will not render chemical rockets null and void. Scale height would be about 9Km, as opposed to the 8Km on earth, but the atmospheric pressure at se level would be slightly higher than earth, maybe about 1.2 to 1.3 bar? (Given how small drag losses are on ascent, putting a rocket into a 300Km orbit shouldn't take more than 12Km/s-1) Both the planet and the moon have a magnetosphere, most likely from having a molten spinning core. Gravity on the moon would be approx. 0.7G, with an atmospheric scale height of around 7.5Km, and about 0.7 to 0.9 bar of pressure on the surface, considering the entire moon is ocean. Bollator (The star Gaia orbits) is very similar to our own star (Sol), but slightly larger and slightly younger. The moon would be orbiting slightly above Geo-Synchronous altitude, so that satellites in synchronous orbit may be pulled into it's SOI. I'm going to say axial tilt for the planet would be about 9 Degrees, and about 1 Degree for the moon.

Edited December 2, 2013 by Deathsoul097

[AngelLestat]

That's an unstable particle that probably decays extremely quickly. We honestly don't have any confirmation that actual matter that makes up the visible universe which interacts chemically is anything other than systems of protons, neutrons and electrons.

You ask me how different structures can be possible, I show you.

That news is just 1 month old. Scientist said that would open a new branch on physsics that they dint know..

You just read it and you already have a posture and an opinion.. seems unserious but nevermind, the answer is:

"we dont know".

I'm talking about life in the form of organized matter, not information. Conscience is hardly relevant here. Tapeworm is alive, yet has no conscience.

But it does not matter what you was talking about, you answer me according to my definition. So you can not change it now.

I said: If we take life like any kind of replicant that evolves, then is difficult to imagine a place where life cant exist.

then Skyler4856 answer me: the center of a star

I respond: Haha, yeah, that seems challenging. But.. who knows..

then you answer me: No. Not possible. Life requires pretty low entropy and any part of any star is highly disordered. There is zero (0) chance life could exist there.

Also I mention conscience just like a possible consequence of the complexity. I dint said that it needs to be included in my life definition.

But this show us how difficult is to define life. What if we compare a Coral with a virtual conscience? One seems only a rock the other may be indistingible from a human.

You said that a Tapeworm it does not have a conscience.. I am agree. but where you cross the line?

Life as we know it is just another equilibrium state of matter.

If you really want to discuss life in the form of information, that information needs a substrate. Again, ordered matter.

What if that substrate matter is just information that we process like matter? This is not easy to understand, but the last advances in quantum computers and links between the thermodynamics laws and the information theorem points in that direction.

There are also real experiments about this conexion between matter and information.

If you want convert lets said a O2 molecule into bits. You need know the state of each subatomic particle with its spin and other atributes. Then you would realize that the amount of information that you need is X bytes. If you erese that information with a super efficient quantum computer you would measure the same amount of heat released by the operation that you would experiment if you convert that O2 molecule into energy.

Search about the Holographic principle if you want to know more.

Memes are certainly not considered alive. Neither are selfish genes. They appear alive in some aspects, but that's it.

there are not alive if you follow which definition?

You have the life definition from the biochemistry point of view, the physiological, religion, genetic, thermodynamics and metabolic point of view.

One of the most used is the thermodynamic definition, just becouse is based in one of the stronger theorem that we got. But we still dont know what is life and when draw the line. So we dont have any real definition yet.

Abour selfish genes... you need to said just "genes". Selfish genes is just the name of Dawkin´s book. A recomended read if you ask me.

About memes, if their enviroment grows, then in theory there are no limit how complex they can be.

I wanted to say that stars are sterile, because they're composed of matter which can not form organized units. Besides various ionic molecules above Sun's surface, our star gets progressively more disordered with depth. Few hundred kilometres below the photosphere there are no molecules of anything.

I am agree from the biochemistry point of view.

Actually our physics works inside black holes. It does not work in their centers. Passing the event horizon is visually interesting, but that's about it.

There might be stable orbits inside certain black holes but chances are extremely slim for anything other than subatomic particles trapped in those orbits.

Here's a paper on those orbits. http://arxiv.org/abs/1103.6140

It does not work, you can imagine what would happen if relativity would still work inside; ignoring the quantum theory.

That is what all scientist do when they talk about wurm holes, FTL, black holes, etc.

They ignore quamtum mechanics concecuences. And in those frames of reference they need to be take it into account.

In the paper I guess you dint read the part when it said:

"To clarify this possibility we suppose that BH interiors are described by the Kerr-Newman metric"

EDIT: sorry, i will answer you later BRDAVIS.. a storm comming.

Edited December 2, 2013 by AngelLestat

[Deathsoul097]

Im sorry, but did you really just call it a Wurmhole!?

Wurm!?

What?

(I apologise, but even if English is a second or third language for you, wow)

(Worm, not wurm)

(Man, my mom really has turned me into a grammar ****)

EDIT: Okayyy, KSP Forums don't like people saying grammar ****.

EDIT EDIT: Oh, COME ON! REALLY!?

Edited December 2, 2013 by Deathsoul097

[hawkinator]

Im sorry, but did you really just call it a Wurmhole!?

Wurm!?

What?

(I apologise, but even if English is a second or third language for you, wow)

(Worm, not wurm)

(Man, my mom really has turned me into a grammar ****)

EDIT: Okayyy, KSP Forums don't like people saying grammar ****.

EDIT EDIT: Oh, COME ON! REALLY!?

You could always try deliberately misspelling it, "natsie" or something like that. Better to not mention it though. People have been banned for incidents involving "not zee's". The expression we're reffering to is pretty safe, but the word itself is not.

Edited December 2, 2013 by hawkinator

[Deathsoul097]

Oh well.

Anyway, back on topic, We are specifically talking about this planet guys, not discussing the possibility of life in black holes. (Actually seems like that may be an interesting topic, if only for a bunch of people getting into an internet war over it)

The planet itself is probably about 3.5 Billion years old, the sun about 4.8 Billion years old. (I guess in the grand scheme of things 200 million years isn't much, but I'm finicky about this kind of thing.)

Also, I do know about Hill Spheres, and that is why I am being kind of cautious about stuff relating to the moon, simply because I don't want to get a rogue planet wandering and causing havoc in the system.

Edited December 2, 2013 by Deathsoul097

[AngelLestat]

Hmm. Tricky.

First I think you can have life in tidally locked worlds (even once-faced worlds tidally locked to their stars it seem are OK if they have even an Earth-normal style atmosphere for heat transfer). I'm mostly pointing out that for a tidally locked satellite the solar day can be fairly long, which is something to consider…

While we're at it, what type of star is this planet orbiting? There's a maximum distance you can have a moon at (related to the SOI, but a little bit different - research Hill Radius).

.

Ok, I will detail a lot more my question.

Lets imagine 2 earth size planets. Both tidal locking to each other. They are close enoght to complete one orbit in 24hs around their baricenter.

Their axis is the same of its star system.

So I assume that how they are tidal locked, there is not friction, earthquakes or other tidal issues related.

The centripetal force would almost nullify any gravitation anomalies due to the close body.

Of course I guess there would be a remarkable gravitation difference between closest face and the hide side.

Also I assume that there is not inwards of outwards forces working around this system becouse there is not variation tidal forces.

About how such system can evolve, seem unlikely bot no less imposible.

I can imagine some sceneraries where this could be possible.

After all, day by day discovering other star system with our telescoles, we already found many of them who challenge all our models about star system formation.

And giving the stability of the system, maybe there is a habitable zone in each planet where life can emerge.

Can be possible, or I am highly wrong?

Anyway, back on topic, We are specifically talking about this planet guys, not discussing the possibility of life in black holes.

Thanks for the correction, but Idk why you did such scadal for one word.

English speakers would have to show some appreciation to those who wanna learn their language so they do not need it.

And I spend time trying to help you with your history, but you ignore all my comments. So I dont know why I can not keep discussing related stuff with other forum users.

Edited December 2, 2013 by AngelLestat

[brdavis]

...the planet's day is about 30 earth hours, due to a larger radius and slightly slower rotation. I will reduce the gravity to 1.1G as well…

So pulling some numbers together from this and other posts, and making some stuff up as I go… let's assume the density of both planet & moon is the same as Earths (5520 kg/m^3), just to ballpark things. If the surface gravity is 1.1 G's, then the radius of the planet is 1.1 R_earth and for a moon surface gravity of 0.7 G's the radius there would be about 0.7 R_earth. Using those radii and the assumed density of 5520, you can calcuate their masses:

M_planet = 7.985e+24 kg (1.34 M_earth)

m_moon = 2.058e+24 kg (0.34 M_earth, or 28 M_Moon, Earth's moon… this is a Big Moon )

...the planet's day is about 30 earth hours… The moon would be orbiting slightly above Geo-Synchronous altitude, so that satellites in synchronous orbit may be pulled into it's SOI.

Well, I'm going to spitball an estimate of the moon being in an orbit with a period of 40 hours… certainly above synchronous orbit. In this system the 40 hours orbit would have a semi-major axis of 70,607 km (18% of the distance between Earth and the Moon). That's pretty close. The SOI for the moon would be around 41,000 km (I say "around", because really a SOI approximation is not going to hold here - the SOI is a significant fraction of the orbital distance), which means that there won't be any stable planet-synchronous orbits… at all. In fact there aren't going to be many long-term stable orbits more than around 25,000 km up around the planet… probably a lot lower. So… that may be a problem.

Scale height would be about 9Km, as opposed to the 8Km on earth, but the atmospheric pressure at se level would be slightly higher than earth, maybe about 1.2 to 1.3 bar?

With a higher gravity the scale height should be smaller, so I'm guessing either you have a higher temperature planet here or one with a significantly different gas mix? For an Earth-normal atmosphere, the slightly increased gravity means the scale height should drop from around 8.4 km for 1 G's to 7.6 km for 1.1 G's. A "sea level" pressure higher than the terrestrial value should be fine… even make sense (larger planet, more to outgas, so perhaps more atmosphere/hydrosphere). Mountain climbing will be a little tougher due to thinner air I guess.

Gravity on the moon would be approx. 0.7G, with an atmospheric scale height of around 7.5Km, and about 0.7 to 0.9 bar of pressure on the surface

Hmm, here I'm confused. With a surface gravity of 0.7 G's, the scale height should be, all other things being equal, much greater than on the planet. H_scale = R T / g, and if R (determined by the gas composition) and T (the atmospheric temperature) are the same, H_planet / H_moon = g_moon / g_planet = 0.7 / 1.1 = 0.636. So if the scale height on the planet was real 9 km, the moon should have a scale height around 14 km. for the 7.6 km I got for an "Earth normal" atmosphere, the moon would end up with a scale height of 11.9 km. Lower surface gravity implies taller scale height, other things being equal. So… are you taking into account some temperatures and gas mixes I'm not, or is something else up? Note that with the reduced gravity, the lapse rate will also change - about 6.9 K/km on the moon. That may present a problem in that the atmosphere will not get terribly cold terribly fast as you go up, so it may lack a good cold trap… which in turn means over geologic time, this moon is likely to start loosing the oceans due to UV photolysis and Jean's escape. Atmospheric loss in general is going to be a potential issue: v_RMS for O at T=1000 K (about the temperature of Earth's exosphere) would be 1,248 m/s, and with an escape velocity of just 7.83 km/sec, there's going to be a significant fraction of free oxygen radicals that are at or above escape velocity. It can probably hold onto an oxygen-rich atmosphere for billions of years, but probably not tens of billions - there might be significant long-term atmospheric loss here.

Both the planet and the moon have a magnetosphere, most likely from having a molten spinning core.

That's going to be an outrageous magnetospheric environment - when they are both aligned, it will be a strong magnetosphere, when anti-aligned I'm not sure what you will get (but, again, atmospheric loss might come up, like Mars in our own system). Probably even the smaller body will have enough internal heat to do this however, so that's not a big problem.

Bollator (The star Gaia orbits) is very similar to our own star (Sol), but slightly larger and slightly younger… The planet itself is probably about 3.5 Billion years old, the sun about 4.8 Billion years old.

More than a billion years between the formation of the star and the formation of the planet? That seems… more than a little long, to me. But probably not an important story detail. star larger than our own and as old or older than our own implies it;s going to be brighter, so the planet (to have Earth-normal insolation) will orbit further away. The details on that will depend on the stars mass (fairly sensitive to it).

I'm going to say axial tilt for the planet would be about 9 Degrees, and about 1 Degree for the moon.

If the moon is in tidal lock, it's going to have essentially zero obliquity relative to its orbit… and furthermore unless the situation is really unusual (look up Cassini states), the moon spin axis will align with the moons orbit will align with the planets spin axis (Earth's Moon being a very unusual exception). So if the planet has an obliquity of 9°, so will the moon.

I do know about Hill Spheres, and that is why I am being kind of cautious about stuff relating to the moon, simply because I don't want to get a rogue planet wandering and causing havoc in the system.

The Hill sphere and stability criterion for this planet, with a moon like that anywhere near synchronous orbit, isn't a problem - it's well within the planet's stability criterion.

Oh yeah, tides. Next post.

[brdavis]

...the next issue would be the tides. You have a few basic options:

1. Give them a tidally locked orbit to where they always have the same side facing one another (like Duna and Ike)…

2. No tidal locking would mean that both planets would have extremely high tides...

3. One or the other could only show one face to the other. Then one of the planets would have conditions like #1 above, and the one would have conditions described in #2.

I was thinking that it would be option two, but the planet/moon would be just far enough away that tides n both would be comparable to earth.

From other comments, I think you mean something like option 3: the planet rotates, and so has tides induced by the moon, but the moon has become tidally locked to the planet, and so has not tidal variation, just "fossil" locked-in tidal bulges. The equilibrium tidal height scales as:

(m_source / m_target) (r_target / a_orbit)^3

where "source" is the object inducing the tides, and "target" is the object experiencing tides. You can use this to compare a system to Earth. For example, here "Earth" and "Moon" pertain to the normal astronomic bodies, where "planet" and "moon" correspond to the objects in the story:

{ (m_moon/m_Moon) / (m_planet/m_Earth) } * { (r_planet/r_earth) / (a_moon/a_Moon) }^3

{ ( 28 / 1 ) / ( 1.34 / 1 ) } * { ( 1.1 / 1 ) / (70,606 / 384,400) }^3

{ 20 } * { 1.1 / 0.1837 }^3

4,294

Very roughly, tides on the planet induced by the (much much more) massive moon that is located (very very much) close to the planet will be huge… roughly 4,000 times higher than lunar tides on Earth, which are on the order of 11 cm. So we're talking tides on the order of half a kilometer, more or less.

Surfing is going to be AWESOME

More likely, tides like these lead to planets scoured flat, or tidal locking occurring in very short periods of time. You can do a rough estimate of the tidal locking timescale (& if you want I can give you a formula), but now all go really well out on a limb and say yeah… these will be very very VERY tidally locked. Mutually locked. So no tides. Back to hawkinator's Option 2.

[Deathsoul097]

So we're talking tides on the order of half a kilometer, more or less.

Surfing is going to be AWESOME

Okaaaaaaaay, that's a bit too much!

Right, moving the moon further out, About 35 to 36 Million metres sound good?

The whole system of gaia and tallifrae is tilted by 9 degrees, and tallifrae is tidally locked to gaia. (But not both to eachother,I like the idea that tallifrae is perfectly calm and gaia is more like earth in that regard.)

Scale height for gaia will be 7.5 Km (and yes, that 100m is so very important. ) Scale height for tallifrae will be about 12 Km, and the average density is about 5390Kg/m^3.

Surface temperature would be between an average of 3(Night) to 20(Day) degrees for gaia, and about 1(Night) to 10(Day) for tallifrae.

And if there is still problems with atmo loss for tallifrae I will just say that the oxygen particles get caught in the magnetospheres of the moon and planet and eventually return to the atmospheres.

(These are all just estimates, because I just finished my exams and I am not doing any more math this year unless you pay me.)

Edited December 3, 2013 by Deathsoul097