OT: An extremely geeky hypothetical

[DaveMunger]

What kind of planetary conditions would be conducive to the development of an actual kaiju genus or phylum? I'm thinking here of a planet crawling with various  speicies like Barugon, Ghidora, Gaos, Godzilla, Rhodan, Gamera, Guiron, etc., and what kind of environment that planet would have to have for natural selection to favor huge, aggressive animals with weird abilities (flying things bigger than an elephant, reptiles that can stay underwater indefinitely, hybernation for periods much longer than a single winter, breathing fire...). Would it be a planet with light gravity and extreme seasons? Would food be very plentiful at times and very scarce at others, so that a good move is to gorge when food is plentiful so that you can grow to the size of a skyscraper so that you'll be able to eat your competitors for food when it get's scarce? Is size more of an asset at low temperatures?

[Scott]

Not sure Dave Munger, but I could only possibly compare "kaiju genus" to our own dinosaurs here on earth. Maybe it could have developed by the type of plant life that was consumed on the surface causing them to grow in great proportions and with what ever strain of genes they come from or adapted (mutated) from. Of course climate, the solar location, and topography that created climate. Both would play an important part in both the type of creature that developed and what it fed on. For extreme creatures to come forward would require possibly extreme conditions. Possibly much hotter than or colder than thought possible, but they wouldn't be able to come to earth. That is if they had to follow any laws of nature regarding oxygen, other gases, gravity, and not to mention bacteria. We know that our climate was much more soup like and who really knows what levels of gases were on earth. Suppose you may have to ask a much higher source about the design of all creatures. Everything else would have to be an experiment on your part in "creating" the unknown.

"W r brn nt th wrld f lmts s w cn knw th nlmtd n th Gdhd." from the Book of Scott.



Post Edited (03-09-05 21:16)

[Menard]

You are trying your darndest to make Buffy's Top Five list, ain't you Dave. (:

[Ed]

OK, I have to say this... I think there would have to be an evolutionary condition for LOTS AND LOTS of latex to rise up and form monster shapes.  
Also a natural source of cardboard for native building materials.

Ducks a wave of thrown calculators and slide rules (look it up).
-Ed

[Mofo Rising]

Well, I think your two major problems are going to be structure and energy.

First, it has been well documented by bad movie fans that you can't just supersize an organism and expect it to function well.  The structural integrity just isn't there.  Things that work very well at one size may do not work well at another.

Second, and this is the major concern, how are they going to get all the energy required to live?  On this planet, almost all of our energy comes from the sun.  The only organism who take direct advantage of this energy are plants (I'm simplifying).  Every other organism must either feed on plants, or feed on the creatues that eat plants.  However, there is an extreme amount of energy lost at each step.  Plants only put about 10% of the energy consumed into their bodies.  The things that eat plants only put about 10% of that 10% into their bodies.  Anything that eats those only gets 1% of the original energy, and so on and so on.

The largest animals on land are herbivores.  The largest animals on the planet (whales) eat plankton: microscopic plants and animals.  If we assume kaiju are predators, which would seem likely due to their combat skills, what are they eating/consuming to get all their energy?  They would need highly concentrated energy in large quantities, like large walking clumps of fat and protein.

Well I wrote too long to invalidate any concerns I had with that last sentence.  So we'll just take those large clumps of fat and protein as a given.  I'll come up with some evolutionary tactics for special abilities later.  Right now I should stop putting off writing that paper.

[peter johnson]

Planet Earth is already weird enough --
Seriously, go to any Archaeology/Paleontology website, & look for clues/links.
Earth is/was weirder than any of us can imagine!
peter johnson/denny crane

[Ed]

I agree with peter.   Check out these models of the fossils foundin the Burhess Shale beds in Canada (Also see Wonderful Life by Steven Jay Gould):
http://www.nmnh.si.edu/paleo/shale/pfoslidx.htm

-Ed

[Chris Reynolds]

It's always fun to do rough calculations about this sort of thing and I'll do the best I can, although I can't guarantee I won't overlook a factor somewhere along the line.

The biggest enemy of kaiju is the inverse square law - if an object gets twice as tall, it will area in cross-section (determining muscle and bone thickness) will increase by 4 times (2x2), and its volume (determining mass) will increase by 8 times (2x2x2). To be able for the kaiju's muscles to be able to support weight that has increased exponentially, the gravity would have to be much lower. (For the case of an object being twice the height, gravity would need to be halved).

Since kaiju are basically are very similar to dinosaurs scaled up, we can look at the biggest dinosaur we can find, assume that this it has reached the limit for its muscles and bones to still support it, and then see by how much gravity would need to be decreased. I'll take bipedal predators as an example, though I suspect the results would be similar for a quadruped. A quick search of the internet reveals that T-Rex can get to about 6m tall, but an incomplete skeleton of a Gigantosaurus has been found to be even bigger - we'll be generous and put the tallest dinosaur at 7m.

Godzilla (a scaled up T-Rex) has had his size vary over the years; a search on the internet has shown that Godzilla was originally 50m tall, but eventually reached 100m by the early 90s but is now back to 55m.

Even at 50m tall, (~7 times the height of the tallest bipedal predator) the gravity would need to be 7 times less - if this planet has the same density as earth, the planet would not be able to maintain any sort of atmosphere. Even if we could assume a very low density planet, I still doubt whether it would be able to maintain an atmosphere. However, if the inside of a planet was hollow - a "Journey to the center of the earth" scenario. At a deep enough level, the gravity would be low enough for such large creatures to exist.

These figures above only apply if the kaiju has to walk on land. For water dwelling kaiju, the water would support their bulk and allow them to grow to vast sizes. The biggest whale on record was over 32m long. That's already approaching kaiju size.

The second limiting factor would be, as mentioned above, food. There would need to be a very large external source of energy for it to be beneficial for a creature to become so large - and especially if the kaiju is going to be a fighting predator. Other posters above have already explained this well. The large energy source could be provided by the planet being close to a sun or by having a very large/powerful sun (or suns in a binary system - this could be even better if the planet's orbit in the binary system meant that it was rare for both suns to set and night to occur). In the hollow earth scenario, energy would have to be provided by heat from the planet's core (it would have to be a very old planet for the core to have cooled down enough to prevent the kaiju from being cooked).

So IMO, two potential kaiju habitats would be in the oceans of a world where the sun (or suns) shine down even brighter than ours does, or in a vast volcanic hollow deep inside an ancient planet.

[Menard]

My position on Buffy's list is seriously being threatened.

trek, Scott, Spiffy, Rich; we need to stand up for ourselves. (:

[DaveMunger]

Cool, looks like I've kicked off the exact kind of Nivenesque scenario I was going for, like Man Of Steel, Woman Of Kleenex: http://www.rawbw.com/~svw/superman.html
I have a bunch of little notions about this up that I'll post a little later.

[ulthar]

Chris Reynolds wrote:

> It's always fun to do rough calculations about this sort of
> thing and I'll do the best I can, although I can't guarantee I
> won't overlook a factor somewhere along the line.
>
> The biggest enemy of kaiju is the inverse square law - if an
> object gets twice as tall, it will area in cross-section
> (determining muscle and bone thickness) will increase by 4
> times (2x2), and its volume (determining mass) will increase by
> 8 times (2x2x2). To be able for the kaiju's muscles to be able
> to support weight that has increased exponentially, the gravity
> would have to be much lower. (For the case of an object being
> twice the height, gravity would need to be halved).
>

Huh? That's not the inverse square law.  The inverse square law has to do with properties that DECREASE as the square of the distance between them; light intensity, gravity, coulombic interactions, etc.

Also, the 'weight' does not increase exponentially, it increases as the cube power.  There's a BIG difference.  And this is for a CUBE, which people/dinosaurs/godzillas are not.  Just for a contrasting shape, a cylinder standing on its end (like a can of coke or shaving cream), the volume is linearly proportional to height.  This means the volume (and hence the mass) increases linearly (ie, the same power) with height if the radius is kept the same.

And, your own math disproves your final statement in this paragraph.  If the height increases by a factor of two, the volume (and hence the mass, assuming uniform density) increases by a factor of EIGHT.  So, for an object twice as tall, half the gravity would not do much at all.

The real issue is the force on the feet or legs.  Your point is correct that area and volume do not scale the same, but the details of your presentation are a bit unclear.

> Even at 50m tall, (~7 times the height of the tallest bipedal
> predator) the gravity would need to be 7 times less - if this
> planet has the same density as earth, the planet would not be
> able to maintain any sort of atmosphere. Even if we could
> assume a very low density planet, I still doubt whether it
> would be able to maintain an atmosphere. However, if the inside
> of a planet was hollow - a "Journey to the center of the earth"
> scenario. At a deep enough level, the gravity would be low
> enough for such large creatures to exist.
>

Again, huh?  Gravity has nothing whatsoever ever to do with DENSITY.  The V/m of the planet does not matter.  The mass is the only property that appears in the Law of Gravitation equation.  The spherical shell (hallow planet) of a GIVEN MASS will have the exact same gravitational effect of a solid sphere of the SAME MASS.
 
Sorry to nitpick; now I gotta get back to that hydrodynamic simulation code I'm elbow deep in.

[BeyondTheGrave]

No one shall take my place on the list. NO ONE!


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You can’t give it, you can't buy it, and you just don't get it!-Aeon Flux

[odinn7]

I dunno about that Rich...after that post that ulthar just made, you in some trouble son.

[DaveMunger]

Notions:

- I'm tentatively thinking here of a place something like Titan, lunar gravity with planetary atmosphere. Maybe it orbits a superjovian planet, a brown dwarf, or the smaller member of a binary pair (if that might have similar implications for holding onto more atmosphere than usual for it's size). Tidaly driven vulcanism, maybe periodic bombardment by icy bodies?

- Again, tentatively, thinking of kaiju as voracious, amphibious, hibernating omnivores. They might strip continent's almost bare, like locusts, then take to the oceans, eat almost everything there, then hibernate for long enough for the food chain to recover. The aggressiveness, fire-breathing, etc, is mostly about the fierce competition between them for territory to feed off of. Given the opportunity though, eating the competition would kill two birds with one stone.

- Oxygen is a problem, especially for flying things. The atmosphere should probably be very dense and have much more oxygen than ours. Maybe there's some weird geology putting extra O2 out there? Lighning or volcanos cracking water molecules, then a lot of the hydrogen escapes into space before it can react with the oxygen again?

- In any case, they'll probably need lungs, gills, and some other supplimental system for getting oxygen to all of that tissue. Maybe tubes running through their whole body, like the Ymir http://badmovies.org/movies/ymir/index.html?

- Biology in general might be pretty weird there. Maybe there are a lot of different kinds of autotrophs, like jet black plants that utilize the whole visible spectrum, or things that use energy from exotic sources, like cosmic rays or radioactive decay of some weird element we don't even have here. Maybe that's making the extra oxygen too. What drove these to develop? Maybe it was a very energy poor world when life first developed, then it migrated inward or one of the suns became more luminous. So you've got very efficient energy users now in an environment with super-abundant energy sources.

- If the green pigment that most of them have is chlorophyl(sp?), that could help a little with the calories and the oxygen (not only getting them, but getting them right in the tissues they're needed in without having to pump them through acres of blood vessels). Of course, by messing with the biochemistry of the kaiju themselves, we could give them titanium skeletons and internal nuclear power plants converting all the CO2 in their blood back to oxygen so that they don't need to breathe at all and they could live on Earth, but that sort of thing should probably be considered cheating at some point.

- Features like Godzilla's floppy stegosaurus plates could be there just to increase surface area, which they'll tend to be short of in proportion to their internal area. They'll need that if they want to do any photosynthesis of their own, or do any respiration through their skin. Also, probably important for regulating their temperatures.

- What should we call this planet? I'm thinking mayby Toho.

[Menard]

Oh..Oh..that is truly grandstanding....blogman.