Thinking through the high gravity of certain planets in Dragonball's Universe.

Kotoroshinoto

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I recall vaguely that planet vegeta was supposed to have 20X earth gravity and king kai's planet 10X.

I know this is a fictional universe, and that Toriyama doesn't have much of a mind for scientific coherence or even remembering his own canon, so taking this too seriously is fraught with problems to begin with, but I became curious about how this relates to density of rocky planets and their cores and how much mass it takes to produce gravitation like this.

I don't think we've been provided with a radius or volume for the planet, which makes figuring this all out a bit difficult, but if the planet has a similar structure to other rocky planets it would have a metallic core with a solid core and possibly liquid outer core, mantle of some thickness, and an outer crust/lithosphere layer.

that outer surface rock is going to have a density that averages around 3 g/cm3, and the mantle density of earth ranges between 5.8 to 4.5 g/cm3. It would probably take a significant shift in elemental makeup or a serious increase in pressure to alter the densities for these layers, even if the planet had significantly more gravity or was larger (and thus the layers had more volume).

Its important to remember, gravity relates to the distance from the center of mass, so these outer layers, being of roughly equivalent density to earths wouldn't contribute enough mass to offset the distance they're adding, so the planet probably has a similarly thin shell of outer rock layers. Thus... all the extra mass must come from the core layers.

But what kind of material could possibly offer that much density? At earth's surface, iron has a density ~7.874 g/cm3 at room temperature and 6.98 g/cm3 at melting point. Since both the solid and liquid core layers are significantly more dense than this (approximately 13 g/cm3 and 11 g/cm3 respectively), it stands to reason that other elements or elemental mixes would also experience a significant increase in density if collected within the core of a planet in large quantities.

Even if we push the envelope and look to Osmium, the densest metal, it is only 22.6 g/cm3. If we were to take earth and straight out replace the existing scenario for a core dominated by solid and liquid osmium (ignoring for a moment the changes to the thermodynamics and likely lack of a protective magnetic field that this would create), and presume that it similarly approximately doubles in density due to the extreme pressure, you'd have a core of ~45 g/cm3 and outer liquid layer probably ~38-40 g/cm3 {bear with me, these numbers are fudged. I'm not sure this is even possible, or how a mostly osmium alloy would actually behave at these temperatures and pressures, it may well have another state that allows for higher density than what we see with iron, but as I'm not as well versed in the physical chemistry properties of elements like osmium, or its behavior under these conditions, I've not got much to go on}. With the same sized core, you'd only end up with the mass increasing by approximately a factor of 1.8, and thus the G's likewise being approximately 1.8 (as the volume/radius is still the same).

So clearly an increase in volume of the core layers or the use of something SIGNIFICANTLY denser than osmium would be necessary to make any major impact. Are we talking white dwarf matter? I'm at a loss with regard to pursuing that line of inquiry, so on to the volumes!

Sticking with these densities, if the inner solid core has a radius ~5 times larger and the outer liquid core ~ 2 times larger, with a mantle ~1.5 times larger and crust of equivalent depth, applying a multiplier for water for the ocean based on the ratio of the surface areas (even though its actually a thin volume, this is probably a good enough approximation), you get a mass almost 2 orders of magnitude higher while only being a factor of 2 larger in the radius. this still only puts us at 7.5 G. We need something denser or a planet that is absolutely VAST. We're probably already beyond the limits of what silicate based planets are capable of.

Its a shame we can't easily map this onto actual physics, but such is the nature of fiction in general, especially when its a Toriyama numbers related ass-pull.

We can also use a cop out claiming fictional dragon ball physics make things like gravity work differently, but its still disappointing that you can't make sense of it.

I'm not sure what the theoretical limit is for the density of matter at the core of a rocky planet (or even just in general, lest it form a black hole), or at what strength of gravity you'd be likely to form a star or a gas giant. 20X earth Gs might already be beyond this limit.

Any suggestions for this, or criticisms of my math? Did I calculate anything horrendously incorrectly or am I missing some material or option that might get us closer?

Edit:

here is a link to google sheet showing the math:
 
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LividJay

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Bruh. It's just Dragon Ball. No need to science the fuck outta it. :lmao:

Seriously though. A lot of thought obviously went into this and it's actually quite interesting when you think about it. I always enjoy when a movie or TV show puts in the effort to be as realistic as possible.

Now, I'll let you go ahead and do calculations for their instantaneous movements which, despite having mass, seem to be able to go faster than light speed.
 

India Actual

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Here’s some math to figure out. So Vegeta is 5’5(164cm) and 123lbs(64kg). We saw him withstand 400 times gravity. How massive would Vegeta have to be to realistically withstand 25 tons?
 

LividJay

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Here’s some math to figure out. So Vegeta is 5’5(164cm) and 123lbs(64kg). We saw him withstand 400 times gravity. How massive would Vegeta have to be to realistically withstand 25 tons?
I think their mass is the least of their worries. How do their bones support that weight without breaking?
 

Kotoroshinoto

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Bruh. It's just Dragon Ball. No need to science the fuck outta it. :lmao:

Seriously though. A lot of thought obviously went into this and it's actually quite interesting when you think about it. I always enjoy when a movie or TV show puts in the effort to be as realistic as possible.

Now, I'll let you go ahead and do calculations for their instantaneous movements which, despite having mass, seem to be able to go faster than light speed.
You're not wrong, I even said as much lol. Its still fun to think about how badly physics is being bent over and taken from the rear.

with regard to instant transmission I always figured it involved multidimensional travel, something akin to using ki to fold space, so the distance traveled was effectively zero.

and with regard to their ability to withstand the bullshit forces they had to generate for their more mundane movement, I figured ki is kinda like magic, so they will invoke the clause of "its magic, I ain't got to explain shit"
 
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LividJay

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You're not wrong, I even said as much lol.
haha I know, I was just playing around.
Its still fun to think about how badly physics is being bent over and taken from the rear.
Totally agree.
with regard to instant transmission I always figured it involved multidimensional travel, something akin to using ki to fold space, so the distance traveled was effectively zero.
Yeah, I had a similar thought, but attributed it to possibly something like transporters in Star Trek where you de-molecularize or something. Either way, even then, it should be impossible to travel faster than light. Some multi-dimensional shit...hmm...I dunno.
and with regard to their ability to withstand the bullshit forces they had to generate for their more mundane movement, I figured ki is kinda like magic, so they will invoke the clause of "its magic, I ain't got to explain shit"
My way of justifying it was always that their ki would push back against anything and prevent the weight from actually falling on their muscles and skeleton...but damn...that's some powerful ki and it would basically be saying they waste a lot of their energy with their ki constantly flowing out of their bodies...but then, that was pretty much addressed in Super.
 

LividJay

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for the sake of argument, the densities of white dwarf material is 1,000,000 g/cm3 and neutron star material 100,000,000,000,000 g/cm3.

So... technically there ARE forms of matter that could get the amount of mass required into a small space, but then if you tried to layer normal planetary material around that shit, it'd probably just eat it.
Maybe they have a lot of dark matter.
 
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India Actual

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for the sake of argument, the densities of white dwarf material is 1,000,000 g/cm3 and neutron star material 100,000,000,000,000 g/cm3.

So... technically there ARE forms of matter that could get the amount of mass required into a small space, but then if you tried to layer normal planetary material around that shit, it'd probably just eat it.
We should hit up Because Science about more Dragon Ball physics. You sir should be our official science representative because you've got astrophysics down like I perfected the art of pissing people off.
 

Kotoroshinoto

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also found this article in my searches: https://www.universetoday.com/13757/how-big-do-planets-get/

"The largest “terrestrial” planet is generally considered the one before you get too thick of an atmosphere, which happens at about 5-10 Earth masses (something like 2 Earth radii). Those planets are more Earth-like than Neptune-like. "

plugging the numbers into the expression for acceleration due to gravity that tops out at around 2.5G, so to get more we'd need to fudge something about the core, much Like my OP mentioned. I'm wondering what sorts of exotic bullshit we could invoke. Dark matter sounds interesting, though that at the moment is still a bit of a placeholder quantity. We don't know if it really exists, and if it does, anything else about its nature other than the gravity we can't otherwise explain.

We should hit up Because Science about more Dragon Ball physics. You sir should be our official science representative because you've got astrophysics down like I perfected the art of pissing people off.
Thanks for the high praise. My area of expertise is actually biomedical science, with a focus on genomics. It just happens that they make you do a lot of basic sciences in general when you are a science major, and especially when your undergrad is a biochem / biotech dual major. This stuff at least isn't approaching the relativistic math or differential equations involved in thermodynamics and equilibrium calculations for chemical reactions etc (its been nearly 10 years since the last time I did one of those problems). Its mostly plug and play, and dividing up the layers into volumes for approximate calculation.

Just don't get me started on how dumb it is to have hybrids between species that don't share recent common ancestry. Its not as if DragonBall is the only offender in this regard (ugh DC, why does supes have a kid with a human... it hurts physically to see that, even though I'm trying to suspend disbelief its like a kick in the head to see that)

1574307265539.png

though... taking a second look at that planet, it does look AWFULLY like the sort of clouds you'd see on a gas giant. Maybe Toriyama knows something we don't XD.
 

India Actual

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Just don't get me started on how dumb it is to have hybrids between species that don't share recent common ancestry. Its not as if DragonBall is the only offender in this regard (ugh DC, why does supes have a kid with a human... it hurts physically to see that, even though I'm trying to suspend disbelief its like a kick in the head to see that
I hate to keep being "that guy" like I'm shamelessly plugging my work but.......
korian family.png
GUILTY!

:cheeky:
 

Kotoroshinoto

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its good art regardless, and since the universe in question already established a precedent I can't really complain about building on it (the complaint merely stands with the establishment of the precedent).

Doesn't meant you can't make interesting content with it. At least in DragonBall it was originally pure fantasy and never stuck too strongly to rules or realism, so i'm not that angry about it, its just something that tends to get me to rant about this trope being abused so often in fiction.

Other universes like Marvel or DC try to play the sci-fi card more frequently, building off of comic-book logic driven pseudo-science. When THOSE violate this, it bothers me much more.
 

India Actual

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its good art regardless, and since the universe in question already established a precedent I can't really complain about building on it (the complaint merely stands with the establishment of the precedent).

Doesn't meant you can't make interesting content with it. At least in DragonBall it was originally pure fantasy and never stuck too strongly to rules or realism, so i'm not that angry about it, its just something that tends to get me to rant about this trope being abused so often in fiction.

Other universes like Marvel or DC try to play the sci-fi card more frequently, building off of comic-book logic driven pseudo-science. When THOSE violate this, it bothers me much more.
I appreciate you taking a scientific approach to your position on the matter. I usually just get “OMG! He’s a furry lover!” or “How does that even work when she’s a rabbit?!”

Like you said precedence exists in universe and its anime, it doesn’t have to make perfect sense as long as it’s entertaining. That is the number 1 take away from all scientific shattering principles in entertainment.

Doesn’t mean we can’t have fun like we are in this thread coming up with utter bs to explain why Dragon Ball does what it does. People need to remember that Toriyama loves two things primarily. Cars and comedy. Pair that up with the fact that he’s a seat of your pants discovery writer means scientific principles were the least of his concern.

I’m having fun with it and I hope everyone else is too. Even if I have to write about scientifically impossible interspecies sexual relations. Now that just sounds weird when you say it out loud.
:curse-you:
 
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Kotoroshinoto

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I appreciate you taking a scientific approach to your position on the matter. I usually just get “OMG! He’s a furry lover!” or “How does that even work when she’s a rabbit?!”

Like you said precedence exists in universe and its anime, it doesn’t have to make perfect sense as long as it’s entertaining. That is the number 1 take away from all scientific shattering principles in entertainment.

Doesn’t mean we can’t have fun like we are in this thread coming up with utter bs to explain why Dragon Ball does what it does. People need to remember that Toriyama loves two things primarily. Cars and comedy. Pair that up with the fact that he’s a seat of your pants discovery writer means scientific principles were the least of his concern.

I’m having fun with it and I hope everyone else is too. Even if I have to write about scientifically impossible interspecies sexual relations. Now that just sounds weird when you say it out loud.
:curse-you:
I also had a concept character that was a hybrid, but I was planning to retcon a few things into the backstory of where saiyans came from to force it to make sense. Idea was that something akin to a mad scientist abducts some ancient humans and mucks about with their genetics to produce the saiyans and another race planting them on separate planets with some livestock and seedstock also modified to suit the local environment based on organisms from earth , in a way similar to the origin of the protoss and zerg from starcraft, but with the same precursor species, just altered differently. The character was to be a hybrid of those.)

So yeah, who am I to judge fan creations lol.
 

Beerus

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Planet Vegeta was originally Planet Plant which should be taken into consideration I think.
Also in GT, it was the Planet Tuffle and those people were geniuses. This may factor into what makes the planet so different or strange when you write down the numbers. They could have altered it.
 

India Actual

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Taking into consideration multiple factors such as hybrid strength that we saw clearly displayed in DBZ with Gohan, Goten, and Trunks. Toriyama's newer S-Cell theory about how the more peaceful a Saiyan lives the higher propensity for these cells to propagate and therefor trigger the Super Saiyan transformation. Also taking into account the actual setting of the story I am writing being Universe 9 which is clearly stated to be a bit of a :poop: hole. All these things combined is why Shihori is so strong at such a young age compared to the other hybrids. I added the je ne sais quoi they lacked to reach their full potential. She's potentially stronger because of her hybrid make-up. On the day to day she lives a relatively peaceful lifestyle mainly due to her father's efforts to keep bad guys in check. Finally, she was raised in a multiple discipline household. I wrote Sorrel growing up very poor and living on the streets. Not wanting that kind of life for her own child she instilled not only street savvy ways that Korian lacks due to growing up in the sticks, but she remains steadfast in providing a good education which both Korian and herself never had access to. On the physicality side of things she has her father to constantly train with as well as receiving a wealth of knowledge from Korian's adoptive mother who is a martial artist by trade.

I'll be honest and my own biases against what Toriyama did with certain characters in his own story shaped the person she would become. She's greater in some ways than other hybrids but she's not a Mary Sue. She has her Achille's heel in the form of that drive to be the best she got from her father and a fiery temper she got from her mother. Also a bit of a penchant for foul language.
 

Beerus

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Taking into consideration multiple factors such as hybrid strength that we saw clearly displayed in DBZ
Isn't the reason behind this dealing with the heart of a human? Like normal saiyans have a slower progression because their pride gets in the way of their heart and mind whereas a human's heart tends to cancel this out.
 

Kotoroshinoto

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Isn't the reason behind this dealing with the heart of a human? Like normal saiyans have a slower progression because their pride gets in the way of their heart and mind whereas a human's heart tends to cancel this out.
I don't think they ever quite explained it.

Gohan also appears to be the only human/saiyajin hybrid that had special potential that was ever explicitly discussed (his rage boosts).

I mean, sure Trunks and Goten were strong and got to super saiyajin level pretty young, but that could easily be chalked up to their being saiyajins and everybody around, including the humans and the namekian being at absurd levels of power. Knock em around a few times in spars and ensure they get healed and zenkai boosts will set the little rugrats on a course to catch up.

Of course, i'm also just ignoring Toriyama's inability to be consistent about anything and his far greater interest in things being "cool" than making any kind of sense.
 
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