The article in question rather long, and goes into the history of Newton's laws of motion and gravity, and how they relate to Einstein's general theory of relativity. Here's the part that gave me the idea on SJ gravity:
The undeniable fact that both [graviatational and intertial] masses are denoted by the same letter m must not cloud the equally undeniable fact that there is no inherent reason why those two should be the same at all. For example, the electromagnetic attraction between two charged particles is given by Coulomb's law:
(13) FEM = Kq1q2 / r2
You'll notice that this formula looks very much like Newton's formula for gravity; it states that the electromagnetic force is equal to a constant K, times the charge on both of the objects, divided by the square of their distance. The difference between Coulomb's formula and Newton's is that the property that generates the electromagnetic force is not mass but charge, while the property that determines the acceleration due to that electromagnetic force is still mass.
While I'm not necessarily opposed to applying real-world physics to Spelljammer (I think these ideas for gravity generators and atmospheric retainers are pretty cool, for instance), I don't see why it's *necessary* to do so to make SJ more palatable.
It makes me laugh when people, with ideas like those in your link, want to "get rid of crystal spheres and the phlogiston".
I think the spheres and the flow are an essential part of what makes spelljammer great. They have a clunky kind of elegance to them.
(People who dislike spheres or the flow usually point out that they are unrealistic, but then usually come up with a bunch of rules to allow spelljamming ships to enter "hyperspace" or travel faster than the speed of light -ignoring the fact that both are believed to be scientifically impossible and are therefore also equally unrealistic.)
However thanks for the link. Hopefully someone will get something useful out of it. I'll add it to my links page.
Wyvern
So what does this have to do with Spelljammer? Well, suppose that in the SJ universe, gravity is not proportional to mass, but instead is a constant for all objects above a certain size.
That is already how Spelljammer gravity works. Most large objects exert a force of 1g. And most large objects only exert gravity within their air envelope.
(For smaller objects, gravity should still work as normal.) You could also allow some objects to have heavier or lighter gravity regardless of their size.
Small objects currenly have zero gravity - not "normal" (I prefer to say "real-life" gravity). (With real life gravity objects all have the same gravity proportional to their mass. With SJ gravity objects have 1G or 0G.) I think that is why they don't make a ship slow to tactical speed. I think the force that makes ships slow to tactical speed is somehow related to gravity (SJ gravity - NOT real gravity).
A small number of things cause variable gravity. I think that it would be easier if gravity increased in integers (0, 1, 2, 3, etc) as this fits in with the current options.
If you want more answers you might be better off posting to the SJML as I'm pretty sure it is more active than these forums.
That is already how Spelljammer gravity works.
I'm aware of that -- look at the title of my post. The point was to provide a "scientific" explanation of how gravity might work as it does in Spelljammer. You obviously don't feel the need for such an explanation (and neither do I, when it comes right down to it), but apparently some people do. My suggestion was intended to accommodate those people.
Small objects currenly have zero gravity - not "normal" (I prefer to say "real-life" gravity). (With real life gravity objects all have the same gravity proportional to their mass. With SJ gravity objects have 1G or 0G.)
This was part of my original idea, but then I noticed a problem. The equation for gravitational force includes the masses of both objects. If an object exerts no gravitational force on other objects, neither can other objects exert any force on it. Of course, I could change the equation to make it one-sided, so to speak, but that has an unusual side-effect. Since force equals mass times acceleration, if all objects experienced the same gravitational force regardless of mass, then more massive objects would actually fall more slowly (for the same reason a lightweight object will accelerate more quickly if you push on it than a heavy one will).
If you want more answers you might be better off posting to the SJML as I'm pretty sure it is more active than these forums.
That may be the case, but I spend too much time reading internet forums and message boards as it is; I don't need to add another one to my list. Besides, if your reaction is typical of what I might expect from posting my idea on the SJML, no thank you.
Wyvern
If I didn't think you were a person worth writing to I wouldn't have written in this thread in the first place. If you don't want me to comment further on your ideas then I won't. Its up to you.
I'm aware of that -- look at the title of my post. The point was to provide a "scientific" explanation of how gravity might work as it does in Spelljammer.
I think the problem that you face if you want to do that sort of thing is that the Spelljammer Campaign Setting is based on old world (incorrect) views of the world, the solar system and the universe that were around before science prooved that they were wrong.
Those views (that we now know are incorrect) are not incorrect in the Spelljammer universe. So the Spelljammer Campaign Setting itself is unscientific. I think that this concept is one of the things that newbie Spelljammer players struggle with - lots of people seem to get the first impression that Spelljammer is a sci-fi game. Using scientific words could actually add to someone's impression that Spelljammer is somehow scientifically accurate.
Crystal spheres belong in the same sort of era where people belived that the earth was flat, the sun orbited the earth and the back of the moon was dark. People playing Spelljammer are already playing a game where dragons, mythical creatures and magic spells are normal. I think that your article should have a tone that fits in with that sort of spirit.
I'd suggest that you look for real works about the theories of crystal spheres, the flat earth and the geocentric universe (where Earth is at the middle). Find old translations of these articles and you will find yourself a bunch of words that evoke that sort of era instead of a modern day era.
You obviously don't feel the need for such an explanation (and neither do I, when it comes right down to it), but apparently some people do. My suggestion was intended to accommodate those people.
I don't need it and you don't need it, but that doesn't mean that I think it shouldn't be written.
An article like that might help DMs help newbie SJ players (that is why I suggested you might want to post on the SJML), but I think that it might be better to adopt a philosophical rather than a scientific approach.
However, I do think you are going to need to target your audence carefully, because you are going to be pitching this to Spelljammer DMs rather than the confused players they would be passing it on to. If you can't get DMs onboard then players won't see it in the first place.
I'd say it should also be short - a one page handout would be the maximum size I'd recommend. Try to break things down to short sentences. Use things like bullet points if you can. And if you are any good at artwork a couple of illustrations (especially ones that show something from SJ) could make the handout look pretty. And the prettier the hand out is the more likely it is that you will get DMs to download it and print it.
This was part of my original idea, but then I noticed a problem. The equation for gravitational force includes the masses of both objects.
This is the basic problem with the scientific explanation of D&D. The game only works within its own bubble of logic. Once you start importing real science into D&D the games bubble of logic goes pop.
Explaining things to players (your fundimental concept) is a good idea. However, I don't think the average man on the street actually cares about how real gravity works. Try explaining gravitational lensing to someone at a party and they will probably think you are a bore.
I think that the trick here is to stop at the equasion for gravitational force. We don't need to have that in Spelljammer for spelljammer to work.
Rather than trying to give people a lession in gravity, I think you should be saying "everything you think you know about gravity is wrong". That is pretty much what it says on the forword of the Concordance of Arcane Space (they say "space" instead of "gravity").
I think you need to be Spelljammer's version of Stephen Hawking and proove that Newton's Theory of Gravity and Einstien's Theory of Relativity are wrong.
If an object exerts no gravitational force on other objects, neither can other objects exert any force on it. Of course, I could change the equation to make it one-sided, so to speak, but that has an unusual side-effect.
That's what I would have done. Keep things one sided if small objects are involved. Don't abandon this process. Throw out the equasion and find another way to make objects fall.
Why can't you just assume a 1G force on anything that enters an air envelope or atmosphere and work from there. This isn't accurate, but it is a lot easier to calculate.
Since force equals mass times acceleration, if all objects experienced the same gravitational force regardless of mass, then more massive objects would actually fall more slowly (for the same reason a lightweight object will accelerate more quickly if you push on it than a heavy one will).
I don't think that is right. I think that is what would happen if all objects experienced the same force. But gravitional force is not a force per object it is a force per mass.
You need to start with the "fact"* that all objects do fall accelerate at the same rate and work backwards from there.
* = I put this word in quotes because I'm talking about a Spelljammer fact - not a scientific fact.
This will give you a gravity fairly similar to real gravity. Gravitational force will act on every atom (if atoms exist in D&D) with an equal force. So a 2 pound mass has twice as much gravity force pulling on it than a 1 pound mass, making both accellerate at the same speed.
The difference in mass times acceleration only really needs to be taken into account when objects hit the ground. At that point you need to be calculating damage. However, you might want to express this as hit points rather than real force.
Spelljamming ships, with their small air envelopes, are generally treated differently to planets, with their big air envelopes. If you want to come up with a pseudo-scientific explanation for things falling on both ships and planets you are going to get tied up with things like terminal velocity and air friction.
I've seen people say that normal (pre-SJ) falling damage rules, put in a maximum damage that allows people with tons of hit points to jump onto a world. I belive that someone proposed that people falling into planets start to burn (from something similar to the heat of reentry).
That is a lot of different concepts that could get sucked into your article. You could end up confusing players who don't know anything about science. I think it would be best for you to invent your own fantasy logic that supports the way that Spelljammer does work.
That may be the case, but I spend too much time reading internet forums and message boards as it is; I don't need to add another one to my list. Besides, if your reaction is typical of what I might expect from posting my idea on the SJML, no thank you.
I have no idea what reaction you would get on the SJML. Some people might love it and other people might hate it. Or it might get ignored. But I do know one thing. The Spelljammer Mailing List is the buisiest Spelljammer community I've ever seen and you are much more likely to get comments on your proposed article there that in these forums.
Its up to you if you subscribe to the list and post this, but if you decide you are interested in the SJML then here are a couple of useful links:
The first is a page on Beyond the Moons where you can read about the Spelljammer Mailing List and read old posts:
http://sjml.spelljammer.org/
And the second is a page on Wizards of the Coasts oracle server where you can sign up to the Spelljammer Mailing List, leave and read recent posts:
http://oracle.wizards.com/archives/spelljammer-l.html
Good luck.
Please don't feel a need to be defensive. I'm not attacking you. I pointed out
issues I had with your ideas. I've not got a problem with you.
For the record, I never took any of your comments as a personal attack. However, your response to my idea prior to your latest post has basically amounted to telling me it's not necessary and isn't how things work in Spelljammer. I understand your point of view, but it means that you're not the target audience, so to speak, of my idea.
Something I see all too often on message boards is that one person will make a suggestion or ask for advice on how to do X, and someone else will respond along the lines of, "X is stupid, why would you want to do that?" Less rude, but no less unhelpful, are those who say "Why would you want to do X when Y is so much better?" A case in point is the recent post on another SJ thread which you chided me for my "rude" response to. It's not that differing opinions aren't valued, but if you're not interested in doing X, you're not doing anyone any good by posting in a thread that's all about doing X.
Those views (that we now know are incorrect) are not incorrect in the Spelljammer universe. So the Spelljammer Campaign Setting itself is unscientific.
I realize that. I still think it can be an interesting mental exercise to come up with "scientific" explanations of fantastic phenomena, even if they don't always work perfectly. In this case, I'm assuming that the "old world" views, as you call them, are correct, and speculating on (alternative) laws of physics that might explain them.
An article like that might help DMs help newbie SJ players (that is why I suggested you might want to post on the SJML), but I think that it might be better to adopt a philosophical rather than a scientific approach.
I'm not trying to write an article. I had an idea I thought was kind of cool and I thought I'd toss it out there and see what people did with it.
I don't think the average man on the street actually cares about how real gravity works.
I'm not talking to the average man on the street. I'm talking to people who actually care about how Spelljammer gravity might work. But apparently, there's nobody around here who fits that description.
I think you need to be Spelljammer's version of Stephen Hawking and proove that Newton's Theory of Gravity and Einstien's Theory of Relativity are wrong.
No, I'm trying to be Spelljammer's version of Isaac Newton -- observing how things work in the Spelljammer cosmos and trying to find a scientific formula to describe it.
I don't think that is right. I think that is what would happen if all objects experienced the same force.
Isn't that what I said?
But gravitional force is not a force per object it is a force per mass.
In real life, yes. My point is that in Spelljammer it's exerted equally by all objects regardless of mass.
You need to start with the "fact"* that all objects *do* fall accelerate at the
same rate and work backwards from there.
* = I put this word in quotes because I'm talking about a Spelljammer fact - not
a scientific fact.
But that *is* how gravity works in real life. A two-pound object falls at the same rate as a one-pound object because the gravitational force on it is twice as strong. That's why it has twice the impact when it lands. If the gravitational force were the same on both objects, the heavier object would fall more slowly -- for the same reason that a heavy cart will move more slowly than a lightweight cart when the same force is applied to both.
The difference between real-world physics and what I'm suggesting is that I'm separating gravitational mass (which determines how much gravitational "pull" an object exerts on other objects) from inertial mass (which determines how much force is required to move an object). I'm proposing that in Spelljammer, the speed at which objects fall is still determined by inertial mass -- just as in real life -- but that gravitational mass is a constant for most if not all objects.
I think it would be best for you to invent your own fantasy logic that supports the way that Spelljammer does work.
That's what I'm trying to do -- take Spelljammer physics as a given and discover the logic behind it. It just seems as though most other people around here are content to wave their hands and say "it's magic" without caring about how it works. I'm sure Ptolemy would never have settled for that.
Crystal spheres belong in the same sort of era where people belived that the earth was flat, the sun orbited the earth and the back of the moon was dark.
Not that it's relevant, but scholars have known the earth was round for over two thousand years. See here for more info.
The Spelljammer Mailing List is the buisiest Spelljammer community I've ever seen
Therein lies my main reason for not joining. When d20 Modern first came out I was an active participant in the d20 Modern forum on these boards, reading nearly every single thread -- until I realized that keeping up with the volume of activity over there was consuming nearly all my free time. Since then I've stayed away from that forum except for a handful of occasions when I've posted a specific idea or asked for help with a specific matter. I'm only willing to devote a certain proportion of my time to RPG message boards, and I'm already pretty much at that limit.
Wyvern
For the record, I never took any of your comments as a personal attack.
OK. That's good to know.
However, your response to my idea prior to your latest post has basically amounted to telling me it's not necessary and isn't how things work in Spelljammer. I understand your point of view, but it means that you're not the target audience, so to speak, of my idea.
I realised that I wasn't your target audience, which was why I had suggested the SJML. I thought there was more chance there might be someone there who might want to discuss this with you.
Something I see all too often on message boards...
I've seen that too much as well. And with Spelljammer I've seen too many people who say: "I'm a big fan of Spelljammer, but I think that x, y or z is stuipd and have decided to create my own version of Spelljammer where replaces the existing rules. Please help me." These guys all seem to want to pull SJ in different directions. Its a bit crazy when people are willing to start a flame war over something like a giant space hampster.
I realize that. I still think it can be an interesting mental exercise to come up with "scientific" explanations of fantastic phenomena, even if they don't always work perfectly. In this case, I'm assuming that the "old world" views, as you call them, are correct, and speculating on (alternative) laws of physics that might explain them.
It can be interesting. I've seen a few debates where good ideas come out of them (like the one on a sister thread where they are discussing flatworlds). However, SJ is fantasy and when science doesn't explain everything, I think you need to invent new mystical forces that hold the D&D universe together.
I'm not trying to write an article. I had an idea I thought was kind of cool and I thought I'd toss it out there and see what people did with it.
I think I saw a DM call that "shovelware"! ;)
Good luck finding a home for your idea.
I'm not talking to the average man on the street. I'm talking to people who actually care about how Spelljammer gravity might work. But apparently, there's nobody around here who fits that description.
There is no justice - there is just us!! ;)
No, I'm trying to be Spelljammer's version of Isaac Newton -- observing how things work in the Spelljammer cosmos and trying to find a scientific formula to describe it.
Well, then you need to find SJ's version of Isaac Newton and get him/her to look at this idea. It took a real Newton to work out the real laws and it will probably take someone with similar knowledge and skills to come up with fantasy laws that look scientific and can be understood by all.
I think that is why the TSR guys created the "big fluffy cloud" where you put in a bit of fantasy, hocus pocus and magic and the Spelljammer Campaign Setting comes out of the other side.
Isn't that what I said?
Maybe I misread you, but I took "more massive objects would actually fall more slowly" as meaning that you were not taking SJ gravity as having a universal 1G force. (To put it another way, in the SJ version of the solar system, called Terraspace, the moon has a gravity of 1G despite the fact that it has a lower mass. Therefore mass does not affect SJ gravitational force or accelleration.)
In real life, yes. My point is that in Spelljammer it's exerted equally by all objects regardless of mass.
That is only half the Spelljammer law of gravity. The full rule would be: "All objects with a mass large enough to generate gravity exert a force of 1G."
But even that might not be the full rule. A spelljamming ship and a planet both have sufficient mass to generate gravity. Does that mean that a spelljamming ship falls towards a planet faster than a 1 copper piece? I'd say no. I'd say they both get a 1G tug on them and (ignoring air friction) fall at the same accelleration and hit at the same speed.
But that *is* how gravity works in real life. A two-pound object falls at the same rate as a one-pound object because the gravitational force on it is twice as strong. That's why it has twice the impact when it lands.
Are you sure, because I'm sure that sounds wrong. Every atom of both hammers has a 1G force on it and both accelerate at the same rate and hit at the same speed. The difference between the two hammers is that the larger one has a larger potential energy and the smaller one has a smaller potential energy. Falling converts potential energy to kinetic energy and the second hammer therfore has twice as much when it hits.
If the gravitational force were the same on both objects, the heavier object would fall more slowly
Not if gravity is a force that creates universal energy transfer, from (gravitational) potential energy into kinetic energy. All objects accellerate at the same rate and impact with kinetic energy proportional to the potential energy (which in turn is proportional to their mass and height).
Gravity is not putting energy into the two objects, it is releasing energy that is already there. And the big hammer holds more energy than the smaller one. (Just like a big can of petrol makes a bigger fireball than a smaller one.)
for the same reason that a heavy cart will move more slowly than a lightweight cart when the same force is applied to both.
That isn't a fair comparison. A horse pulling either cart pulls with a force of 1 horse power. He has to use his own energy to overcome friction and create kinetic energy. Planets do not need to use any energy to move things that fall into their air envelopes and can therefore accelerate objects of all sizes at the same rate.
I'm proposing that in Spelljammer, the speed at which objects fall is still determined by inertial mass -- just as in real life -- but that gravitational mass is a constant for most if not all objects.
But all objects falling in a 1G environment would fall at the same speed in a vaccum. Inertia and mass do not make any difference to the rate that anything falls at.
If gravity is universal at either 1G or 0G then things either stay still or accelerate at a known rate (whatever the value is on Earth). You don't need any further calculations (unless you want to work out how much kinetic energy has when it lands).
That's what I'm trying to do -- take Spelljammer physics as a given and discover the logic behind it. It just seems as though most other people around here are content to wave their hands and say "it's magic" without caring about how it works. I'm sure Ptolemy would never have settled for that.
The people who say it is magic (along with the people who think that helms create gravity or air envelopes) are wrong. Spelljammer gravity is something natural. Everything above a given mass (or perhaps volume - I'm not sure) has a gravity of 1G.
In real science we don't know why gravitational attraction happens. If you are attempting to understand real gravity then you will never do it. I think that you have got the answer in front of you and don't believe your own calculations.
Not that it's relevant, but scholars have known the earth was round for over two thousand years. See here for more info.
It might be off-topic, but it would be useful to know if you were using groundling cultures based on real Earth cultures. I think that religious organisations (mostly the old "witch burning" Catholic Church) were responsible for supressing information they saw as conflicting with the bible.
Therein lies my main reason for not joining. When d20 Modern first came out I was an active participant in the d20 Modern forum on these boards, reading nearly every single thread -- until I realized that keeping up with the volume of activity over there was consuming nearly all my free time. Since then I've stayed away from that forum except for a handful of occasions when I've posted a specific idea or asked for help with a specific matter. I'm only willing to devote a certain proportion of my time to RPG message boards, and I'm already pretty much at that limit.
We all have lives (hopefully) and that limits the amount of time we can spend reading this sort of thing.
I thought the SJML might have helped you, because every post goes to every subscriber. People who wouldn't surf here might have seen your post and been inspired to argue out the truth with you. I suppose you could join, invite people to come here and then stop reading, but then people might answer you on the list anyway.
It's up to you. But as nobody except me is writing here (and you want more support) I'd suggest reading a few of the recent posts in the SJML archive to see if you are willing to spend time skimming through its mailouts.
Either way, I don't think I can say much more about this without decending into being pedantic. I think you need someone new to come in and support either side of the argument.
And as you don't want to write an article yourself (and Wizards of the Coast periodically errase these threads) you could also do with attracting someone willing to write this up for you and post it to Beyond the Moons.
Otherwise any conclusions of this conversation will just get dumped next time WotC prune this forum.
Good luck!
Maybe I misread you, but I took "more massive objects would actually fall more slowly" as meaning that you were not taking SJ gravity as having a universal 1G force. (To put it another way, in the SJ version of the solar system, called Terraspace, the moon has a gravity of 1G despite the fact that it has a lower mass. Therefore mass does not affect SJ gravitational force or accelleration.)
What I mean is this: IRL (and presumably in SJ too, since I see no evidence to the contrary), gravity is a two-way force. That is, two objects exert an equal gravitational force on each other. The more massive a falling object is, the stronger the mutual attraction between object and planet. If gravity were a one-way force exerted by a planet equally on all objects, less massive objects would fall more quickly because they have less interia to overcome.
But even that might not be the full rule. A spelljamming ship and a planet both have sufficient mass to generate gravity. Does that mean that a spelljamming ship falls towards a planet faster than a 1 copper piece? I'd say no. I'd say they both get a 1G tug on them and (ignoring air friction) fall at the same accelleration and hit at the same speed.
I agree that both would fall at the same rate, but not because the same force is applied to both. It's because both are attracted by a force proportional to their mass. If an equal force were applied to both, the ship would fall more slowly because it has greater inertia. Imagine you have a tennis ball and a bowling ball. You set both on a pool table and strike both with a pool cue using the same amount of force. Which will move faster?
Are you sure, because I'm sure that sounds wrong. Every atom of both hammers has a 1G force on it and both accelerate at the same rate and hit at the same speed. The difference between the two hammers is that the larger one has a larger potential energy and the smaller one has a smaller potential energy. Falling converts potential energy to kinetic energy and the second hammer therfore has twice as much when it hits.
Everything you've said is correct, but you're missing a few key points. Each atom in both hammers is subject to the same amount of force (ignoring the internal gravitational forces between atoms for the sake of simplicity), but the two-pound hammer has twice as many atoms, therefore the total force exerted on the two-pound hammer is twice as strong.
I was slightly off in my statement that twice the force equals twice the impact on landing. You're correct that it depends on kinetic energy, which is not directly dependent on force -- it depends on mass and velocity. A two-pound hammer falling at the same velocity as a one-pound hammer will have twice as much kinetic energy.
However, the two-pound hammer would not fall at the same velocity as the one-pound hammer unless the gravitational force it felt was twice as strong. Force equals mass times acceleration -- therefore if mass increases, force must also increase for accleration to remain constant. (Another way to say this is that force divided by mass equals acceleration.)
That isn't a fair comparison. A horse pulling either cart pulls with a force of 1 horse power. He has to use his own energy to overcome friction and create kinetic energy. Planets do not need to use *any* energy to move things that fall into their air envelopes and can therefore accelerate objects of all sizes at the same rate.
Force != Energy != Power.
But all objects falling in a 1G environment would fall at the same speed in a vaccum. Inertia and mass do not make any difference to the rate that anything falls at.
Yes they do, because force equals mass times acceleration.
Spelljammer gravity is something natural.
If it's natural, it can be investigated scientifically.
In real science we don't know why gravitational attraction happens. If you are attempting to understand real gravity then you will never do it.
Newton didn't explain *why* gravitational attraction happens -- he simply described, in mathematical terms, *how* it happens. I'm just trying to do the same for SJ gravity.
I think that you have got the answer in front of you and don't believe your own calculations.
No, you're the one who doesn't believe my calculations. I've told you how gravity probably works in Spelljammer, scientifically speaking, given what we know about how real-world gravity works and the difference between RW gravity and SJ gravity. I'm not trying to make any changes to SJ gravity, I'm just speculating about the underlying principles.
I think that religious organisations (mostly the old "witch burning" Catholic Church) were responsible for supressing information they saw as conflicting with the bible.
That's a misconception which I'm trying to dispel. Some quotes from the article I linked to:
A few--at least two and at most five--early Christian fathers denied the sphericity of earth by mistakenly taking passages such as Ps. 104:2-3 as geographical rather than metaphorical statements. On the other side tens of thousands of Christian theologians, poets, artists, and scientists took the spherical view throughout the early, medieval, and modern church. The point is that no educated person believed otherwise. ... In my research, I looked to see how old the idea was that medieval Christians believed the earth was flat. I obviously did not find it among medieval Christians. Nor among anti-Catholic Protestant reformers. Nor in Copernicus or Galileo or their followers, who had to demonstrate the superiority of a heliocentric system, but not of a spherical earth.... No one before the 1830s believed that medieval people thought that the earth was flat.
...
But now, why did the false accounts of Letronne and Irving become melded and then, as early as the 1860s, begin to be served up in schools and in schoolbooks as the solemn truth? The answer is that the falsehood about the spherical earth became a colorful and unforgettable part of a larger falsehood: the falsehood of the eternal war between science (good) and religion (bad) throughout Western history.
And here's a quote from a response to the above article, by "Paul J. Gans":
Paul [Halsall] has softened the blow to some extent. He gave a capsule review of how the flat-earth myth began, but did not stress the main promoters of the idea, though he did give their names. One was a president of Cornell, the other a distinguished professor of chemistry at NYU. Both were virulently anti-catholic and both wrote books on the subject of church control of what catholics were allowed to believe. They pushed the myth as an example of the church enforced ignorance of catholics. It was conscious slander, not in any way an accident.
And another from an article on Strange Horizons which originally referred me to the other article:
The people who believed in a flat Earth have been few and far between. It does not take a genius to see a ship sail over the horizon or to look down on a plain from a mountain and thereby realize the curvature of the Earth. That Columbus somehow proved that the Earth was round is therefore preposterous. ... Our modern myth that medieval people thought the Earth was flat rests in two misconceptions. First, as mentioned above, people have misread medieval maps. In particular, modern readers have seen the T-O maps as representing a flat, disk-shaped Earth rather than the projected hemisphere that they really represent. Second, most modern readers have assumed ignorance on the part of medieval people, just as they have assumed medieval people were dirty and lived in dank and dark hovels. There is little truth in either assumption; both are misconceptions begun in the Nineteenth Century as part of a reaction against the Catholic Church.
Wyvern
but i do remember reading up on a few planets that had abnormal gravity... and i think they were official, though it could have been elsewhere.