Would intelligent aquatic creatures with opposable thumbs ever develop Newtonian mechanics?
By Thoreau
Well, would they?
I was talking to a guy who observed that misconceptions about physics persist because in a world full of friction, and where gravity is always dragging things down to the ground (where friction can then take hold of them) it’s not at all obvious that an object at rest will remain at rest (in the absence of an external force) and an object in motion will remain in motion (in the absence of an external force). We rarely encounter a situation in which external forces (or at least net external forces) are negligible. And with air resistance it’s not at all obvious that gravity accelerates all objects at the same rate. It took a long time for these things to be figured out, after careful experiments in which different phenomena were separately quantified and/or minimized.
So would a society of mermen ever figure out Newtonian mechanics? They’d live in a world in which some things fall (rocks) and other things don’t, and where the non-falling things are constantly feeling the effects of currents.
And does this have any implications for alien life in oceans?
As you can tell, the conference is boring right now. But it was interesting earlier.
Comment by Andromeda —
November 10, 2007 @ 4:16 pm
Humans figured out hydrodynamics, didn’t we?
Comment by Bill Kaminsky —
November 10, 2007 @ 6:08 pm
The standard history of science implies that we humans had quite a bit of trouble figuring out Newtonian mechanics. Isn’t it the case that humanity never realized until Galileo that were it not for air resistance a falling object’s acceleration would be independent of the object’s mass? In your scenario of undersea intelligent creatures, I’d bet there would eventually be some undersea Galileo who’d realize that were it not for water resistance, everything would be falling toward the center of the earth with the same acceleration. On the other hand, I’d bet that if the undersea creatures *never look at the stars*, then their classical mechanics might well be stunted indefinitely. In my opinion, the development of physics requires not only new thinking about tangible, everyday phenomena, but also experience with new phenomena far from what one can hold in her or his own hands/flippers/etc.
Comment by matthew hogan —
November 10, 2007 @ 7:54 pm
Is there a porpoise behind all this?
Comment by Dave Trowbridge —
November 11, 2007 @ 1:13 am
I agree with Bill. It would happen, but it would likely take longer.
The physics of O’Neill colonies can be weird, too, and someone who didn’t grow up on one could get in a lot of trouble, especially up near the spin axis, where denser objects “fall” more slowly than less dense ones. And just think about what a waterfall on one of the end caps would look like!
Over time, the very archetypes of people living in such habitats (highdwellers) would change. For us planetdwellers, up is awesome and masculine, down is comforting and feminine. To a highdwellers, up (in) is feminine and nurturing, down (out) is masculine and threatening (there’s vacuum under their feet). Anyone with a strong response to the Atlantis archetype (the giant wave overtopping the works of man) is going to have a hard time when he or she looks spinward or counter-spinward, as the “land” curves upward and hangs overhead. And, the Icarus myth is reversed–up near the spin axis you can strap on wings and fly, but if you fly too low, you get too heavy for your wings and you fall out of the sky.
Comment by Eric the .5b —
November 11, 2007 @ 1:27 am
Actually, I suspect intelligent undersea creatures would more easily grasp the concept that things stop due to resistance than land animals.
We have to move our arms quickly to get perceptible air resistance, but even then, it’s a rather feeble resistance. A merman of comparable strength is going to feel much more resistance to quick movement of his arms, along with the sensation of vortices swirling against them if his skin sensitivity is near human – and his tail is going to feel quite a bit of resistance as it, er, swishes against the water to propel him forward. For that matter, you have to get to the point of having wheels to replicate on land what’s very easy to do in water – swish one’s tail hard (or kick off of something) and then allow oneself to be carried by momentum a short ways.
Now, if these creatures devise spears or darts to use underwater (tricky to get them to go useful distances, but useful enough to devote a lot of effort towards doing so), watching those projectiles make the idea of resistance-free motion a lot clearer to some bright merman.
Comment by Joshua Holmes —
November 11, 2007 @ 2:38 am
Is there a porpoise behind all this?
Dolphinitely.
Comment by Michael B Sullivan —
November 11, 2007 @ 3:38 am
Just to go totally off-point, the first thing to wonder is whether a society that almost certainly could never industrialize fire would ever get far enough up the technological ladder to have a literate class of thinkers who could ponder things like Newtonian mechanics.
Newton’s comment about standing on the shoulders of giants is to the point: you don’t just have to have a genius who works out some cool experiment or thought experiment, you’ve got to have a lot of them, and they’ve got to learn about each other’s thoughts.
Comment by Nick S —
November 11, 2007 @ 6:05 am
If Einstein could work out relativity based on the Michelson-Morley, even though he lived in an apparently non-relativistic environment then anythings possible I suppose.
Comment by Thoreau —
November 11, 2007 @ 7:25 am
Eric-
That’s a good point about things stopping due to air resistance. We’re familiar with terminal velocity (just drop a feather) but stopping is more subtle.
As to fire, yeah, that might be a problem. Although perhaps there would be some other way for merman society to generate an agricultural surplus (bone tools? shell tools?) and have a class of tinkerer specialists.
Comment by Gene Callahan —
November 11, 2007 @ 8:09 am
1) “If Einstein could work out relativity based on the Michelson-Morley…”
Professional historians of science have concluded that Einstein was barely aware of Michelson-Morley, and that the experiment was definitely not the motive behind his relativity theories. The view that the experiment was crucial was simply made up to preserve the naive, Bertrand-Russell-style model of science that is presented in basic textbooks and popular science works.
2) “Isn’t it the case that humanity never realized until Galileo that were it not for air resistance a falling object’s acceleration would be independent of the object’s mass?”
No, Airstotle figured this out. He used it as evidence that a vacuum can’t exist, since it is absurd to suppose we would find light objects falling at the same speed as heavy ones!
3) “it’s not at all obvious that an object at rest will remain at rest (in the absence of an external force) and an object in motion will remain in motion (in the absence of an external force).”
Note that what Newton did was to make this principle definitionally true! How do you detect a force? Something is not in uniform motion! How do we tell no forces are acting? We observe uniform motion!
As Sir Arthur Eddington said (I quote from memory), the first law could be read, “A body will remain at rest or in uniform motion except when it doesn’t.”
Newton’s brilliance was to have arrived at such a fruitful set of basic assumptions — but these are not “empirical facts” he finally observed correctly.
Comment by Thoreau —
November 11, 2007 @ 9:35 am
Gene-
First, good point about Einstein. If anything, his motivation seems to have been to figure out the contradiction between Newtonian mechanics (where it would seem that light should slow down or speed up in different reference frames) with Maxwell’s electromagnetic equations (where the speed of light is the same in all frames).
Second, you make a good point about Newton and recognizing that a slowing down or speeding up object is the sign of a force. However, in a world where resistance (friction, air, etc.) and gravity are ubiquitous, it’s not at all obvious that we need to think about these things as “forces” rather than as “natural” facts of motion. As you say, the idea that objects are acting under the influence of forces rather than some sort of “natural tendency” could not come from any simple empirical observations (although more sophisticated measurements might lend support to that idea).
Comment by Neuroscientist —
November 11, 2007 @ 6:35 pm
We’re assuming one thing here, that the aquatic intelligences would have developed reasoning that’s like ours. Since there is considerable evidence that certain aspects of logic and inference are conditioned by our sensory motor apparatus, an animal with a very different sensorium might not reason like we do at all. So any “physics” they develop might well be different from ours, if only because their “mathematics” would be different as well.
Recall Nagel’s question: “what is it like to be a bat.” A hell of a lot different than what its like to be a human. One presumes that extends to how the world is modelled.
Comment by RSA —
November 11, 2007 @ 7:03 pm
The standard history of science implies that we humans had quite a bit of trouble figuring out Newtonian mechanics.
A couple of speculative thoughts on this point: First, in a pre-scientific world, it’s hard to think of things that are obviously “true” and still worth testing. The speed of falling objects is such a thing. Even today people are likely to believe that heavy objects fall faster than light ones, despite their having been taught differently in high school. (And this general bias against testing obvious stuff isn’t limited to laymen; there was a famous case, if I remember correctly, in T cell testing with chimpanzees.)
Second, the speed of falling objects might not have been tested because it might not have been viewed as being useful in practice. You’d expect a military thinker to have worked it out, maybe thinking about catapults or cannons, but it might have been enough to know that heavy objects require more force than light objects to travel the same distance through the air, and nothing more.
As I say, pure speculation on my part.
Comment by Eric the .5b —
November 12, 2007 @ 1:17 am
I’d note that one of the few human societies to come up with an “agricultural surplus” without actual agriculture were fishing tribes in the Pacific NorthWest.
Comment by Alex —
November 12, 2007 @ 5:11 am
It’s only a problem if you assume they have to be mammals; the other likely candidates would be cephalopods, and squid would surely find Newtonian physics very intuitive indeed.
Comment by Stevo Darkly —
November 12, 2007 @ 6:39 am
“Is there a porpoise behind all this?”
Dolphinitely.
The Undersea Pun Police would give you a cetacean for that.
Comment by Thoreau —
November 12, 2007 @ 12:13 pm
Stevo Darkly wins at the internet!
Comment by Zathras —
November 12, 2007 @ 1:34 pm
I agree that the development of science would be impeded for the merpeople. However, this does not give the entire picture. In short, the merpeople would be worse off in science but better off in engineering. Once engineering students are indoctrinated into the perfectly frictionless world of physics, the ideal viewpoint tends to be overused. Sources of error are overlooked. The first-order approximation becomes the only approximation that is done. If 2nd-order effects become an inherent part of the analysis, engineers might be better off.
Comment by lunchstealer —
November 13, 2007 @ 3:42 pm
What’s Zathras doing using first person?
The biggest problem I’d see for merpeople (or my personal favorite, future-evolved sentient octopi or cuttlefish) developing modern science would be chemistry. It would be frightfully difficult do develop aqueous chemistry in a subaqueous environment. They might be able to make some non-polar chemistry advances using lighter-than-water oils and hydrocarbons as the solvent, using an upside-down version of our gravity-contained aqueous setups. But working submersed in such a dominant solvent as water would be a tremendous hurdle to overcome.
Comment by Stevo Darkly —
November 20, 2007 @ 1:16 am
It’s only a problem if you assume they have to be mammals; the other likely candidates would be cephalopods, and squid would surely find Newtonian physics very intuitive indeed.
Because — I am sure you mean — cephalopods often employ jet propulsion to move themselves rapidly, squirting water out of a tube whose name I forget. (Maybe “the syphon”?) Thus “every action has an equal and opposite reaction” would be second nature to them.
But I’ve thought about this, and I think the fact that employing Newtonian physics too “intuitively” would be a handicap to articulated understanding, actually.
Consider an intelligent cephalopod observing how human beings move on land: we push down and backward with our relatively rigid limbs, tottering forward but constantly adjusting the way we push our feet against the ground to keep our balance while we push ourselves forward. The intelligent squid might concluded that we must all be geniuses when it comes to the physics of force-vectors, since we employ them intuitively — it’s second nature to us. In fact, we don’t even notice it!
Which, I think, is the problem. Employing laws of phyiscs intuitively is very different from understanding them rationally. That’s why it’s impossible to “explain” to someone else how to ride a bike — or how to walk. I learned to walk as a toddler, but I didn’t actually encounter force vectors as a science (actually, a math) until I was in high school, and they still confuse me sometimes.
Comment by Stevo Darkly —
November 20, 2007 @ 1:17 am
Agh! Supposed to close the italics after “too”!
Should be:
But I’ve thought about this, and I think the fact that employing Newtonian physics too “intuitively†would be a handicap to articulated understanding, actually.
Consider an intelligent cephalopod observing how human beings move on land: we push down and backward with our relatively rigid limbs, tottering forward but constantly adjusting the way we push our feet against the ground to keep our balance while we push ourselves forward. The intelligent squid might concluded that we must all be geniuses when it comes to the physics of force-vectors, since we employ them intuitively — it’s second nature to us. In fact, we don’t even notice it!
Which, I think, is the problem. Employing laws of phyiscs intuitively is very different from understanding them rationally. That’s why it’s impossible to “explain†to someone else how to ride a bike — or how to walk. I learned to walk as a toddler, but I didn’t actually encounter force vectors as a science (actually, a math) until I was in high school, and they still confuse me sometimes.
Comment by Whatever-ishere —
November 21, 2007 @ 12:20 pm
thanks for the GREAT post! Very useful…
Comment by HeavyGod —
November 27, 2007 @ 3:36 am
Really good and really interesting post. I expect (and other readers maybe
) new useful posts from you!
Good luck and successes in blogging!