Playing Ball in Space

oo7tushar writes "Although most experiments in space seem simple they have profound results. Take this for example, astronauts trying to catch a ball in space. What's so hard about that? Nothing much really, down here on Earth. In space it's a completely different story. Here on earth our eyes see the ball and our brain anticipates it's movement according to gravity. In space the brain continues to anticpate gravity but unlike motion sickness (which is adapted to within days), astronauts continue to anticipate the path of a ball for 15 days (after which they start to show progress). What are the ramifications? The brain must have some sort of internal gravitation model."

Comments

Constants

[Jouster]

But is it 9.80 m/s/s or 32 ft/s/s in our heads?

Jouster

Re:Constants

[zapfie]

Your brain does not have really have all the information it needs (posititon of the object, current velocity of the object, etc) in numeric form to make precise calculations on the fly. It's probably more of something the brain sees, makes an educated guess about, and fine-tunes that guess as it gathers more information about the event it is seeing.

Or were you asking whether or not our brain thinks of it in imperial units (e.g. the right way), or metric units (e.g. the wrong way)? ;)
*ducks an angry barrage of balls being thrown at him*

Re:Constants

[xonker]

The brain may have a pre-programmed response to gravity on earth

I doubt that it's pre-programmed. We learn to respond to gravity the same way that we learn to walk, talk or catch a ball on Earth. If you took an infant to a zero-gravity environment (ignoring any other potential ill-effects like bone-density loss...) they would simply grow up used to that gravity. If you brought them back to Earth (again, ignoring the fact that an infant raised in zero-gravity would be a helpless whelp if brought to Earth later in life) they wouldn't automagically be able to adapt to the cause and effect of the stronger gravity. It's not innate, it's learned.

Just like...

[niftyeric]

this article. Oh well..

Re:Just like...

[Gaijin42]

This article talks about the experiments where people do things like wear mirrored goggles that reverse vision, or flip vision upside down. All the experimentation done so far says people can adjust in about one month. And vision is something that we have done every day, all day, since early life. If we can fix that kind of stuff, catching a ball seems easy as well.

the Guinness effect

[tongue]

Does that explain why a dozen pints of guinness seems to amplify earths gravity to the point that I can't pick myself up off the bar or floor?

Nothing special...

[tom_newton]

about us having a "gravitation model" in our heads.
Surely it's just called "experience"?

Re:Nothing special...

[evilrunner]

I would think that the reactions would be based more off of observed behavior and experience than a "hard wired" instinct. It would be interesting to do the test on young children who have the motor skills but do not have the experience level of the adult participants.

Re:Nothing special...

[clearcache]

right...probably related to "muscle memory"... ever try to type at a new keyboard...where the keys might be just slightly misaligned compared to your ol' betsy that you've been using for years?

Singers also have a type of muscle memory that helps them approximate accurate pitches. I'm not talking about perfect pitch, but perfect relative pitch...it seems logical that, after years of catching a ball in earth's gravity, you continue to react as you had been conditioned to on earth.

Re:Nothing special...

[Bullschmidt]

To be fair though, it is thought (at least from my old psych class, taugh by Pinker, who has strong thoughts on evolutionary psychology) that the often intense fear of heights is something that is *not* learned, but rather instinctual. It could be seen how evolution might account for this (those who don't go near the edge of that big cliff don't fall off and die!). I see how your argument might apply here if it weren't for the fact that the huge reaction is *instantaneous* and *involuntary * (physically, that is - increased heart rate and alertness, etc). I would expect a smaller reaction for learned responses.

My guess would be that a fear of falling/heights/awareness of gravity is somewhat engrained, but can be overcome with training. Also, consider that what makes a baby afraid of falling? Sure, I guess a baby could figure out that gravity implies falling, but with no experience of falling, whats to make a baby believe that falling is bad? Maybe thats a stupif question, I don't know, but I figured I'd throw it out.

But then again, I'm no psychologist!

Re:Nothing special...

[silicon_synapse]

I would guess it involves the loss of control (real or percieved) over the individual's situation. When you begin to fall, you lose much control over where you go. Similarly when you find yourself stumbling upon a grizzly, you are no longer in total control of your immediate future and become frightened. I think lack of control is the root of many of our fears.

Re:Nothing special...

[bughunter]

I agree.

It's been long known that the cerebellum, those two lobes at the back of the brain, is where complex motions are learned and "hard wired." My neuroanatomy professor expressed his awe at how well our brains can learn exactly how far to swing and where to grab, or precisely how to swing a bat, or balance on ice skates... and all without conscious control. It's done mostly in the cerebellum, and is established only through practice, practice, practice.

Now, when it comes to catching a ball, that's something that a child learns early in his or her life, and it is generic enough that we get lots and lots of practice, so it becomes very firmly entrenched. No wonder it's hard to "unlearn."

This experiment proves nothing except that our brains are adapted to learn and adapt further. It would have been better if they had taught the astronauts a new skill a few weeks before launch, and then measured how quickly they could relearn it after arriving on station.

Re:Nothing special...

[CmdrPinkTaco]

so you are going to imply that the infant had no prior experience with gravity? That would effectively mean that the infant never observed anything being attracted in any way shape or form towards the earth. This does not imply that the infant understands WHY gravity exists, or how it even works, but it understands the consequences and has observed the effects of gravity. Now if the article had said "a baby that was raised in zero-gravity and had never had any experience with gravity was placed on a glass table and grew fearful of falling" I might be more convinced, but the mind understands and learns and adapts VERY quickly.

You are discrediting the power of the brain to learn by assuming that the infant doens't understand falling simply because it has never fell.

Re:Nothing special...

[MrFredBloggs]

You dont need prior experience of falling, seeing as they`d have prior experience of gravity, momentum etc. When you are new-born, you are actually 9 months old. Given that its been shown that children can pick up songs their mother has heard/hummed, what makes you think even less abstract concepts are not going to be picked up?

What a bunch of crap

[yatest5]

What are the ramifications? The brain must have some sort of internal gravitation model."

Er, no, maybe it has some capacity to learn the way things move, which surprisingly, after 30-odd years of the same observed behaviour, proves a little hard to unlearn.

The ramifications? Well, people are going to, like have to, like, train for the new environment! Quick, call the cops!

Re:What a bunch of crap

[bourne]

I agree completely - it's a little stupid to expect decades of muscle memory to change within 15 days. Frankly, I think the real lesson is that it only takes 15 days for such massively ingrained learning to start being corrected!

Sure, they learned to deal with naseau within 3 days - that's 72 hours of constant, unremitting weightlessness, awake and asleep, that they are adjusting to. I'll bet the 15 days of playing catch was more like 15 or 30 hours, spread out over the two weeks, so there's no comparison.

Re:What a bunch of crap

[Reality Master 101]

You beat me to it -- in fact, you used the exact subject I was going to use. :)

Try throwing a ball to a small child and see how naturally they compensate for gravity.

Sheesh, if you ever doubt that scientists follow the same idiot/smart ratios as the general population, take a look at something like this.

Re:What a bunch of crap

[yatest5]

You beat me to it -- in fact, you used the exact subject I was going to use. :)

I think it's because our brains have some form of 'slashdot post subject writing model' - the fact we both came up with the same idea *proves* it :).

Re:What a bunch of crap

[JordanH]

• The ramifications? Well, people are going to, like have to, like, train for the new environment! Quick, call the cops!

A much more serious ramification is that researchers are noting that children exposed to gravity seem to have a much greater facility with walking down staircases than those who aren't. It's a mutation!

Re:What a bunch of crap

[rmayes100]

Exactly. I doubt the brain is doing any complex calculations simply just taking into account the thousands of other times it's seen projectiles and guessing based on that data where this one is going to go. I've been trying to teach my young children to catch for years and they still have trouble figuring out where the ball's going to go every time. They simply don't have the experience to pull from in every case yet.

Re:What a bunch of crap

[Reality Master 101]

That was my point: anyone with children knows that they have absolutely no built-in catching ability. Actually, my boy is 2 1/2 and very advanced when it comes to hand-eye coordination, and there is no way that he had any natural ability to catch.

This really should be obvious: the brain is going to have as little built-in as possible, since that makes it that much easier to pass traits to the next generation. Actually, another thing that I think is a fallacy is any sort of built-in 24-hour day, like many theorize. There simply isn't a need for it, since people get exposure to it automatically.

Re:What a bunch of crap

[dylan_-]

Er, no, maybe it has some capacity to learn the way things move, which surprisingly, after 30-odd years of the same observed behaviour, proves a little hard to unlearn.

Sounds reasonable, but I think you're wrong.

I recall reading (sorry, no cite due to faulty memory) that we don't have to learn to catch; it comes automatically as soon as we can control our limbs properly. Sure, we get better with practise, but we can do it without.

It was assumed that this was due to our "excellent" hand-eye co-ordination, but this experiment seems to show that instead we're predicting the motion in a gravity field. It shouldn't have taken 15 days for the astronauts to learn to adjust if they were really following the movement of the ball.

An example given in the brief article was that a baby placed on a glass table became distressed even though it should know it was going to fall.

The guy doing the experiment is a neuroscientist. I think he would have considered the simpler explanation first, don't you? Just because the article doesn't give a complete account doesn't mean that work wasn't done.

Re:What a bunch of crap

[wickidpisa]

It was assumed that this was due to our "excellent" hand-eye co-ordination, but this experiment seems to show that instead we're predicting the motion in a gravity field. It shouldn't have taken 15 days for the astronauts to learn to adjust if they were really following the movement of the ball.

You are jumping to conclusions there. Even if you are right about the ability to catch being inherent rather than learned (I have doubts that it is. Don't believe everything you read.) it would have little bearing on this experiment. To test what you claim is true, you would need to have people who have not been catching under earth's gravity for the past X years try to catch in zero G. It is entirely possible that catching is inherent, yet because these scientists have been exposed to it for so long, they have also learned what to expect, and that may be why it took them longer to re-learn to catch. Someone with no experience catching under gravity may have been able to learn it more quickly.

Re:What a bunch of crap

[dhogaza]

Actually, another thing that I think is a fallacy is any sort of built-in 24-hour day, like many theorize. There simply isn't a need for it, since people get exposure to it automatically

Research strongly indicates a built-in cycle of a bit over 24 hours, actually. Experiments have been run with people kept in isolation without timekeeping devices, and their day slowly advances. The effect's repeatable in different subjects.

So living normally, where we're exposed to the natural cycle of day and night (or in an isolated environment that provides replacement cues), appears to counter that tendency by causing our brain to do a minor reset, if you will.

Re:What a bunch of crap

[Reality Master 101]

Research strongly indicates a built-in cycle of a bit over 24 hours, actually. Experiments have been run with people kept in isolation without timekeeping devices, and their day slowly advances. The effect's repeatable in different subjects.

I've heard of those experiments, and I'm not sure it says anything other than people tend to want to sleep longer. :)

The only experiment that would really tell us anything is to raise children in a 12 hour cycle or an 18 hour cycle and see if they adapt. I have a feeling they would, which would argue against a "built-in" amount of time.

I suppose it would also be interesting to observe a tribe in isolation in an extreme northern latitude where you don't have much difference between night and day. Probably not possible in today's age where there really aren't any "tribes in isolation" anymore.

Re:What a bunch of crap

[IainMH]

Actually, my boy is 2 1/2 and very advanced when it comes to hand-eye coordination

You realize you sound like a jewish grandmother.. :-)

Encoding Specificity

[Transient0]

An internal gravitation model would be theorizing far more than is necesarry to account for the data. In cognitive science, there has long been an understanding of encoding specificity. This simply means that data, including skill knowledge, is best retrieved from human memory under the same conditions which it was learned.

An example from the real world is underwater welding. When underwater welders were first being trained, the companies tried to simply train professional welders in all the ways that underwater welding was different from normal welding. But, in diong this, they found that when they were underwater, the welders had serious trouble calling on those skills which supposedly transferred over unchanged. As a result, they had to be entirely retrained in skills they had apparently already learned.

Similarly, if you lose your keys while you're stoned and then can't find them the next day. Psychological evidence shows that your best chance to find them is to get stoned again and then look for them.

Any number of other controlled psychological experiments have been performed to domonstrate this same effect(memorizing words under different lighting conditions, etc.). I don't see why gravitation would be any different.

Re:Encoding Specificity

[sunhou]

Re: learning welding underwater -- when I visited Australia, driving was a somewhat similar experience (driving on the opposite side of the road from what I was used to).

At first, it was hard because everything was the opposite of what I knew. But within a few days, I simply learned to reverse my innate responses, since I knew that those responses were backwards, and so it got easier. But after a couple of weeks, I had started to get accustomed to the new configuration, and so some of my natural responses were correct. That meant I could no longer just "do the opposite of what felt natural", and it actually got harder again and took more thought; I always had to think "is my gut feeling about what to do an old gut feeling from the US, or a newly acquired gut feeling from the past couple of weeks in Australia?"

I was there for about 4 or 5 weeks. When I got back to the US, within a day, I promptly drove on the wrong side of the road. (It was a small road with no traffic, so fewer cues, and I did catch myself within a few seconds before causing any major havoc.)

Re:Encoding Specificity

[nusuth]

An internal gravitation model would be theorizing far more than is necesarry to account for the data. In cognitive science, there has long been an understanding of encoding specificity. This simply means that data, including skill knowledge, is best retrieved from human memory under the same conditions which it was learned.

All true, but how does this apply in this case? If your theory is that astronout fails to remember how one correctly responds to falling balls in space because he has not learned that skill in that environment, that is also theorizing far more than data suggests. Also that theory will have hard time explaining why non-motor skills related to gravity does not suffer likewise in space.

OTOH, assuming having expectations about how the world and objects in it will behave without resorting to a native bias for that expectations can be easily justified. Under this assumption, astronouts inability to efficiently catch those balls simply results from failure to correctly foresee how objects will behave, gravity-wise. They learn slowly because of a negative interference from long term behavior they enjoyed on Earth. They relearn in Earth's gravity quickly because of the experience's deep roots from childhood.

But this is also a simple to understand layman's theory, requiring no expansive speech to express. So I understand why it is unpopular among us, the cognitive scientists.

Re:Encoding Specificity

[yesthatguy]

That's actually a very common occurrence. Many left-handed people who are forced to do things with their right hand will develop dyslexia, from a minor case that requires them just to think a little harder, similar to what your wife has, to a more severe case where they show more obvious signs of dyslexia like greatly troubled reading, etc.

Or...

[ruiner13]

It could be that a baby born in space would not have such models. I'm guessing that is a learned response of the brain, not an inherited one. I took a Psychology of learning class in college once, and i learned many interesting things. For one, spacial perceptions depend a lot on the environment in which you are raised. For instance, if you live in a rectangular type house, you can generally make good guesses as to the dimensions of other rectangular shaped rooms. If you bring that person into a round room, the estimations are way off. It works in reverse, too. If you live in a round hut your entire life, you won't be able to make good guesses about rectangular rooms. Seems kinda analogous to the gravity story. I say we get some randy astronauts to give birth on the space station, and kinda have a truman show in space. We'll see how that baby will catch a ball then.

Re:Or...

[Shalda]

There is really no question that this is a learned response. However the article belies a basic understanding of how atletic actions work. Most notably, when you catch a ball, you don't actually look at the ball as you catch it. You anticipate the path of the ball and keep your gaze steady.

This is further complicated by the lack of gravity. You move your arm and it torques the rest of your body out of position and throws off your reference frame too. I want to get paid to write stupid papers like that. Oh, wait, I'm getting paid right now...

Re:Or...

[Peyna]

Yeah, reminds me of "The Forest People", by Colin Turnbull. He took a pygmy out of the forest where he lived and up on this mountain, and the guy thought that everything he saw was miniature versions of what they really were. His eyes had never had to look at anything more than 15-20 feet in front of him in the forest, and he had no clue what things looked like when they were that far away.

illusion

[alanak]

isn't this more or less just like another optical illusion. Our brains are "wired" or just merely used to seeing things one way, so when something suddenly goes wrong, our brain simply pretends everything's normal. Internal gravity mechanism? hmmph, just call it millions of years living on a planet with constant gravity.

Unlearning

[redelm]

Well, doh! Those astronauts are all-American boys who know how to play ball in gravity. Probably made some sort of ball sports team. Of course they're going to have trouble in zero-gee. They'll have to unlearn all the trajectory compensations they learned in practice. I'd expect someone who who didn't make the team and doesn't know throwing/catching to do alot better. Habits are harder to unlearn than to learn.

Practical Implications

[Proaxiom]

This means that Quidditch must be an even harder game than I thought.

Just more kudos to Harry Potter, who can catch that Snitch even though it seems completely unaffected by gravity.

Now I think would be a good time to propose a Quidditch Module to be added to the International Space Station. Then all the funding countries could make teams and send them up.

Badminton

[the eric conspiracy]

It's a remarkable parallel to playing the game of badminton. The air resistance of the shuttlecock is much higher than that of a normal ball, so the flight trajectory is not what a person used to playing other games would expect. As a result a novice player has an adjustment period before he can really anticipate where a shot is going to go.

Re:Badminton

[Tackhead]

> Once, back in school, the PE dept. decided that we all had to play Tennis, which was fine, except that I played badminton regularly, of course if you play a badminton shot with a tennis ball, it doesn't really go where you meant!

Huh? I don't get it. I remember putting on our spacesuits for recess at Lunar Educational Module Delta, and we'd go outside the airlock to play.

We tried your Earthborn games of badminton and tennis, but couldn't tell the difference.

What's the difference between using that feathery-cone-shaped thing, the hollow rubber thing that just freezes solid (and sometimes shatters)? Cost us a fortune to get those sent up here, and for what? Why not just bat a rock around? Rocks are cheap, plentiful, and in a vaccuum, fly the same way.

LOL

[recursiv]

It takes 100 million years to learn to adapt to a new strength of gravity? I suppose that's why they can start to make progress in just 15 days.

And on top of all that, even if any of that was correct g hasn't changed that much. Can you explain why g isn't much different on the equator than at the poles?

Anyway, I know IHBT, but I just wanted to make sure no one else buys into this.

Re:What a ridiculous notion

[alnapp]

Also, I'm guessing these guys are in their thirties. Now, had they been in a weightless environmentr for those 30 odd years they could easily catch a ball in those conditions, but I bet they'd fail to do it in our gravity.

This isn't an "inbuilt" ability, its practise

Maybe it isn't the gravity...

[qurob]

Whenever the jocks threw balls at the geeks at school, they never caught them either :)

Fluids in the ear?

[ebbomega]

If fluids in the ear are what help us for balance and orientation, why _wouldn't_ it be able to compensate for gravity? Once the nausea has been overcome for lack of gravity, all of your other orientation skills (ie gravitational compensation for prediction of a ball) should follow suit. The nausea stage is where you're body is trying to adjust, I'd assume that the mind is doing the same.

I would have emailed about the duplicate story

[Unknown Poltroon]

but tacos link goes to his home page, insted of his e-mail. Oh well, as long as hits on his web page are more important, then i dont feel guilty about karma whoring.

http://slashdot.org/article.pl?sid=02/03/18/2055 25 9&mode=thread

Or you could read this article...

[pwagland]

also on Slashdot...

And again, I say, so what? It takes the human body a while to accustomise yourself to a new environment, this is hardly breaking news!

Any SysAdmin who has gone from Solaris to AIX could tell you exactly the same thing! :-)

Re:Well..

[ergo98]

Really, eh? Perhaps soon we'll see remarkable breakthroughs like "Right-handed Man has trouble writing with his left hand, but after 15 days can do so with some trouble." "Lady churns gears on her manual transmission : Is an automatic transmission ingrained in her mind?"

However personally when I read the article I thought it was much more intriguing : I thought it was saying that the astronauts were having flashbacks of some ball slowly coming towards them 15 days later....

.. Then get Drunk!

[Emugamer]

its easy. For anyone who has been totally wasted, you know that all sense of gravity seems to be scewed. That way the only thing working against you is keeping from passing out, and the mental capacity of maybe 1/10th your normal capacity. So other then the fact that when you hurl it won't be as easy to find (It doesn't just go down and hit the ground) You would have a great advantage over everyone else in your allstar baseball-in-space .... right? right?

Re:What a ridiculous notion

[iolaire_in_swe]

Err, what?
You claim a 50% INCREASE in g due to higher centrifugal force (current is 9.8ms^-2). This is clearly nonsense. Also: "100 million years ago the Earth's day was only about 18 hours long." is very unlikely - The geology doesn't bear it out at all (and yes I do have a degree in geology, so I may know what I'm on about).

Even if our day lasted only 12 current hours, that would not result in 50% of our current gravity - the mass of the earth masks any such effect. The variation of g from the pole (no angular motion) to the equator (max angular motion) is only about 0.6ms^-2.

Finally, there's no such thing as centrifugal force - it's simply the tendency of objects to continue in a straight line. Any high school student studying physics should be able to tell you that.

*sigh*

Isaac Asimov used this for a SF story

[Seth Finkelstein]

Isaac Asimov wrote a prescient short story "The Singing Bell", about this effect. The plot hinges on proving that a man has recently been to the moon, by catching him off-guard in catching something as if he was on the moon (i.e. he had adapted to the lunar gravity in terms of ball-catching). Absolutely great science-fiction story.

Sig: What Happened To The Censorware Project (censorware.org)

Re:Isaac Asimov used this for a SF story

[sunhou]

Asimov wrote another cute little short story called "Belief" in which a scientist was able to levitate simply because he believed he could. (I think it first started happening in his sleep, and then he was able to do it awake.)

Re:Isaac Asimov used this for a SF story

[jejones]

A shame that the Good Doctor wasn't around to hear of this. Anyone who hasn't read his Wendell Urth short stories or his other SF mysteries should hasten to a book store; they're great fun.

Re:Isaac Asimov used this for a SF story

[Nyarly]

&ltheresy>I've always found Asimov's novels slow, the characters flat, and the style dry.&lt/heresy> But, his short stories are execellent. The same style that makes his novels tedious make his shorts amazingly satisfying. A science fiction story doesn't need incredible depth of character, it gets by entirely on an idea and its presentation. And Asimov's ideas, I won't deny, were truly excellent.

My favorite story of his, by far, is The Billiard Ball, wherein a scientist kills the engineer who has been leeching off his work for decades by potting a billiard ball through the zero-mass field the engineer has built. Very nice story.

Re:What a ridiculous notion

[well_jung]

That it took practice is exactly correct. It's like catching a ball from a different quarterback that throws sidearm with his left hand. If the trajectory and acceleration are substantively different, it will take a while to get comfy. I suspect a well practiced juggler could adjust to the diffences in Space fairly quickly.

Honestly, that a coupla of guys with PHDs in Physics couldn't catch a ball doesn't suprise me all that much.

Where is the control?

[plover]

This is a really flawed argument. Since every single human they've tested with was conceived, born, and grew up subjected to gravity, a *model* is hard wired?

I think before he can claim this, we'd need to see the results of testing on space-born and -bred animals.

Dogs, calculus, and fetch.

[B1]

Has anybody else read Dirk Gently's Holistic Detective Agency? (Douglas Adams)

In one passage, I believe Dirk is explaining that we don't give credit to dogs for their ability to perform complex calculus in realtime.

For example, when you play fetch, your dog is able to analyze the trajectory and velocity of a thrown ball. Based on his observation of the throw, he solves a complex three-dimensional physics problem involving a system of differential equations based upon the underlying physics. He does this fast enough that he is able to position himself to catch the ball.

Of course, that's *most* dogs...our dog wasn't so good at catching things. I think he was more of an "arts" dog. :)

Re:Dogs, calculus, and fetch.

[sammy baby]

...And if you're throwing a frisbee, the odds are that the disc will veer away from the vertical plane of its initial vector, especially if the frisbee isn't perpendicular to the force of gravity.

Re:Dogs, calculus, and fetch.

[foobar104]

Tragedy shouldn't take away from comedy, at least not in the long term. Something horrible happens, and it takes time to get over it. During that time, one's sense of humor is seriously impaired. Hell, nothing was funny on September 12th. But eventually you have to go back to laughing at things. It's the only way to get through a life otherwise filled with pain, fear, and grief.

I forget who said it, but it resonates nonetheless: I laugh only that I may not weep.

Re:Dogs, calculus, and fetch.

[Omerna]

I've read that book, and yes, you're correct. That was the first thing that came to mind when I read that article.

BTW, that series is really good if all you've read of his books is the Hitchhiker series.

Eyesight....

[davidfsmith]

IIRC there is some study about eyesight that seems to think that the brain adjusts within about 2 weeks as well... an experiment was done where people wore glasses that inverted vision, however after 2 weeks the brain had "corrected" this and vision appeared returned to "normal"

IIRC this also led to the conclusion that babies see updside down for the first 2 weeks of there lives before the brain "fixes" the problem....

;-)

of course i could be making it all up

Re:What a ridiculous notion

[iolaire_in_swe]

"I suspect a well practiced juggler could adjust to the diffences in Space fairly quickly."

I doubt that: the balls wouldn't come back to you.

:P

You learn how to catch SOONER in life.....

[RobertAG]

... and you learn to deal with motion issues later in life.

This would be especially true with astronauts. A lot of them learned to deal with motion issues as adults during pilot/aviation training in previous careers. For the rest, you learn to deal with motion issues when learning to drive a car or ride a bike.

Contrast this with learning about gravity and trajectory. One learns to catch and throw at a relatively young age (say 1 1/2 to 3 years old). Such learning is deeply embedded and may well take longer to "unlearn."

Hmmm gives new meaning to gravitational model...

[Psarchasm]

*homer gurgle*

People versus animals

[sunhou]

With people I think it's easy to ascribe this to learning, rather than built-in gravity models. A more interesting example is with animals.

My neighbor's dog (an Australian cattle dog) is fantastic at catching tennis balls. If you throw one, he can go running, look up over his shoulder, and catch the ball in midair over the shoulder. If you throw farther and he gets there too late, he's very good at knowing where it will go on the bounce and doing a flying leap to catch it off the bounce.

If we built a little enclosed park with atmosphere on the moon, I wonder how long it would take him to adapt the model in his brain to calculate the new trajectories? (I guess I believe that even in dogs, it's learned -- of course there weren't any tennis balls bouncing around over evolutionary time scales, and probably not a whole lot of birds falling out of the sky and bouncing in parabolic trajectories either.)

Gives new meanig to gravitational model...

[Psarchasm]

<imagines the shape of breasts for the colonies of women that grow-up in low grav>

*homer gurgle*

(Forgot to escape my symbols :P)

Re:Let's concentrate on real problems

[Hiro Antagonist]

Urm, I hate to tell you this, but "ball games and other sports" are hardly the opiate of Joe Sixpack; that award goes to professional American football[1]. Many intelligent people, astrophysicists and neuroscientists even, enjoy spending time cycling, playing tennis, volleyball, or a pick-up game of basketball. The most intelligent people I know spent years studying martial arts.

The ability to use the body does not impinge upon the ability to use the mind, and learning to use both provides a much greater benefit than having skill solely with one or the other. The pudgy no-exercise anti-sports nerd lies at the same level of extreme as Mr. Pro Football Joe Sixpack.

As to your last comment, hey: I'm a cyclist. I play basketball during the summer (despite my abject lack of talent), practice martial arts, and I lift weights. I also code heavily in four languages, run Linux on all my hardware (even my older SPARCs), and dabble with electronics and amateur radio when I have time.

Only difference between you and I is that I can still see certain important organs when I look downward...

[1] Not to be confused with Football, known to us Americans as "Soccer".

Is *that* really thr problem?

[chinton]

Perhaps they did the experiment with the nerdiest batch of astronauts. I can hear the new phrase now... "Ha ha! You throw like an astronaut!"

What a load of crap.

[FallLine]

Athletic ability and intellectual ability are two entirely seperate things and are not mutually exclusive by any means. Just because so-called nerds don't engage in sports doesn't make this any less true. Especially when you take into consideration the fact that "nerdiness" and intelligence are often divergent qualities.

I've known many stupid nerds.

I've known many highly intelligent and intellectual people that not only have substantial athletic ability, but also enjoy playing a number of sports whenever they have the time and opportunity.

In fact, there are many people in education that would be quick to point out that athletic success/ability is correlated with academic success (likely because those that succeed in sports also have the drive to succeed in academics and other pursuits).

Wha?

[sporty]

That doesn't make sense. If someone lob's a ball to me, I can anticipate that it will curve and will land in a certain place.

If someone pitches a ball at me, then I know its not going to curve as much.

I play v-ball, if someone spikes a ball, it ain't curving.

Yes, there is some learning in terms of catching a ball, but I just think those guys up there can't throw/catch.

Have these astronauts never played video games?

[Remus Shepherd]

I find it hard to believe that it took 15 days for the astronauts to acclimatize to projectile motion without gravity. Any video game veteran has learned that instinct by interacting with Descent: Freespace, XWing, or even 3D Pong. These video games serve as excellent simulators; the astronauts must have never played any of them.

If aliens invade, I pray that Defender becomes standard training for our fighter pilots.

Re:Have these astronauts never played video games?

[Uttles]

Video games are a far cry from reality my friend. Pressing some buttons does not equal duplicating the actual physical motion. I agree 15 days seems a lot, but don't compare it to using a joystick.

Re:Have these astronauts never played video games?

[Remus Shepherd]

But the researchers are arguing that it's a matter of how the brain predicts motion in a 3D space. The physical training is not supposed to be the issue here. The researchers are blaming the eye part of the astronauts' eye-hand coordination, and that's something that video games can train.

I'm left with two conclusions, both of which are likely: That this research conclusion is either seriously flawed, or these astronauts have never played video games in their lives. :)

Come on now, don't be so lame..

[Uttles]

The brain must have some sort of internal gravitation model.

It's not a model, it's just a reaction. You live all of your life under the earth's gravity, so your brain is used to how things react in that system. The brain doesn't come with, or even learn, some sort of function to calculate gravitational effects, the brain just gets used to the way things happen.

In other words, your brain doesn't see a ball coming at you and do this:
Ball approaching at 40 mph and presently 12 ft altitude.
Based on calculations of gravity and wind resistance, ball will arrive at 35 mph and 4 ft altitude
Move hand to location

It's more like this: Ball approaching. Based on the millions of times I've experienced this, the ball will arrive at about right here (hand goes into place)

Re:What a ridiculous notion

[Flavio]

I thought this stupid thread would've died already, but since it hasn't let's use some high school physics to show how wrong you are.

*Suppose* that 100 million years ago the earth's day were only 18 hours long. I don't know if it was, but suppose that.

Then the measured gravity acceleration would be

g = g_0 - Rw^2, where w is omega (the earth's period)

w = 2pi/64800
g = 9.8 - 6,37e6*(9.7e-5)^2 = 9.8 - 0.06 = 9.74 m/s^2

So I can't see how g could've been about 15.2 m/s^2, because reducing earth's period doesn't make much of a difference (as many people have stated without proof before me).

What amazes me is that you state that g was actually HIGHER (15.2 m/s^2) back in that day. Would you mind elucidating that?

Re:What a ridiculous notion

[ralphb]

"I suspect a well practiced juggler could adjust to the diffences in Space fairly quickly."

This has already been done. Senator Jake Garn is a juggler, and attempted to juggle while on a space shuttle mission in 1985. They also played with Slinkys, Yo-yos, and Wheel-Os.

Ralph

awesome troll

[joss]

Nice one, good experiment. Just how much plausible sounding but preposterouis bullshit can you fit in 3 sentences and still have people take you seriously ?

our brain learns for us.

[joopsTao]

The article does seem incredibly counter intuitive. The human brain learns through experiance, when learning to play badminton or tennis your brain builds a mental model of how the ball will travel to you.

IT also builds a mental model of how the ball will travel away from you when struck.

This just takes exposure and practice. (However I could believe that the brain has developed the ability to learn patterns of motion)

During our lives we watch leaves fall, we play ball games, we do the thing out of aliens with the knife. All of this allows our brain to predict how things will happen around us.

Maybe the scientists are right (I really have no educational basis for what I say) but I feel that too often people have a theory, they do an experiment and then merrily claim that the experiment proves the theory. Without exploring the alternatives. (I apologise to scientist types, I do not meen to generalise and I only refer to the "weird" experiments that make it into the main stream press) Cheers.

How long did it take you to learn in gravity?

[weave]

How long did it take you to learn to catch a ball on Earth?

My father was never one who was into sports until one day when he felt guilty I guess and bought me a mitt when I was 8 and took me out back to play catch.

Guess what, I sucked. I don't know how long it took me to learn but I tell you what, once in a while someone tosses a set of keys to me across the room and I still can't catch em half the time.

So I don't see why this is a big deal. Now if it was a story about the difficulties of re-learning how to have sex in space, then I'd be interested! (No, my dad didn't teach me that either, thank god)

Re:What a ridiculous notion

[well_jung]

"I suspect a well practiced juggler could adjust to the diffences in Space fairly quickly."

I doubt that: the balls wouldn't come back to you.

My point wasn't that he could juggle in space. The point is that he would be used to varying rates of speed, direction, and distances. Therefore, his muscle memory would not as rigid in focus as somebody that plays catch with a baseball.

I appreciate the humor, but in this experiment the balls were thrown at them. It was just catching, no throwing.

Wow, imagine...

[AndroidCat]

A Bowwoofwoof cluster of them! :^)

Juggling??

[Russ Nelson]

So, how would you juggle in a zero-gravity environment?? Has anybody tried it? Or is the very concept void and null?
-russ

And If They Don't Catch The Ball...

[GeekLife.com]

I recommend they follow the lead of these firemen. Nothing like fear of negative reinforcement to improve performance.

Brain learning mechanism

[sphealey]

The ramifications? Well, people are going to, like have to, like, train for the new environment! Quick, call the cops!

Wish I had some mod points - this comment nails it (so to speak).

My thought is that there must be an amazingly powerful adaptive learning mechanism built into the brain if it can reprogram itself to compensate for zero G (no, I won't say "microgravity". Nor "Shuttle" without an article, nor "liftoff" instead of "blastoff". Take that NASA!) trajectories in 15 days. I started playing catch with my boys when they were 8 months old or so - something burned in that deep and the brain can still adapt. Amazing.

sPh

Re:What a ridiculous notion

[Latent IT]

I juggle.

Actually, a whole lot of juggling is putting your hand in the right place at the right time. You're not really watching all the balls in the air, if you're doing more than 3. If anything, a juggler relies on the anticipation *more* to catch a ball than say, a baseball outfielder, who can just follow the single ball in with his vision.

That being said, and getting back to the humor, yeah, I bet I could catch the ball better than those physics guys any day. ;)

I watched my friends baby learn to walk...

[rarose]

and it was obvious that he picked up standing while holding onto something (i.e. the muscle coordination involved) before he picked up "standing while counterbalancing gravity. He would stand next to his toybox while comptemplating which toy to grab... then he'd let go off the toybox to grab a toy and fall down. You could see that he had *no idea* of why he fell down initially.

So yes... I find it quite believable that gravity is modeled in the brain separately from kinematics and that therefore new kinematic skills (like learning to catch in 0-g) have a hard time disengaging the gravity model.

rat

[Toshito]

I saw a documentary where there was a rat (I think, or another small furry ball of some sort) that was given a small piece of food. This piece of food was dropped in a hole in front of the animal's eyes and was exiting on the bottom. There was several holes on the top of the box and another row of holes in the bottom.

The experiment was to drop the piece and see where the animal would expect it to fall. Well, it seems that the animal always expected it to fall from the hole directly under the one it was dropped into, and when it wasn't the case the animal was confused.

So they found that this animal was expecting the piece of food to follow the law of gravity.

It takes 22.5 years

[drew_kime]

You can simulate this

[Scratch-O-Matic]

by laying on your back and throwing a ball straight up. Once you get the hang of throwing it straight up, which is a challenge in its own right, you will be catching the ball with the same trajectory as the astronauts. It's difficult to throw it straight up for the same reason it's difficult to catch in space: your brain ends up compensating for gravity, so your first several (or several dozen) will probably go back over you head. I discovered this exercise when I was about 10; I was quite surprised at how difficult it was to catch at first.

I propose that future astronauts perform this exercise for 15 days before their flight. That way, they will be able to play catch right away, with no "warmup period," thus making them more productive. And to think my Mom said I was wasting time!

Re:You can simulate this

[mikewas]

This is a different effect.

Humans' 3d vision is effective over a very short range. the spacing of our eyes is optimized for accurate depth perception at arm length. It is still usable to several feet -- maybe 10s of feet, but with ever reduced accuracy until it fails us entirely.

Beyond this limited range, we rely on a number of other cues -- comparing an object with nearby objects of known size, reduced detail at distance, and observed change of anglular direction to a moving object.

Humans use the latter -- observation of the angle to a moving object, to catch a ball. The effect is easily visible when driving down a road at constant speed. Watch the telephone poles by the side of the road -- they appear to "speed up" as they get closer. It's because they're off to the side, as they get closer even though the car's speed hasn't changed, the rate that the angle to a given pole changes more rapidly until it is exactly opposite you. You could also plot it. If you drive straight at a pole (don't try this at home), this cue doesn't exist, and bifocal vision doesn't help until possibly too late.

We use this to determine a moving ball's distance. Watch a baseball outfielder. if the ball is coming straight overhead, as he runs back to get the ball he'll actually run to the side, then veer back in to meet the ball. I suspect that when you were throwing a ball up & catching it, you were subconsiously learning how long it takes for a ball to come down for a given force of throw. Had you had the ball dropped from straight above, from a random height, you'd still be unable to accuratly time the ball's arrival & miss the catch.

Re:You can simulate this

[Scratch-O-Matic]

Interesting...

While I don't agree 100% with your disagreement, you did make me realize one thing: the ball being caught in the "laying on the back" experiment is accelerating, while the ball thrown in space is not. That may be a significant difference.

Your analysis of our use of 3-d observations to catch a ball is interesting, but I don't think that's the whole story. Your explanation is relevent to how we track the ball with our eyes, but it doesn't take into account the timely placement of our hand in a position to intercept the ball. It's not good enough to see where the ball is and put our hand there; we have to put our hand in the right spot before the ball gets there. To do this, I think our knowledge of how gravity affects the trajectory is very important. To use an example from above: a parachute landing. Sure, you can watch the ground and make a pretty accurate judgment about how high you are, but at the very last second you will most likely raise your feet too early because you are used to "falling" at a certain rate of acceleration. Change the acceleration, and your brain no longer knows how to compensate. I did 20 jumps years ago, and I jarred my shins every single time, even though the rate of descent was no greater than hopping of a picnic table.

Re:You can simulate this

[Scratch-O-Matic]

I spent some time flying military jets (not the pilot, the 'other guy'.) The training for parachute descents is as you describe...wait for your feet to hit the water. I recall one time during carrier training, we were launched off the front and flew straight ahead for several miles. I looked out and wondered why we were skimming along just above the water...we appeared to be no higher than the flight deck we had just left. I checked the altimeter and it read 600 feet.

Re:You can simulate this

[Scratch-O-Matic]

Perhaps my best deal of all was survival training in Pensacola, when we went up in a modified parachute that was rigged like a parasail. We'd get up to altitude, maybe 200 feet or so, then cut loose and ride the chute into the water. I'd like to buy a beer for the guy who dreamed that one up.

It was my understanding...

[Guppy06]

... that simple ballistics is one of the few instincts we humans are born with (such as holding our breath when under water), an innate ability to judge an object's motion in free-fall. Something that came in handy when we were jumping from branch to branch or throwing stuff at predators. Something akin to the way cats can always land on their feet.

Of course, I'm not a biologist so I could be wrong...

Re:Astronauts Join the Major League

[bluGill]

Not really, in space there is a pretty good vacuum, so no wind resistance to worry about. Throw a baseball out the window of the shuttle (exercise for the reader to figgure out HOW to open a shuttle window), and you can expect it will remain in orbit for a few days before something affects it enough that you can't guess based on initial parameters where it will be.

bees, parachutes, & linear thinking

[hawk]

From other seminars I've attended in the past:

there's a certain amount of linear modeling the brain can do. Note that, for a small enough interval, a linear model can be made "good enough".

The interesting examples:

1. Move a beehive by a fixed amount each day while they're out gathering. The bees adjust to this (e.g., 10feet/day), and head to where they know it *will be*. Increase this amount by a fixed amount (10, 11, 12, etc.) and they can't do it.

2. Parachute landing. Don't look at the ground. You're falling at a rate the brain can't handle; if you watch, you compensate incorrectly, and often hurt yourself. (so hear the brain seems to expect the gravity induced quadratic, whereas you're moving at a linear rate?).

hawk

What about a frisbee?

[Glorat]

I'm sure this has been mentioned before... but what about throwing a frisbee? A good frisbee will travel exactly horizontally from source to target and us humans have no problem catching it.

I'm trying to imagine what I would do in space. I can see myself trying to anticipate the not dropping ball and messing up. I can also see myself catching a frisbee with few problems in space. Maybe our brains have learnt from experience that balls tend to drop and frisbees don't as much

Re:Astronauts Join the Major League

[Tackhead]

> > astronauts continue to anticipate the path of a ball for 15 days
>
> Wow, those astronauts sure have strong throwing arms.

Hmm, anyone for "playing ball" on an asteroid? No team required, you can do it solitaire!

You pitch the ball to the east, go home for lunch, change uniforms, do some math, and walk over to the plate with a bat.

If you hit the ball, you do some calculations, change uniforms again, and go hopping around the asteroid with a glove attached to a tall pole to try and snag it out of orbit. (If you hit it hard enough, the ball achieves escape velocity! Home run!)

If you swing and miss, you go back home, change uniforms, and come back with a catcher's mitt.

Hmm... Heinlein said it first, I think...

[Dr. Zowie]

... in one of the "future history" series. I forget which one -- but it was one of the lunar stories. The Rolling Stones? The Moon is a Harsh Mistress? The Menace from Earth? I remember one of his Knockout-Nobel-Laureate-Who-Just-Wants-To-Make-Bab ies women talking about it...

Learn the vocabulary, dimwit

[plastik55]

"The brain must have some sort of internal gravitation model." -- You live all of your life under the earth's gravity, so your brain is used to how things react in that system.

Speaking as a neuroscience grad, I'm going to say this once: The second sentence above says the same thing as the first. "Internal model" is a fancy way of saying that the brain will predict the behavior of something. No more, no less.

In other words, your brain doesn't see a ball coming at you and do this:
Ball approaching at 40 mph and presently 12 ft altitude.
Based on calculations of gravity and wind resistance, ball will arrive at 35 mph and 4 ft altitude
Move hand to location

Calculations dont have to be in base 10, or involve digits at all, in order to be calculations. Analog computers are still computers.

It's more like this: Ball approaching. Based on the millions of times I've experienced this, the ball will arrive at about right here (hand goes into place)

There's a big "at this point, a miracle happens" moment in that sentence. Unless you claim that you can only catch balls that travel in exactly the same trajectory as balls you'e seen before, you're going to need to generalize their behavior a bit. Once you generalize the behavior, you've got an internal model.

Reminds me of a Doctor Who episode...

[Artifice_Eternity]

...where the 5th Doctor (Peter Davison) is floating outside a huge spaceship, trying to get to the TARDIS hovering nearby. He's somehow lost his momentum (this is bad physics, unlike what follows).

His solution: he pulls out a cricket ball, throws it at the spaceship, and catches it on the rebound. Voila...thrust. He drifts on to the TARDIS, and all is good.

Hey, it's really not off-topic if you think about it.

Re:What a ridiculous notion

[daniel_isaacs]

That's a better anoalogy, the baseball outfielder. He catches balls from a great variety of distance, angle, and speed. He reacts to the ball.