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Gravity Hard-Coded Into The Brain
guiding_knight writes: "A study by French scientists suggests that gravity is imprinted in the human brain. Interesting article, tells of human ability to calculate effects of Earth-normal gravity and how difficult it is to adapt to another model."
with a little genetic engineering, we can all go around floating?
Sounds to me like the scientists in space adapted to a new situation. You don't just erase 30 years of subconscious heuristic calculation overnight.. We don't even understand how the brain learns to catch, or how it stores the information, so how can we speculate on how hard it is to change that?
Anyone reading this article will see a big red "DUH!" in their mind. They're taking astronauts, presumable 30+ years old, and having them perform various experiments in alternate gravity situations. 30 years of experience on earth with 9.8m/s^2 gravity will surely look like hard-coded parameters when you try tossing a ball in zero-g for 5 minutes. Now if they could bear a child up in weightlessness, and raise that kid in space, teaching him to play catch without gravity, then that kid would be just as messed up once he'd return home and tried to play his game.
Brains do not store any hard-coded information, they just adapt; once they've adapted to something, it takes an equal amount of effort to change that knowledge. Say you've been playing Pacman for the last 20 years, and can pull a perfect game up to the 112th level. Then you play Virtual Fighter for the first time in your life, and get your ass savagely beat within 4 seconds. DUH! Your knowledge of Pacman's rules and strategies means nothing once you move to a new game. Same thing applies here.
-Billco, Fnarg.com
I was able to accurately play video games that used non-earth physics when I was younger. This can't be too different. I am sure it got to the point that I did not have to think about compensating for constant speed rather than acceleration.
Okay, so that wasn't a scientific experiment, I just find that there reasoning is quite poor, baby's on a glass table are scared, ya, that is really good scientific proof.
One way to figure this one is to test one of those dudes whose been in space for months, and then test him just as he get's back to earth, I bet for at least a few hours he would be on "space gravity".
just my $.02
http://monkeyserver.com --- weeeeee
Also look at computer games which can have arbitrary G constants. People playing video games can get very very good at predicting when their character hits the ground no matter what G is thrown in.
Upon reading the article, it looks as though they have found evidence that we are attuned to normal earth gravity but they have proven nothing. Their experiments are all done with people who, after having grown up in normal gravity, are thrown off by less gravity. I don't think they have much in the way of nature/nurture on this. Better experiments would involve raising a kid in space and seeing how he could catch a ball.
I would not be suprised if we somewhat expect earth's gravity after years of evolution (the same way we are easily get phobias of snakes but not much more dangerous things like cars and electricity), but humans obviously have wide skills with other acceleration constants. This study is hardly conclusive from the summary of it in the news article.
It's also possible that the brain is able to learn and retain multiple models of acceleration.
:P
Like multiple hardware profiles? I don't know about this, my brain couldn't even switch back over to the "short hair profile" of my past when I went back to having short hair.
proton != antielectron
...that the material presented in the article suggests the exact opposite of its hypothesis. As was stated, the astronauts began to adapt after a little while days. (The article also suggests that new models can be learned--but isn't that the opposite of hard-wiring?)
Think of it this way: A little kid can't just start catching a ball naturally. It takes a while for it to click. It just so happens that, by the time someone is a teen-ager, they've had to catch things so often that they do it without thinking about it. That's not hard wiring, it's conditioning. Of course, when you've been conditioned to do something over a long period of time, it takes a little while to unlearn it.
Anyway, I just don't see any solid evidence from the material presented that predicting gravitational acceleration is hard-wired into the brain. Take some kids who haven't yet learned to catch into a zero-G environment (Vomit Comet, anyone?) and do the experiment with them. That way, conditioning won't contaminate the results.
It's one thing to try and do something WITHOUT gravity, that I had originally learned how to do WITH gravity. That's what this experiment was attempting to do.
I'd be more interested in how well they did learning, for example, to play hacky sack (passing a small, bean-filled leather bag using only your feet). if they had no prior experience with the game, I'd be interested in seeing how well they did, learning it in zero-G; compared to others learning how to do it with normal gravity. That would be a more valid experiment in my book.
Not at all, considering gravity hasn't significantly changed on this planet for probably the past 4 billion years or so, or at the very least in the lifetime of man and all his ancestors. It's only us silly hairless monkeys who insist on leaving this Earthly paradise and venturing into inhospitable territory such as the moon, other planets, or open space that fucks things up.
It hurts when I pee.
I not trying to troll or flame you or anything, but could you please tell me where you get the 100 million BP? Also, just because a perception of gravity may have evolved 100 million BP doesn't mean that it can't be "updated" through time to incorporate the new values of g. It seems that the astronaughts adapted in as much as 15 days. Not perfectly, but who knows what 30 day could do; or a year; or a century; or 100 millino years. In addition, it seems to me that the study does not determine that gravity is genetic or in the brain from birth, but that by the time someone is old enough to get on a space shuttle and play around in zero-G, they have some kind of subconscious understanding of gravity.
Rhapsody in Numbers
Indeed, what a ridiculous post.
First, your figure of "100 million years" seems to have been completely fabricated. Care to back that up?
Your number for day length of 100 MYA is also rather off. Day length change is approximately 2 milliseconds per century, meaning that even 100 MYA, the day could not have been more than 2000 seconds (considerably less than 6 hours) shorter than it is currently. The actual day length was actually longer than what these quick calculations indicate, given changing rates, but your numbers are completely out of the ballpark.
In addition, your very concept of gravity seems to be off. Gravity is the attraction of two bodies with definite mass, and is equal to G_c*m_1/d^2. Rotational speed doesn't affect gravity at all -- only mass does.
Heck, you even contradict yourself, not to mention practically all scientific knowledge we have. A weaker gravitational force means a lower gravitational acceleration constant, which is rather inconsistent with your figure of 15.2 m/s^2, which is rather more than the 9.8 m/s^2 we have now!
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Floccinaucinihilipilification - the action or habit of judging something to be worthless
Despite its title, the article states the scientists are unsure of how "hard-coded" gravity is in the brain:
It's possible that the astronauts did adapt to 0-g, and then readapted back to 1-g again. It's also possible that the brain is able to learn and retain multiple models of acceleration. In different situations, it might simply choose which one to apply. That, in fact, is what McIntyre and his colleagues believe is going on.
In other words, like on Slashdot and other publications, the headline writers didn't read the article, or deliberately misstated its conclusion in the interest of an exciting headline.
evanchik.net
But what irks me about your post is the comment, "baby's on a glass table are scared, ya, that is really good scientific proof." Do you even know what that experiment is, who conducted it, and what were the follow-up studies? It's one of the classics of developmental psychology. And they were careful not to draw too many conclusions from it. But it does support (not prove, nor does it claim to) the notion that our sense of gravity is innate.
"Hardly used" will not fetch you a better price for your brain.
The problem with this article is, not that they assume that gravity is hardwired, the article actually states that they are not sure, but rather that there assumptions are off base.
They say that it takes about 2-3 days before you get over the (lack of) motion sickness. That is, it takes the human body roughly 48-72 hours of doing something that it considers really wrong before it gets used to it.
Now consider the throwing, they say that after 15 days the astronaughts were getting used to it. Lets assume (for sake of argument) that they were throwing the ball 3 hours a day. It might seem unlikely given the cost of putting someone in space that we would give them them such a task, but even if we did, then we are saying that after roughly 45 hours of practice the body is getting used to something that it considers really wrong.
Am I really the only one that sees the parallel here?
Here is an interesting story about Penn Jillette (of Penn and Teller) and his experiences with zero-g. It's pretty long, but it's detailed and amusing.
Kittens raised in a room with nothing but horizontal stripes on the walls will be forever blind vertical stripes and vice versa. Kittens raised without any light will be completely blind. Is it any wonder that humans experience a mild timing error in zero G? At least we are not "blind" to free fall.
If voting were effective, it would be illegal by now.
I didn't mention centrifugal force because it had no relevance to debunking what the original poster stated. The original post gave a value of 'g' of 15.2 m/s^2 if the Earth rotated faster, corresponding to INCREASED gravity.
Of course, this has no grounding in fact, as gravitational force relates only to the masses of the objects in question and the distance separating them, and neither the mass of the Earth nor its radius has changed significantly enough to change the value of g to only one decimal place.
Presumably, the original poster was referencing the apparent force felt by objects on the Earth. Assuming the presumed increased centrifugal force to be significant, that would mean that g would instead be less than its current value --- the exact opposite of the larger value of g that the post gives.
Now then, if we wish to calculate the effect of centrifugal force... F_c = mv^2/r, so a_c = v^2/r, where v is the velocity, and r is the distance from the centre of the circle. v is proportional to 1/t, so using 86400 s and 84400 s, we get a change of less than 5% as a rough figure.
Now, calculating a_c, we use the Earth's rotational velocity and the radius for v and r. At the equator, these are approximately 460 m/s and 6378.1 km, respectively. Using the formula for a_c, we obtain a figure of approximately 0.03 m/s^2 at the equator, and values that decrease the further we get from the equation. A 5% change on 0.03 m/s^2 gives us less than 0.002 m/s^2, which is hardly even detectable without highly sensitive instruments!
The estimated change in centrifugal force at the equator from 100 MYA is less than 0.02% of g --- which is hardly even noticeable!
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Floccinaucinihilipilification - the action or habit of judging something to be worthless
I think a more valid conclusion from that experiment might be that free fall makes you clumsy.