zero gravity

http://vimeo.com/29017795

SO COOOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!111
Comments
38
im pretty sure that people plummeting has something to do with gravity.
some nice shots tho
indeed its actually just zero weight :\
Parent
also wrong.
wingsuits utilize updrafts but people still fall. zero gravity means the absence of weight which is clearly not the case.
after all this video is just some guys basejumping with wingsuits which has been new and exciting 4 years ago.
Parent
Technically they're only weightless for like 3 seconds. After that they don't accelerate anymore and have reached their terminal velocity
ARE YOU A WIZARD?
Parent
no, just chuck testa .
Parent
It's called physics
Parent
I can only into chemistry!
Parent
They experience air resistance right from the beginning, not only after a few seconds have passed. The force becomes more noticeable when speed increases, though.

Also you can't exactly reach terminal velocity by falling since the drag slows down the acceleration. You just get closer.
Parent
terminal velocity is the point where air resistance equals gravity andt is different for every object. the moment they dont accelerate any faster they reached their terminal velocity. there is no such thing as _the_ terminal velocity, so "nearing it but not reaching it" is technically not correct. :)
Parent
this makes me confused, which science man to believe?!
Parent
think about the classic "throwing a penny from the empire state building" example.
many of the people going up there try it cause common believe has it that even a penny, dropped form that height, can kill a person.
but it does not have enough mass to accelerate.
or think about a skydiver (or any other non solid mass) while falling changing shape does alter the speed, hence mass and shape influence terminal velocity, it is no general constant.
Parent
I know this but this wasnt the issue here, was it? more like if terminal velocity is the speed the object will reach in freefall despite the air resistance or not?
Parent
my first point was that naming the video "zero gravity" is bullshit.
my reponse to Vanhaomena was that
QuoteAlso you can't exactly reach terminal velocity by falling since the drag slows down the acceleration. You just get closer.
isnt correct cause terminal velocity is determined by "gravity equals wind resistance" meaning that as soon as gravity (more or less a constant) equals the (initially increasing but at that point stable) drag you reach terminal velocity (per deffinition) so you reached it, your not getting close to it.
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Quoteterminal velocity is the point where air resistance equals gravity andt is different for every object.

True.
Quotethe moment they dont accelerate any faster they reached their terminal velocity.

True, but I said this moment can never occur in the real world, and upon research I still agree with myself:
Quote by wikipediaMathematically, an object approaches its terminal velocity asymptotically.

See the word "approaches"? The velocity of a falling object approaches the terminal velocity as time spent falling approaches infinity, in other words it will never exactly reach it, which is what I thought and still think.
Quotethere is no such thing as _the_ terminal velocity

Now you lost me, try rephrasing that.

Of course I am just nitpicking, for all practical purposes "a velocity immeasurably near the terminal velocity" or >99% of it is reached quite fast, but 100% will never be reached.
Parent
drop a penny from space and it will initially increase in speed but fall for (more or less due to density of the atmosphere layers and so on) the same speed for nearly all of its falling distance. that then is the terminal velocity of that penny. it is not a mathematical constant but determined by shape and weight (and air density for that matter).
i just argued that the moment the falling rate is constant the terminal velocity is already reached and not approached but never reached. thats my practical understanding of the concept. i dont understand the "comming close but never reaching it" part.
and ofc we arenitpicking, we always are.
Parent
Pay attention to this part:
QuoteMathematically, an object approaches its terminal velocity asymptotically.
It's from this article.

To simplify (values completely made up but should help with the general idea):

Penny from space experiment: left is time spent falling, right is % of terminal velocity
0s 0
1s 10
10s 99
30s 99,99
5min 99,99999999999999999
Infinite (theoretical) 100
Parent
i didnt know that there is a constant increase in speed (even if ever increasingly marginal) and i think that in real life application this is not taken into account but each object can be assigned a falling distance after which it (practically) reaches its terminal velocity.
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Since fishbot opened the discussion with the word "technically", it kind of gives me a permission to go full velocity ahead in counter-nitpicking the nitpicker with technical and completely impractical facts, doesn't it :)
Quote by Bureaucrat #1.0 from FuturamaTechnically correct is the best kind of correct
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oh without a doubt. being anal wins in a smartass competition.
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see? he won, I agree with him.
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his maths > mine.
i lost, gg :C
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I study engineering, it's pointless to see a difference between 99,999999999 and 99,999999999999999

It's plain bullshit
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Someone could say "I study [some humanist soft science], it's pointless to see a difference between gravity and weight".
It's best to know the difference but conveniently ignore it when you should.
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Well there is a difference between weight and gravity, weight is the thing we measure when something is suspended or is standed upon, like stated below by HugTheSub.
If you're floating you don't have a weight but gravity is still there
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this scientific answer is more approvable than the one given earlier. +1
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I can consider myself as one yes
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moest t kennen voor examen
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they dont float hence they are never weightless.
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Technically true, but you know what I meant
Parent
Some great shots :)
WELKE TS ZITTEN JULLIE ?
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Quality gaming. check PM
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