Feather in Vacuum - Backstage Science
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- Опубликовано: 23 июл 2012
- Dropping a feather and metal balls in a vacuum chamber to see what gravity is really all about... The astronaut David Scott performed a similar experiment on the Moon with a hammer and feather.
More Backstage Science at www.backstagescience.com/
Films by Brady Haran for the STFC 
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how can you suck air out without the feather sucking into the pump?
"how about that!" quote of the day..
I remember this experiment taught to me in my grade 6 science, but always wanted to see it if it was true. and now i have seen it and i am happy. Good job guys
"How about that!" was an expression of genuine relief that the demonstration was pulled off without a hitch. This experiment was rehearsed in an suited-astronaut-containing vacuum chamber on Earth, where the feather appeared to fall at a slower rate due to static charge of the feather causing "cling" issues and a delayed release. The feather was coated with a very thin gold film before heading to the moon but there was no time to retry the test in the full size vacuum chamber before launch.
great video now i belive air resistince
Feather drop test proves they are really on the moon.
WOW! this is great stuff! Thank you or your work taking the time to educate us. Thanks for the upload(s). for me I am priveledged to see these videos & feel part of the movement.
Continuing what you wrote, both objects are accelerated at a rate g, and (assuming they at some point move at the same speed) both are being slowed down with the same force F. Because of this, acceleration is reduced by the amount a=F/m. This reduction is less significant for the heavier object.
There is something so amazing about this it makes me almost want to cry
It's the obvious result but it is so cool to actually watch it. Thanks for the video!
makes your heart stop, when the astronaut mentions Galileo on the moon.
Such a fascinating world we live in
Love Brady's comment. "It's going to be like space!" XD
It's moon experiment is cool. You can see the acceleration of the hammer and the feather during the drop--plus, it's on the moon.
One correction here, it was said "the feather falls much slower, that's due to air resistance, not due to the mass"
Actually it is due to both factors, the feather and the ball are accelerated at the same rate by gravity but they have different masses so have different weights and therefore are resisted by air at different rates.
Makes me wonder why we dont see more of Peta, I would watch all her videos, very good stuff !!! I suspect she is from Sweden ....
As I understand, air resistance depends mostly on geometry (size, shape). Drag in liquids also depends on object's material, as it plays a role in friction between the object and the fluid, but that is a different topic.
Weight equals mass times acceleration and it only describes the force with which an object is being pulled towards the planet.
Rockets get their propulsion solely by ejecting their fuel as it burns. Jets, on the other hand, use a mixture which consists mainly of incoming air. The incoming air is sucked in at a relatively slow speed, then heated up and ejected at a much higher speed.
For sake of clarity I looked it up. Energy is equivalent to force applied over a certain distance. In base units that is
[N] = [kg * m/s^2], whereas
[J] = [kg * m^2/s^2] = [kg * (m/s)^2].
That's the point, since m*g*r = v^2*m, at the exact value of g at a certain altitude, the true g = v^2/1, so m*g = m*v^2. Like the weight of a mass at a certain g is equivalent to the energy of a mass at the corresponding velocity.
I think I got what you mean now. If two objects of same shape but with different masses fall through air, both are affected by the same amount of drag. The force that is trying to stop them is the same, however the heavier object is accelerated with a grater force and overall we get that the heavier object is affected less by drag, so it falls faster.
I think what you wrote in the second paragraph is wrong. Force is measured in Newtons and energy is Joules - they're related but not equivalent.
In the list of liquid propellants in wikipedia it says LOX, which stands for Liquid Oxygen.
The guy has a Royksopp t-shirt! A question though. Why when you go down a snowy hill in a slide the heaviest people/slide go farther?
Yeah exactly what I mean.
As for Joules and Newtons, they measure the same thing, force or energy, except that Newtons are used in the gravity context. I think that just confuses things really.
Nice shirt John!
Now show me a rocket launch in a vacuum chamber.
The geometry of an object plays a part in air resistance as well, but in this case it is irrelevant, and the weight is the important factor, for instance if the ball had the same shape as the feather it would obviously still fall faster due to its greater mass.
As you may know the air drag/friction of an object depends also on the force/weight that it has. Weight is equivalent to energy as m*v^2 = m*g.
The drag is very complicated to calculate. Even for simple objects like spheres or cubes there is different equations depending on the speed of the object, the density of the air (which depends on altitude and temperature). Basically in the end you have to rely on the data from someone else experience.
That camera guy is a legend - he has a Royksopp T-shirt.
Royksopp. Respect!
madjimms: yes higher mass objects experience greater gravitation force (proportionate to mass & inversely to square of distance between centers), but need more force applied to achieve the same acceleration - outcome is same rate of fall. True, it is the mutual (combined) gravitational force (i.e. object pulls on the Earth too) but even a 10km asteroid has negligible mass compared to Earth, and made no real difference to any dinosaur fleeing to escape orbital velocity crashes (say 20 km/s)
Yep. Propulsion works because of conservation of momentum.
If you were resting in space and then threw a ball with some mass to one direction, you would accelerate to the opposite direction...
you must also consider density and buoyant force of air on both..
We know what it takes to get a "Saturn 5 Rocket" into orbit but please feel free to explain what is the method of propulsion for "The Lem"
If there is no air resistance in the vacuum what would the rocket push against.
Is there terminal velocity without air, or would a falling object keep accelerating until light speed?
Did she do an experiment?
You can the metal ball fall on the metal ground. Metal on metal makes vibrations whits you can hear.
...oh you solved Naiver-stokes-problem... Nobel prize!!!!
The missus has banned me from sticking things in the vacuum.
Does that ding ding bigger+
So the moon has static and the static is not conducted to the feather through the suit?
I can prove that all things of differing mass fall at the same speed in gravity fields without a vacuum chamber.
Assuming that:
Kinetic Energy(KE) = 1/2*mass(m)*velocity(v)^2
and:
(gravitational)Potential energy(PE)= m*gravity(g)*height(h)
and assuming all PE is converted into KE:
1/2mv^2 = mgh
divide by m:
1/2v^2 = gh
times by 2:
v^2 = 2gh
square root and we find that:
velocity = 2 * gravity * height
Since mass(m) is not a factor in this final equation we know that mass does not affect velocity
Neat.
Kinetic energy. With the same velocity due to gravity, more mass will have more energy. Imagine dropping a bowling ball and a basketball at the same time from the same height.
It wasn't falling slower, it just dropped a little later.
Think about what you are saying instead of just repeating it. It's only a vacuum in the sense that there is no air inside of the chamber, once the balls hit the side of the chamber they are hitting a very densely packed collection of atoms which certainly are not in a vacuum. The sound is carried through the metal of the chamber instead of the air.
I think you're wrong. The acceleration due to gravity would be the same for objects with different mass. You're confusing force with acceleration, even though the force is different, the acceleration isn't, since the objects also have different mass.(a=F/m)
From what I could find on wikipedia, air drag force only depends on the object's shape and more importantly, on its speed.
If both objects have same acceleration (gravity), they'll have the same speed at some time, and same air drag force.
I misread the title. I thought it said "Father in a Vacuum" I was expecting a completely different video. :)
What camera did you guys use to record the slow motion?
Royksopp!!
Don't they add oxygen to the fuel in space rockets?
That's Peta Foster. She's a physicist.
Wow. Smart AND beautiful!
You don't. Your best bet is measuring it since this kind of complicated fluid dynamics is impossible to solve by "normal methods". The only other way is a time expensive computer simulation on a super-computer but that's not as reliable as actually testing it. That's why wind tunnels, drop towers etc. exist. :P
Technically wouldn't the higher mass object have a stronger gravitational pull? So lets say you (theoretically) drop an asteroid & a feather... which one will land first? I'm putting my money on the higher mass object. ( I realize this doesn't apply to small objects)
Gravity can also be described mathematically as a push force.
experiment starts at 3:50
Spaaaaaaaaaace
For some reason I read the title as "Father in Vacuum." And I was confused.
Lol the heaviest ball fall the last.
The sound propagated trough the metal of the chamber into the surrounding air. No mistery here, walk along.
Video starts at 2:38
Thumbs up for the royksopp tee. Lol
"Mr Galileo"
a quick google search of her name reveals: not so ditsy
they see you trollin' they hatin'
"Mr. Galileo", I love calling him that!
Am I the only one who wants to see bubble wrap in a vacuum chamber?
What happened to it =/
Feather in a vacuum, please talk free.
The door is locked just you and me.
Can I take you to a restaurant that's got glass tables?
You can watch yourself while you are eating.
space?SPAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACE!
Look ma! We got a gramar naci!!
2:40 That's what she said.
Ooh... now put a politician in the vacuum chamber and see what happens! (I've got a pretty good idea, but I'd like to see it all the same).
It's Röyksopp - you don't seem to have an ö key :D
But I noticed it too. Great music :-)
Galileo Galilei (1564-1642) proved this very same thing in about one minute with a few metal balls and a ramp. :)
Who the Hell tells you everything on the Moon must be 250 degrees hot?
WACUUM CHAMBER
through not trough
mystery not mistery
/watch?v=Obd_jTO66-0
Now who's akhunt?
9.8 meters per second bitches!
Go bak and get the landing in the shot. We didn't see the feather land.
He looks like ChinmeySwift11
Not even wrong.
put a marshmellow in there next time
per second
can you guys finally put an end to all the controversy and put a rat in your vacuum so that the whole world can see what it happens? cause im sick of theories and i can get no way near equipment such as yours(otherwise i wouldve experimented myself).
LOL...
im gonna be honest the only reason i clicked this was because she was glowing in the thumbnail
lol
Wtf is your point?
But it's a vacuum, sound can not travel in a vacuum.
Balls? Who's balls?
Zeus aint got shit on Thor.(commence mythical gods youtube battle)
wut?
its not helping, totally different that what i wanted and implied.
i need a living organism put in vacuum, to simulate what would happen if you were in space without a space suit (and already sucked out of your spaceship/whatever )
Gravity. Its just a theory.
heh heh - she is such a girly girll!! all good, great vid as usual, thanks! ;)
If you are interested, you can easily find out. I would explain, but your username and the use of the expression 'please feel free to' are somewhat off-putting. Rockets work in a vacuum, if that's what you are on about.
Why should the feather and the hammer falls so slowly if they are on Earth?