Analyzing the Apollo 15 Feather and Hammer Drop - A Basic, Introductory Free-Fall Problem

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  • Опубліковано 11 січ 2025

КОМЕНТАРІ • 253

  • @monteiro5306
    @monteiro5306 7 років тому +10

    Amazing video. I was 9 years old at the time and still remember. Thanks Professor, awesome job.👍👍

  • @wellesmorgado4797
    @wellesmorgado4797 2 роки тому +5

    One of the most interesting aspects of a Moon film, that people rarely notice, is the absence of dust! At the end of the hammer + feather video, the astronaut shuffles his feet around and kicks a lot of dirt but there is no cloud of dust. No air, no dust. Dust is a suspension of very small grains on the air.

    • @wellesmorgado4797
      @wellesmorgado4797 2 роки тому +6

      On the Moon, those small grains fall to the ground as fast as the hammer, of course.

    • @kitcanyon658
      @kitcanyon658 2 роки тому +1

      @@wellesmorgado4797 exactly.

  • @peatmoss4415
    @peatmoss4415 Рік тому +4

    This one tiny video proves it was done on the moon, that is why there are no moon "lunatic deniers" on the page. Which is a bummer because I love reading their out of this world explanations!

  • @agerven
    @agerven 4 роки тому +7

    Great learning.
    Remember having seen this video live at the time, thanks to my dad. And guess what, I got to study physics! Great learning with this video, thanks for that.

  • @criztu
    @criztu 6 років тому +8

    The "feather" bounces back in the air after hitting the ground at 1:20. Are you sane enough to see the truth?

    • @coach714
      @coach714 5 років тому

      It DOES bounce! WTF?!

    • @JT_1
      @JT_1 5 років тому +1

      What truth?

    • @yeahright7339
      @yeahright7339 5 років тому +2

      Sounds normal.

    • @mesonparticle
      @mesonparticle 4 роки тому +3

      Actually it flips over on itself. Why would a feather NOT do that? Particularly as feathers are not symmetrical around all axes. And also, they are somewhat flexible, meaning when dropped there is also the potential for energy to go into bending the shaft of the feather which can then be released. I'm really puzzled why this is a problem for you :D

    • @antoniopione4545
      @antoniopione4545 4 роки тому +1

      u right

  • @saadzubair8262
    @saadzubair8262 3 роки тому +4

    love your teaching method, and i have same questions that your student asks from you.lots of love from pakistan.
    keep it up sir.

  • @karlfridrik3435
    @karlfridrik3435 6 років тому +3

    Flippin physics.. love those mathematic skills and explanation.. how ever i am skeptic about the apollo bs. Sowy.
    But keep those videos rolling, you are in your zone there. 👍👌
    Thanks.

  • @moviephysics5459
    @moviephysics5459 8 років тому +8

    It could have been more fun to estimate the height and time from the clip to find g(moon) and then use that to estimate the mass of the moon?

    • @FlippingPhysics
      @FlippingPhysics  8 років тому +8

      True, however, that takes quite a bit more physics understanding. It's a good idea though. Perhaps I'll do that problem when I get to Newton's Universal Law of Gravitation!

  • @rvsamsung77
    @rvsamsung77 6 років тому +5

    David Scott's height is 1.83m. And he drops it from the height of his chest which is 1.45-1.6m. But the calculated dropheight is only 1.2m... the explanation of this could be the camera on the moon only had a frame rate of 24 fps...

    • @klaragoiz2089
      @klaragoiz2089 5 років тому +2

      R Sorensen David Scott was the tallest of that crew. You’re right, the calculated height is shorter by more than 25 cm, but that inconsistency can’t be solved guessing 24 fps because it wasn’t a film camera but a television footage. Even worse, falling time is not longer than 1.1 sec but this video forces it to make it 1.2 sec

    • @markyounger1240
      @markyounger1240 4 роки тому

      Good observation

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому +2

      Correct. And it's confirmed. They recorded a screen at Houston with another camera. So there's two different frame rates.

  • @kingvt817
    @kingvt817 2 роки тому +1

    you are a phenomenal teacher

  • @stardustypsyche8468
    @stardustypsyche8468 7 років тому +3

    Actually acceleration due to gravity is not independent of mass, but the mass of a planet (moon) is so much greater than either the hammer or the feather that the difference is below the resolution of a simple visual experiment, yet calculable.

    F
    =
    G


    m
    1

    m
    2


    r
    2



    {\displaystyle F=G{\frac {m_{1}m_{2}}{r^{2}}}\ }
    Then calculate the acceleration of each body with a=F/m

    • @FlippingPhysics
      @FlippingPhysics  7 років тому +1

      picking it up where you end: a = F/m
      the force there is the net force in the y direction, the only force there is the force of gravity which is down and = mg
      therefore a = -(mg)/m => a = -g
      Therefore proving the acceleration of an object in free fall is independent of its mass.

    • @stardustypsyche8468
      @stardustypsyche8468 7 років тому +1

      "In order to show that the acceleration due to gravity is independent of mass"
      "Therefore proving the acceleration of an object in free fall is independent of its mass."
      These are two very different statements.
      F=G*m1*m2/r^2
      F=m*a
      so
      m*a=G*m1*m2/r^2
      But which m is m? If we let the m on the LHS be the object in question (hammer or feather) and we assume that the other m is constant then indeed acceleration is independent of *it's* mass (the m of the object cancels and thus we can calculate an acceleration constant for a particular mass such as the moon).
      But acceleration due to gravity is not, in general, independent of mass. The moon also accelerated and the moon will accelerate differently for each different mass that is dropped. Further, in general, the force is dependent on the product of the masses, and thus acceleration varies with mass in the Newtonian model.
      BTW, cool video, lunar landing deniers are idiots, using frame rates and working "backwards" to find height was a clever approach, I am just a pain in the ass about plain text literal meanings of words.

    • @carultch
      @carultch 3 роки тому

      @@stardustypsyche8468 Given that the mass of the moon is significantly greater than the mass of the hammer and feather, we can approximate the situation such that the moon has infinitely more inertia than either of them, such that its own motion is unaffected by this experiment. This is the assumption when we make, with the free fall acceleration being independent of mass.
      Your point is based on the fact that gravity is a two way street. If you account for the fact that the moon also accelerates as a consequence to the hammer's acceleration, you will get the following formula for the acceleration of the hammer (m1) in the reference frame of the moon:
      a = G/r^2*(m2 + m1)
      Plugging in the mass of the moon, m2 = 7.35e22 kg, and the mass of the hammer 1.3kg, you will see that for objects significantly less massive than the moon, this reduces to G*m2/r^2, and is independent of m1.

  • @chauphan2983
    @chauphan2983 8 років тому +1

    Is the acceleration due to gravity on y-axis always negative 9.8 m/s^2? What is the acceleration when we throw a ball up before it goes back down ?

    • @FlippingPhysics
      @FlippingPhysics  8 років тому +2

      Please watch my video about Common Free Fall Pitfalls; it will answer these questions. www.flippingphysics.com/common-free-fall-pitfalls.html

    • @borismaiorov3358
      @borismaiorov3358 6 років тому +2

      9.8 is on earth. The moon is much smaller so gravity there is also smaller

    • @agerven
      @agerven 4 роки тому

      Good questions! And good answers in reply.

  • @markyounger1240
    @markyounger1240 4 роки тому

    If you want to get REALLY technical. The drop is not totally on the Y axis due to tidal difference as his arms were laterally displaced

  • @tokay.
    @tokay. 6 років тому +3

    3:55 no way he did all that math in his head

  • @FlyBoyGrounded
    @FlyBoyGrounded 9 років тому +3

    1.2 metres doesn't seem high enough to me. David Scott is 6ft tall and he's dropping from nearly shoulder height. You show where 1.2 metres come up to on you but how tall are you?

    • @FlippingPhysics
      @FlippingPhysics  9 років тому

      FlyBoyGrounded Sadly, you are correct that my calculation doesn't appear to be as close as I would like it to be to what you see in the video. You can measure my height in the video because I stand next to a meter stick, however, I'll let you know, I am about 5 feet 8 inches tall.

    • @FlippingPhysics
      @FlippingPhysics  9 років тому

      Bruce Sullivan Yep. Wished I had noticed that before I made the video. Oh well. : ) nssdc.gsfc.nasa.gov/planetary/lunar/apollo_15_feather_drop.html

    • @carolco2
      @carolco2 9 років тому

      +Bruce Sullivan so does it mean the video was not made on the moon?

    • @FlippingPhysics
      @FlippingPhysics  9 років тому +3

      +tim klausevitz It probably just means the frame rate is incorrect. 😞

    • @carolco2
      @carolco2 9 років тому

      +Flipping Physics in this case can you please remove your video? It's misleading and is damaging to NASA.

  • @dks13827
    @dks13827 6 місяців тому

    I well remember Dave Scott doing that demo...........at Hadley Rille.

  • @spinfowars8958
    @spinfowars8958 6 років тому +5

    the easiest way I can think of to prove that they were in a vacuum on the moon would have been to take a plain piece of paper and show that it is thin and flexible by waving it showing that it bends - then hold it at the top and let it hang straight down - then let it go -
    [
    if there were no atmosphere then the paper would fall straight down without fluttering to the side at all
    [
    that test would have been so easy - they did not do that though
    ]
    if there were any atmosphere - then the paper would flutter to the side and then continue to flutter to the ground
    [
    they could have also flipped the paper - rotating axially against the flat face - and it would continue rotating in a vacuum, but in atmosphere it would rapidly slow down and stop and change rotation
    ]

    • @joevignolor4u949
      @joevignolor4u949 6 років тому +4

      There are videos around showing the rooster tails that formed behind the wheels of the lunar rover. How the dust was kicked up and fell back down prove the whole thing happened on the moon. Here is one such video: ua-cam.com/video/ZdfSoWb6W54/v-deo.html

    • @JT_1
      @JT_1 5 років тому +3

      clutching at straws, because you have been shown the evidence and now you move the goal posts

    • @Bobbymac747
      @Bobbymac747 4 роки тому +6

      You missed the point of the exercise. They weren't trying to "prove" there was no atmosphere. They were already well aware of the fact... hence the bulky pressure suits! He was using the opportunity (no atmosphere) to recreate a well-known experiment to a degree that most people don't get to witness on Earth, since most people don't have access to a vacuum chamber. We did the feather part of this with a bell jar and a vacuum pump in high school science lab in the '70's. Drops like a rock.

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому

      Look at the string they used to pull open the rover bay door. It wasn't acting like a vacuum.

    • @joevignolor4u949
      @joevignolor4u949 4 роки тому +1

      @Comb Filter The trajectories of the dust particles seen in the videos were analyzed mathematically. The variables were set to 1/6G and zero psi and the trajectories seen in the videos matched what the mathematical equations predicted. Then when the variables were set to 1G and 14.7 psi the predicted trajectories were far different from what's seen in the videos.

  • @hulkflattt7854
    @hulkflattt7854 4 роки тому +3

    if you do a test at home with a falcon feather and hammer you will get the same results

    • @G-ra-ha-m
      @G-ra-ha-m 4 роки тому

      Especially with the metal feather they used.

    • @Bobbymac747
      @Bobbymac747 4 роки тому +3

      Yes, IF you happen to live somewhere with no atmosphere.

    • @G-ra-ha-m
      @G-ra-ha-m 4 роки тому

      @@Bobbymac747 Not so, drop a feather point down 1m and it hits the ground in about 0.45s, same as a hammer.
      Instead of a hammer and feather why didn't NASA take a proper experiment?

    • @robmc1232
      @robmc1232 4 роки тому +4

      @@G-ra-ha-m I see your "point"... it works over short distances, since feathers are, by nature, quite aerodynamic. Of course, it doesn't work in atmosphere if you hold the feather in a horizontal position, due to air resistance. It only works that way in a vacuum. You can get that by using a vacuum chamber, or, you know, going to the moon, as in this example.

    • @G-ra-ha-m
      @G-ra-ha-m 4 роки тому

      @@robmc1232 The real question Rob, is why NASA did this experiment in such a way that was easy to fake and impossible to verify. There is a very consistent pattern with all of the actions, videos and photographs that never include anything difficult - like Buzz or Neil taking a deliberate photo of the earth or stars - but always of stuff they would have had on earth like the LEM, dusty footprints, weather cleaned rocks etc.

  • @helpawhiteguy
    @helpawhiteguy 9 років тому +1

    The camera they used was 10 frames per second, not 29.97. See imgur.com/Jqz9Myk for specifics, from NASA docs here www.hq.nasa.gov/alsj/Electronics-670306.pdf This significantly changes the time base used to calculate the free-fall time

    • @FlippingPhysics
      @FlippingPhysics  9 років тому +2

      +helpawhiteguy The Apollo 15 mission was in 1971. The NASA link you provide is from 1967. I would suggest you instead use this link for the photography equipment used during the Apollo 15 mission: www.lpi.usra.edu/lunar/missions/apollo/apollo_15/photography/
      In addition, you can download the Apollo 15 video I used and see it has a frame rate of 29.97 frames per second. nssdc.gsfc.nasa.gov/planetary/lunar/apollo_15_feather_drop.html

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому

      The frame rate is misleading. They recorded the video off a tv in Houston onto the network camera. The frame rate could have been tampered with. Just use a stop watch to time it. Either way... It doesn't add up.

  • @coach714
    @coach714 5 років тому

    Hey professor, why does the feather bounce (as asked by someone else in the comments)? Frame rate issue, or a moon thing or because it's a falcon feather which has a different buoyancy than other birds....

    • @mesonparticle
      @mesonparticle 4 роки тому +4

      Actually the feather appears to just flip over on itself. Why would a feather NOT do that? Particularly as feathers are not symmetrical around all axes. And also, feathers are flexible (they're adapted for flight, remember?). This means when dropped there is also the possibility for the shaft of the feather to bend, even if only very slightly. This energy can then be released.

  • @scottwins2
    @scottwins2 8 років тому +1

    What about the difference in gravity, is exeleration greater on earth by 6 times?

    • @FlippingPhysics
      @FlippingPhysics  8 років тому +1

      +Scott M The acceleration due to gravity on Earth is roughly 6 times what it is on the Moon.

    • @scottwins2
      @scottwins2 8 років тому

      Flipping Physics Yes I agree but is the acceleration in this moon footage accurate? Many people believe man did not go to the moon. There should be a six times difference.

    • @FlippingPhysics
      @FlippingPhysics  8 років тому +6

      +Scott M It takes the objects longer to fall on the moon than on the Earth. Because acceleration is in meters per second squared, it actually takes the square root of 6 or roughly 2.5 times longer to fall, not 6 times longer.

    • @scottwins2
      @scottwins2 8 років тому

      Flipping Physics thanks so does this film show the true moon speed?

    • @3089280288
      @3089280288 7 років тому +1

      Scott M if you look at how slow the astronauts fall to the moon when they walk then you have to ask why didn't the hammer fall as slow.

  • @hk1963
    @hk1963 9 років тому +4

    Saying delta-t is 1.201201s is bad. You imply you measured the freefall time with an accuracy of one millionth second, which is far from the real thing. At best, you could determine the time by +/- one or two frames. With the knowledge of all the inaccuracies, you would simple divide 36/30 to get 1.2 seconds without any calculators and go on with this value.

    • @FlippingPhysics
      @FlippingPhysics  9 років тому +6

      +Ha Ka I agree "you could determine the time by +/- one or two frames", however, I don't agree that I "imply [I] measured the free fall time with an accuracy of one millionth [of a] second". You should not round in the middle of a problem, you should only round at the end of the problem. Which is why the answer is 1.2 meters with two significant digits.

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому

      Using the frame rate is bad. The height of the astronauts is more certain than the video frame rate.

  • @hajarahelbarra
    @hajarahelbarra Рік тому

    You're the GOAT

  • @danshearer7627
    @danshearer7627 6 років тому +9

    And thank you for destroying every moon landing hoax conspiracy ever made. Salute!

    • @michelsonmorley5318
      @michelsonmorley5318 6 років тому +3

      Destroyed how? What was the hammer made of? What was the feather made of? Were they free-falling or rigged on wires?
      Videos are proof of nothing.

    • @danshearer7627
      @danshearer7627 6 років тому +2

      Really? We landed there and the proof cannot be disputed... I guess Travis Walton did get abducted by UFOs. OMG you cannot deny this... Why do you insist?

    • @michelsonmorley5318
      @michelsonmorley5318 6 років тому +8

      @@danshearer7627 Actually Dan in 2019 it's 100% clear that NASA faked everything.
      They can't send anyone to the moon now, you think they did it 50 years ago?! 238,000 mile trip each way (6 times) and since then no one has been further than (an alleged) 250 miles up? (Allegedly because they're also filming the ISS footage on Earth).
      They destroyed *all* the original Apollo telemetry data because it was obviously fake and they couldn't risk it being analysed by modern technology.
      They are lying to the world about Mars. But the majority of people are gullible.
      What do you think cannot be disputed about the Apollo missions? They filmed that footage on earth using front screen projection. Some of the astronauts were on wires and the videos are played in slow motion. They never jumped higher than a few centimetres off the ground as they would have been able to in 1/6 gravity and they never captured a 360 view on camera (because the film-crew and studio stage were behind them). They have impossible photos and obvious fakery throughout the imagery and films they have supplied.

    • @danshearer7627
      @danshearer7627 6 років тому +5

      Keep living in that dream world of yours. If this was a hoax, why did we do it 6 times with a failure of Apollo 13? A hoax is 1 time not 6 and the evidence supports a landing and not a hoax. Ugh! You are too much.

    • @michelsonmorley5318
      @michelsonmorley5318 6 років тому +4

      Dan Shearer. What do you mean by a hoax is a one time thing? Lies have to be covered up by more lies. NASA has been lying about every single space mission for the last 60 years. Manned and unmanned. It's not just NASA, so don't be offended if you are patriotic. All space agencies, public and private, are lying to you my friend. Why do you think they are telling us they are going to Mars and the far side of the moon?
      If they pretended they were going to the near side of the moon, even with a rover, the public now has the technological capability to verify it. So they are faking missions that can't be scrutinised from Earth.
      It would also be very reasonable to expect extremely high definition photo or video of Earth from a modern lunar rover. The agencies would have no reason to deny that. So it's easier not to go "back" to the moon.
      As for being in a dream world, you have to be asleep to believe what they are telling you. Why do you think ISS astronauts are faking their footage using wires, cables, hairspray and green screens? Because they are here on Earth.

  • @richardmourdock2719
    @richardmourdock2719 6 років тому

    Good stuff. Thanks

  • @bitukukuasukgremany3
    @bitukukuasukgremany3 5 років тому +2

    If you speed the moon vid's up they move like people on Earth so this vid is half speed like the others right?

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому

      And... 1200 N on earth would equal 200 N on moon. Walking becomes jumping.

  • @lerisleris3234
    @lerisleris3234 3 роки тому

    Po obejrzeniu całego " wywodu naukowo-fizycznego " mam pytanie.Dlaczego pióro i młotek spadają tak szybko a "astronauci" skaczą jak piłeczki?

  • @mrvanderhorst
    @mrvanderhorst 9 років тому +1

    Excellent! The explanation is clear, the equations are used very well (good notation), and it is very interesting! Thanks for sharing!

  • @Patmosentertainment
    @Patmosentertainment 6 років тому

    The camera used on the apollo mission shot at 10 fps and was converted to 30 fps when broadcasted to US televisions. This would affect the actual speed of the footage we see.

    • @FlippingPhysics
      @FlippingPhysics  6 років тому +2

      "The camera used on the apollo mission shot at 10 fps and was converted to 30 fps when broadcasted to US televisions." Could you please provide me with a link with the source of this information?

    • @Patmosentertainment
      @Patmosentertainment 6 років тому

      Its on wikipedia if you search "Apollo TV Camera" or this link: en.wikipedia.org/wiki/Apollo_TV_camera. Thanks for your videos!

    • @Patmosentertainment
      @Patmosentertainment 6 років тому +1

      Correction: The Apollo 15 mission used a updated camera which was 29.9 fps just as you had stated.

    • @FlippingPhysics
      @FlippingPhysics  6 років тому

      Great. Thanks for the link!

    • @JT_1
      @JT_1 5 років тому +1

      @@Patmosentertainment owned lol

  • @mc2594
    @mc2594 6 років тому +1

    so why didn't you do an Earth version and show the gravity acceleration differential
    / time difference if you had the height? what was the point otherwise? the Moon isn't only airless it also has 1/6 gravity and the rate of fall is also 1/6? was what Galileu mainly meant didn't he? 'a given gravity field'

    • @joevignolor4u949
      @joevignolor4u949 6 років тому +1

      The problem with doing this on the earth is the atmosphere. The aerodynamic drag would have a larger effect on the feather than it would on the hammer. Galileo knew this because when he dropped two balls of different sizes and weights from a tower they only fell at approximately the same speed. He realized the slight difference that he observed was caused by the air dragging more on the larger object with more surface area. However, at the time there was no way to try the experiment in a total vacuum to eliminate the effects of air resistance. Then when they got to the moon and performed the same experiment with no air present the two dissimilar objects fell at exactly the same speed.

  • @scocassovegetus
    @scocassovegetus 5 років тому +1

    How do you know at what speed it was filmed at? How do you know it wasn't filmed in slow motion? How do you know it was really a feather?

    • @edwardthetwentyfifth6462
      @edwardthetwentyfifth6462 5 років тому +6

      How do you know your entire life isn't a dream? How do you know you're not imagining everything you see?

    • @danzusername
      @danzusername 3 роки тому

      @@edwardthetwentyfifth6462we dont know. cool right?

  • @gilsonmozart1530
    @gilsonmozart1530 5 років тому +3

    Hey genius, explain why the feather bounces when it hits the ground.

    • @Bobbymac747
      @Bobbymac747 4 роки тому +4

      It's actually not very surprising when you think about it. Hold a feather in your hand and run your finger along the barbs (the "hairs" of the feather). You'll notice that they bend under pressure, and then spring back somewhat into their original shape. This demonstrates a storage of elastic energy. When the feather hits the ground, the barbs bend, then spring back. Remember, the elasticity of the barbs of a particular feather is an intrinsic property, so it will be the same on the moon (assuming the feather was dry) as it is on Earth. BUT, the weight of the feather on the moon is only about 1/6 it's (already very light) weight on Earth. In the absence of atmosphere and the low gravity of the moon, this small amount of elastic energy is enough to bounce the feather. I'm not affiliated with Flippin' Physics, but I've been to a seminar taught by Jonathan, and I'm pretty sure he actually *is* a genius. He's also very respectful.

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому

      @@Bobbymac747 there's no storage of elastic energy. There's only a reaction from the sand like dirt which would absorb most of the shock.

    • @carultch
      @carultch 2 роки тому +1

      @@Bobbymac747 Excellent response, Bobby.

  • @prophetictimes1968
    @prophetictimes1968 6 років тому +1

    You definitely should have shown the time difference between the earths gravity and the moons gravity of the falling objects, thus proving it happened in one sixths gravity. Can you please show that.

    • @ashsmitty2244
      @ashsmitty2244 5 років тому +1

      Looks like you won’t get what you’re asking. 5 months and still no joy.

    • @CarbonTech19
      @CarbonTech19 Рік тому

      Objects on Earth fall at 9.8 metres per second²
      On the moon, they fall at ≈1/6 that rate, so 1.62 metres per second²
      In order for an object on Earth to freefall for the 1.2 seconds it took the hammer and feather to fall to the moon's surface, it would have to be dropped from a height of just over 7 metres(almost 23 feet).
      An object dropped from a 1.2 metre height on Earth would take 0.4974 seconds to hit the ground as opposed to the 1.2 seconds it takes on the moon.
      Finally, the hammer hit the moon traveling at 1.9718 m/s. Dropped from the same 1.2 metre height on Earth, it would be falling at 4.85 m/s.
      (I used the online Omni Freefall Calculator to first figure out the Earth drop height based on a 1G, 1.2 second freefall, then to figure out the time a 1.2 metre freefall would take and finally to figure out the freefall speed, Earth vs moon, as I cannot, and never could, do math like Flipping Physics, lol.)

    • @srinitaaigaura
      @srinitaaigaura Рік тому

      What just time the video and calculate it yourself.

  • @ytubesucksazznow
    @ytubesucksazznow 5 років тому +2

    feather looks a little thick wink wink

  • @romeomk510
    @romeomk510 8 років тому +4

    Do brains poop? Cuz I think mine just had diarrhea -- watery diarrhea. I do not like Physics. Good video, nonetheless.

  • @BRETTHC
    @BRETTHC 4 роки тому +1

    The temperature during the day on the moon is reportedly up to 127°C. That feather would melt. The gravity is supposedly 1 sixth of Earth's so why do they fall so fast?

    • @kitcanyon658
      @kitcanyon658 3 роки тому +2

      Do the math, bro. It’s not hard. Do you need help?

    • @carultch
      @carultch 3 роки тому

      Look how long the shadows are. It is not peak noon at the time the astronauts walked upon it, which is when you would expect its peak temperature.
      The temperature of the moon surface during the Apollo missions was from -23C to +7C, and it was strategic that they scheduled the landings for dawn at the locations of the landing sites. This is cold from our point of view on Earth in ordinary clothing, but cold has an advantage when you are in a giant space suit, and you only have radiation heat transfer available for exhausting your body heat.

  • @pascalxavier3367
    @pascalxavier3367 5 років тому

    I have this to say:
    1) If the astronaut gave an initial speed to the hammer and feather, then it is a negative one, and not a positive, for, in order to give an initial positive speed, the astronaut would have had to move down his arms when he dropped the hammer and the feather, and, on the video, we can clearly see that he moves them up before dropping the hammer and the feather, not down!
    2) The difference of time with the time it would take in the earth can easily be explained: When I have sampled the sequence (at 10 images per second), I have noticed duplicated images; here I show a slowed down animation of the sequence, in which I display a red progress bar on each image, which moves each time that there is a change of image, and we can clearly see that, on several occasions, the progress bar moves without the image changing because of a duplicated image.
    www.angelfire.com/moon2/xpascal/MoonHoax/HammerFeatherShow.GIF
    These duplicated images have been inserted into the sequence in order to artificially slow it down, but the fakers knew that there would be people who would notice it (otherwise, they could have filmed it fast et replayed it slowly if they really wanted to be convincing).
    When the duplicated images are removed from the sequence, the hammer and the feather fall faster, like they would on earth.
    If you don't believe me that there are duplicated images, then sample the sequence yourself, I am not cheating (why would I).

    • @pascalxavier3367
      @pascalxavier3367 5 років тому

      @Gerry Berry Australian dish which was managed by american engineers, like Jodrell bank in England which was equipped by the americans; and I can prove that the graph of the descent of Apollo 11, recorded by Jodrell Bank, contains hints which prove that it can't show the descent of Eagle on the moon: www.angelfire.com/moon2/xpascal/MoonHoax/JodrellRadar/JodrellRadar.HTM

  • @spinfowars8958
    @spinfowars8958 6 років тому +1

    too bad the video was so bad you couldn't really see the feather position changes as it dropped - it seemed to pivot from level to non level before it hit the ground and it seemed that the pivot did not start from the initial drop point, but started about halfway down in its travel path - a close up shot with better resolution may have been able to see the structure of the feather and whether or not it was influenced by atmosphere

    • @JT_1
      @JT_1 5 років тому

      It was shot in 1971 you twat and then beamed 384,400 km to earth sheesh!

  • @AbdulAziz-fr9vm
    @AbdulAziz-fr9vm 3 роки тому

    Look at when the feather on the grounnd, it's bounching, and do u know what its mean, it's not feather.

    • @kitcanyon658
      @kitcanyon658 3 роки тому +2

      Then why didn’t the hammer bounce?

    • @carultch
      @carultch 3 роки тому +2

      Pick up a feather and try compressing the quills. Notice how they spring back against you? There's a lot of elastic capacity for feather quills to absorb the impact slowly and restore some of the kinetic energy after impact. The feather also absorbs most of the energy, since its material is the most flexible, when compared to the rocks below it.
      A feather will also bounce upon impact, if you drop it in a vacuum here on Earth.
      ua-cam.com/video/s9Zb3xAgIoY/v-deo.html
      We don't usually notice this on Earth, because the air slows down the feather. Feathers are made to have a lot of exposure to forces from air, since birds depend on this to fly.
      The reason the hammer didn't bounce, is that the rocks absorbed most of the energy, rather than the hammer. The rocks aren't as stiff as the hammer, so they absorb the energy. And the rocks absorb the energy inelastically as thermal energy, rather than elastically with the capacity to restore the energy. Try dropping the hammer on an aluminum platform, and I would expect you will see it bounce.

  • @CapitanTavish
    @CapitanTavish 5 років тому +2

    1.2 meters in 1.2 seconds ... Illuminati confirmed

  • @brianlin7791
    @brianlin7791 9 років тому

    are those all you?

    • @FlippingPhysics
      @FlippingPhysics  9 років тому +8

      Duckmotion Nope, I was never on the moon. All the other characters, yes.

  • @momowawa447
    @momowawa447 4 роки тому

    I'm still confused about how the density of both objects don't affect the gravitational effects of each of them, let's say a comet and a feather free falls to the moon with initial velocity of zero...I'm just can't believe an object with a density almost nule, will hit ground at the same time.

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому +4

      Mass density does affect it. Because of inertia. The smaller mass will actually reach first. But it's such a small difference, you need a really big mass to see it.

    • @carultch
      @carultch 2 роки тому

      The reason it doesn't matter how massive an object is, when it comes to ideal free fall, is that "everybody brought mass to the party". Both the inertial property of matter, and property that governs participation in gravitation, are proportional to an object's mass, and come as a package deal. This is true no matter what substance you have, and as long as it is insignificant compared to the mass of the world you are standing on, it doesn't matter how much mass the objects have either.
      Density comes in to play, when air drag is significant, which is an entirely new force to add to the picture. It is a factor that is a lot more complicated to calculate. It really isn't density, but rather mass to area ratio, that makes the difference in how fast an object will really fall.

  • @jasonsmith8210
    @jasonsmith8210 4 роки тому

    It's not correct. Scott was around six feet. 1.2 meters is just shy of 4 feet. And I clocked it at .9 seconds.

    • @DANGJOS
      @DANGJOS 4 роки тому

      @Jason Smith Really? What did you use, your stopwatch?

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому

      @@DANGJOS yep

    • @DANGJOS
      @DANGJOS 4 роки тому +1

      @@jasonsmith8210 Hand timing with stopwatches (or any other device) is notoriously inaccurate. Frame counting is a much better method.

    • @jasonsmith8210
      @jasonsmith8210 4 роки тому

      @@DANGJOS I took multiple timings. Frame rate count is irrelevant if the video has been tampered with.

    • @DANGJOS
      @DANGJOS 4 роки тому

      @@jasonsmith8210 And did you calculate your uncertainties and consider the systematic errors? Frame rate is the most sensible way to count the time, and I don't know why you would expect the footage to be tampered with. If that's the case, you can't prove anything either way.

  • @atrixgaming150
    @atrixgaming150 7 років тому

    are those students you????

    • @FlippingPhysics
      @FlippingPhysics  7 років тому

      I'll let you decide. flippingphysics.com/making-a-video.html

    • @sarubobo_art
      @sarubobo_art 7 років тому +1

      +Flipping Physics Sir I just finished watching the time lapse, you put in a lot of work for every video. I am so full of inspiration. Now. Subscribed.

  • @davidsoom1551
    @davidsoom1551 4 роки тому

    Unless they had reason to change the frame rate before they released this video. Scientists assume too much when they're careers, one way or another, will at some point rely on government funding or general peer acceptance. Everything else is "Conspiracy Theory" meaning the ones who speak of it are stupid! But they generally think everyone else is "stupid".

  • @antonionovais5257
    @antonionovais5257 5 років тому

    Vejam O engano da lua:som no vácuo?Pêndulo?Martelo e pena?

  • @helpawhiteguy
    @helpawhiteguy 9 років тому

    And what in the HELL is going on at 1:10 to 1:15 with the zooming in and out. Specifically, behind Scott's left shoulder, beyond the lander. This looks like a poorly-done green-screen that doesn't zoom when everything in the foreground does.

    • @FlippingPhysics
      @FlippingPhysics  9 років тому +5

      +helpawhiteguy It was filmed on _the moon_ in 1971. Sorry the video quality isn't HD. 😊

  • @randyfielding246
    @randyfielding246 6 років тому +3

    Fake Hammer and weighted feather..if it was even a real one?

  • @bradstudio
    @bradstudio 5 років тому +4

    Awesome, this video just destroyed all moon-hoax conspiracies, using fricking math! Excellent work!

    • @xismxist
      @xismxist 5 років тому

      Actually it just proves the opposite, since you cannot grip a feather inside a vacuum. The smallest object they could grip had to be atleast approx 1 inch thick

    • @Mandelbrot_Set
      @Mandelbrot_Set 4 роки тому +2

      @@xismxist Prove it!

  • @wesbaumguardner8829
    @wesbaumguardner8829 Рік тому

    He did it wrong. He should have had the head of the hammer at the top and the handle at the bottom. That way, if the hammer flipped, it would be another disproof of the hypothesis.

  • @erickaminski1472
    @erickaminski1472 7 років тому +1

    ALL ONE HAS TO DO IS CHANGE THE FREQUENCY OF ALTERNATING ELECTRIC CURRENT AND ONE WILL GET DIFFERENT FRAMES PER SECOND. THAT CAN BE DONE IN ORDER TO SLOW DOWN THE FALL OF HAMMER AND FEATHER. THAT IS HOW ONE CAN MAKE AN ILLUSION OF GUS IN ASTRO SUITS MOVE SLOWER AS IF UNDER 1/6 GRAVITY OF EARTH. ephemetherson

  • @camilserapian7675
    @camilserapian7675 5 років тому

    ???

  • @gonzogeier
    @gonzogeier 6 років тому

    With a stopwatch my result is 0,96 s. Ok, this is not exactly. But what a mad idea to take a hammer and a feather to the moon, when every kilograms cost 10. thousands of dollars! You can do this experiment also on Earth in a Vakuum Pipe! 😀 Why didn't they use a moon stone and a piece of paper instead? Why they need a hammer and a feather?

    • @BrickTsar
      @BrickTsar 6 років тому

      Ralf Kath umm because they were actually using the hammer. They already had it.

    • @gonzogeier
      @gonzogeier 6 років тому

      BrickTsar Okay maybe you are right. But they declare they want to proof, that two things in a vacuum are falling with the same speed. But much more interesting would be: How things fall in 1/6 gravity! But at such a short distance, the difference is only a fraction of a second! Hard to proof.

    • @kneelingcatholic
      @kneelingcatholic 6 років тому

      Hey Ralph! I timed it with a stopwatch as well and came up with just under one second and sometimes 0.95. Maybe that’s why flippin physics decided not to use the stopwatch which happens to be standard issue lab equipment in anyphysics classroom. Even before everyone had Olympic grade stopwatches in their phones.
      Using yours and my timing (as 1 sec) you can only get a height of 2‘8“ which would be a little embarrassiing unless you think astronaut Scott was only 4 feet tall...
      Counting frames? How does he count the frames? Seems like a Rube Goldberg distraction to keep people from asking why he didn’t just use a stopwatch.
      .

    • @rwj1313
      @rwj1313 6 років тому +1

      kneelingcatholic stated "Counting frames? How does he count the frames?"
      Any budget/consumer-grade video editing software shows frame numbers. I have NERO Platinum 12 and I counted exactly 36 frames as well. The frame counter in Nero 12 indicates time in the following format hh:mm:ss:ff Which is Hours: Minutes: Seconds: Frames
      In my copy of the video, the drop starts at exactly 00:00:36:18 and ends at 00:00:37:24
      You subtract the start time of 36 seconds and 18 frames from 37 seconds and 24 frames and you get 1 second and 6 frames. 1 second is 29.97 frames or (30) so:
      30 + 6 frames = 36
      Exactly 36 frames
      A stopwatch is a terrible way to measure the time. Human reaction time is brought into the equation when using a stopwatch. The average reaction time for humans is 0.25 seconds to a visual stimulus, 0.17 for an audio stimulus, and 0.15 seconds for a touch stimulus.
      That's one-quarter of a second! At 29.97 FPS your stopwatch measurement would be off by at least 7.5 frames.
      Counting frames is a far more accurate method and it is repeatable.
      There is no distraction. His measurement method is spot-on.

    • @kneelingcatholic
      @kneelingcatholic 6 років тому

      Than you Rick Jones for keeping me on the reservation! I also slowed the vid down to quarter speed and found you were right.
      Since I have you on the line I’d like to bounce another idea off you... to verify lunar vids.... shouldn’t we be able analyze some if the astronauts jumping vids to see how they Match up with calculated projectories... you get the idea.... calculate the first few frames of vertical speed to get a lift off velocity and then predict how high an object should rise before falling back moon ward.... what do you think? (Or go the other way and find a vid where we get s good look at jumping height and calculate what must have been the initial vertical velocity and ck to see if that is plausible)

  • @christophermckeon9030
    @christophermckeon9030 5 років тому +1

    Why didn't you finish the calculation? Using your variables in the formula for acceleration (a=delta-v/delta-t) I get a lunar gravity acceleration of .831667 m/s^2. That's pretty far off from the accepted 1.625 m/s^2. I would like to see Brian Cox's variables for his experiment in Ohio but I can't find that data anywhere, like he's hiding it because it shows a discrepancy with accepted grav accel on earth just as Scott's video shows wrt the moon. Just sayin.

    • @ashsmitty2244
      @ashsmitty2244 5 років тому

      I was thinking this is the perfect opportunity to cross reference these claims. You did exactly what I was thinking. If we know those values we can determine gravity.
      Something is amiss and definitely needs explaining. Just saying ;).

  • @cm601_plays
    @cm601_plays 3 роки тому

    I thought that there was no gravity

    • @kitcanyon658
      @kitcanyon658 3 роки тому +4

      Not at all. Lots of people have that misconception that because you’re in space, or somewhere without atmosphere there is no gravity. Keep in mind that the two, gravity and atmosphere, are not the same things. The moon has gravity, about 1/6th that of earth.

  • @MrBarrynicholas
    @MrBarrynicholas 4 роки тому +2

    All that effort and they weren’t even on the Moon.

  • @murtez22
    @murtez22 6 років тому

    مخنوگ 💔🚬

  • @timhansen3376
    @timhansen3376 Рік тому

    Man. This should be duplicated with vacuum . Evacuated glass cylinders. If this would be done then the obvious would be seen. The stunt was done on earth. They just slowed down the speed. Of course now we also might consider the possibility that the video was altered by computer.

    • @kitcanyon658
      @kitcanyon658 Рік тому

      This has been done on each in a vacuum chamber. Many, many times. Have you difficulty operating search engines on your computer?
      No, the stunt wasn't done on earth as this was broadcast live. You know, like in real time and not filmed on 16mm?

    • @LaurentCassaro
      @LaurentCassaro Рік тому

      "Altered by computer"
      In 1971 ? A decade before the first graphic card was invented?
      Oh boy ... 🤦‍♂️

  • @isaacstone7899
    @isaacstone7899 8 років тому +1

    The feather and the hammer's handle must be burned on the moon and astronauts' motion mustn't actually like on the earth's motion. And the feather must never bounce on the moon.You can feel the moonlight warm on your skin during the night that means no one can survived on the moon.

    • @owbeer
      @owbeer 7 років тому +6

      wtf did i just read

    • @grahvis
      @grahvis 7 років тому +5

      owbeer
      Lol, rather goes against all those flat earthers who claim moonlight is colder.

  • @Racheal1of144000
    @Racheal1of144000 4 роки тому +1

    Yet another BIG lie...

    • @kitcanyon658
      @kitcanyon658 3 роки тому

      What’s that? A feather won’t fall at the same speed?

  • @markmeade478
    @markmeade478 6 років тому

    mate I did that myself and the hammer hit the floor first, mate your talking BS

    • @Tim22222
      @Tim22222 6 років тому +5

      Because you didn't do it on the moon, you did it in an atmosphere.

    • @JT_1
      @JT_1 5 років тому +3

      Haha you moron

    • @carultch
      @carultch 2 роки тому

      I've found a chopstick that weighs as much as a feather. Do it with a chopstick and a hammer, and they will hit the ground at the same time. The reason the feather is slower, is that its material is intentionally spread out to maximize the forces it receives on the air, so that the bird can use it to fly. If you melted the keratin of the feather into a ball, it would fall just like the hammer, even here on Earth.

  • @ghengisnghe
    @ghengisnghe 4 роки тому

    The feather would have more coefficient drag than the hammer and would therefore fall slower even if there is a so called vacuum up there . And under the 250 degree temperatures I doubt the feather would be a feather anymore.

    • @agerven
      @agerven 4 роки тому +3

      Explain coefficient drag? And 250 degree is probably supposed to mean around 23 Kelvin or -250 degree centigrade, but will that affect mass or the gravitational constant?
      I'm sure you have the intention to say something significant here, but I fail to understand.

    • @carultch
      @carultch 3 роки тому +1

      Extreme temperatures were not an issue for this experiment. The surface temperature of the moon was from 250K [-23 C] to 280K [+7C]. So it was about the temperature of winter in upstate New York. Cold temperature has an advantage, in order for the astronauts' space suits to radiate their body heat to the surroundings.
      The moon landings were scheduled for a time shortly after sunrise on the moon. You can tell by the long shadow lengths. It takes the moon about 29 hours for the sun to move the equivalent angle in the sky as it moves in just 1 hour on the Earth, so they had plenty of time to carry out the mission, without the sun climbing too high in the sky. The moon has an extreme temperature swing as a dry & airless world, but the landings were planned for a time when they could avoid the extreme temperature.