1. nanotchi

    nanotchi Member

    [Debunk in post #2, below]

    Alright now... Found this today, it sounds really weird... o3o;;; can anyone take a shot at trying to debunk it?

    January 4th 2014 – Planetary Alignment Decreases Gravity – Float For 5 minutes! #ZeroGDay: http://news-hound.net/january-4th-2...es-gravity-float-for-5-minutes/#ixzz2nnPXtH9F

    Last edited by a moderator: Dec 29, 2013
  2. hemi

    hemi Senior Member

    It's a very old April Fools' Day joke.

    http://en.wikipedia.org/wiki/Jovian–Plutonian_gravitational_effect



    [Added by Mick:]
    The simplest debunk of this is to note that the Moon is the only planetary body that produces observable gravitational effects (the tides), and that those effects are not noticeable when jumping up and down (you feel the same weight at high tide and low tide). Jupiter and Pluto have no effect on the tides, and so must have an effect that is much less than the moon.

    Hence the alignment of Jupiter and Pluto must have at most an effect that is twice something that is much less than the moon, which is not noticeable. So this effect will not be noticeable itself.

    One could also do the math, which is more complicated, but not incredibly so.

    The acceleration of a planet like Jupiter acting on you is G*(mass of Jupiter)/(distance squared). (source: http://en.wikipedia.org/wiki/Gravitational_acceleration)

    G = 6.67384*10^-11 (source: http://en.wikipedia.org/wiki/Gravitational_constant, and note that G is different from g)
    Mass of Jupiter = 1.898*10^27 kg (source: http://en.wikipedia.org/wiki/Jupiter_mass)
    Closest Distance to jupiter = 588,000,000 km = 5.88*10^11 m (Source: ttp://www.space.com/18383-how-far-away-is-jupiter.html)

    So acceleration from Jupiter = 6.67384*10^-11 * 1.898*10^27 / (5.88*10^11 * 5.88*10^11)
    = 3.664*10^-7 = 0.0000003664 m/s^2

    Compare that with Earth gravity, g = 9.8 m/s^2, Jupiter has an effect of 0.0000037% of normal earth gravity. So with Jupiter at its closest a 200 pound person would feel 0.0000074 pounds lighter.

    Pluto being aligned with that will simply add a very tiny, but basically negligible, amount to that, because Pluto is a very small body (about 1/100000th the mass of Jupiter), and is much further away than Jupiter. I leave it as an exercise to the reader to calculate how much acceleration Pluto will add at its closest point. But it's significantly less than Jupiter, and hence basically nothing.
    Last edited by a moderator: Dec 30, 2013
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  3. M Bornong

    M Bornong Senior Member

    It was definitely Kurt Vonnegut, I think it was "Hocus Pocus", the Chinese learned to control gravity. Everybody knew they were doing it because every male got a hard on. I'll let you know on the 5th if gravity was affected.:)

    Last edited: Dec 17, 2013
  4. Mick West

    Mick West Administrator Staff Member

    A 37 year-old joke being recycled. Quite amazing, and it speaks to the longevity of hoaxes, urban legends, and conspiracy theories. If you've not seen it before, then it's new to you, so there's always a fresh batch of people to run the joke on.

    Patrick Moore died last december. I remember him on TV when I was young back in the UK. He had an interesting life:
    http://en.wikipedia.org/wiki/Patrick_Moore
  5. JRBids

    JRBids Senior Member

    It's just amazing how some people will believe ANYTHING. A N Y T H I N G.
  6. Joe

    Joe Active Member

    You mean that comes from the mouth of our political leaders ? Sorry couldnt resist :)
  7. nanotchi

    nanotchi Member

    Or from random people on the Internet? :p
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  8. cosmic

    cosmic Senior Member

    Recycled and embellished. :)

    I missed it being a hybrid hoax on my first reading, but this bit...:



    ... is lifted directly from the Wiki entry for Gribbin's Jupiter Effect. The second sentence has been changed from "But no effect could be expected as the gravitational effect of the other planets on the Earth's crust is minimal even at their closest approach."

    Needless to say, there's no such "alignment" on January 4th; the referenced syzygy took place on March 10th, 1982. Smithsonian has a recap (see #8) in Ten Notable Apocalypses That (Obviously) Didn’t Happen.
    Last edited: Dec 18, 2013
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  9. Mick West

    Mick West Administrator Staff Member

    I expanded @hemi's post slightly, as this thread is getting a lot of traffic.
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  10. Mick West

    Mick West Administrator Staff Member

    And I've now added the relevant math to post #2
    • Like Like x 1
  11. Soulfly

    Soulfly Senior Member

    "BEEP BEEP Richie! They ALL float down here. When you're down here with us, you'll float too!"

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