# Debunked: January 4th 2014 – Planetary Alignment Decreases Gravity – Float For 5 minutes!

Discussion in 'Science and Pseudoscience' started by nanotchi, Dec 17, 2013.

1. ### nanotchiMember

[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. ### hemiActive Member

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

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

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 BornongSenior 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

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. ### JRBidsSenior Member

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

6. ### JoeSenior Member

You mean that comes from the mouth of our political leaders ? Sorry couldnt resist

7. ### nanotchiMember

Or from random people on the Internet?

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8. ### cosmicActive 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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