Exposing PseudoAstronomy

April 11, 2010

What Happens When All the Planets Line Up Against Us?


Introduction

This is a claim that has persisted for a long time, and though people who believe in the 2012 stuff have propagated it, it is not specifically a Planet X / 2012 claim: If all the planets (plus our moon) lined up opposite the sun, they would pull us out of orbit. As the “lolcatz” say, “Oh noez!”

Gravity

The force felt by an object due to gravity is a very simple mathematical function, codified by Newton’s Universal Law of Gravity:

In this equation, F is the force felt, G is the Gravitational Constant, M m are masses of the two objects in question, and r is the distance that separates them.

To figure out how much more or less two different objects will pull on the same object, we can simply remove one of the two masses, so the equation simplifies to F = G * m / r2.

The Math

To determine the relative forces, one simply needs to know the mass of the planets and sun, and the distances between Earth and those objects. This can be found in any basic astronomy textbook or online source. One then can simply plug in the numbers and figure out the forces.

For the sake of argument, let’s say the sun is on one side of this tug-of-war, and the moon, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, and even Pluto are all on the other (Venus and the sun don’t count ’cause they would have to be on the sun’s side). Let’s calculate the force first due to the sun:

Object
Mass (1024 kg)
Distance from Sun (106 km)
Distance from Earth (106 km)
Relative Force
Sun 1,989,100 149.6 0.0059

Alright, now let’s do all the rest, remembering that for the planets, we’ll need to subtract out the distance between Earth and the sun from what are commonly quoted as the planets’ distances:

Object
Mass (1024 kg)
Distance from Sun (106 km)
Distance from Earth (106 km)
Relative Force
Moon 0.07349 0.3844 3.32·10-5
Mars 0.6419 227.9 78.32 6.98·10-9
Jupiter 1,899 778.6 629.0 3.20·10-7
Saturn 568.5 1434 1284 2.30·10-8
Uranus 86.83 2872 2723 7.82·10-10
Neptune 102.4 4495 4345 3.62·10-10
Pluto 0.00125 5906 5756 2.52·10-14
Ceres 0.00095 415 265.4 9.00·10-13

Final Thoughts

This is a really short post because it doesn’t need to be long. To be perfectly honest, I was actually surprised at how small the force of Jupiter actually is on Earth relative to the sun. If we add up the force from all of the other objects, we only get a force that is 0.566% as strong as the sun’s. And then if we take the moon out of the equation because that would be the first to move out of the alignment, then we have a force of only 0.000592% as strong as the sun’s.

If we look at Venus if it were also lined up, helping the sun, its force is 1.90·10-7, or about half as much as all the other planets (again, leaving out the moon), so it would cancel 54% of the effect of all those other objects (again leaving out the moon). The force from Mercury is only about 1/3 that of Mars.

So really, if anyone who makes this claim were to bother to spend about 10 minutes looking up the numbers and plugging them into an Excel equation (what I did), they would quickly see that this claim is simply and utterly nonsense. And this is besides the fact that the planets aren’t lining up any time soon on the other side of Earth to try to pull us out of orbit.

About these ads

16 Comments »

  1. [...] What Happens When All the Planets Line Up Against Us? [...]

    Pingback by Planet X and 2012: My Posts So Far « Exposing PseudoAstronomy — November 6, 2010 @ 12:13 am | Reply

  2. i only raise an objection regarding the sentence you used “If we add up the force from all of the other objects…” I am not sure if you can simply add forces… what i am implying is that you cannot add 2 forces lets say from mars to earth and from jupiter to earth in order to estimate a total force and then compare it to the sun’s force.

    Comment by rosa — March 23, 2011 @ 6:43 pm | Reply

    • Rosa – Actually, adding forces is a basic part of Newtonian physics. A quick search came up with this page that explains it.

      Comment by Stuart Robbins — March 23, 2011 @ 7:12 pm | Reply

  3. thanks, i confused the addition of the gravitational forces with the problem of solving the motion equations for a system of 3 objects..

    Comment by rosa — March 23, 2011 @ 7:27 pm | Reply

    • Rosa – You’re confusing a three-body dynamics problem with adding force vectors at an instant in time. At an instant, if all the planets were on “one side” and the sun were on the other …. or even if all the planets AND the sun were on one side and we were on the other, then you can add all the forces together from the other objects on Earth to see what the sum is (and there’s just a tiny difference from the sun itself).

      Comment by Stuart Robbins — March 24, 2011 @ 2:13 am | Reply

  4. It wont pull the Earth out of orbit, but how about the asteroids. Sum of the gravity of planets when they will align will affect asteroids amd in a manner they is not favorable for us. I am not saying “lets run for cover” but perhaps we should give this a closer look.

    Comment by ARKADIY — April 27, 2011 @ 8:37 pm | Reply

  5. Good job.
    I’m windering what would be the force that can pull the earth out of its orbit?
    Anywone know how we can determine that?
    Thank you

    Comment by Abel Ludba — April 29, 2011 @ 3:13 pm | Reply

  6. many forces! but it depends how strong the earth is then and how strong of a mass it will take for the force.

    Comment by happy happy — February 4, 2012 @ 2:36 pm | Reply

  7. IT’S NOT ABOUT EARTH BEING KNOCKED OUT OF ORBIT, ITS ABOUT THE TIDES ON THE EARTH. IF IT TAKES A CHANGE OF 0.0059 TO O.566 RELATIVE FORCE THAT’S 100 TIMES GREATER THEN WHAT WE SEE EVERY MONTH. WITH THE INTERACTION BETWEEN THE MOON AND THE SUN. THIS EQUATES TO 100 TIMES THE MONTHLY AVERAGE OF HIGH TIDE ………..SUCH AS 27 FEET X 100 OR 2700 FEET HELLO THIS IS WHAT I’M TALKING ABOUT. THE COASTAL AREAS ARE GOING TO GET A RISE DURING THIS PERIOD MOST COASTAL CITIES ALL THE WAY TO LOS ANGELES ARE BARELY 432 FEET ABOVE SEA LEVEL. DO THE MATH. SORRY BUT YOU BETTER GET TO HIGH GROUND IN DECEMBER IF YOU WANT TO LIVE……!

    THAT’S GOING TO BE TO CATASTROPHY, A LOT OF PEOPLE ARE GOING TO DROWN i.e. MILLIONS.

    I HOPE TO GOD I’M WRONG, BUT IF I’M NOT GO FIGURE.

    Comment by SUSIE — March 12, 2012 @ 5:29 pm | Reply

    • I suppose God hath come, because you’re wrong. Tidal force goes as 1/r3, as opposed to gravitational force which is 1/r2. The gravitational force on Earth from the moon relative to the sun is only 0.56%. The tidal force is 218%. This doesn’t change much at all. For Jupiter, the gravitational force is about 0.005% the Sun, whereas the tidal force is about 0.001% the sun. Do the math yourself. What you wrote does not make sense. The sun’s force can’t increase by a factor of 100 just because you want it to.

      Comment by Stuart Robbins — March 12, 2012 @ 5:36 pm | Reply

    • and please stop SHOUTING :)

      Comment by tropez — March 14, 2012 @ 3:15 pm | Reply

  8. So it’s not going to end

    Comment by miranda — August 3, 2012 @ 12:25 am | Reply

  9. so by how much will the sea rise by?

    Comment by alex — December 18, 2012 @ 3:54 pm | Reply

    • Did’ja read the post? Zero.

      Comment by Stuart Robbins — December 18, 2012 @ 4:31 pm | Reply

  10. so you are saying the planets will actually line up and will not have a great affect on earth?

    Comment by anon — December 20, 2012 @ 9:33 am | Reply

    • I’m saying they WON’T, and even if they did, the effect would be zero.

      Comment by Stuart Robbins — December 20, 2012 @ 10:05 am | Reply


RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

The Rubric Theme. Create a free website or blog at WordPress.com.

Follow

Get every new post delivered to your Inbox.

Join 1,254 other followers

%d bloggers like this: