h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

...and I will move the Earth.

How true is this? Could I lift a skyscraper if I had a long/strong enough lever and correctly placed pivot points? Has anyone ever publicly tried to lift a truly massive object this way?

I suppose there are the things like "how long can you make a lever", and "how can you make a lever that doesn't flex at all, or break from the force applied" that get in the way. But the theory works in practice too. Using an iron spit for moving boulders in the garden usually...

These figures are _very_ approximate....

Assuming you were on an infinite flat planar surface with constant gravity

The earth weighs approximately 6.0x10^24 (6 with 24 zeros after it) kilograms
Stick it on a lever which is one metre from the fulcrum (tipping point).
The fulcrum itself is a human hair (approx 0.1 mm high)...
Assuming you weigh more that 60 kg and you can climb up a stepladder to hang onto the other end of the lever...

To lift the earth 0.2 mm, the other end of the lever would have to be about 1x10^20 km long (approximately 10,000,000 light years) - or 2/3 of the way across the visible universe...

Oh, and your stepladder would have to be 20,000,000,000,000 km high (very roughly 2 light years - or just under half way to Alpha Centuri).

Anyone want to check my maths? My head's about to explode with all these zeros...

Plus, any lever that long would have lots of mass, so it would take a lot of strength to overcome the lever's inertia. So I am afraid that if I climbed up Whisky's stepladder half the way up to Alpha Centauri and then walked over into the gamma quadrant to jump on the lever, the earth would still be unmoved.

Y.

Good point, I completely forgot about the weight of the lever itself ...

But having said that, it would actually work in your favour... as the vast majority of the weight would be on the side you're attempting to push down then it'd mean the lever wouldn't have to be as long.

If your end of the lever was somewhere out in space, wouldn't you be weightless? How would this affect your ability to push down on the lever?

And, if my memory hasn't given up completely, the fact that the lever weighed that much wouldn't actually prevent a lever moving... What it would do is to slow things down a hell of a lot...

Force = mass x acceleration... You're looking at a stable body and you're applying a force of 500 Newtons to it... given the enormous masses in question the acceleration is going to be miniscule - you're going to have to wait a hell of a long time before it's visibly apparent that your end of the lever is moving... And it's going to take a _very_ long time for you to get back down to earth.

So it's only really a few small practical concerns that make this difficult. It should work theoretically; we just can't test it on that scale. OK, what about smaller massive objects, like buildings; we could test that, right? (assuming decoupling from the foundations)

A building would work... Only I'm too tired to do the math - what does a house weigh?

Well yes, of course levers work. We know it (Mills'a spit (post 2) works a treat on a human scale.
On a larger scale, buildings have been and continue to be moved from place to place by using (modified) levers.
On a cosmic scale you'd need further modification...

Lifting an empty shipping container 6 inches to put blocks under it is feasible with a 12 foot long timber pole, one corner at a time.

Been there, done that

Oh and the fulcrum (log) has to be as close to the container as possible even if that means digging part way into the ground, we got it to about 3 inches from the edge of the container.

[BB]

Sounds reasonable, Bald Bloke.

Containers - not levers but a different aspect (post 'quake).
They've just, a few days ago, removed a 3-high stack of containers from our high street. Not for shops, they had been leaning, slightly, towards a three-storey building. Odd. But then, they'd been filled with concrete - just in case the building fell down, outwards.

- - OK back on track.

Moving the earth, no levers needed. Back in 1969, fixing a thread to the moon would mean that we could be pulling on it.
2012, changing that to a piece of string and tying the appropriate place on it to the string that will soon be tied to Mars and we're on the way to the stars - but we'll need rope for that.

Another problem with moving the Earth, is getting the fulcrum to stay in one place. There's not really anything to place it on or attach it to.

One should always recognise the limits to extrapolation.

Interestingly (to me anyway) I have just realised
that I have always assumed the moon would be the
obvious fulcrum for such an experiment.

Curious how I now realise this idea was never expressed
(here or prior occasions) and yet I assumed it in such
an obvious way, that I am now startled to see it is NOT
the universally accepted notion.

It ain't easy being green.

~jwf~