The physics of swinging in a hammock and how to make it frictionless

**MAD777** · 01-23-2014, 15:14

I've always wanted to hire a Sherpa; not to carry my backpack, but to swing my hammock all night.

**obmit** · 01-23-2014, 16:00

Originally Posted by NJTroutstalker

This is incorrect. Ever see the pendulum at the smithsonian? It swings all day with one "push".

The Foucault Pendulm swings due to the rotation of the earth and does not need a push. They have one at our local university and it is really cool to watch.

Now if you could rig it up to a hammock, your problem would be solved.

**vanRijn** · 01-23-2014, 16:04

LOL! Wow, thanks everyone for the answers! Some of you are crazier than I am, which is good to see. =

I'm going to answer a couple of comments in a sec... hope I don't annoy anyone further. Now, if I could just find myself a Sherpa, elf, or Foucault Pendulum, I'd be all set. =:P

**NJTroutstalker** · 01-23-2014, 16:05

Read the article you posted. The pendulum path traces a circle but it's still a pendulum.

"Air resistance damps the oscillation, so some Foucault pendulums in museums incorporate an electromagnetic or other drive to keep the bob swinging; others are restarted regularly, sometimes with a launching ceremony as an added attraction." - Wikipedia

**NJTroutstalker** · 01-23-2014, 16:06

Supports exactly what I was saying.

**CamoDeafie82** · 01-23-2014, 16:16

when I worked the church nursery long ago, we had those clockwork baby swings.... that would be one way to mechanically extend the length of time spent swinging......

**XTrekker** · 01-23-2014, 16:16

I would just recommend you hang your hammock suspension from the ceiling and utilize a ridge-line with low stretch materials. Using polished metal hardware for the connection point between the suspension and the anchor in the ceiling might help also. If the ceiling connection isnt possible then the rest is still recommended. Unless you want to try and take on some of the ladder recommendations, there is simply only so much you can do. As mentioned in my first post, greater hang angles will significantly help you out; thus the ceiling mount recommendation.

**OneEye** · 01-23-2014, 16:22

Originally Posted by obmit

The Foucault Pendulm swings due to the rotation of the earth and does not need a push. They have one at our local university and it is really cool to watch.

Now if you could rig it up to a hammock, your problem would be solved.

It does need a push to get started, and occasionally needs another push to replace momentum lost due to air drag and friction in the attachment for the pendulum. What the earth's rotation does is rotate the plane the pendulum swings so over the period of one or more days it rotates through 360°. You may want to read the article you posted again:

"Air resistance damps the oscillation, so some Foucault pendulums in museums incorporate an electromagnetic or other drive to keep the bob swinging; others are restarted regularly, sometimes with a launching ceremony as an added attraction"

**ratrodder69** · 01-23-2014, 16:25

Put a big magnet on your butt and one on the floor and you will be one of those old School desk ornaments

**SilvrSurfr** · 01-23-2014, 16:26

Originally Posted by NJTroutstalker

Read the article you posted. The pendulum path traces a circle but it's still a pendulum.

"Air resistance damps the oscillation, so some Foucault pendulums in museums incorporate an electromagnetic or other drive to keep the bob swinging; others are restarted regularly, sometimes with a launching ceremony as an added attraction." - Wikipedia

The other problem is that a hammock is not a pendulum, having two points of attachment (not one), exerting horizontal, and diagonal forces, not just vertical.

The best way to maximize your hammock swing times would be to sleep in a vacuum, but it might be hard to breathe!