# would this Lenz law based inertial dampener work?

Basically this "Inertial Dampening" systems works like a magnet falling though a cooper pipe https://youtu.be/5BeFoz3Ypo4

But replace the falling magnet with a crew capsule surrounded by a powerful electromagnet with a magnetic field reflective material in-between. And replace the cooper pipe with a long elevator shaft which is also insulated on the outside with a magnetic field reflective material to prevent damage to outside electronics.

Basically, when the ship is doing a high g burn the crew capsule will be in a very slow freefall down the long elevator shaft like a magnet through a copper pipe.

• a magnetic field reflective material? what is it how does it work?
– L.Dutch
Commented Jul 9, 2022 at 5:33
• youtu.be/nD2f_gGedhU Commented Jul 9, 2022 at 7:08
• It strikes me that the tricky bit isn't the principle, but the aim - i.e. hitting the entrance accurately whilst doing Mach 25. Commented Jul 9, 2022 at 9:41
• A magnet falling through a metal pipe is not in free fall, just like a parachutist is not in free fall. (I would have thought that this was obvious -- it falls much slower than what would be expected from free fall.) Commented Jul 9, 2022 at 10:32
• It is the magnetic field and force that imparts the acceleration of the ship onto the crew capsule. Otherwise the crew capsule, being completely independent of the ship, would not accelerate until the 'bottom' of the tube caught up with it. Commented Jul 9, 2022 at 11:17

For a Few Seconds

I guess you mean the spaceship is the copper tube and the metal bit in the middle is a suspended capsule that contains the crew.

In the video the capsule gets accelerated downwards and the Lenz law slows down the acceleration. By symmetry the same should work if the tube was instead accelerated upwards.

The problem is that if the tube (spaceship) accelerates too long the capsule will hit the back wall of the ship. For example an acceleration of 1g for ten seconds needs a spaceship 500m long -- if the capsule stays still -- otherwise the ship moves beyond the capsule.

This problem has nothing to do with the Lenz effect. It comes up no matter what trick you use to move the capsule slower than the ship containing it. Eventually the ship has moved fast enough for long enough that it outstrips the capsule.

However!

This might be a good way to build an "inertial dampener" as understood in Star Trek, i.e the thing that stops the Crew from flying into the wall when something bumps the ship as high speed. A magnetised crew capsule inside a Lenz sphere would smooth out all these bumps.

This isn't an inertial dampener, it's a magnetic brake. The energy of the object moving gets dissipated into heat, just as if it were being rubbed against the sides. Cargo would get squished against the front of the capsule.

Big shock at the end

As shown in the video,

• the magnet has freefall before it enters the copper pipe.
• the magnet falls slowly inside the pipe because of the Lenz law.
• the magnet has freefall again when it comes out of the copper pipe and it hits the table.

The same thing will to the crew. When the capsule comes out of the copper pipe, it will hit the end of the ship, giving a big shock.

Flip the pipe at proper intervals

One way to overcome this is to flip the copper pipe at proper intervals so that the capsule remains inside the pipe. See 0:36 of this video.

Alternating pipes

Another way is:

Put capsule in pipe A. It will slide down. As it enters pipe B, Bring pipe A under it and so on.