# Recent content by Rene Dekker

1. ### Floating a cruise ship in a bucket of water

I wasn't, I was speaking of objects that are lighter than water, that are held to the floor through a water-tight seal. Although it does not matter for the principle. Your rubber ball example shows exactly what I was pointing out. There is a buoyancy force on the ball, that is counteracted by...
2. ### Floating a cruise ship in a bucket of water

I would judge that in this case, where the water cannot get beneath the object, there is still the same buoyancy force, equal to the weight of the displaced water. But there is an extra downwards force on the object, due to the pressure difference of the water above the object with the...
3. ### Floating a cruise ship in a bucket of water

Thanks for pointing out that typo. I took the simplification that the underside of the ship is simply rectangular. We are talking about an imaginary theoretical exercise anyways, so there is no point in discussing all kinds of practical details. We just need an idea of what order of magnitude...
4. ### Floating a cruise ship in a bucket of water

We take a typical cruise ship size, with a length of 202m, width of 28m, and draft of 6.3m (I took the first one from https://www.cruisemapper.com/wiki/753-cruise-ship-sizes-comparison-dimensions-length-weight-draft). Then the surface area of the ship under water is 2 x 6.3 x (202 + 28) + 202 x...
5. ### I The twin paradox

In your clarifications, it seems clear that you imagine that all the O's meet all the A's simultaneously in A's reference frame (and similarly for the B's). That automatically means that the proper distance between A's is smaller than the proper distance between O's (and the proper distance...