# JimA

Members

5

## Posts posted by JimA

### Jim' slippery feet

Anyone else confirm my observation ?

### Jim' slippery feet

When relaxing in the bath with my knees raised and my feet maybe 2/3 down the bath, my feet slide to the far end.

Why do they slide very slowly and at essentially a constant speed?

• My feet move very slowly - approx 1mm/5sec or 1mm/10 sec --- initially hard to discern movement at all.
• It can't be elasto-hydrodynamic - which would cause rapid movement.
• It can't be just gravity induced forces and friction --- the forces would have to be exactly equal !

• Can it be viscosity in the thin water film under my feet ?
• Can it be stick/slip at the many micro contacts of my feet to the bath ?

If you are a "shower person", then this will mean nothing to you. Pass it on to a "bath person" for confirmation.

I think this is a "Do try this at home".

### Definition of particle and black hole

It seems that a particle can be completely described by 1) mass, 2) charge 3) spin (or angular momentum)

It seems that a black hole can be completely described by 1) mass, 2) charge 3) spin (or angular momentum)

Is there a reason for this similarity ?

### Space and Dimensions

On 4/9/2021 at 9:21 PM, Phi for All said:

Scale. The higher dimensions predicted by string theory are Planck-sized.

You aren't "changing" either space or dimensions. If you were, I think there would be more support for string theory.

On 4/9/2021 at 9:21 PM, Phi for All said:

Scale. The higher dimensions predicted by string theory are Planck-sized.

You aren't "changing" either space or dimensions. If you were, I think there would be more support for string theory.

(I'm still floundering with the website)

I don't see "scale" as relevant. I agree - the normal dimensions can be of any size, and the higher dimensions are shrunk (as you say) down to very small.

The normal space is said to be changed by mass - particularly large concentrated masses (forming black holes).

The higher dimensions are talked about as shrunk --- from any size down to Plank sized

### Space and Dimensions

Space - with its 3 dimensions (+ time) is distorted by mass --- no mention of changing dimensions.

Possible extra dimentions (beyond the 3 +1) are considerred to only make sense if the dimensions are "wrapped up small" --- no mention of changing space.

Why the different approach ?

×