voltage change on the capacitor

If a capacitor has 1V on both the top and bottom plate, and a voltage source 2V is short to the bottom plate, the top plate voltage is floating and it will change to 2V? How to understand the top plate voltage will change to 2V? Thank you.

you are saying the cap is uncharged initially ( 1V on both plates w.r.t. some unknown reference ) connecting any plate to a 2V ( relative to earth ? ) source will push the other plate to the same potential - i.e the cap remains uncharged - if the plates had differing voltages afterwards - some charging would have had to take place - drawing power from some source - this did not happen, ergo the plates remain at the same potential difference to each other - zero - ...

I guess this has to do with the concept of static charge which is a different animal from current electricity. We don't commonly consider static electricity in a capacitor although it is indeed there along with our familiar usage of them charging and discharging.

When I ponder similar thought experiments, my mind runs to ever greater questions...

Such as what if I attach 10,000 V to one plate? Is it conceptually different from attaching 2V to one plate?

What if the 10,000 V comes from a spark jumping from my finger? Did I just charge the capacitor to 10,000V?

What if I chop the plates in half and assemble these smaller capacitors in series? Is the resulting charge doubled, or does combining the middle negative and positive plates result in cancelation of their charge, thus reducing overall charge?

What if I widely separate the plates? What amount and polarity of charge does each retain? Do I still have a capacitor? Why or why not?

If there is no change in charge on the capacitor (as has to be the case if one terminal is floating) then whatever voltage is applied to one terminal will appear on the other floating terminal, whether it is 2V or 10,000V.

The dielectric of a cap is a good insulator. If it is not connected to ground and kept floating, that is analogous to a insulated wire. The wire will be at the applied voltage and the insulation will measure at zero volts with reference to ground. So the floating plate will measure zero volts and the cap will not have and voltage across it. Is there any voltage between the wire and insulation of an insulated wire within a activated circuit?

Ratch