Give an elevator in an evacuated shaft. The cable snaps,
it falls freely.

A drop of mercury sits on the floor. What happens to it,
during the fall?

A burning candle sits in a candle holder, mounted to
the wall. How is it affected by the fall?

--
Rich

On 11/5/2022 7:39 PM, RichD wrote:
> Give an elevator in an evacuated shaft. The cable snaps,
> it falls freely.
>
> A drop of mercury sits on the floor. What happens to it,
> during the fall?
>
> A burning candle sits in a candle holder, mounted to
> the wall. How is it affected by the fall?

How long is the evacuated shaft? Is a source of gravity at a fixed
location at the end of the shaft? Does the elevator continue to fall
until it reaches some sort of terminus? So many questions--so little
time...

Den 06.11.2022 01:39, skrev RichD:
> Give an elevator in an evacuated shaft. The cable snaps,
> it falls freely.
>
> A drop of mercury sits on the floor. What happens to it,
> during the fall?

Depends on the size of the drop.

(In 1g, very big drops of mercury will split
up in many smaller drops.)

A small drop will be almost globular at 1g,
and then very little will happen when it becomes 0g.
It will stay very close to the floor.

A bigger drop will be an oblate spheroid in 1g.
In 0g the drop will become perfectly spherical,
which will make it drift slowly upwards from the floor.

Can you explain from where the kinetic energy
(in the "elevator frame") of the drop comes?

>
> A burning candle sits in a candle holder, mounted to
> the wall. How is it affected by the fall?

My guess:
It will probably go out.
The hot burning gas will not leave the wick,
and no new air with oxygen will reach the wick.

(When the proper acceleration of the elevator is 1g,
the air pressure will be slightly higher at
the bottom of the elevator than at the top, so
there will be a slight movement of the air when
the proper acceleration becomes zero. But this
will be so slight and last so short that it
will have no consequence for the candle.)

--
Paul

https://paulba.no/

A: This is a thermometer, it works on mercury.
B: But it doesn't show anything!
A: This is earth!

On Saturday, November 5, 2022 at 5:39:07 PM UTC-7, RichD wrote:
> Give an elevator in an evacuated shaft. The cable snaps,
> it falls freely.
>
> A drop of mercury sits on the floor. What happens to it,
> during the fall?
>
> A burning candle sits in a candle holder, mounted to
> the wall. How is it affected by the fall?
>
> --
> Rich

Why does the falling metal become a sphere?

On November 6, Paul B. Andersen wrote:
>> Given an elevator in an evacuated shaft. The cable snaps,
>> it falls freely.
>> A drop of mercury sits on the floor. What happens to it,
>> during the fall?
>
> Depends on the size of the drop.
> A small drop will be almost globular at 1g,
> and then very little will happen when it becomes 0g.
> It will stay very close to the floor.
> A bigger drop will be an oblate spheroid in 1g.
> In 0g the drop will become perfectly spherical,
> which will make it drift slowly upwards from the floor.

Right. Surface tension will restore it to spherical.
It will bounce between the floor and ceiling.

> Can you explain from where the kinetic energy
> (in the "elevator frame") of the drop comes?

Surface tension stores energy.
>> A burning candle sits in a candle holder, mounted to
>> the wall. How is it affected by the fall?
>
> My guess: It will probably go out.
> The hot burning gas will not leave the wick,
> and no new air with oxygen will reach the wick.

Right. Specific weight is meaningless in zero G.

--
Rich

Den 07.11.2022 21:19, skrev RichD:
> On November 6, Paul B. Andersen wrote:
>>> Given an elevator in an evacuated shaft. The cable snaps,
>>> it falls freely.
>>> A drop of mercury sits on the floor. What happens to it,
>>> during the fall?
>>
>> Depends on the size of the drop.
>> A small drop will be almost globular at 1g,
>> and then very little will happen when it becomes 0g.
>> It will stay very close to the floor.
>> A bigger drop will be an oblate spheroid in 1g.
>> In 0g the drop will become perfectly spherical,
>> which will make it drift slowly upwards from the floor.
>
> Right. Surface tension will restore it to spherical.
> It will bounce between the floor and ceiling.
>
>> Can you explain from where the kinetic energy
>> (in the "elevator frame") of the drop comes?
>
> Surface tension stores energy.

Right.
And the surface tension energy is less
when the drop is perfectly spherical
than it is when the drop is an oblate spheroid.

>
>>> A burning candle sits in a candle holder, mounted to
>>> the wall. How is it affected by the fall?
>>
>> My guess: It will probably go out.
>> The hot burning gas will not leave the wick,
>> and no new air with oxygen will reach the wick.
>
> Right. Specific weight is meaningless in zero G.
>
> --
> Rich

--
Paul

https://paulba.no/

On Tuesday, November 8, 2022 at 1:45:05 AM UTC-8, Paul B. Andersen wrote:
> Den 07.11.2022 21:19, skrev RichD:
> > On November 6, Paul B. Andersen wrote:
> >>> Given an elevator in an evacuated shaft. The cable snaps,
> >>> it falls freely.
> >>> A drop of mercury sits on the floor. What happens to it,
> >>> during the fall?
> >>
> >> Depends on the size of the drop.
> >> A small drop will be almost globular at 1g,
> >> and then very little will happen when it becomes 0g.
> >> It will stay very close to the floor.
> >> A bigger drop will be an oblate spheroid in 1g.
> >> In 0g the drop will become perfectly spherical,
> >> which will make it drift slowly upwards from the floor.
> >
> > Right. Surface tension will restore it to spherical.
> > It will bounce between the floor and ceiling.
> >
> >> Can you explain from where the kinetic energy
> >> (in the "elevator frame") of the drop comes?
> >
> > Surface tension stores energy.
> Right.
> And the surface tension energy is less
> when the drop is perfectly spherical
> than it is when the drop is an oblate spheroid.
> >
> >>> A burning candle sits in a candle holder, mounted to
> >>> the wall. How is it affected by the fall?
> >>
> >> My guess: It will probably go out.
> >> The hot burning gas will not leave the wick,
> >> and no new air with oxygen will reach the wick.
> >
> > Right. Specific weight is meaningless in zero G.
> >
> > --
> > Rich
> --
> Paul
>
> https://paulba.no/

The motion of a falling elevator gives it a small time dilation
and more energy by speed... in space.

Mitchell Raemsch