Re: Want to prove E=mc²? University labs should try this!

Am Mittwoch000020, 20.11.2024 um 16:57 schrieb ProkaryoticCaspaseHomolog:

On Wed, 20 Nov 2024 14:46:05 +0000, rhertz wrote:
 

As I wrote before, the cavity NEVER reaches a steady state (thermal
equilibrium is just one possible goal to reach a steady state).
>
The stored energy increases constantly until the temperature of the
cavity
walls (not cancelled by any means) destroy the material that form the
cavity (either coatings or places on the cavity surface, making holes).

 No, because the temperature of the foil rises until the power emitted
equals 5 watts. Once that happens, no further increase of stored
energy occurs.
 P = ε * σ * T^4
 Let us assume a 10x10x10 cm cube with surface area 0.06 m^3
So 5 watts total power emitted means 83 watts/m^2
Assume ε = 0.13
 Let T_i be 273 K
 83 = ε * σ * (T_f^4 - T_i^4)
11,260,344,593 = (T_f^4 - 5,554,571,841)
T_f = 274.8 K
 In other words, the temperature of the foil rises to 1.8 degrees
above room temperature.
 

In physics, a steady state is a condition in which a system or process
does not change over time, or any changes are balanced out. This means
that the variables that define the system's behavior remain constant.
Some examples of steady states include:

Nature does not have 'closed systems'.
What we  call a system, that is actually our decision.
Therefore the notation of 'elementary systems' (e.g. particles)  is wrong.
We decide, what we regard as a closed system, even if such things do not exist.
Therefore we distinguish between a particle and its surrounding space and perceive the particles, as if it would be a thing (a closed system).
But, in fact, e.g. an electron isn't particularly closed, because a pointlike thing ('the electron itself') is surrounded by its field.
Now we have a contradiction between 'closed' and 'surrounding field'.
But this contradiction occurs with other systems, too.
Now 'steady state' and 'closed system' are seemingly interchangeable, hence a system is an entity, which lasts at least for some time, for which 'the defining variables' are constant.
...
TH