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John Rennie's answer is good already, but I want to add a single point: These fluctuations are very very short. In quantum mechanics you've got Heisenbergs uncertainty principle, which is often stated as $$ \Delta x \cdot \Delta p \le \frac \hbar 2 $$ and which means, that for any quantum object (think of an electron or a positron created in such a vacuum ...


I think the key conceptual hurdle is that the vacuum state is not nothing. Quantum field theory describes matter as excitations in quantum fields. These quantum fields are very strange things, and I don't know of any easy way to explain to a non-physicist what a quantum field is. The key thing is that the quantum fields fill all of spacetime. So a vacuum is ...


Second answer, what about the phenomenon of “Quantum Locking”? Right now it is being used to levitate superconductors over magnets, but I am sure you could exploit the phenomenon to transmit torque. Plus, you can put the superconductor on the vacuum side of the seal to keep it cold.


Take a look at the torque converters of cars with automatic transmissions. They are rotational couplings where the working fluid is completely sealed from both the source and sink environments, so one of those could be vacuum. One shell of the device rotates inside the other, to the outer one could be stationary and form an integral (welded) part of the wall ...


One standard way is a rotary fitting using a ferrofluidic seal. These are fairly standard parts in your favorite vacuum components catalog. Often used in semiconductor processing equipment.


I can think of two reasons why we need a lower bound, one statistical, one inuititive. First, the intuitive: The annihiliation/creation operators represent adding/removing particles (or excitations, or whatever). The vacuum state as lowest energy state represents obviously the empty state from which no further particles can be removed. It is also clear (in ...


Permeability is Constant of negative energy. Its counterpart-permittivity- is Constant of positive energy. Interaction between both of them create a physical entity called SPACE-TIME geometry. It is this space-time geometry which makes the speed of light finite. Negative energy attracts inward and acts as glue to make the universe finite and positive energy ...


Objects exiting the spacecraft have inertia - they will continue to move at the same speed as the spacecraft. There is nothing to slow them down enough to drop them out of orbit, so they remain orbiting the earth.


Conventional theory calls it spacetime, which I would assume refers to an unidentified amount of space over an unidentified amount of time but both distance and time are measurements of properties of matter and are dependent upon relative matter, example. Time is the measurement of relative movement, thedistance the sun can travel in a second is different ...

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