Spinning Superconductor Questions

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Discussion Overview

The discussion revolves around the properties and behaviors of spinning superconductors, including their lifting capabilities, energy requirements, and the conditions necessary for their operation. Participants explore theoretical aspects and specific phenomena related to superconductivity, particularly in relation to the London moment.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Jake inquires about the types of materials that a spinning superconductor can lift and whether its lifting ability is directional or limited to opposing gravity.
  • Jake questions if cooling is necessary for the operation of spinning superconductors.
  • Jake seeks clarification on the energy required for a superconductor to exert a force of one Newton and whether this relationship is linear.
  • Another participant references the London moment, explaining that it describes a spinning superconductor generating a magnetic field aligned with its spin axis, and provides a formula related to the magnetic field strength.
  • Jake asks for clarification on the parameters in the formula, including the meaning of M and Q, and whether they apply to the superconductor or the object it supports.
  • Jake also questions if the superconductor can only lift magnetic objects.

Areas of Agreement / Disagreement

The discussion contains multiple questions and uncertainties, with no consensus reached on the various aspects of spinning superconductors, including their lifting capabilities and operational conditions.

Contextual Notes

Participants express uncertainty regarding the definitions of variables in the referenced formula and the conditions under which spinning superconductors operate, such as the necessity of cooling and the types of objects they can lift.

jaketodd
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If someone(s) would be so kind, I have some complicated curiosities about spinning superconductors. This is not homework.

What types of materials can a spinning superconductor lift?
Does it only work against gravity, or can it work in any direction?
Does it have to be cooled?
How much energy per second would a superconductor need in order to spin in such as way as to continuously exert one Newton on something very near to it? Is this relationship linear (between energy and Newtons)? Also, is the relationship between acceleration due to Newtons applied, and the mass the Newtons are applied to, linear?

Thanks,

Jake
 
Physics news on Phys.org
are you talking about this?

http://en.wikipedia.org/wiki/London_moment

The 'London moment' is a quantum-mechanical phenomenon whereby a spinning superconductor generates a magnetic field whose axis lines up exactly with the spin axis

The magnetic field strength associated with a rotating superconductor is given by:

b092013d67c39380ba4bf3df25d858cd.png


where M stands for the mass of the mass, and Q for the charge of the superconducting carriers. For the case of Cooper pairs of electrons, M=2me and Q=2e. Despite the electrons existing in a strongly-interacting environment, me denotes here the mass of the bare electrons [6] (as in vacuum), and not e.g. the effective mass of conducting electrons of the normal phase.
 
Does M = 2me for an arbitrary mass? Is M for the spinning superconductor or the thing it is supporting? Does Q = 2e for an arbitrary mass (arbitrary number of electrons)? Is Q for the spinning superconductor or the thing it is supporting? And I assume w is rotational frequency of the superconductor? Does it need to be cooled? And I assume it can only lift magnetic objects?

Thanks!

Jake
 
it should be 2me

e stands for 'electron'
 

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