🚀 go-pugleaf

THE TIME TRAVELLER'S HANDBOOK 2

7.	"imagine blowing negative-pressure stuff into a balloon and
seeing the balloon deflate as a result" p.175

8.	Sarfatti Commentary (in Tradition of Rashi): You can
correctly picture the classical kinetic theory of negative
pressure as caused by the random collisions of exotic
antiparticles of positive energy moving backwards in time
with an ordinary wall made up of positive energy particles
moving forwards in time. Exotic matter differs from
ordinary matter in the kind of Feynman boundary conditions
on the quantum field propagator as well as in the shape of
the mass shell. Exotic matter has anti-causal boundary
conditions in which exotic particles of negative energy
move forwards in time - this is equivalent to exotic
antiparticle of positive energy moving backwards in time.
An exotic antiparticle does not annihilate an ordinary
particle. The mass shell of an exotic particle in imaginary
time Euclidean metric is E^2+p^2 = m^2 (c=1). However this
exotic particle moves in real time with real E and real p
with the mass shell a circle of radius m. Compare to the
hyperbola E^2 = p^2 + m^2 of an ordinary particle of same
invariant mass m, charge e and spin s. Exotic matter
wavefunctions in flat spacetime are irreducible
representations not of the Poincare group but of the
imaginary time version of the Poincare group in the Wigner-
Bargmann sense. The spin-statistics connection of exotic
particles is opposite that of ordinary particles. Scalar
spin zero exotic particles are fermions ans spinor spin 1/2
exotic particles are bosons etc.

9.	"In fact, negative pressure not only can be produced in
theory but has been produced, and measured, in the
laboratory." p.175

10.	"the Casimir effect ... two parallel metal plates, placed
very close together with nothing in between ...
electromagnetic waves would only be able to form certain
stable patterns ... like the waves on a plucked guitar
string. ... no photon corresponding to a wavelength greater
than the separation between the plates can fit into the
gap. This means that some of the activity of the vacuum is
suppressed in the gap between the plates, while the usual
activity goes on outside... in each cubic centimeter there
are fewer virtual photons bouncing around between the
plates than there are outside, and so the plates feel a
force pushing them together .. negative pressure... The
force has been measured for a range of plate gaps from 1.4
nanometers to 15 nanometers... and exactly matches
Casimir's prediction." p.178

11.	Sarfatti Commentary: On the difference between real and
virtual particles (including photons). Real particles are
on the mass shell. Therefore, for example, real photons
move at the speed of light. In contrast, the virtual
photons of the quantum vacuum state move either slower or
faster than light. In Feynman's diagramatic expansion of
quantum electrodynamics, the largest contribution to the
Coulomb force between two charges is due to the exchange of
a single faster-than-light or "spacelike" virtual photon.
Indeed, the three-fold quark-like substructure of the
individual proton seen at SLAC is due to a superluminal
virtual photon! This is standard physics described in a
non-standard but technically correct way.