Kaku is being sloppy again this use of "negative Casimir energy" is pure
nonsense.

What needs to be negative is not "Energy" but

Energy Density + 3Pressure

When that is negative you get universal repulsive gravity in the
Newtonian-Galilean limit of GR.

All zero point energy obeys the rule

Energy Density + Pressure = 0

This is required by

Lorentz invariance + Equivalence Principle.


On Oct 24, 2005, at 7:22 PM, wrote:

To: Jack Sarfatti
From: Richard D.K. Johnson
aka Dick Johnson
aka Richard Baird (pen name)
President, San Francisco Science Fiction Society

Date: Mon. 24 October 2005
United Nations Day

In Michio Kaku's January 2005 book Parallel Worlds
he talks about building a warp drive (pages 334-336):

He says:

"One possible way to [travel across interstellar distances]
is to use the Alcubierre warp drive machine...you would have
to employ large quantities of both negative and positive energy'
to power your starship. (Positive energy could be used to
compress the space in front of you and negative energy to
lengthen the distance behind you.) To use the Casimir
effect to create this negative energy, the plate would have to
be separated by the Planck distance, 10^-33 centimeters....To
build such a starship, you would have to build a sphere
[or a saucer?!] and place the passengers inside...Russian
physicist Sergei Krasnikov showed...the inside of the
starship is disconnected from the space outside the ship---that
is, once inside the ship, you cannot change the path of
the starship. The path has to be laid out before the
trip is made. One could...[lay out an interstellar]
railway by fist using conventional rockets that travel at
sublight speed to build rail stations at regular intervals
between stars. Then the starship would travel between
these stations at super light speed according to a timetable.."

Do you agree with the above analysis?

NO!

Yours, Richard