On May 28, 2004, at 9:55 AM, Hermann and Christine Bondi wrote:

It would be nice to hear from you after all these years. Hermann Bondi

Dear Professor Bondi

It's too bad I missed you when I visited Trinity College last September.

I remember fondly your wonderful performances with Ivor Robinson on third floor of Newman Laboratory at Cornell with Hans Bethe, Phil Morrison, Tommy Gold, Ed Salpeter in his kakhi shorts looking like Indiana Jones, Kinoshita, Robert Wilson, Robert Woodward, Jay Orear, Ronnie Peierls et-al lecturing on general relativity. You had us all in stitches with your wonderful Lewis Carrollian/Monty Python/Gilbert & Sullivan sense of British humor, whilst teaching Einstein's ideas in a most entertaining and inspiring way. Is Ivor still among us?

One of your talks which stuck in my mind for more than 40 years now was on "negative matter" and how that could cause propulsion in combination with ordinary matter. Robert Forward of course wrote about that years later citing your work. I did not know until looking at Forward's paper that Yakov Terletskii, Stalin's nuclear spymaster, also was interested in that idea.

I am working with some far out scientists in USG Military/Intelligence circles and also with Nick Cook at Jane's Defence Weekly, Simon Daniel, a Cambridge physics grad in London, and other eccentric Brits who "go out in the noonday sun" on the idea of "dark energy," which has the properties of "negative matter" and whether or not it can be "bottled" for practical "negative matter propulsion" of "Unconventional Flying Objects."

Now I see you have signed that letter in May 22, 2004 on the alternative cosmology dating back to Tommy Gold's and Fred Hoyle's ideas. That is how I realized you were still at Cambridge. Perhaps we can discuss that next time I am in UK. I do have an idea that both dark energy and dark matter are real enough as w = -1 zero point energy density of negative and positive pressure respectively. The sign of the zero point pressure depends on something I call "vacuum coherence," that you can picture as a vacuum condensate of virtual electron-positron pairs something like a BCS superconductor inside the vacuum, which is also the inflation field. This vacuum coherence also explains why Einstein's cosmological constant /\ ~ (Hubble radius)^-2 rather than ~ (hG/c^3)^-1.

Therefore, I have natural dynamical explanations for dark energy, dark matter and the inflation field in terms of rather elementary battle-tested ideas of Einstein's 1916 version of GR, Heisenberg's uncertainty principle, and the spontaneous broken ground state symmetry of condensed matter physics that P.W. Anderson has generalized to "More is different" in accord with Andrei Sakharov's idea of emergent gravity.
In the Cornell tradition of more with less, string theory and loop quantum gravity do not seem to be needed. Also this new picture, in which the effective gravity coupling seems to be strong on short scales, has consequences for particle physics like the old problem of the stability of the classical electron as a spatially extended charge distribution as well as the universal slope of the Regge trajectories of the hadronic resonances. The invisible sphere of the galactic halo that prevents our solar system from escaping into outer space may be the same zero point energy density of positive pressure that prevents the charge on the electron from exploding where the electron is Wheeler's geon of "Mass without mass" and "Charge without charge" but now the effective G* >> G on the scale of a fermi.

I will be in London at Thistle Hotel 104 Bayswater Rd July 13-17 and then at Herbert Park Hotel in Dublin July 18 - 25 for GR 17? Will you be at GR 17? I will also come back to London later in the fall of 2004.

Live Long and Prosper :-)

One of your admirers

Jack Sarfatti