Hawking Stephen Theoretical Physicist (4 results)

4to. (203:254 mm). 1 page. On headed notepaper. Hawking encloses an improved version of a paper co-authored with George Ellis (the work, not present here, was 'The Cosmic Black-Body Radiation and the Existence of Singularities in Our Universe', The Astrophysical Journal, Vol. 152 (April 1968), p. 25], noting that the 'calculations of the convergence condition have been redrawn'. Hawking enjoyed his visit to Maryland, which prompted some ideas about Misner incompleteness that he intends to put into a paper when he has time. He continues: 'I heard Stan Deser outline his proof that mass is positive definite. He claims that a function whose only critical value is zero and which has a local minimum there is necessarily positive elsewhere. It seems to me that there are counter examples to this in finite dimensions not to speak of the infinite dimensions case'. A reminder about payment for his last week at Maryland and travel expenses ends the letter, Hawking professing himself embarrassed, but mentioning it in case the cheque might be missing in the post. - Stephen Hawking first met the American physicist Charles W. Misner during the latter's 1966-67 visit to Cambridge at the invitation of Hawking's postgraduate supervisor Dennis Sciama; the two became close, and Hawking visited Misner at his own institution, the University of Maryland, at the end of 1967. Hawking's work on singularity theorems, which he first published in his 1965 doctoral thesis, overlapped with the research Misner was undertaking on geodesical incompleteness, a notion at the centre of the concepts Hawking was developing with Roger Penrose (the 'Penrose-Hawking singularity theorems'). Here, Hawking seemingly refers to a proof that another of their colleagues in the field, Stanley Deser, would publish the following year in the Physical Review Letters, in a paper entitled 'Positive-Definiteness of Gravitational Field Energy'. - Provenance: Charles W. Misner.

4to. (197:244 mm). 1 page. On headed "air letter" paper. One of Hawking's students, Gary Gibbons, is to attend the meeting of the American Physical Society in New Orleans from 23-25 November, "where he will report on the British work on the design and construction of gravitational wave detectors. We think that, without the use of liquid helium, we can improve the sensitivity by a factor of 100. The first of these detectors should be operating before the end of the year, and the second one at Reading should follow soon after". Hawking hopes that Gary might stay on after the New Orleans meeting to attend the relativistic astrophysics conference in Austin, with a visit to the University of Maryland in between, and asks for Misner's help in organising this visit: [Joseph] Weber will be too busy to show Gibbons around, but Hawking notes that Gary should really see Misner and [Dieter] Brill: "he is primarily a theoretician and is interested in the problem of how much gravitational radiation would be emitted by a collapsing object". Hawking also announces the birth of a little girl, "Catherine Lucy, though we will probably call her Lucy", born a little plumper than Robert, and very well behaved. - In 2016, over 45 years after Stephen Hawking's hopeful mention in the present letter of the gravitational wave detectors being built in England - and one hundred years after Albert Einstein first predicted the existence of gravitational waves - scientists would finally have proof of these elusive ripples in space-time: the unmistakeable "ringing" as two black holes collides was heard at the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) on 11 February 2016. When asked for comment, Hawking said that the discovery would "revolutionise" astronomy, noting also that it had proved his calculations of 1970 to be correct: "The observed properties of this system are consistent with predictions about black holes that I made in 1970 here in Cambridge". Hawking and his student Gary Gibbons would go on to collaborate in their research, lending their names to the "Gibbons-Hawking effect", "Gibbons-Hawking space", and the "Gibbons-Hawking ansatz". - Provenance: Charles W. Misner.

8vo (230 x 153mm). Text illustrations. Publisher's black quarter cloth, blue pictorial dustjacket. First American edition with authorial thumbprint of Hawking's bestselling science classic. A fine copy, 'signed' with an authorial thumbprint on front free endpaper. - Provenance: Judy Fella (Hawking's first secretary, and later PA and nursing coordinator: Fella worked with Hawking on the first draft of "A Brief History of Time").

Pas de couverture. Condition: Bon. - Exceedingly rare piece with superior provenance - Book sticker signed by Stephen Hawking using his thumbprint in April 1989. The sticker is accompanied by an autograph letter signed in French from his wife Jane Hawking and the handwritten envelope. " Sir, Thank you for your kind letter of March 26 in which you expressed your appreciation of my husband's book, A Brief History of Time. I have the honor to send you herewith my husband's thumbprint as a dedication of your copy. I assure you, Sir, of the expression of our most respectful feelings. Jane Hawking " Size : 4x9 cm (sticker). Condition : please see scans. Provenance : Gérard Leman collection. Certificate of Authenticity and lifetime guarantee. Signé par l'auteur.