Excursion to Hatfield.—May 13, 1876

Onset of carbon isotope excursion at the Paleocene-Eocene thermal maximum took millennia, not 13 years.

The Paleocene-Eocene thermal maximum (PETM) may represent the best paleo-analog for rapid and massive carbon release to the ocean and atmosphere. Thus, constraining the carbon release rate at its onset is critical. Wright and Schaller (1) use records from apparently rhythmically layered shelf sediments to argue that the layering is annual and that the onset of the carbon isotope excursion (CIE,...

Ca and Mg isotope constraints on the origin of Earth ’ s deepest d 13 C excursion

Understanding the extreme carbon isotope excursions found in carbonate rocks of the Ediacaran Period (635–541 Ma), where dC of marine carbonates (dCcarb) reach their minimum ( 12&) for Earth history, is one of the most vexing problems in Precambrian geology. Known colloquially as the ‘Shuram’ excursion, the event has been interpreted by many as a product of a profoundly different Ediacaran carb...

Brownian penalisations related to excursion lengths, VII

Limiting laws, as t →∞, for Brownian motion penalised by the longest length of excursions up to t , or up to the last zero before t , or again, up to the first zero after t , are shown to exist, and are characterized. Résumé. Il est prouvé que les lois limites, lorsque t → ∞, du mouvement brownien pénalisé par la plus grande longueur des excursions jusqu’en t , ou bien jusqu’au dernier zéro ava...

An Excursion to the Kolmogorov Random Strings

We study the set of resource bounded Kolmogorov random strings: R t = fx j K t (x) jxjg for t a time constructible function such that t(n) 2 n 2 and t(n) 2 2 n O(1). We show that the class of sets that Tur-ing reduce to R t has measure 0 in EXP with respect to the resource-bounded measure introduced by 17]. From this we conclude that R t is not Turing-complete for EXP. This contrasts the resour...

Alfred Newton Richards 1876-1966.