Item #1192 A Cyclic Model of the Universe. A Cyclic Model of the Universe by Paul Steinhardt and Neil Turok (Science 296 No. 5572 pp. 1436–1439, May 24, 2002) WITH Why the Cosmological Constant Is Small and Positive by Paul Steinhardt and Neil Turok (Science 312 No. 5777 pp. 1180 - 1183, May 26, 2006). [TWO RELATED PAPERS (2002 & 2006) IN SEPARATE ISSUES & ORIGINAL WRAPS]. Paul J. Steinhardt, Neil Geoffrey Turok.

A Cyclic Model of the Universe. A Cyclic Model of the Universe by Paul Steinhardt and Neil Turok (Science 296 No. 5572 pp. 1436–1439, May 24, 2002) WITH Why the Cosmological Constant Is Small and Positive by Paul Steinhardt and Neil Turok (Science 312 No. 5777 pp. 1180 - 1183, May 26, 2006). [TWO RELATED PAPERS (2002 & 2006) IN SEPARATE ISSUES & ORIGINAL WRAPS]

New York: American Association for the Advancement of Science. 1st Edition. TWO 1st EDITION PAPERS IN ORIGINAL WRAPS: STEINHARDT & TUROK’S 2002 CYCLIC THEORY OF THE UNIVERSE & THEIR 2006 EXPLANATION OF HOW THIS THEORY CAN RESOLVE THE COSMOLOGICAL CONSTANT PROBLEM. “The cyclic universe theory is a model of cosmic evolution according to which the universe undergoes endless cycles of expansion and cooling, each beginning with a “big bang” and ending in a “big crunch” (Steinhardt, Cyclic Universe Theory, 2009). We have a second copy of both the 2002 and 2006 paper and offer each separately.

The model has also been known as the ekpyrotic cyclic universe theory. Paul Joseph Steinhart is an American theoretical physicist and cosmologist, currently the Albert Einstein Professor in Science at Princeton University. Beginning in 2001 and working with the South African physicist Neil Geoffrey Turok, Steinhardt and Turok put forth the ekpyrotic theory which, in essence, envisions a big bounce rather than a big bang. “According to this model, the current expanding universe emerges from a bounce that occurred 13.7 billion years ago and that is a result of the preceding (contracting) universe. The smoothing and flattening of the universe and the generation of density variations occur during the phase of slow contraction before the bounce and remain after the bounce” (Wikipedia). In their own words: “The Cyclic Model attempts to resolve the homogeneity, isotropy, and flatness problems and generate a nearly scale-invariant spectrum of fluctuations during a period of slow contraction that precedes a bounce to an expanding phase. Here we describe at a conceptual level the recent developments that have greatly simplified our understanding of the contraction phase and the Cyclic Model overall (Steinhardt & Turok, 24 May 2002).

In 2002 and with the paper offered, Steinhardt and Turok rolled their ekpyrotic theory into a far broader one, the cyclic theory of the Universe. This model theorizes that the Universe has been expanding and contracting repeatedly “over timescales that make the 13.7 billion years that have passed since the Big Bang seem a mere blink. This makes the Universe vastly old. And that in turn means that the mysterious 'cosmological constant', which describes how empty space appears to repel itself, has had time to shrink into the strangely small number” (Cyclic Universe Could Explain Cosmic Balancing Act, 4 May 2006).

One of concepts within string theory is that our universe is an eight- dimensional D-Brane consisting of three normal dimensions plus five curled-up dimensions. A very small distance away in a ninth dimension is another D-Brane. In Steinhardt and Turok’s cyclic model of the universe, these D-Branes collide every trillion years or so, creating a burst of new energy and material that result in what is normally attributed to the big bang. They believe that the gravitational potential between these branes is the source of dark energy, and its current increase is indicative of the fact that the branes are moving apart at the moment. When they start to approach each other again the dark energy will diminish. This differs from the standard cosmological model in many ways. One is that the bang that began the expansion of our visible universe is not the result of a singularity, and the theory of cosmic inflation is unnecessary.

Again, first paper listed describes the theory and the second paper draws on the theory to explain how this theory can resolve the cosmological constant problem. “In 2006, Steinhardt and Turok showed how the cyclic model could naturally incorporate a mechanism for relaxing the cosmological constant to very small values, consistent with current observations” (WP). Item #1192

CONDITION & DETAILS: New York: American Association for the Advancement of Science. Two complete 1st editions in original wraps, complete. 8vo. Both in fine condition. Pristine.

Price: $375.00