What's Cooking!?

The concepts of time and change may emerge from a universe that, at root, is utterly static.

Time may exist only by breaking the world into subsystems and looking at what ties them together. In this picture, physical time emerges by virtue of our thinking ourselves as separate from everything else.

Full text may be found here.

Daarnet ben ik even in NetVibes gedoken en heb daar een widget gemaakt: een klein programmaatje waarop de laatste posts van mijn blog te zien zijn. Het werkt op Windows, Mac, NetVibes, iGoogle en de iPhone. Volgens mij wordt alleen OS/2 niet ondersteund.

Geen quantumfysica maar wel handig als je eenvoudig op de hoogte wilt blijven. Of gewoon tijd over hebt.

Door: Ewoud de Kok, Joachim Jansen, Martijn Snelling Berg, Mathijs de Bruin

Een verkenning van onconventionele duurzame technologieën naar aanleiding van het honoursvak 'Energie en Klimaat' van de Universiteit van Amsterdam. Download de PDF: http://db.tt/q5CavR

Er is ook een bijbehorende presentatie beschikbaar, deze is de vinden op: http://prezi.com/g-lmpillc5gz/

(Reuters) - Last month was the warmest May on record, the U.S. National Oceanic and Atmospheric Administration said on Tuesday.

by Lorenzo Maccone

One of the most puzzling aspects of our universe is the fact that its initial state had entropy so much lower than we see today, making the initial state highly unlikely. Joining the above hypothesis of a zero-entropy pure state of the universe with the second law considerations analyzed in this paper, it is clear that such puzzle can be resolved.

The universe may be in a zero entropy state, even though it appears (to us, internal observers) to possess a higher entropy: our situation is similar to the one of Alice, who, just after the measurement sees her lab in a nonzero entropy state, whereas to the super-observer Bob her lab maintains a zero-entropy state all along.

The arrow of time dilemma: the laws of physics are invariant for time inversion, whereas the familiar phenomena we see everyday are not (i.e. entropy increases).

I show that, within a quantum mechanical framework, all phenomena which leave a trail of information behind (and hence can be studied by physics) are those where entropy necessarily increases or remains constant. All phenomena where the entropy decreases must not leave any information of their having happened.

This situation is completely indistinguishable from their not having happened at all. In the light of this observation, the second law of thermodynamics is reduced to a mere tautology: physics cannot study those processes where entropy has decreased, even if they were commonplace.

Het electorale draagvlak moet tegenwoordig gewonnen worden in een permanent gevecht vol hapklare brokken in de media. Hoe functioneert de moderne democratie en welke risico’s draagt zij in zich? En is deze mediademocratie eigenlijk wel wat wij willen? Tegenlicht onderzoekt de houdbaarheid van de democratie.