Tag: Universe

An unchanging quantum universe
This another one of those bizarre thoughts that cosmology throws up which manages to be both simple and profound. Imagine the wave function for the whole universe. By its nature the universe cannot change its quantum state: it’s the ultimate closed system. Of course there is a probabilistic distribution of energy inside the system but […]

A (final) speculation from “The Hidden Reality”
I have just finished Brian Greene’s The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, so want to take this opportunity to once again endorse it and also to restate or reprise one of his speculations in the book: this time one grounded firmly in computing rather than string theory or conventional […]

Why isn’t the universe of infinite density?
Another speculation produced by Brian Greene’s The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. Imagine the universe was infinite (along the “quilted multiverse” pattern – namely that it streched on and on and we could only see a part). That would imply, assuming that the “cosmological principle” that one bit of […]

Cosmologists’ problems with alephnull and the multiverse
This is another insight from Brian Greene’s book The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos – well worth reading. Alephnull () is the order (size) of the set of countably infinite objects. The counting numbers are the obvious example: one can start from one and keep on going. But any […]

The second law of thermodynamics and the history of the universe
I had to go on quite a long plane journey yesterday and I bought a book to read – Roger Penrose‘s work on cosmology: Cycles of Time: An Extraordinary New View of the Universe I bought it on spec – it was on the popular science shelves: somewhere I usually avoid at least for the […]