Tag: Cosmology
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Crazy ideas you have in the bath
You know how it is … you go for a run and then lying in the bath you read a New Scientist article about Dark Energy and you think of two crazy ideas which you hope some respectable scientist will at least have stuck a paper on arXiv on, so you can at least say…
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Is cosmology completely broken?
Thirty years ago, when I was taught cosmology as an undergraduate, it felt pretty much like a subject that was close to being fully described: indeed this was the era when Stephen Hawking could announce that we were close to a “theory of everything”. In simplified form the cosmology was this: the universe (and there…
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The gravitational perpetual motion machine?
Perhaps I should have thought about this years ago – when I was surrounded by physicists and cosmologists and the like, and so could have got an answer: but I didn’t – until I started reading Lee Smolin‘s Time Reborn: From the Crisis in Physics to the Future of the Universe. Here’s the issue: as Smolin…
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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…
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A probably entirely naïve question about the principle of relativity
Surely I can quite easily design an experiment that shows the relativity principle is false. If turn around on the spot the principle, as I understand it, asserts that I cannot build an experiment that proves it was me that moved as opposed to everything else that moved while I stayed still. But the rest…
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Copernicus was wrong (maybe)
No, I haven’t taken leave of my senses and decided the Sun moves around the Earth (but here is a pop quiz for all of you laughing at that idea – can you think of a simple experiment that would prove to a 10-year-old that the Earth moves around the Sun?). In fact the issue…
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Why we’ll never meet aliens
Well, the answer is pretty plain: Einstein‘s theory of general relativity – which even in the last month has added to it’s already impressive list of predictive successes – tells us that to travel at the speed of light a massive body would require an infinite amount of propulsive energy. In other words, things are…
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Review of “The Black Cloud”
My interest in astronomy and astrophysics comes from childhood and when I was much, much younger I had an (unscientific) fondness for the “steady state” theory of cosmology, which, in the early 1970s was not as thoroughly discredited as it is today (though, of course, many newer cosmologies borrow from it or show similarities to…
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It’s official: we’re getting bigger all the time says Nobel Committee
The decision to award this year’s Nobel Prize for Physics to three astrophysicists who, through measuring the brightness of distant supernovae showed that the expansion of the universe is accelerating, is simply the highest possible confirmation of what most if not all in the field have accepted for a decade or more. That idea is…
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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…
cartesian product ... stuff about computing mostly 