Time: a glacier, not a stream

Via Sean Carroll: I Tweeted the following inscrutable remark. Probably best left unexplained, but upon reflection I can’t resist. My consciousness freely travels up and down my world line, but sadly it only carries the memories appropriate to the moment it inhabits. The point is that (some) people don’t think about the flow of time [...]

The big questions

Given special relativity, by which events taking place at near-light speeds over nonzero spans of space can be described in multiple, contradictory, but equally correct sequences by various observers in different frames of reference, it might be a meaningless question to ask whether Han shot first.

WE ARE SURROUNDED BY ANTIMATTER EVERYBODY PANIC

THE ONLY WAY OUT IS TO TUNNEL THROUGH THE EARTH AND BEG THE HYPERBORIANS FOR SAFE PASSAGE THROUGH THE FOURTH DIMENSION GIVE THEM ANYTHING THEY WANT OUR CIVILIZATION IS AT STAKE. PRIDE IS A LUXURY OF AN AGE OF INNOCENCE WE SHALL NEVER KNOW AGAIN. TELL US OF OUR DOOM, BBC! A thin band of [...]

What if you’re somebody’s shadow?

Two days ago, I discussed several theories which call for universes parallel to our own. Brian Greene, writing in Discover Magazine, floats another one even queerer than the three I mentioned. Whereas the other worlds in my last post were causally isolated from our own, this hypothesis posits that all the events in our universe are [...]

Inflationary multiverse theory may have recieved first direct empirical evidence

Democritus, or perhaps Leucippus, was the first Western thinker to propose an infinite universe. Many of Democritus’ commentators in early Greek philosophy, most notably Aristotle, found the hypothesis extravagant. However, numerous strands of 20th century physics suggest Democritus not have gone far enough, and advance a succession of theories positing an infinite number of universes. Quantum [...]

Some hobbyists collect stamps; others probe the very heart of matter

To each their own. Via the Washington Post:  A Swedish man who was arrested after trying to split atoms in his kitchen said Wednesday he was only doing it as a hobby. Richard Handl told The Associated Press that he had the radioactive elements radium, americium and uranium in his apartment in southern Sweden when [...]

Stock in Spinoza

Rebecca Newberger Goldstein, writing in Prospect: Thinking of buying shares in a great philosopher? The first question you need to ask is whether you’re interested in long or short-term investment. If you are looking long-term, then prepare yourself for serious scholarship. Alternatively, short-term investment could merely involve comparing the battle over women’s hemlines on catwalks [...]

Towards an antimatter Periodic Table

…and some of the difficulties along the way: Because the production of antimatter takes incredible amounts of energy, and because of the short life expectancy of antimatter in our matter-rich neck of the universe, making antielements is tough work. But two recent discoveries have bolstered the hope that we can—someday—fill in more of the anti-periodic [...]

Astronomical survey seems to confirm existence of dark energy

Via BBC News: First results from a major astronomical survey using a cutting-edge technique appear to have confirmed the existence of mysterious dark energy. Dark energy makes up some 74% of the Universe and its existence would explain why the Universe appears to be expanding at an accelerating rate. The finding was based on studies [...]

Some black holes may predate Big Bang

Via Technology Review’s Physics arXiv Blog: Black holes are regions of space in which gravity is so strong that nothing can escape, not even light. Conventionally, black holes form during a gravitational collapse, after a large supernova for example. But there is another class of objects called primordial black holes that cosmologists think must have [...]