…f spatial regions. However, William and the astronaut will agree about the order in which time-like separated events occur: first Harold is crowned, and then Harold is slain. Figure 1: An observer on Earth and an astronaut traveling away with velocity c/2 will describe two different foliations of spacetime into space-like hypersurfaces of simultaneity. On the other hand, an accelerating observer will not generally agree about the order in which th…
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…k does is circulating on the inter-tubes. If you look around a bit, you’ll likely be able to find and download a copy for free. Just throwing that out there. See also my advice about reading on the cheap, and about learning GR online. This list was inspired by a recent post over at It’s Only a Theory — further suggestions are more than welcome. Happy reading! (*) Added Feb. 11 – Thanks commenters! Soul Physics is authored by Bryan W. Roberts. Than…
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…m the description and explanation of empirical fact, as is the language of prescription and justification. Although Sellars was concerned with the philosophy of mind, there is something important here for philosophers of physics to learn as well. A major activity of physics is the collection of empirical facts. Another is the prediction and justification of these facts. But the activity of investigating meaning is a distinct activity altogether. T…
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…ch (one hopes) would still give rise its successful predictions. A feeling like this that seemed to be lurking behind each of the day’s lectures. What I learned by the end of the day is that there are many different ways that this upset-feeling can be appeased, if you work hard enough. Each of the four talks presented some new mechanism capable of modeling certain quantum phenomena. You might try to describe some correlations using classical theor…
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…real cause of the Supertide. It is because the earth, moon and sun looked like this: Here is the summary of what makes a tide stronger than normal. Strong tide: New moon (sun and moon align — sometimes also causes eclipse) Stronger tide: New moon + Perigee (Perigean tide) Strongest tide: New moon + Perigee + Spring (Spring Perigean tide) The Supertide was just a Spring Perigean tide that occurred the day before the equinox. That is the main reaso…
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