At risk of shameless self-promotion, here's a video I recorded with Brady Haran at the University of Nottingham. It's an 'intro to phil time' piece.
Posted by Jonathan Tallant on September 08, 2011 at 03:39 AM | Permalink
What is it that makes it true that dinosaurs used to exist? Their bones are (presently) in the ground and museums. We extrapolate along lines of causality and infer they used to exist. So the truthmakers are the (present) bones and our (present) extrapolations.
Paul Merriam |
September 09, 2011 at 02:02 PM
Why do you believe so strongly in special relativity? If, for instance, the following "paradox" is in fact an absurdity, special relativity is false and you can safely say 'I am a presentist':
"The bug-rivet paradox is a variation on the twin paradox and is similar to the pole-barn paradox.....The end of the rivet hits the bottom of the hole before the head of the rivet hits the wall. So it looks like the bug is squashed.....All this is nonsense from the bug's point of view. The rivet head hits the wall when the rivet end is just 0.35 cm down in the hole! The rivet doesn't get close to the bug....The paradox is not resolved."
Pentcho Valev firstname.lastname@example.org
Pentcho Valev |
September 09, 2011 at 02:21 PM
You can also get convinced that special relativity is false by imagining an observer that suddenly starts moving towards the light source. Obviously the frequency and the speed of the light wave (relative to the observer) increase:
Professor George N. Gibson, University of Connecticut: "However, if either the source or the observer is moving, things change. This is called the Doppler effect. (...) To understand the moving observer, imagine you are in a motorboat on the ocean. If you are not moving, the boat will bob up and down with a certain frequency determined by the ocean waves coming in. However, imagine that you are moving into the waves fairly quickly. You will find that you bob up and down more rapidly, because you hit the crests of the waves sooner than if you were not moving. So, the frequency of the waves appears to be higher to you than if you were not moving. Notice, THE WAVES THEMSELVES HAVE NOT CHANGED, only your experience of them. Nevertheless, you would say that the frequency has increased. Now imagine that you are returning to shore, and so you are traveling in the same direction as the waves. In this case, the waves may still overtake you, but AT A MUCH SLOWER RATE - you will bob up and down more slowly. In fact, if you travel with exactly the same speed as the waves, you will not bob up and down at all. The same thing is true for sound waves, or ANY OTHER WAVES. If you are moving into a wave, its frequency will appear to you to be higher, while if you are traveling in the same direction as the waves, their frequency will appear to be lower. The formula for the frequency that the observer will detect depends on the speed of the observer - the larger the speed the greater the effect. If we call the speed of the observer, Vo, the frequency the observer detects will be: f'=f(1+Vo/Vwave). Here, f is the original frequency and Vwave is the speed of the wave."
"vO is the velocity of an observer moving towards the source. This velocity is independent of the motion of the source. Hence, the velocity of waves relative to the observer is c + vO. (...) The motion of an observer does not alter the wavelength. The increase in frequency is a result of the observer encountering more wavelengths in a given time."
Roger Barlow: "Now suppose the source is fixed but the observer is moving towards the source, with speed v. In time t, ct/(lambda) waves pass a fixed point. A moving point adds another vt/(lambda). So f'=(c+v)/(lambda)."
"La variation de la fréquence observée lorsqu'il y a mouvement relatif entre la source et l'observateur est appelée effet Doppler. (...) 6. Source immobile - Observateur en mouvement: La distance entre les crêtes, la longueur d'onde lambda ne change pas. Mais la vitesse des crêtes par rapport à l'observateur change !"
The Invalidation of a Sacred Principle of Modern Physics
Stephan J.G. Gift
"For a stationary observer O, the stationary light source S emits light at speed c, wavelength Lo, and frequency Fo given by Fo=c/Lo. If the observer moves toward S at speed v, then again based on classical analysis, the speed of light relative to the moving observer is (c + v) and not c as required by Einstein's law of light propagation. Hence the observer intercepts wave-fronts of light at a frequency fA, which is higher than Fo, as is observed, and is given by fA = (c+v)/Lo > Fo. (...) In light of this elementary result invalidating STR, it is difficult to understand why this invalid theory has been (and continues to be) accepted for the past 100 years."
Pentcho Valev |
September 09, 2011 at 03:55 PM
I'm currently attending the Colorado Summer Seminar, and have been enjoying lectures by Brad Monton, a philosopher of physics. Brad talked about the STR objection to presentism, and seemed disappointed that no philosophers seem to mention that SR is false.
Posted by: Justin Snedegar | July 22, 2007 at 04:02 AM
George Orwell: "Crimestop means the faculty of stopping short, as though by instinct, at the threshold of any dangerous thought. It includes the power of not grasping analogies, of failing to perceive logical errors, of misunderstanding the simplest arguments if they are inimical to Ingsoc, and of being bored or repelled by any train of thought which is capable of leading in a heretical direction. Crimestop, in short, means protective stupidity."
Pentcho Valev |
September 16, 2011 at 04:45 AM
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