Sagittarius A-Star's latest activity
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Sagittarius A-Star replied to the thread Undergrad Could the (SR) forbidden photon's own referential mean something?.It makes no sence to speak of the perspective of a photon because a rest-frame of a photon does not exist. -
Sagittarius A-Star reacted to Roberto Pavani's post in the thread Undergrad Why is gravity a fictitious force? with
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I agree that in GR free-falling particles follow geodesics and experience no force by definition. My point was simpler (for... -
Sagittarius A-Star replied to the thread Undergrad Why is gravity a fictitious force?.If small bodies follow their geodesics, that is in GR not considered as an interaction force. Consider in flat spacetime two small... -
Sagittarius A-Star replied to the thread Undergrad Why is gravity a fictitious force?.That are in GR not gravitational interaction forces but electric forces within the extended object. -
Sagittarius A-Star replied to the thread Undergrad The effect of a radio wave on an electron.That's almost correct. It moves a distance ##a (1 \text{s})^2## ahead. Please see above. -
Sagittarius A-Star replied to the thread Undergrad The effect of a radio wave on an electron.That's wrong. Besides the fact, that the physical units on the left and right side of the equation are different, ##x(2s)## cannot be... -
Sagittarius A-Star replied to the thread Undergrad The effect of a radio wave on an electron.That would be in average the case for electrons in a resistor, but in the OP screenshot, the electron is - according to the problem - in... -
Sagittarius A-Star replied to the thread Undergrad The effect of a radio wave on an electron.##v(t) = \dfrac{a_0}{\omega} (1 -\cos\omega t)## Assume you repeat periodically: accelerate your car from 0 mph to 65 mph, then press... -
Sagittarius A-Star reacted to Roberto Pavani's post in the thread High School A question about special relativity with
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A.T. gave an excellent answer in post #2, but perhaps the original question was even simpler than we made it: if a clock moves fast... -
Sagittarius A-Star reacted to A.T.'s post in the thread High School A question about special relativity with
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It should be noted that no matter what the axis of the local motion in the rocket is, over an entire local motion cycle it is slowed by... -
Sagittarius A-Star reacted to DennisN's post in the thread Anyone like “2001: A Space Odyssey?” with
Informative.
Oh yes, he was a remarkable filmmaker! :smile: And I also like Barry Lyndon and The Shining. By the way, by coincidence a friend of... -
Sagittarius A-Star replied to the thread High School A question about special relativity.The calculation result depends on the direction of movement of things in the moving frame. Assume the two coordinate systems in... -
Sagittarius A-Star replied to the thread High School Do Dark Energy and the Casimir effect indicate Exotic Matter could exist?.The relativity (kinematics) chapter of Morins classical mechanics book is also online available... -
Sagittarius A-Star reacted to Demystifier's post in the thread Graduate Six Textbook Mistakes in Quantum Field Theory with
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I joined this forum soon after writing this paper, so this is how I have chosen my name. :smile: -
Sagittarius A-Star reacted to SiennaTheGr8's post in the thread High School Lorentz Transformation of Electric & Magnetic Fields Visualized with
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I've made some more improvements to this app, including: Made the two-column desktop layout more convenient: the visualization remains...