Recent content by Elroch

  1. Elroch

    I A one-way twin paradox

    I am glad it was not inadvertently objectionable! You achieve a very good tone in your contributions.
  2. Elroch

    I A one-way twin paradox

    Yes, while that was key, it is worth emphasising. It is of course only possible for the proper times to be different in the two diagrams because they start at different points in the lives of the twins (or they are different pairs of twins). You rightly draw attention to something that I should...
  3. Elroch

    I How to prove that some fields are different aspects of one general field?

    Not quite. A new theory must give predictions (what you meant by "results"?) that are compatible with the existing empirical data to within experimental uncertainty. These predictions way well be slightly different to those of an existing theory that is also compatible (to within experimental...
  4. Elroch

    I A one-way twin paradox

    I don't have any problem agreeing with your unambiguous statements. "their starting ages are frame dependent" "there is always of which was born first according to any given pair of synchronized clocks at the events" " different pairs of synchronized clocks at the births disagree on their...
  5. Elroch

    I A one-way twin paradox

    Yes. But if they are essentially stationary relative to each other there is an objective answer to the question of which was born first according to either of the clocks they carry with them (because these clocks run at the same speed and can be synchronised at any time in a unique, consistent...
  6. Elroch

    I A one-way twin paradox

    There is an objective answer to the question of whether A or B is younger (age in proper time) when they meet. Thus, with all due respect, this answer simply cannot be frame dependent. With the planets having relative velocity zero and with the watches being synchronised (by say one twin sending...
  7. Elroch

    Can a cornering motorcycle go faster if the rider puts a knee down?

    Yes, I made my post more precise as you were posting! The reason for referencing the rider's anatomy was that back somewhere in this discussion we were discussing a claim that a rider had to rest their head on something. The tilt of the rider's head in your penultimate photo makes some of this...
  8. Elroch

    Can a cornering motorcycle go faster if the rider puts a knee down?

    You agree the 2g ( (1+k)*g in my post), as measured by an accelerometer on the rider say, is near enough along your blue line (presuming that goes through the centre of gravity).
  9. Elroch

    Can a cornering motorcycle go faster if the rider puts a knee down?

    Do you accept the point that if you pick your frame moving with the bike, so that the plane through the points of contact and the centre of gravity is considered as "vertical", then in this frame, the artificial centrifugal force (which results from the fact that the frame is rotating) and the...
  10. Elroch

    Can a cornering motorcycle go faster if the rider puts a knee down?

    Yes, but you can combine gravity and centrifugal force (the fictitious force in the non-intertial frame of reference is the relevant one), as I did earlier. A consequence is that the angle of the road changes. For a bike, this force is along the line between the tyre's contact with the road and...
  11. Elroch

    Can a cornering motorcycle go faster if the rider puts a knee down?

    Short answer: not correctly! Long answer leaves me skeptical for a different reason. For a car, in the frame where the road is horizontal, you can think of the component of the centrifugal force that is perpendicular to the road as being an increment k * g to gravity so g is replaced by g * (1 +...
  12. Elroch

    Can a cornering motorcycle go faster if the rider puts a knee down?

    This cannot be strictly true. The sideways component of the force is of the order of 1.5 g, because it is limited by the friction of the tyres on the road. See https://www.f1technical.net/forum/viewtopic.php?t=20627 for data for F1. The support would make it a lot more comfortable and less...
  13. Elroch

    A Dark matter and energy explained by negative mass

    If the net mass is positive, all the masses (both negative and positive) would gravitate towards the centre of mass, at which point you can imagine the (positive) total net mass existing. While this is an imprecise description, I think it might clarify the issue.
  14. Elroch

    A Dark matter and energy explained by negative mass

    Well, both particles accelerate in the direction of the positive mass particle but, if the masses are equal, their relative velocity remains constant. So, given your description, they get further apart. The distance between them is thus O(time) and the interaction forces and the accelerations...
  15. Elroch

    A Dark matter and energy explained by negative mass

    No, I was referring to the inverse square law of gravitation which determines the acceleration of the each of the two particles just like for positive masses, except both accelerations are in the same direction. This law gets very accurate as two objects move apart in general relativity (it's...
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