From: nicolaas.vroom@pandora.be   
      
   On Tuesday, 30 July 2019 15:59:35 UTC+2, Sylvia Else  wrote:   
   > On 30/07/2019 4:49 pm, Nicolaas Vroom wrote:   
      
   > >   
   > > If you drop an hourly glass, which internal operation is based on gravity,   
   > > during the fall the internal glass particles will not move towards the   
   > > other container, thereby increasing the cycle time i.e. the time that one   
   > > container becomes empty and the hourly glass has to be turned over. As a   
   > > consequence the hourly glass will run slower (just like a moving clock).   
   >   
   > An hours glass just doesn't work when it is in free fall.   
      
   I agree.   
      
   > While certainly a consequence of physical law, its failure has nothing to do   
   > with the relativistic slowing (in another frame) of an otherwise   
   > functioning clock.   
      
   I comparing performance of an hourly glass with a clock in extreme.   
   That means the hourly glass falls (with an average speed v) and the clock   
   moves almost at the speed of light (c). Result both don't work.   
   However if the speed of the hourly glass is 0.1*v and the speed of the clock   
   0.1*c both will function (operate) however as a clock each will run slower.   
      
   [[Mod. note --   
   In relativity, we need to (implicitly or explicitly) qualify statements   
   of the form "X moves with speed V" with the reference frame with respect   
   to which the speed is defined.  E.g., "if the speed of the hourly [sic]   
   glass is 0.1*v" needs to be expanded into something like "if the speed   
   of the hour glass WITH RESPECT TO SUCH-AND-SUCH AN OBSERVER is 0.1*v".   
      
   And, suitable clocks (e.g., the decay of unstable elementary particles)   
   work just fine when moving almost at the speed of light with respect to   
   a laboratory.   
   -- jt]]   
      
   > > What is also interesting is that the behaviour of a clock is influenced   
   > > by the speed of light (photons) and an hourly glass by the speed of   
   > > gravity (gravitons).   
   > > Both are also influenced by external (temporary induced) forces.   
   >   
   > The behaviour of the clock in a different frame depends on the universal   
   > constant c. Light travels at that speed, but photons are not causing the   
   > relativistic effects.   
      
   Photons are the physical reason that a clock operates i.e. functions   
   as an oscillator and ticks.   
      
   For an hourly glass this are the glass particles. A human is required   
   to take care that the hourly glass becomes an oscillatot i.e. for time keeping.   
      
   > I have no idea what is meant by "induced forces". It sounds like   
   > something that has been made up.   
      
   In order to operate properly, a clock or a hourly glass should stay at rest   
   and not be moved.   
   Moving a clock (or hourly glass) will influence this normal operation.   
   (And the clock will start ticking slower)   
   To move a clock (or hourly glass) you need an external induced (applied?)   
   force. Dropping an hourly glass mimics such a force.   
      
   [[Mod. note -- Again, phrases like "should stay at rest and not be moved"   
   are ambiguous, because they don't specify a reference frame.  For example,   
   does "stay at rest and not be moved" mean (a) "not be moved with respect   
   to a laboratory located at the Earth's south pole"?  Does "stay at rest   
   and not be moved" mean (b) "not be moved with respect to a laboratory   
   located on the Earth's equator"?  (Since the Earth's equator moves at   
   about 460 meters/second relative to the Earth's south pole, it's impossible   
   to be at rest with respect to both of them simultaneously.)   
      
   And that said, some types of clocks (e.g., radioactive decay)   
   	[That is, our "clock" is a mass of some radioactive   
   	isotope, and we measure time by counting decays/second   
   	and using the isotope's known half-life to determine   
   	elapsed time since we set up the clock.]   
   don't need any external forces to operate.   
   -- jt]]   
      
   The same problem exists when you place a chronometer on board of a ship.   
   Special design of such a chronometer is required to minimise the influence   
   of the waves. All of that is physics.   
      
   Nicolaas Vroom   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)