XPost: sci.astro   
   From: '''newspam'''@nonad.co.uk   
      
   On 05/02/2026 06:23, Jan Panteltje wrote:   
   >> Thomas 'PointedEars' Lahn wrote:   
   >> However, our universe is expanding, and there are points whose distance from   
   >> each other increases faster than light could propagate between them.  So   
   >> even if our universe would be closed, it would not be possible for light to   
   >> arrive at its point of emission by going around our universe.  Maybe that is   
   >> the reason why this has never been observed.   
   >   
   > Just a simple question, I am no astrofishycist,   
   > is that 'expansion' we observe deduced from the red shifts we measure?   
   > Or brightness of some stars?   
      
   Actually both. Redshifts give the most reliable data at cosmological   
   distances and you can see all the clouds of neutral hydrogen along the   
   like of sight if you find a suitably bright remote quasar. The so-called   
   Lyman forest of absorption lines.   
      
   https://en.wikipedia.org/wiki/Lyman-alpha_forest   
      
   In addition there are also certain stars like a particular class of   
   supernova type IA that due to how they arise go bang at more or less   
   exactly the same total mass every time and so from the lightcurve and   
   it's peak brightness you can work out how far away it is. The brightest   
   of the standard candles these supernovae can outshine their entire host   
   galaxy for a couple of weeks. Catching them early helps astrophysicists   
   pin them down and amateur supernova surveys with CCD cameras assist.   
      
   https://science.nasa.gov/mission/roman-space-telescope/type-ia-supernovae/   
      
   New professional hardware is coming online to speed discovery up.   
      
   There is no way for us to know if the universe itself is infinite or   
   just very very big. There is always going to be a finite limit to the   
   region that we can ever know about (ignoring for the moment that at the   
   greatest distances it is an optically opaque hot plasma now seen as the   
   4K microwave background radiation.   
      
   > How about tired light theory (light slowing down causing redshift)?   
      
   Doesn't really hack it at all. Pauli's phrase "Not even wrong" is   
   probably the kindest description for Le Sage Theory.   
      
   https://en.wikipedia.org/wiki/Not_even_wrong   
      
   > Personally I am with Le Sage theory, for me it explains much, like clocks   
   > slowing down near a heavy object.   
   > I also think 'science' should stop babbling about infinities,   
   > mamaticians doing a divide by zero all the time   
   >   Singularities   
   > There are no 'infinities' in nature!   
   > Something will always break down, give way!   
      
   Curiously you may well be right about that - some apparent infinities in   
   physical theories can be effectively magicked away by the right use of   
   mathematics (aka renormalisation theory). QCD depends on it.   
      
   > And Le Sage does explain some internal heating of stellar objects, say Pluto   
   for example.   
   >   https://en.wikipedia.org/wiki/Le_Sage%27s_theory_of_gravitation   
   > In short, we need a MECHANISM to explain things, like we need ELECTRONS in   
   electronics   
   > Not math and Spices   
      
   Mathematics *is the tool* for explaining physics - hand waving woolly   
   word salad has no predictive power and is fundamentally untestable.   
      
   --   
   Martin Brown   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)