Minkowski Light cone and an antique sand watch ( hourglass )
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Minkowski explained the spacetime by using the ''Light cone'' scheme.
   Minkowski light cone
''Light cone in 2D space plus a time dimension.. . , .
A light cone is the path that a flash of light, . . . through spacetime''
(light travel from an enormous  past light cone through a place
of the very tiny present to an enormous future light cone)
     
https://en.wikipedia.org/wiki/Light_cone
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Antique  sand watch ( hourglass )
Sand in hourglass flows from the upper vessel (place of a past)
 through very tiny hole (place of the short present life) to the lower vessel
( place of the future )    / look the picture /
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We can turn over the hourglass and the time will flow vice versa.
Similar: . . .  the light in an absolute Minkowski  spacetime can travel
 backward in time, according to ''The law of conservation and
 transformation of energy-mass''  and  the entropy principle.
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The Minkowski scheme of Light cone has three systems
of coordinate: past, present, future . . . for light traveling
with constant speed the time is ''frozen'' . . . the present
state is the border between past and future . . . light takes
 an important place in the present system . . . .
(from photosynthesis . . . to atoms, cells, living creatures  . . .)
To go from past to future Light must change its parameters
in the present system according to ''The law of conservation
and transformation of energy-mass''. The concrete changes
of quantum of light in the present time were described
  by the ''Lorentz laws of transformation''
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Practically Minkowski ''cone'' is a flat, homogeneous, isotropic.
Mathematically Minkowski ''cone'' is an abstract construction.
 Practically, according to the WMAP (2013 measurement) the
 Cosmic Space is ''pretty flat'' to within 0,4% - 0,5%
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  Minkowski's  kamuflage.
The ''time'' in Einstein's SRT was negative.
Minkowski saw that mathematically it is ''ugly'' and he
 changed negative time into positive time by the beautiful
mathematical construction ''an absolute spacetime-4D ''.
 Minkowski did not create a new theory, he only masked the negative
 time problem, he only masked the reference frame for ''spacetime''. 
 Where can we see the negative time and spacetime in nature?
 The unity of space / time we can only see in the cold cosmic vacuum.
The structure of the cold cosmic vacuum doesn't have ''time''
My conclusion:
 Einstein's SRT (1905) has only one absolute reference frame.
This absolute reference frame. is a cold , flat, homogeneous,
 isotropic cosmic vacuum.
All other reference frames are relative systems.
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Clock's time
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After Newton's work the  world was accepted as a mechanism of clock which showed exactly time to everybody.
After Quantum development Newton's mechanical world ''has gone crazy'',  because the clock became  very strange . . . 1 - two observers looking at the same clock saw different time . . . 2 - the clock never showed the exact time . . . This clock enigma brought Physics to the philosophical reflections, whose solution has not yet been found
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Nature existed before the first neanderthal scientist began to study the problems of ''observation and measurements''. . .   they took nature as it is . . .  but the modern scientists started to doubt  if nature  is real or not: . . . '' Is the moon there when nobody looks? '' . . .  “Everything we call real is made of things that cannot be regarded as real.”  ―  Niels Bohr . . .  in the quantum physics the problem of   ''observation and measurements the known / unknown quantum particle by a clock in a time''   is still unsolved problem 
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I prefer ice cream cones

blindfaith wrote:I prefer ice cream cones

Good appetite

I prefer a lite scone myself. If it’s too lardy the texture is just wrong.