Evidence required for key element - SRT

Ozziemate, you have a really weird of slander and flaming. I don't recall anyone else with so little understanding of what they were talking about being treated so relatively respectfully.
 
It looks like ozziemate is just impressed with the phrase "hypersurface of the present", maybe thinking that "hyper" means important.
The OT in his previous thread on this subject (Help with defining a point - light cones) has an image from the Light cone article in Wikipedia with a label for this hypersurface. The description does not mention the hypersurface
Given an event E, the light cone classifies all events in spacetime into 5 distinct categories:
  • Events on the future light cone of E.
  • Events on the past light cone of E.
  • Events inside the future light cone of E are those which are affected by a material particle emitted at E.
  • Events inside the past light cone of E are those which can emit a material particle and affect what is happening at E.
  • All other events are in the (absolute) elsewhere of E and are those that will never affect and can never be affected by E
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It is easy to see that the hypersurface of the present falls into the last category since all its points except that occupied by the observer are outside the light cones.
 
Vorpal said:
"I find this counter-intuitive, so how do I know it's 'really' that way or just conspires to act that way in all respects?"
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Or, as my dad would always tell me, "The Iliad wasn't written by Homer, but by another man of the same name."
 
Simultaneity is a definition not a physical state, though that definition cannot run afoul of effect preceding cause. The simple logical fact is that if two separated observers cannot agree on the rate of time they cannot agree on the simultaneity of separated events. You even conceded the time dilation in the OP. The relativity of simultaneity simply derived an operational definition that all observers can agree with. The simultaneity of two event at the same point in space are never in question.

SR was derived under the logical positivist school of thought. I don't strictly hold to such a school of thought but its strength is that it remains mathematically valid regardless of what interpretation you put on it. Conceding time dilation but questioning the relativity of simultaneity is a lot like conceding Earth has a surface but questioning whether it has a center or not.
 
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ozziemate said:
IMO SRT has put forward a counter intuitive proposition, that observers at relative velocity do not share the same Hyper surface of the present [ other wise known as "now"] I ask is there evidence to support accepting such a counter intuitive proposition?
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What kind of evidence are you looking for?

Or, let me put it this way: What evidence do you think there is for the proposition that observers in relative motion do share the same notion of "now"? Why is that the intuitive proposition, rather than the opposite one?
 
my_wan said:
Simultaneity is a definition not a physical state, though that definition cannot run afoul of effect preceding cause. The simple logical fact is that if two separated observers cannot agree on the rate of time they cannot agree on the simultaneity of separated events. You even conceded the time dilation in the OP. The relativity of simultaneity simply derived an operational definition that all observers can agree with. The simultaneity of two event at the same point in space are never in question.

SR was derived under the logical positivist school of thought. I don't strictly hold to such a school of thought but its strength is that it remains mathematically valid regardless of what interpretation you put on it. Conceding time dilation but questioning the relativity of simultaneity is a lot like conceding Earth has a surface but questioning whether it has a center or not.
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good counter argument and enquiry thanks...

if evidence can be obtained to support the non-simultaneity of t=thsp of observers at rel. velocity I would be a lot happier.
I am aware that the compounding nature of time dilation would intuitively lead to non-simultaneity however to confirm that non-simultaneity is actual and not merely a theoretical outcome of compounding time dilation effects would make the theory rock solid.
Not finding evidence would not in any way diminish the theory but being thorough would be great.
 
ozziemate said:
good counter argument and enquiry thanks...

if evidence can be obtained to support the non-simultaneity of t=thsp of observers at rel. velocity I would be a lot happier.
I am aware that the compounding nature of time dilation would intuitively lead to non-simultaneity however to confirm that non-simultaneity is actual and not merely a theoretical outcome of compounding time dilation effects would make the theory rock solid.
Not finding evidence would not in any way diminish the theory but being thorough would be great.
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Yes, during to time I was chasing SR in circles to search for holes I much appreciated empirical data in spite of apparent logical consistencies. Here the existence of matter waves is given as direct experimental evidence of the relativity of simultaneity. See the section on De Broglie waves.
http://en.wikibooks.org/wiki/Special_Relativity/Simultaneity,_time_dilation_and_length_contraction

This one is probably easier to follow. This guy goes to great lengths to very pictorially show how Stellar Aberration is a direct observational result of the Relativity of Simultaneity.
http://www.pitt.edu/~jdnorton/Goodies/rel_of_sim/index.html
That is probably the one you need to spend time to understand. If you want a downloadable PDF version go here;
http://philsci-archive.pitt.edu/archive/00002734/
 
my_wan said:
Yes, during to time I was chasing SR in circles to search for holes I much appreciated empirical data in spite of apparent logical consistencies. Here the existence of matter waves is given as direct experimental evidence of the relativity of simultaneity. See the section on De Broglie waves.
http://en.wikibooks.org/wiki/Special_Relativity/Simultaneity,_time_dilation_and_length_contraction

This one is probably easier to follow. This guy goes to great lengths to very pictorially show how Stellar Aberration is a direct observational result of the Relativity of Simultaneity.
http://www.pitt.edu/~jdnorton/Goodies/rel_of_sim/index.html
That is probably the one you need to spend time to understand. If you want a downloadable PDF version go here;
http://philsci-archive.pitt.edu/archive/00002734/
Click to expand...

Brilliant links My wan, fantastic...thanks so much...will take a bit of a read though and the description of Broglie waves is facinating....

Shall get back after a bit of assessment time...thanks again:)
 
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