Phyti interpretation of Mac's #905;-If the charges are approx. adjacent at the origin, as I thought your original proposal, then they would be simultaneous (as if one explosion) in their frame and all other frames.
Phyti Post: "When James included fuses 3m in length, then the spatial separation allows for simultaneity differences between frames. There will be a drawing relating to simultaneity in a separate post."
Yes absolutely. What James, Billy T and others seem to want to ignore is that this situation has a component not of standard relativity of simultaneity.
Relativity of Simultaneity affects:
1 - Distance causes a shift in apparent timing with or without velocity. It affects things in two ways. Ground and craft clocks have been synchronized:
a - If a blast occured at 12 noon in the local TNT frame it might appear to have occured at 12:01PM at 1 light minute distance but will appear to have occured 40 years, 309 days, 2 hours, 10 minutes, 9 seconds later according to sound if at common rest. Motion however would affect the sound aspect of relativity of simultaneity in this case.
b - If the blast occured at 1 PM in the local TNT frame but that frame had achieved an inertial velocity relative to the ground frame then the craft clock has been ticking more lowly than the ground clock and in addition to the relativity of simultaneity caused by distance you have time dilated clocks reading different accumulated times and the additional shift depends on the duration of the relative velocity to the ground rest frame.
So the fuse length does generate some relativity of simultaneity affects but this scenario is to show an additional affect which is NOT relativity of simultaneity in spite of James R or Billy T's trying to ignore it and just talk about relativity of simultaneity as though that is the answer.
-The moving flame is an illusion. Each molecule in the fuse moves at v, the speed of the frame, until it disappears in a cloud of combustion by-products. The 'burn line' is just a sequence of events, and events don't move. The 'addition' formula determines the relative speed of a
moving mass based on the speed as calculated by a 2nd frame. There is no
inertially moving mass except the charges and fuses, and the by-products
are dispersed at random. SR didn't invoke it, James did.
Velocity Addition
2 - I have to disagree. James R is correct to compute the flame speed but not to arguing about it and still invoke the affect I sought it expose, consider the TNT's don't have fuses but primer charges and you use two bullets fired simultaneously in the TNT frame to cause detonation.
Those bullets are mass and clearly fall within the velocity addition claim.
Now you have not only the distance between the gun to the TNT (equivelent of a fuse length) but you have the rate of detonation changed. This shifts detonation locally by more than just the distanceof the fuse.
I agree some of it is illusory but object more to the interpretation in magical terms, which is in contradiction to the 'rules of physics' postulate. The procedures, i.e. transformations are taken too literally. In its defense, it does agree with observations, despite its lack of explaining itself.
Only partially correct. It has good utility at predicting results but only when you stipulate who has motion based on actual physics. That is the SR claim that James makes about reciprocity of time dilation and length contraction being physically real is not supported by emperical data.
Both observers see each other as dilated and that is what SR claims but for those that add words to Einstein's mouth and claim that is physical reality have done him no favor because it is not true and is not supported and is totally assinine physics.
The only thing actually emperically supported and logically possible is the dilation of a clock that switched frames (i.e. - accelerated and achieved actual velocity to an inertial rest frame.). The clock in the common rest frame NEVER becomes dilated physicallym even though it may appear dilated during relative veloicty.
Billy T's arguement that neither length contraction nor time dilation are physically real is equally flawed in that an accelerated clock will display less accumulated time subsequent to having had relative veloicty to the resting clock when compared in tthe common rest frame.
To produce a real physical change there must be a real physical cause.
That being the case one must now decide is it length contraction according to SR or is it time dilation of clocks.
A change in velocity is a change in energy and hence makes some sense that that might affect atomic vibrations or ticks of a clock.
A changing of distance by length contraction however produces several unacceptable consequences such as getting closer to something the faster you receed.
Therefore whicle either can cause the observed dilation of the clock it seems time dilation is the more logical choice for physics to consider.
That being the case one can then see that when timing a trip the physically dilated conditon of the traveling clock fully accounts for the accumulated time of the trip and NO length contraction can exist.
That is OK since it conforms with observation since length contraction has never been recorded and certainly does not exist as a physical change subsequent to having had relative veloicty and compared in a common rest frame.
Hope this clarifies my views.