Reply To: Proliferation?

[Brian H]

Aeronaut wrote: Ok, Brian, this might be a head-scratcher for you. Might not, lol.

I worked a radar in the navy when I wasn’t cleaning and painting. We needed to calculate the bearing, range, and time of each contact’s CPA (Closest Point of Approach) so we could avoid getting run over by ships that were much, much larger. Given that radar is lightspeed, and all motion is relative to my ship, cruising in a long-term straight line at .5C,

1. What frame is each radar pulse in? My ship’s, general space-time, or a contact’s frame?
2. Would a radar even work above .25 or .5C? If so, would it only “see” contacts on the same course and speed?
3. In general, do frames become ever more isolated as the speed becomes more relativistic?

1. Both. But at different frequencies. The pulse is stretched or compressed from the POV of the target, but consistent from your POV.
2. Yes. The pulse does not carry your cruising speed as part of its own velocity, although it seems that way from your viewpoint. It is actually always moving at C in every frame. But the frequency changes to compensate, as does your “clock”.
3. Their isolation is a matter of time stretching and mass. They are not isolated from signals, but the characteristics of the signals alter depending on direction of travel (with or opposed to flight vector).

Those are my understandings. I am not a physicist, however!