Time Dilation

Bill Woods wrote:

Lord Skimper wrote:What about the wormhole junctions though. The 3 or so seconds in the transition would be how many years or days or what?

Oh well, someone losing a few seconds several times a day is losing, say
10 sec/day * 360 days/year = 3600 sec/year = 1 hour per year.
Over the course of a 100-year career, that's about four days.

IIRC the wormhole duration was described as sobering like 'an instant that couldn't be measured in any clock' and 'instantly'

So I don't think there's any measurable elapsed time.

But I assume (because nothing to the contrary has been mentioned) that people don't experience any time dilation (or loss) in a transit. However Honorverse wormholes are powered by plot; so they work however RFC wants them to. They don't really appear to correspond to hypothetical real physics wormholes. If he wants them to have relativistic effects then they would...

Lord Skimper wrote:Also wondering about missiles as they fly passed at fairly high rates of speed they must be having time dilation on their systems, computing, and responding to commands etc.... Even with Apollo FTL comms the message to the missile would have to be very short and the response time of the missile would be tiny. I'm surprised missile can hit anything at all, rather than the Manticorian missiles missing or hitting two ships when they meant to all miss is astounding. And before Laser heads even more astounding. Counter missiles even more so.

Don't forget, before the MDM a missile could only achieve about 0.25-0.3c from a standing start. Executing a c-fractional strike (0.9+c) required the launch ship to get up to 0.7-0.8c before firing.

Dafmeister wrote:
Don't forget, before the MDM a missile could only achieve about 0.25-0.3c from a standing start. Executing a c-fractional strike (0.9+c) required the launch ship to get up to 0.7-0.8c before firing.

i think you're misremembering. That's more like a single drive missile.

An MDM, accelerating a 48,000g for nine minutes, can approach 0.84c (That's the Newtonian accel formula; I didn't bother calculating ithe relativistic ones, which would come out a bit lower)

Lord Skimper wrote:Also wondering about missiles as they fly passed at fairly high rates of speed they must be having time dilation on their systems, computing, and responding to commands etc.... Even with Apollo FTL comms the message to the missile would have to be very short and the response time of the missile would be tiny. I'm surprised missile can hit anything at all, rather than the Manticorian missiles missing or hitting two ships when they meant to all miss is astounding. And before Laser heads even more astounding. Counter missiles even more so.

What you're talking about is the most difficult part of the tech in the Honorverse, because of the near relativistic speeds of the missiles; it's also why I tend to not have as much trouble with the "one channel per missile" origins in the early books; tracking a missile at near-relativistic speeds and hitting it with any kind of useful electronic instruction is by necessity a copperplated -itch. Part of the idea is that due to the distances, it's still a fairly straight line to all of the missiles in a salvo, and each missile knows which signal to pick out of the mix, with what would be AD2015 "supercomputer" capacity targeting in the missiles themselves. The difficulty for those computers is trying to go up against PD19XX supercomputers on the ships trying to electronically fool those missiles into a slight miss (less than 1/200 of a degree), then hitting them with super-significant armor busting energy hits.

Then again this is science fiction, in which case not every physics problem is pronounced solved, but at least RFC/MWW's "math" tends to be consistently applied and not "sudden plot wavium" at the deux ex machina level. Perhaps the biggest bit of wavium is lessened by Honor's battle "survivor's guilt": the number of time that the bridge she was on suffered super-significant fatalities or injuries from which she emerged relatively unscathed (War Maiden, Nike, Wayfarer, , her runabout at the end of AoV etc.) or where ships in the same formation/size class as hers were blown to bits where hers survived.

Lord Skimper wrote:What about the wormhole junctions though. The 3 or so seconds in the transition would be how many years or days or what?

Transition through a wormhole takes zero seconds. No time passes at all. It is instantaneous. I'm really not sure how you can not know this--it is explicitly stated several times thoughout the books.

Lord Skimper wrote:Also wondering about missiles as they fly passed at fairly high rates of speed they must be having time dilation on their systems, computing, and responding to commands etc.... Even with Apollo FTL comms the message to the missile would have to be very short and the response time of the missile would be tiny. I'm surprised missile can hit anything at all, rather than the Manticorian missiles missing or hitting two ships when they meant to all miss is astounding. And before Laser heads even more astounding. Counter missiles even more so.

Yes, missiles do experience time dilation. The text even mentions this! But this does not have any deleterious effect on the accuracy of the missiles. From the point of view of the missile, the rest of the universe slows down, so the missile has lots of time to take it's sensor readings and adjust course. Messages which are received time-dilated can be easily slowed down in processing. It doesn't cause a problem.

SWM wrote:

Lord Skimper wrote:Also wondering about missiles as they fly passed at fairly high rates of speed they must be having time dilation on their systems, computing, and responding to commands etc.... Even with Apollo FTL comms the message to the missile would have to be very short and the response time of the missile would be tiny. I'm surprised missile can hit anything at all, rather than the Manticorian missiles missing or hitting two ships when they meant to all miss is astounding. And before Laser heads even more astounding. Counter missiles even more so.

Yes, missiles do experience time dilation. The text even mentions this! But this does not have any deleterious effect on the accuracy of the missiles. From the point of view of the missile, the rest of the universe slows down, so the missile has lots of time to take it's sensor readings and adjust course. Messages which are received time-dilated can be easily slowed down in processing. It doesn't cause a problem.

In the rest frame of the missile, the rest of the universe slows down, but it also gets squashed, so the window in which the missile has to fire still shrinks.

Jonathan_S wrote:

Dafmeister wrote:
Don't forget, before the MDM a missile could only achieve about 0.25-0.3c from a standing start. Executing a c-fractional strike (0.9+c) required the launch ship to get up to 0.7-0.8c before firing.

i think you're misremembering. That's more like a single drive missile.

Well, he said, "before the MDM".

Jonathan_S wrote: An MDM, accelerating a 48,000g for nine minutes, can approach 0.84c (That's the Newtonian accel formula; I didn't bother calculating ithe relativistic ones, which would come out a bit lower)

It'll reach 0.69c, if that's 9 minutes by the clock on the missile;
or else 0.65c, if that's 9 minutes by the clock on the ship that launched it.

Bill Woods wrote:

Dafmeister wrote:
Don't forget, before the MDM a missile could only achieve about 0.25-0.3c from a standing start. Executing a c-fractional strike (0.9+c) required the launch ship to get up to 0.7-0.8c before firing.

Jonathan_S wrote:i think you're misremembering. That's more like a single drive missile.

Well, he said, "before the MDM".

Jonathan_S wrote: An MDM, accelerating a 48,000g for nine minutes, can approach 0.84c (That's the Newtonian accel formula; I didn't bother calculating ithe relativistic ones, which would come out a bit lower)

It'll reach 0.69c, if that's 9 minutes by the clock on the missile;
or else 0.65c, if that's 9 minutes by the clock on the ship that launched it.

Oops, I misread that; I blame the phone;)
Thanks for posting that out and doing the calculations. (I assume it's be 9 minutes on the missile's 'clock' since its limited by burnout of the missile's drive nodes. And they're in its reference frame.

SWM wrote:

Lord Skimper wrote:Also wondering about missiles as they fly passed at fairly high rates of speed they must be having time dilation on their systems, computing, and responding to commands etc.... Even with Apollo FTL comms the message to the missile would have to be very short and the response time of the missile would be tiny. I'm surprised missile can hit anything at all, rather than the Manticorian missiles missing or hitting two ships when they meant to all miss is astounding. And before Laser heads even more astounding. Counter missiles even more so.

Yes, missiles do experience time dilation. The text even mentions this! But this does not have any deleterious effect on the accuracy of the missiles. From the point of view of the missile, the rest of the universe slows down, so the missile has lots of time to take it's sensor readings and adjust course. Messages which are received time-dilated can be easily slowed down in processing. It doesn't cause a problem.

I would think a missile flying at a high fraction of c would experience a 'slow down' of its own internal clock.

To me it would seem like this would be a disadvantage in terms of 'reaction speed' to anything happening in the rest of the universe, since the missile would get less computing time to respond and its responses would be slower. (Overall I don't think its a big deal during approach, but may make the firing solution harder at the end).