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Daryl wrote:A random late at night thought of mine was -
If a hollow core starship was transparent, travelling at 0.8 C, a kilometre long, and some one shone a torch (flash light) from the back to an observer at the front, what would be seen?
My take is that the observer in the ship would see normal light travelling at C; while an external observer would also see light travelling at C, but it would be frequency shifted.

tlb wrote:

Daryl wrote:A random late at night thought of mine was -
If a hollow core starship was transparent, travelling at 0.8 C, a kilometre long, and some one shone a torch (flash light) from the back to an observer at the front, what would be seen?
My take is that the observer in the ship would see normal light travelling at C; while an external observer would also see light travelling at C, but it would be frequency shifted.

Exactly, light is always seen to travel at c; it is only the frequency that changed based on whether you are stationary compared to the source (as when both are on the ship, so wavelength the same) or moving compared to the source (the external observer, so wavelength longer or shorter).

Theemile wrote:Light always travels at C In a Vacuum. It travels slower in other media (due to interactions with the media).

Daryl wrote:A random late at night thought of mine was -
If a hollow core starship was transparent, travelling at 0.8 C, a kilometre long, and some one shone a torch (flash light) from the back to an observer at the front, what would be seen?
My take is that the observer in the ship would see normal light travelling at C; while an external observer would also see light travelling at C, but it would be frequency shifted.

cthia wrote:And you can definitely count on the first unveiling of this acceleration to be devastating, catching a defender off-guard. The range at the moment the missile goes "supernova" will catch all evasive maneuvers off guard. And remember, even though the launch won't be as good as Lays Potato Chips, you will only need to eat just one.

ThinksMarkedly wrote:What does the acceleration have to do with anything? The missile is ballistic at the end, meaning it's moving at constant speed and direction.

cthia wrote:And another thing, totally unlike when a missile goes ballistic and you don't know where it is. In this case when a missile goes supernova, you may not realize that it has gone supernova. And possibly neither will your sensors and defensive systems realize what is coming if it can no longer detect a launch that is now traveling at such speeds.

"WTF? Did it just go ballistic?"

Uh uh.

ThinksMarkedly wrote:More like "WTF are you talking about?"

A missile that goes ballistic is a hunk of metal and molycircs that is going on a very, very predictable pattern.

In some other Sci-Fi, I've seen missiles that consume themselves by converting into plasma and held by some sort of magnetic field so they don't dissipate immediately. At that point, the plasma is indeed moving ballistically and can't change direction. And since it's just a ball of ionised gas, it can't be shot down either. The only defence against those is to not be where it'll be.

But that's even more detectable than a rail gun round, because plasma is radiating energy away.

ThinksMarkedly wrote:The relativistic mass is on the eye of the beholder because of time dilation and space contraction. On its own frame of reference, the ship can continue to accelerate at 500 gravities, but it gets no closer to the speed of light. But another observer would see it accelerating less and less. If the force is constant, then the reduction is acceleration is explained classically by an increase in mass.

This all assumes that the acceleration imparted by the wedge does not, after all, depend on some other, non-local frame of reference. Unfortunately, we do have evidence that there is another frame of reference that matters, because ships can't enter hyperspace at above 0.3c. That and the fact that the spider drive works by pulling on and pushing the hyperwall leads to the conclusion that the hyperwall is a physical thing. Since the impellers do draw energy from hyperspace through the hyperwall, the acceleration that they can impart may depend on the relative velocity of the wedge and the wall.

But if it did, we'd still see relativistic effects, just inverted. If a ship could maintain 500 gravities indefinitely from the point of view of an observer at rest relative to the hyperwall, then the observer aboard the ship should be seeing the acceleration increase as the speed goes up. This also leads to the theoretical possibility of going faster than light, if not a practical one.

cthia wrote:Not only that, but time slows as C is approached. At what point would the observer observe the missiles' approach (speed) to suddenly cease?

I did some related work with the equations when I was researching the Schwarzschild radius of a black hole. The physics gets a little hinky at C.

So I am uncertain that HV sensors will operate appropriately at such enormous accelerations, as is. Just like Peep point defense shut down at the first sign of blossoming images of Manty missile tracks. The sensors simply might not be up to the task of accurately reporting what they "see." Even if the sensors don't just hiccup.

tlb wrote:<snip>

What I do not understand about what you are saying:
I do not remember anything from college Physics classes that said as an object's speed increases, time will slow and so the object will appear to stop to an outside observer. As I remember it, the Lorentz-FitzGerald contraction acts on space and not on time.

tlb wrote:What I do not understand about what you are saying:
I do not remember anything from college Physics classes that said as an object's speed increases, time will slow and so the object will appear to stop to an outside observer. As I remember it, the Lorentz-FitzGerald contraction acts on space and not on time.

Theemile wrote:INTERNALLY time will slow as you approach C, with time flowing "normally" externally.

Called the Twins paradox, a young twin accelerated to near C will barely age, but will return to find an old twin waiting for him.

OR vice versa, from the perspective of the object moving at C, the external time seems to speed up.

cthia wrote:Indeed, but I am considering a missile that has a turbo mode that kicks in right before its final run which quickly accelerates the missile from .8C to damn near light speed. Thousands of missiles accelerating to just under the speed of light at those ranges will be unavoidable once they commit.

cthia wrote:Not only that, but time slows as C is approached. At what point would the observer observe the missiles' approach (speed) to suddenly cease?

I did some related work with the equations when I was researching the Schwarzschild radius of a black hole. The physics gets a little hinky at C.

So I am uncertain that HV sensors will operate appropriately at such enormous accelerations, as is. Just like Peep point defense shut down at the first sign of blossoming images of Manty missile tracks. The sensors simply might not be up to the task of accurately reporting what they "see." Even if the sensors don't just hiccup.