I have a theory about Light speed. In the novel I am currently working on, when a ship breaks the speed of Light, a Photonic "Boom" is created in much the way of a Sonic Boom. However, I am not sure of the feasibility of this and I also would like some idea as to how I could pull this off without it being the Star trek "Warp Flash". I had thought of the Ship suddenly emitting all the colours of the spectrum as it Breacks the Light barrier, but does anyone have any better suggestions?
Modern physics is currently struggling with the idea of multiple dimensions and "variable speed of light" in the earliest moments of the Big Bang. You should spend quite a bit of time reading about these themes and develop your premise after absorbing some of the details. Ultimately, the effects are entirely up to the writer, but if readers are to be able to suspend their RL belief systems and enjoy the fable, then you need to help them with some kind of reasonable stretch of imagination. Here is a premise I am using in a current sci-fi series: At this time in OUR universe, the speed of light is a barrier to long distance travel. As any object approaches the speed of light, it's mass increases with velocity until there is a theoretical conversion of all the mass into light...and the velocity of this light would still be limited to its present day speed. Therefore, it would take 4.3 years to reach the closest star, Proxima Centauri. With this speed limit (even if it was achievable), intra-galactic travel would be impossible, much less inter-galactic travel. So, how do I plan to breech this barrier? A parallel universe, existing in superimposed dimension, might very well have different "physics" than our own. Perhaps, long distance space travel can be accomplished by "warping" into the parallel environment where distances can be traversed at much higher velocity. Upon arriving at the destination coordinates, a vessel slips back into our space-time continuum, where only a few hours have passed. If you used a similar mechanism, then you would only have to decide what residual effects might be viewed in this space-time continuum as your vessel makes these jumps. The special effects are entirely up to the writer...and the willingness of the reader to believe such representations.
I'm not sure if you are referring to a "Boom" as in sound, or as in some sort of light show/visual effect. If it's the former you have a problem, I think. I'm admittedly not very good at the scientific stuff, but I am sure that sound waves can't travel in the vacuum of space. I don't know if initiating the jump into "light speed" changes the physics of the surrounding area. Maybe you could invent something to this effect? One thing that always got me was the sounds of explosions when a ship exploded/was destroyed on Star Trek. The only way this could be accomplished is if another ship picked up the brief sound from the interior of the exploding vessel. You could be referring to the sound heard from the interior of the vessel jumping to light-speed. It was hard for me to tell from the way your question was posed. Even still, I don't think a "boom" could be heard.
You cannot accelerate past the speed of light. Period. The closest thing to your "photonic boom" is Cherenkov radiation, but despite appearances, the speed of light remains inviolate even there. If you're writing fantasy, you can ignore physical laws. Science fiction, however, should not break fundamental laws of physics. You can stride through unknown territory, but the limiting nature of teh speed of light is not simply an isolated law. Throw it away, and half of modern physics goes with it. If you can bypass space (hyperspace jumps, wormholes...). you're in unknown territory and can speculate pretty freely. Buty forget about exceeding the speed of light in normal space. Really.
As Cognito said, the speed of light is fixed point and if you try to "break" it without using something like H-space you're going to make your readers shake their head at you. Do a research into "hyperdrive" and "warp drive" and learn the differences between them before taking another step. Yes, while you can make a lot of things up in sci-fi and fantasy, some things you just can't change. So, go do a little bit a research and get your head around the issues at hand before making an idea to circumvent it.
You know. When NaCl mentioned seeing the effects of a jump from the point of view of our dimension the first thing that popped into my mind was the Flying Dutchman. With that kind of thing you've got all sorts of possibilities for ghost ships.
I'm going to assume that fantasy plays a large role here. What if the boom was actually trans-dimensional waves the extended out from the craft like ripples in a pond? You can show how the waves bend the space/time fabric along the way. Anything caught in the Ripple Effect is thrust in and out of other dimensions till the ripples pass. I love fantasy!