Theemile wrote:Jonathan_S wrote:Your eyes are sensitive enough to green light that the path of most green laser pointers can be seen in normal indoor lighting - just from the stray dust particles they hit in the air. (They're still limited to the same <= 5 mW as any other laser pointer - but your eyes can detect fewer photons in the green spectrum so it's easier to pick out their beams against the brightness of indoor lighting)
Interplanetary space has a lot less dust than the average building's air; but the energy mounts are unfathomably more powerful and range from about 1/3rd of a meter up to around 3 meters in diameter -- so fire them over hundreds of thousands of km and they're going to hit enough particles for sensors to pick up the 'flashes' of that. (Plus as you turn the target's hull into plasma the energy beams will show up clearly through that expanding plasma)
So I'm not surprised that the nearby SLN ships could actually tell that no energy beam had been fired at the station (not that Bing waited for that information before stupidly starting a war)
But those examples all contain photons moving at the visible frequencies - any beam of photons moving at frequencies above or below is not visible (say infrared, radio, or x-rays), and any technology not using photons would not be visible (say Gravity based technologies), unless caused by a secondary effect. While a big part of how we interact with the universe, the visible frequencies are a very small portion of the full EM spectrum.
Jonathan_S wrote:I agree the gravity based technologies wouldn't create that kind of visible scattering/excitation - but I was replying to the side-tangent on energy weapons; which are lasers are grasers. (Though at least once you get up to the power levels of a wedge you can see the grav effects affect ambient photons -- an active impeller wedge "twisted photons into pretzels" [HAE]; and even sidewalls distort and bend the path of photons, so I guess it's possible that at even lower power levels your sensors might be able to notice the acceleration/deflection of photons passing through the grav effect -- should there be any)
And while their x-rays wouldn't scatter like visible wavelengths of light from a laser pointer, as they annihilate space dust, micro-meteorites, and other particles those would emit photons of their own and that's what you'd be seeing.
Certainly the wedge should be seen, or evidence of a wedge because of the highly concentrated gravity affecting photons locally. But I would expect a gravity-based propulsion system deployed by the spider-drive tractors to also be of such a high concentration that there should be a noticeable effect created around local space-time. A concentrated gravitic phenomena is responsible for propelling a massive object like the LD. If the gravitic tractors are akin to steel chains for sake of conversation, they'd have to be very "powerful" chains lest they break. I'd expect there to be some sort of localized distortion. As areas of highly concentrated gravity create a phenomena called frame-dragging in local space-time, which is a very visible effect, as I mentioned in the Attacking Darius thread when discussing infinite mass projectiles. And I think that should be detectable without a complex spider drive detector.
I don't suppose we know the range of the LD's tractors?