In Jack Campbell’s "The Lost Fleet," why do ships exiting a jump point see enemy ships before the enemy sees them?
Hi fellow sci-fi lovers!
I’m reading The Lost Fleet by Jack Campbell, and I love how he tries to keep space combat realistic with light-speed delays and distances. But here’s something that’s confusing me:
When ships exit a jump point, they can immediately see enemy ships that are, say, 2 light-hours away. Yet, those enemy ships only detect the newly arrived ships 2 hours later. Why is that?
For example, here’s a quote from the book:
"The hypernet gate was almost five light-hours away now, so that Syndic flotilla they were just now seeing had arrived five hours ago. But the Syndics in that new strike force had seen the Alliance fleet the moment they arrived, and had already had five hours to size up the situation and make plans."
Is this just how jump points or sensors work in the lore, or is there a physics-based explanation I’m missing?
Edit: Thanks everybody for your answers. I get it now.