The EXACTO Sniper Rifle Program

[Raellus]

Originally Posted by Targan

Sure, but in the time that it took him to work out what that impact on his ruck might have been, further thought processes would have been severely disrupted by an acute case of death. I guess what I'm trying to say is, in hindsight it might seem strange that he didn't react but I suspect he was suffering from what psychologists nowdays refer to as "cognitive dissonance". In the absence of easy to recognise clues, no discernable targets in front of him, possibly no bang or crack or flash, his brain may not have had enough information to reach the correct conclusion about what was happening (at least not in time to react appropriately anyway).

Edit: And now that I think on it further, at what altitude did this engagement take place? The speed of sound is different at altitude compared to at sea level. Up in the mountains would the round still be travelling fast enough to break the sound barrier? Is the speed of sound higher or lower at higher altitudes? (Embarassing, I should know this off the top of my head but I've just finished a very tough day at work and my brain is completely fried).

That makes sense. I still wonder what was going through that poor sod's head, though. I figure he must have been on a mountainside trail with a steep wall of rock on one side and a sheer drop-off on the other (i.e. no cover).

I would also imagine that even at a mile or so away, the sound of a .50 firing would be audible, especially at high altitude. The atmosphere would be thinner and air pressure lower up there- wouldn't make the bullet and/or sound waves travel further and faster? It's been quite a while since I took physics.

[pmulcahy11b]

Originally Posted by Raellus

I would also imagine that even at a mile or so away, the sound of a .50 firing would be audible, especially at high altitude. The atmosphere would be thinner and air pressure lower up there- wouldn't make the bullet and/or sound waves travel further and faster? It's been quite a while since I took physics.

The bullet would retain velocity for a longer period, but the sound would propagate less well -- sound needs a medium to travel through. It's why "in space, no one can hear you scream" -- there's virtually nothing up there for sound waves to propagate through. Or conversely, why whalesong can travel for thousands of miles -- the water is a denser medium and allows sound waves to propagate faster and further.