I think the problem here is everyone is trying to apply logic where logic (or indeed physics) don't apply.
Indeed:
...you're applying logic and reasoning to something where it actually won't hold up to that kind of scrutiny.
1) Because any completely enveloping system large enough to house a Space Marine would require a prodigious amount of power output.
It's the faaaaar future, my question would be why
aren't there near-unlimited power supplies, at a small scale? Makes as much sense as a lot of the other ridiculous crap in the universe.
2) A continuous shield would prevent necessary oxygen from entering outside the shield.
SF writers have come up with various wrinkles on the idea of a shield that limits high-speed projectiles but provides no barriers to lower-speed penetration (e.g. "The slow blade penetrates the shield.") So air would continuously exchange across the barrier while providing projectile defence.
3) A Flickering shield would more than likely be a technological nightmare to maintain for the duration of a campaign. Thus you're stuck with a continuous shield. Refer to 2.
Only if you decide that's the way it has to be. In our imaginary future it could be just as easy to make as one that runs continuously.
How about one that only flicks into life when high-energy particles that will intersect the space of the wearer are detected (Haldeman?), or one that angles the shield
to deflect the projectile back towards the firer (Banks), or one that forms a shield that encloses the incoming projectile (Einion)?
If you're going to invent things you might as well make it really interesting instead of some hackneyed stuff we've seen in cartoons or comic books for the last 40 years.
A force field wouldn't stop an HE Rocket.
Why not? Because you decide that it won't. Why? Because you decide that it can. The decisions are entirely arbitrary and down to considerations in addition to merely what makes sense on an individual level.
You want to answer a tough one? Why the hell do two lightsabers clash together?
You want a tough one, in personal combat why don't Space Marines use even rudimentary tactics that an experienced FPS shooter without pube one can develop by himself playing in his bedroom?!
:rotfl:
i imagine the whole point of having major shielding is cost. cheaper to train a new soldier than to protect a current one.
Cheaper to educate, feed and house from birth, as well as the cost of his training
and the armour/equipment he's carrying (which there's some assurance will be lost to you, or at least uneconomical to repair)?
Einion