[Wild Goose]

Originally Posted by arkhangelsk

Are you sure that a better explanation is not that the tranquilizer dart still has somewhat more mass, plus a much pointier needle head that allowed it to produce a higher local pressure that allowed it to penetrate where a bullet failed?

Well, it can't be a pointier needle head, because in another episode O'Neill throws his combat knife into a System Lord's hand (either Apophis or Klorel, most definately not Anubis, Sorak or Ba'al); IIRC what happened was that he whipped out his P90, which shoots very pointy 4.7mm AP rounds, fired, it didn't work, he threw his knife and embedded it in the System Lord's hand. Or did he skip the shooting and throw? It's been a while since I saw that episode, but he definately threw the knife into the System Lord's hand. And the knife blade isn't as pointy as a needle.

Mass is possible but depends on the weight of the dart and the type of dart: time to break out the statistics. Commonly-used Pneudarts darts range from 6-14gs (6 being 1ml, 14 being 5ml, fully loaded). A typical 9mm round is 8-9.5 g. On the other hand .45ACP rounds weren't used (typical weight of a military .45 round is 15 g, which is heavier than a pneudart), so we can't really say for sure it's mass. *shrugs* If they were using reusable Cap-Chur darts, then for sure it's a mass issue; Cap-Chur darts range from 7 g to around 18.5 g, much, much heavier than 9mm or 4.7mm rounds.Still, as I said, how does this not work? Even discounting that we don't see mages deflecting bullets with their BJs, we still see here that the swords and Belkan melee weapons, having greater mass and momentum than beams which are primarily energy with lower mass, penetrating the BJ defensive complex to cut the fabric of the barrier jacket. So how does this not make sense?

You can obviously tell that I hate this explanation, at least without a physically logical mechanism (for example, energy-only resistance, weaker to momentum, weaker to pressure are all legitimate).

What about quicksand, which sucks you in faster with the more energy and momentum you use in trying to get out? (Getting this out of the way before someone else says it.)

Anyway, as mentioned above: the tranq darts have greater mass than SMG & PDW rounds. The arrows have greater mass. The KNIFE (a K-bar, IIRC) has greater mass. All went through. Thus it would appear that Goa'uld personal shields, being geared to energy defense, don't do so well against mass weapons.

(Mind you, there's always the possibility that O'Neill's knife went through just because he's that damned badass. It does seem that Stargate has always run on a mix of Sci-fi, plausible science, some applied phlebotium, and TV tropes XD Though I'm actually impressed that they manage to make a fairly cohesive whole with regards to their tech and stuff, unlike Star Trek which is full of contradictions and holes.)

This is because otherwise, such kind of shields are total plot contrivances. They have no real basis in practical engineering. Their only reason to exist is that the author likes swordfighting and needs something to make it look more sensible. And the soldiers do look more sensible given something like this. The price is that the defense makers look like imbeciles - you simply change the question from "Why don't the solidiers use guns" to "Why don't the shieldmakers create useful defenses against this new threat - it is not like it is physically harder?

Well, the Goa'uld shields were geared to defend against energy weapons. Stargate has little to no swordfighting; what melee combat there is consists of hand to hand fighting, mostly amongst unarmored, unshielded charecters (Goa'uld personal shields are really freakin' rare) or knife fights. And most of the time the Tau'ri are perfectly happy to stay at range and fill people with lead.

And as I mentioned above, this all makes sense. The shields are geared to stop energy. They block bullets due to the lower mass of the bullets, but do not block the greater mass of the arrows or knife or tranq darts.

Thus returning to my analogy, the Barrier Jacket's Barrier is set protect against incoming magical energy, probably lasers or beam weapons, and while it may or may not be penetrable by bullets, swords and melee weapons with a significant amount of mass, inertia and momentum to them (especially when compared to a beamspam attack) can get through this Barrier since the Barrier isn't set to filter these threats.

Whaddya know. Magnum Stake just got THAT more viable. I win.

Originally Posted by arkhangelsk

Well, I think it is quite hard to say that they provide much protection physically, but at least so far, we know they do provide protection against gases. It also won't strain physics credibility to say they block energy. They can even block laser light by taking advantage of polarization (it is unlikely the laser's light, which is polarized in a fixed direction, will be of the correct polarization to get through a polarizing barrier).

The BJ did seem to protect Nanoha against Vita's fire magic. Of course, there was probably enough obscuration there to have an active defence, but in the absence of necessity it'll be additional, unjustified complexity.

(However, if in Season 4, a hot pancake starts to melt a Barrier Jacket, we might have to give this a rethink...)

Perhaps this is the real reason why the Belkans weren't annihilated, instead of idiot engineering. By the time they made barrier jackets, everyone has gone "beyond" projectile pea-shooters and are using laser or particle weapons. Note that we see what seems to be particle beams in their Reminiscence of the Past scene, rather than projectile guns like ours. This energy-shielding invention sharply reduced the effectiveness of such weapons.

At the same time, in Velkan society, swords and other melee weapons had been relegated to ceremonial status, a prestige symbol. Then, one day, someone realized that their ceremonial swords can easily slice apart people wearing barrier jackets. Boom, melee society goes up.

Really a little like KOTOR's Energy / Mass sort method, but then, this model is at least justifiable from an engineering viewpoint.

*sighs* This is what I was trying to get across. *sighs* That the BJ protects against magic, thus the swords and the like can get through it. While my original idea of being lower velocity didn't make the cut, the fact that we now have a viable theory means it's all worth it...

*looks up*

...Oi, this is essentially what I was saying! Minus the historical speculations!

EDIT: Damnit Keroko! Let a man reply first! *reads Keroko's post*

*headdesk* AARRRRRRRGGGGGGGGGGGGHHHHHHHHHHHHHH!!!!!!!!!!!!!!! !!!! It's a motherfscking MAGICAL GIRL SHOW, STOP THINKING ABOUT IT SO MUCH!!! ALL OF YOU!

[Wild Goose has reached his limit and must be sedated.]