Gravity arcing in SW blaster bolts

[Darth Wong]

There is a persistent, long-running argument here about whether SW blaster bolts are affected by gravity. It usually goes like this:

SW blaster bolts don't drop in gravity the way you'd expect from their APPARENT speed, so-

Who says they don't?

Everyone with eyes. And the literature goes into more detail about-

I reject the literature.

Blow me. It's official.

Nope, I hate Curtis Saxton. Satisfy my assholery! Accept my rules, not Lucasfilm's rules!

OK fine, asshole. We can see from any of the goddamned films that SW blaster bolts don't arc.

Oh really? I don't see that.

What are you, fucking blind?

Nope, but I don't see why you should expect to see a lot of arcing in a shot which is only in the air for a second or so.

You should.

Prove it. I reject your claims until I see evidence.

YOU bear the burden of proof to show something in the films that contradicts the literature.

I disagree.

What the fuck kind of rebuttal is that?

Darkstar said you would act this way.

Fuck off.

Ha ha, you resorted to an insult! I win!

Bullshit.

This exact same argument has taken place many, many times. And it's fucking tiresome. So here, for your perusal, is a short Divx video clip of a modern vehicle firing rounds which are in the air for less than a second and which show very obvious arcing.

http://www.stardestroyer.net/Empire/Tec ... Firing.avi

For you people who say we shouldn't be able to visibly see arcing with rounds moving at a km/s or more, stick that in your pipe and smoke it. BTW, it's only a 300kB file, so 56K modem users should be able to download it with only moderate pain.

[Vympel]

Cool. Where'd you get the clip of that BTR-80A firing? IDEX 2003? Looks like an arms demonstration.

(these are 30mm rounds, in case anyone is wondering)

[D.Turtle]

How fast are those shots moving?

[Crown]

How fast are those shots moving?

Mach 1.2 - 1.8 I think.

[Darth Servo]

I take it we have your permission to post a link to this video from other discussion forums?

[Vympel]

Mach 1.2 - 1.8 I think.

If it was firing the older Russian AP-T, muzzle velocity was 970m/s. If it was new APDS ammunition (which is not unlikely, dependent on the date of this video), it would be 1,120m/s. If it was HEI-T, it would be 960m/s.

I have no idea how the conversion to Mach works, never had reason to do it.

EDIT: using WWW unit converter, 960m/s comes out to Mach 2.821096- unless I'm read it wrong. So there's your lower limit considering the ammunition candidates.

[Andras]

speed of sound at sea level is roughly 1100fps or 335mps IIRC

[Connor MacLeod]

How fast are those shots moving?

Mach 1.2 - 1.8 I think.

For normal humans who might not know how fast that is thats roughly around 400-600 m/s, give or take ten or fifteen meters.

[D.Turtle]

Thanks to all of the above ^^

[Illuminatus Primus]

For normal humans who might not know how fast that is thats roughly around 400-600 m/s, give or take ten or fifteen meters.

I think HDS' measurements and speed charts from AOTC compare favorably with that velocity...and taking into account the rifle blasts traveling kilometers across the Geonosian plains...

[Darth Wong]

How fast are those shots moving?

Mach 1.2 - 1.8 I think.

For normal humans who might not know how fast that is thats roughly around 400-600 m/s, give or take ten or fifteen meters.

Vympel's figures are more accurate. Roughly 1 km/s, or nearly Mach 3.

[Illuminatus Primus]

Actually faster than many of HDS' estimations, which were in the 300-500 m/sec range, and would arc even more noticably over the same distance, which supports the "no arcing" argument.

[Darth Wong]

Cool. Where'd you get the clip of that BTR-80A firing? IDEX 2003? Looks like an arms demonstration.

It was an arms demonstration, but I don't know what year it was. IIRC, there's a cool clip of a T-80U climbing over a low concrete wall and blowing stuff up with the Refleks system. There were several clips from the demo in a TV documentary.

[SPOOFE]

Is it me, or does it look as if the bullets arc even more than the tracer rounds?

[MarkIX]

It's obviously some sort of optical illusion caused by swamp gas reflecting light of a weather balloon.
Tracers get lighter as they go so their flight profile isn't the same as a normal round, I have seen them bounce off the ground and go almost vertical in small arms calibres.

[Icehawk]

Question for HAB, but I was wondering why that vehicle has such a slow rate of fire? The Apache flings 30mm rounds at something like 625 rd/pm so you would think an armored vehicle cannon would do that as well... Or are they just purposely firing slow?

[Eframepilot]

Very interesting. So... what's the accepted explanation for why blaster bolts fail to arc? I can think of a couple of possibilities:

They are not any more "real" than shadows; the actual blaster beam is invisible and travels far far faster with the visible "bolt" just some sort of pulse along it. This fails since damage not only is usually associated with the visible bolt, but also Jedi can deflect the visible bolts with sabers without keeping the lightsaber fixed in relation to the blaster while the deflected bolt heads back to the target.

The bolts are real but made of some exotic particles that ignore gravity. (All known matter and energy curve in a gravitational field; we just don't see the arcing of laser beams since photons move at c). Maybe tibanna gas has some sort of natural repulsor effect when heated. This doesn't jive with the geometric interpretation of gravity as an effect of the curvature of spacetime, but neither does the entire concept of repulsorlifts.

[Rogue 9]

For some odd reason, my computer is only playing the sound file. No video.

[YT300000]

For some odd reason, my computer is only playing the sound file. No video.

Ah, Windows Media Player.

You need the DivX codex.

[YT300000]

Question for HAB, but I was wondering why that vehicle has such a slow rate of fire? The Apache flings 30mm rounds at something like 625 rd/pm so you would think an armored vehicle cannon would do that as well

That's like asking why combat rifles have semi-automatic firing modes.

[Darth Wong]

Very interesting. So... what's the accepted explanation for why blaster bolts fail to arc? I can think of a couple of possibilities:

They are not any more "real" than shadows; the actual blaster beam is invisible and travels far far faster with the visible "bolt" just some sort of pulse along it. This fails since damage not only is usually associated with the visible bolt, but also Jedi can deflect the visible bolts with sabers without keeping the lightsaber fixed in relation to the blaster while the deflected bolt heads back to the target.

Those hand blaster bolts might be like ion cannon blasts rather than turbolaser blasts (yes, I disagree with the interpretation that ion cannon blasts cause no physical damage).

The bolts are real but made of some exotic particles that ignore gravity. (All known matter and energy curve in a gravitational field; we just don't see the arcing of laser beams since photons move at c). Maybe tibanna gas has some sort of natural repulsor effect when heated. This doesn't jive with the geometric interpretation of gravity as an effect of the curvature of spacetime, but neither does the entire concept of repulsorlifts.

Incorrect. Repulsorlifts do not necessarily violate the concept of curved spacetime. If one could develop a technology that can apply force to electro-neutral matter, one would have a repulsorlift. There's no need to ignore relativity.

If hand blaster bolts are indeed like ion cannon blasts rather than turbolaser blasts, then I suppose one might invent the explanation that the bolt's shape has enough aerodynamic lift to keep it flying roughly level in typical breathable atmospheres. Alternatively, one could imagine that there's a teeny little device in there.

Of course, that would only work for hand blaster variants which require ammo packs. Something like a T-21 or E-Web which can run indefinitely as long as it has power would be a different case (not to mention a serious problem for the "tibanna gas" interpretation), but as I said earlier, it's possible that some blasters actually fire miniature ion blasts while others fire miniature turbolaser blasts.

[Vympel]

It was an arms demonstration, but I don't know what year it was. IIRC, there's a cool clip of a T-80U climbing over a low concrete wall and blowing stuff up with the Refleks system. There were several clips from the demo in a TV documentary.

The T-80U clip sounds familiar- I may have it somewere, or a similar one- showing off Refleks is popular

Question for HAB, but I was wondering why that vehicle has such a slow rate of fire? The Apache flings 30mm rounds at something like 625 rd/pm so you would think an armored vehicle cannon would do that as well

The 2A72 cannon on that BTR-80A does 330 rounds per minute, maximum. A word about rate of fire: aircraft cannon's usually have higher ROF than those on armored vehicles, because they have less time to engage the target. Rate of fire on the Bushmaster of the Bradley is 200 rnds/m.

[Cal Wright]

For what it's worth, if the Clone Wars cartoons count they show laser fire arcing. The heavy weaponary firing onto the capital city on Munillist.

[Howedar]

Those were clearly a different sort of weapon, if you're talking about the SPHA-T's.

[Illuminatus Primus]

For what it's worth, if the Clone Wars cartoons count they show laser fire arcing. The heavy weaponary firing onto the capital city on Munillist.

You realize the blue bolt-firing AT-TE main cannons are mass-drivers, right?