Physics error in #622

[fangthane]

Yes, that's right. I'm actually calling Rich out on something this inane. In my defense though, it's only the quality of the artwork and the Giant's usually superlative attention to detail which makes me point it out :) (like with the show tune lyrics and a few other typos/mistakes I've seen in the past)

The mirror physics in #622 are inaccurate. In order to look from the "camera" perspective over toward the image of the hand-mirror in the large mirror, we need to look at an angle which produces a much larger angle of incidence (and thus reflection). To look at the handmirror directly requires a divergence of somewhere around 15 degrees from a straight forward direction. In order to look through the mirror, the angle is unclear but is at least 30-45 degrees. That being the case and playing around a bit with the thought-experiment "light ray path to the virtual camera", the small mirror's reflection should yield a view not of Haley's head (as is just barely visible) but rather of the side/front of the barber's face.

Arrgh, the laws of physics be a harsh mistress.

[hamishspence]

I'm willing to put it down to it being a mirror at an angle to the viewer rather than straight on, but held in such a way as it looks like its straight on.

Or, just a shortcut to communicate that its the back of Haley's head that Haley is looking at.

[fangthane]

Most likely - and actually, looking at what I typed it's not quite accurate anyhow, as when we look directly at the smaller mirror, the light collision (photons with the large mirror) that I was thinking of in terms of incidence/refraction doesn't actually happen; what I meant was that the angle to the smaller mirror, from either approach path, must be different. But I expect you're right, it's a matter of artistic shorthand interfering with optical physics. Or vice versa. :) Sort of like the Evasion jumps, I guess, though that's a commentary on the rule's sometimes-silly results. Plus side, he DID reverse the reversed image at least, so while it's not accurate it's not as jarring as it could be. ;)

[factotum]

You're right, of course. It's also quite obvious that the people in this comic should not be able to support themselves on those skinny legs they have; that their heads are far larger compared to their bodies than they should be; and that the perspective on many long shots (especially those in Azure City) makes no architectural sense whatsoever.

The next question is, is any of that important? It's a stick figure comic, one cannot expect perfect perspective and correct reflections in every shot...

[shadowkire]

Actually from what is shown in the hand mirror it seems that Haley is sitting in between the two mirrors, which would mean the hand mirror would be facing away from the barber making it impossible to see him in it.

You really shouldn't call out a stick figure comic about a game that emulates worlds filled with magic and dragons out on something as pointless as apparent mirror angles displaying incorrect images.

[teratorn]

A wizard did it!

A wizard flooded the market with cheap magical screen like devices which show you the view from any angle you want. Obviously those were readily adopted by the barber and hairdresser industry.

[Nimrod's Son]

There's any number of examples of mangled perspective in OotS, such as Haley pulling the cart in the first panel of this (http://www.giantitp.com/comics/oots0524.html) comic, or the armchair in Pete's study (http://www.giantitp.com/comics/oots0614.html).

But that said, there's no way the rain could just pass through the guildhouse door the way it does in panel two of #621 (http://www.giantitp.com/comics/oots0621.html). The angle's all wrong. Sort it out, Burlew! :smallwink:

[Yakk]

You aren't seeing a ray trace. You are seeing a projection of a depiction of what the various (tending towards central) characters are seeing on each surface from their perspective, rather than what you would see from your perspective.

Because, really, there isn't anyone looking from your perspective. :p

[RebelRogue]

I'm a physicist and I don't care one bit...:smalltongue:

[ericgrau]

And if you take a look at the corner of the room below the mirror, you'll notice that the builders used 150 degree angles instead of 90 degree angles in this part of town... Orrrrrr it's a matter of perspective, both the mirrors - like the wall - aren't angled at all, both are pointed directly at Haley, the back of the hand mirror is toward the barber and cannot reflect his image from any point of view, and the reflections are accurate. Ha! (sorry, that was an Ace Ventura moment for me)

[Trisk]

Actually from what is shown in the hand mirror it seems that Haley is sitting in between the two mirrors, which would mean the hand mirror would be facing away from the barber making it impossible to see him in it.

You really shouldn't call out a stick figure comic about a game that emulates worlds filled with magic and dragons out on something as pointless as apparent mirror angles displaying incorrect images.

But why not? I mean he's not saying the comic sucks because of this, but in this world images are to reflect normally. There is gravity and air. Simply because unrealistic things exist doesn't mean it isn't an error.

[Xerrik]

Personally, I don't think it matters. Physics was never supposed to be the focal point of this comic, humor and an adventure using 3.5e rules was and still is. The mirror's probably only like that to show how short it REALLY is.

[Assassin89]

Remember that the laws of physics do not always apply in Order of the Stick or in D&D. Shadows exist, but the comic does not include them in order to create a joke about the shadow dancer.

[JaxGaret]

You aren't seeing a ray trace. You are seeing a projection of a depiction of what the various (tending towards central) characters are seeing on each surface from their perspective, rather than what you would see from your perspective.

Because, really, there isn't anyone looking from your perspective. :p

That's not a bad way of thinking about it. What you're seeing is a figurative representation of the scene as a whole, rather than a dead accurate depiction of what is actually happening.

Just like when you play D&D.

[Starwaster]

Man you've got some issues to work out if you're criticizing physics in a stick figure comic.

[Xerrik]

Man you've got some issues to work out if you're criticizing physics in a stick figure comic.

Hear, hear.

[Underground]

Such tricks are absolutely common and normal in comic strips; to get the point through, the artist choses an impossible composition. Thats the freedom of the art of making comics, you dont need to care about perspective and such things, just as long as the reader gets the right idea about what you want to express.

[Berserk Monk]

A wizard did it.

[Pronounceable]

Arrgh, the laws of physics be a harsh mistress.

They were told to shut up and sit down a long time ago.

[Epinephrine]

The mirror physics in #622 are inaccurate. In order to look from the "camera" perspective over toward the image of the hand-mirror in the large mirror, we need to look at an angle which produces a much larger angle of incidence (and thus reflection).

The mirror is actually a very odd shape, and looks square because it is held on the correct angle to provide that view. With no stereo vision, I can create a situation in which the angles are exactly right, since there are quadrilaterals that will map to the 2 dimensional profile of the mirror for infinitely many orientations.

[Xerrik]

A wizard did it.

Thus demonstrating the all too true happening: anything out of the ordinary was done by magic.

[WoDHells]

Following that train of thought, all the arrows in the comic go straight to their targets in a straight line (as you can see in strip nº454 (http://www.giantitp.com/comics/oots0454.html)), when, in reality, they tend to fall a bit (especially in long distances). It is a minor detail really, but, as an archer, I noticed it the very moment I saw it. Of course, I don't care much about that, for the quality of the comic in general compensates for these small things.. but if it were my strip, I would try to pay attention to all those things. In fact, I do in mine, as far as I can.