Wang / Sagnac Devices
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From: Androcles on 25 Oct 2009 20:52 "Jonah Thomas" <jethomas5(a)gmail.com> wrote in message news:20091025193145.41daecce.jethomas5(a)gmail.com... > "Androcles" <Headmaster(a)Hogwarts.physics_p> wrote: >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote >> news:20091025183002.5fbe3867.jethomas5(a)gmail.com... >> > Sam <shayiam(a)yahoo.com> wrote: >> >> Jonah Thomas <jethom...(a)gmail.com> wrote: >> > >> >> > If a ballistic theory predicts that the speed of light >> >> > depends on the speed of its source, then in every early >> >> > Sagnac experiment the light went the same speed in two >> >> > different directions, according to an inertial observer. >> >> >> >> Right, relative to the instantaneous rest frame of the emission >> >point.> So, relative to the Galilean rest frame of the hub, the light >> >is going> faster in the direction of rotation than in the opposite >> >direction. >> > >> > No, the light goes the same speed >> >> No, relative to the Galilean rest frame of the hub, the light is going >> faster in the direction of rotation than in the opposite direction. > > Look at your diagram of the original Sagnac experiment. There is one > light source that points in one direction, backward compared to the > direction of motion. The light leaves the source at one speed. It goes > into a beam-splitter and comes out as two beams. Do they travel at > different speeds? Sure, some emission theories say they do, notably the > Ritz version. But not all. They bounce off mirrors. Look at a flight attendant on a plane. Do they walk at 3 mph? How come they can cross the Atlantic, 3000 miles, in just 6 hours? That's 500 mph, nobody can walk that fast. Maybe they bounce off fuckin' mirrors. > Do they then travel at different speeds? Sure, some emission theories > say they do. But not all. > > If a particular emission theory says they travel at diferent speeds in > different directions in the Sagnac experiment, it is because it says the > beam-splitter nd mirrors change the speed. Let me tell ya something. A plane flies at 500 mph. A flight attendant flies at 503 mph and overtakes the plane and all its passengers. Then she bounces off the flight deck door and flies backwards at 497 mph and the plane overtakes her as she walks past the passengers on her way to the rear of the plane. See if you can say "r-e-l-a-t-i-v-e m-o-t-i-o-n" and find out what it means. No, r-e-l-a-t-i-v-e to the Galilean rest frame of the hub, the light is going faster in the direction of rotation than in the opposite direction. No, relative to the Galilean r-e-s-t f-r-a-m-e of the hub, the light is going faster in the direction of rotation than in the opposite direction. > The light is emitted at one > speed for every theory, emission, classical, relativist, you name it. The flight attendant walks at 3 mph in every theory, emission, classical, relativist, you name it. How come they can cross the Atlantic, 3000 miles, in just 6 hours? That's 500 mph, nobody can walk that fast. Maybe they bounce off fuckin' mirrors. All speeds are relative. Get used to it.
From: Sam on 25 Oct 2009 21:03 On Oct 25, 2:30 pm, Jonah Thomas <jethom...(a)gmail.com> wrote: >> As a result, relative to the hub frame, the forward >> pulse is always moving faster than the rearward pulse, >> because the mirrors are moving in the forward >> direction, and the pulses are moving at c relative >> to the mirrors. > > This requires a particular emission theory, one that > says light is reflected at c relative to reflectors. Well, that's exactly the theory that I was explicitly addressing in that part of my message, and I clearly distinguished between this theory (the simple straightforward ballistic theory, in which light is supposed to move like little Newtonian elastic particles in Galilean space and time) and other kinds of theories that make different assumptions about what happens at reflections. I guess you overlooked that distinction in my message, and the remainder of my message in which I addressed the other kinds of theories. No harm done. So, at this point, we're in agreement that the Sagnac effect is inconsistent with the simple ballistic theory. > To avoid problems for non-ballistic theories the > re-emission has to happen instantaneously. Start > with a nonemission theory approach to a fiber-optic > system. The light travels at about 2/3 c. If the > other 1/3 of the time the light is being absorbed > and re-emitted, then the light will travel at > 2/3 c + 1/3 v in one direction, and 2/3 c - 1/3 v > in the other. So, now you're talking about NON-ballistic and NON-emission theories? That isn't really specific enough to be able to make any definite statements. Also, I don't think exploring your ideas about how light may propagate in unspecified non-ballistic theories is a very good way to help you understand the implications of ballistic theories for how light propagates. Rather than confusing yourself by combining the Fizeau effect (which you obviously don't understand) with the Sagnac effect, wouldn't it be better to first work on trying to understand the pure Sagnac effect with just 3 or 4 mirrors in vacuum from the standpoint of your ballistic theory, and then move on to the effects of differing indices of refraction? We've agreed that the straightforward ballistic theory gives no Sagnac effect, so what we need is for you to articulate the non- straightforward ballistic theory that you believe gives the observed Sagnac effect. You need to state how light behaves when it is reflected, i.e., what speed the light has after it has encountered some material particle and been reflected by it. If you want to claim (for example) that in any reflections light propagates from the reflection event isotropically with speed c relative to the rest frame of the original emitter at the moment of emission, then you should address the criticisms that apply to that hypothesis, some of which I've mentioned previously. Basically, that is not a logically coherent hypothesis. If your point is simply that you personally have not yet grasped the incoherence of that hypothesis, then that's fine, but I think it's premature for you to be philosophizing about the lack of vision of scientists based on your present (rather primitive) level of understanding. My advice is to think about your proposed emission theory a bit more.
From: Jonah Thomas on 25 Oct 2009 23:11 "Androcles" <Headmaster(a)Hogwarts.physics_p> wrote: > "Jonah Thomas" <jethomas5(a)gmail.com> wrote > > "Androcles" <Headmaster(a)Hogwarts.physics_p> wrote: > >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote > >> > Sam <shayiam(a)yahoo.com> wrote: > >> >> Jonah Thomas <jethom...(a)gmail.com> wrote: > >> > > >> >> > If a ballistic theory predicts that the speed of light > >> >> > depends on the speed of its source, then in every early > >> >> > Sagnac experiment the light went the same speed in two > >> >> > different directions, according to an inertial observer. > >> >> > >> >> Right, relative to the instantaneous rest frame of the emission > >> >point.> So, relative to the Galilean rest frame of the hub, the > >light> >is going> faster in the direction of rotation than in the > >opposite> >direction. > >> > > >> > No, the light goes the same speed > >> > >> No, relative to the Galilean rest frame of the hub, the light is > >going> faster in the direction of rotation than in the opposite > >direction. How come? > > Look at your diagram of the original Sagnac experiment. There is one > > light source that points in one direction, backward compared to the > > direction of motion. The light leaves the source at one speed. It > > goes into a beam-splitter and comes out as two beams. Do they travel > > at different speeds? Sure, some emission theories say they do, > > notably the Ritz version. But not all. They bounce off mirrors. > > Look at a flight attendant on a plane. Do they walk at 3 mph? > How come they can cross the Atlantic, 3000 miles, in just 6 hours? > That's 500 mph, nobody can walk that fast. Maybe they bounce off > fuckin' mirrors. That's a pretty picture but I don't see how it applies. The flight attendant walks and makes the plane go faster or slower? > > Do they then travel at different speeds? Sure, some emission > > theories say they do. But not all. > > > > If a particular emission theory says they travel at diferent speeds > > in different directions in the Sagnac experiment, it is because it > > says the beam-splitter nd mirrors change the speed. > > Let me tell ya something. A plane flies at 500 mph. A flight attendant > flies at 503 mph and overtakes the plane and all its passengers. > Then she bounces off the flight deck door and flies backwards > at 497 mph and the plane overtakes her as she walks past the > passengers on her way to the rear of the plane. See if you can > say "r-e-l-a-t-i-v-e m-o-t-i-o-n" and find out what it means. > > > No, r-e-l-a-t-i-v-e to the Galilean rest frame of the hub, the light > is going > faster in the direction of rotation than in the opposite direction. It wasn't going faster when it started out. What made it increase its speed? > No, relative to the Galilean r-e-s-t f-r-a-m-e of the hub, the light > is going > faster in the direction of rotation than in the opposite direction. > > > The light is emitted at one > > speed for every theory, emission, classical, relativist, you name > > it. > > The flight attendant walks at 3 mph in every theory, emission, > classical, relativist, you name it. > How come they can cross the Atlantic, 3000 miles, in just 6 hours? > That's 500 mph, nobody can walk that fast. Maybe they bounce off > fuckin' mirrors. > > All speeds are relative. Get used to it.
From: Jonah Thomas on 25 Oct 2009 23:21 Sam <shayiam(a)yahoo.com> wrote: > Jonah Thomas <jethom...(a)gmail.com> wrote: > >> As a result, relative to the hub frame, the forward > >> pulse is always moving faster than the rearward pulse, > >> because the mirrors are moving in the forward > >> direction, and the pulses are moving at c relative > >> to the mirrors. > > > > This requires a particular emission theory, one that > > says light is reflected at c relative to reflectors. > > Well, that's exactly the theory that I was explicitly addressing in > that part of my message, and I clearly distinguished between this > theory. No harm done. So, at this point, we're in agreement that the > Sagnac effect is inconsistent with the simple ballistic theory. Ohhh, that's premature. What we have at this point is that your simple ballistic theory does not give a difference in arrival time for the light. We have not yet estasblished that it does not do interference. > > To avoid problems for non-ballistic theories the > > re-emission has to happen instantaneously. Start > > with a nonemission theory approach to a fiber-optic > > system. The light travels at about 2/3 c. If the > > other 1/3 of the time the light is being absorbed > > and re-emitted, then the light will travel at > > 2/3 c + 1/3 v in one direction, and 2/3 c - 1/3 v > > in the other. > > So, now you're talking about NON-ballistic and NON-emission theories? > That isn't really specific enough to be able to make any definite > statements. So, you refuse to discuss this situation. OK, no problem. > We've agreed that the straightforward ballistic theory gives no Sagnac > effect, Not yet. > so what we need is for you to articulate the non- > straightforward ballistic theory that you believe gives the observed > Sagnac effect. You need to state how light behaves when it is > reflected, i.e., what speed the light has after it has encountered > some material particle and been reflected by it. Here's one: Light is emitted at c relative to its source's rest frame. It continues to travel at the same speed until it is absorbed etc. It reflects off mirrors at the same speed, but when traveling through a refractive medium it slows for that. > If you want to claim > (for example) that in any reflections light propagates from the > reflection event isotropically with speed c relative to the rest frame > of the original emitter at the moment of emission, then you should > address the criticisms that apply to that hypothesis, some of which > I've mentioned previously. Basically, that is not a logically coherent > hypothesis. OK, what is it that destroys every possible version of this?
From: Tom Roberts on 25 Oct 2009 23:32
Jonah Thomas wrote: > "Inertial" <relatively(a)rest.com> wrote: >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote >>> When you start with one light source, that >>> light source has a speed. Period. >> It has an infinite number of speeds. You guys are arguing right past each other, because you are ALL using language that is too imprecise. And you are not specifying which specific theory you are considering. Until you make your statements considerably more precise, and specify your model, you will all remain mystified, and will be unable to communicate. No matter which theory you use, whenever you say "speed", you MUST specify the coordinates relative to which that speed is measured. Generally this only makes sense for inertial coordinates, but if one is VERY careful then rotating coordinates can be used as long as you remember that most theoretical statements about speeds do not apply to rotating coordinates (e.g. in no theory does light propagate isotropically with constant speed relative to rotating coordinates). In an emission theory, the speed of light is c in the inertial frame in which the source is at rest. If the source is on an accelerating or rotating platform, then you can only discuss a short pulse of light, and the relevant frame is the instantaneously comoving inertial frame when the pulse is emitted. For a mirror, Snell's law holds ONLY in the inertial frame in which the mirror is at rest. If the mirror is accelerating or fixed to a rotating platform, then you can only discuss a short pulse of light, and the relevant frame is the instantaneously comoving inertial frame when the light pulse hits the mirror. This is all VERY BASIC, and is independent of theory. Tom Roberts |