Ballistic Theory, Progress report...Suitable for 5yo Kids
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From: George Dishman on 8 Oct 2005 07:36 <jgreen(a)seol.net.au> wrote in message news:1128765654.176021.112400(a)f14g2000cwb.googlegroups.com... > > George Dishman wrote: >> <jgreen(a)seol.net.au> wrote in message >> news:1128499223.209426.270620(a)g14g2000cwa.googlegroups.com... >> > >> > George Dishman wrote: >> >> <jgreen(a)seol.net.au> wrote in message >> >> news:1128419173.735037.311150(a)g49g2000cwa.googlegroups.com... >> ... >> >> > George, my old computer died on me, losing the email I remember >> >> > quite >> >> > vividly (from you) saying how sagnac machine works because the TIME >> >> > OF >> >> > TRAVEL of the signal alters. If you cannot see/understand that this >> >> > refers to VELOCITY, as the DISTANCE does NOT ALTER, that is too bad! >> >> >> >> Sadly it seems you also lost my response to your comment, >> >> the distance does alter Jim, the detector MOVES while the >> >> light is in transit. In the experiment, the length is >> >> known to change because we know the speed of rotation of >> >> the table, the time is measured to change and when you >> >> calculate the speed as distance/time you always get c. >> > >> > "Time" is MEASURED to change????? >> > Say the path around the machine is 3 meter. Time for circuit of light >> > is >> > 10^-8 sec. Now do a fast turn. >> >> Let's assume 600 rpm, 10 rev per second. > > The passengers would all be DEAD! You said "Say the path around the machine is 3 meter". That description fits the usual Sagnac experiment with a spinning turntable of less than 1m diameter so that's how I answered. No passengers. Again, if you give me insufficient details, I may guess incorrectly. Anyway, regardless of all that, the Sagnac experiment measures the speed of the light of the source moving on the turntable and gives a value of exactly what SR predicts, c in vacuum or just the right amount lower depending on the refractive index in fibre. > George, I am referring to the rotation of the aircraft ref the earth, > which you claim to be able to "time" (the difference in a photon doing > one rev of the attached sagnac machine) when the aircraft is proceeding > straight, and comparing to the "time" of that photon doing one rev when > the plane is changing direction- say 180degrees (half the circumference > of the sagnac) per HOUR! An iFOG will do slightly better than that. The thing you don't seem to grasp is that engineers like me work on such devices for years finding ways to eliminate errors and improve the performance by doing things like modulating the light beam and using configurations in which noise cancels out. > Whatever your sagnac animation is doing, it is NOT comparing measured > times of photon circuits. That is precisely what it does Jim, in some case by direct measurement or sometimes by placing a delay circuit into the optical loop and using a closed-loop servo to null the difference. As I said: >> In fact the technology is much better than the example >> given above. If you had read the web sites on iFOGs we >> were talking about, the best can measure a few tens of >> degrees per hour. They can measure the rotation of the >> Earth with a bit of care once properly calibrated which >> is about 100,000 times better than above in a box only >> a few cm across! Ring lasers are even better. You don't >> seem to realise just how powerful modern technology has >> become. >> >> >>It is ASSUMED! >> >> So how does the commercial kit know how fast it >> is rotating if we humans only assume it? Where >> do the numbers on the dial come from Jim? Why >> don't the planes fall out of the sky? > > Q: If the machine is set at 600rpm grounded, how many rpm is it doing > when the airframe to which it is attached is doing 1rpm > (Hint: either 601 or 599) The Sagnac experiment I described in the lab was doing 600rpm. In the case of an aircraft trying to fly straight, an error in the iFOG might give a drift of 20 degrees per hour. The stability is around 1 degree per hour so if you measure the offset for a given device and apply a fixed correction, the plane won't deviate more than 1 degree off course in an hour (I'm ignoring temperature effects). http://www.kvh.com/pdf/DSP3000_5.04.pdf The drift would usually be corrected by compass or GPS. The role of the iFOG is primarily to provide dynamic information with a fast response as part of the autopilot but is quite adequate to control a plane as a backup should say the GPS box fail. > So now the poor old sun has only managed 4.6 / .22 = 20 revs > around the galaxy :-( .....hardly seems fair......... A galaxy is a very dynamic place, astronomy might be as boring as a kid's roundabout if not :-) George
From: "Androcles" <Androcles@ on 8 Oct 2005 07:48 <jgreen(a)seol.net.au> wrote in message news:1128765654.176021.112400(a)f14g2000cwb.googlegroups.com... | | George Dishman wrote: | > <jgreen(a)seol.net.au> wrote in message | > news:1128499223.209426.270620(a)g14g2000cwa.googlegroups.com... | > > | > > George Dishman wrote: | > >> <jgreen(a)seol.net.au> wrote in message | > >> news:1128419173.735037.311150(a)g49g2000cwa.googlegroups.com... | > ... | > >> > George, my old computer died on me, losing the email I remember quite | > >> > vividly (from you) saying how sagnac machine works because the TIME OF | > >> > TRAVEL of the signal alters. If you cannot see/understand that this | > >> > refers to VELOCITY, as the DISTANCE does NOT ALTER, that is too bad! | > >> | > >> Sadly it seems you also lost my response to your comment, | > >> the distance does alter Jim, the detector MOVES while the | > >> light is in transit. In the experiment, the length is | > >> known to change because we know the speed of rotation of | > >> the table, the time is measured to change and when you | > >> calculate the speed as distance/time you always get c. | > > | > > "Time" is MEASURED to change????? | > > Say the path around the machine is 3 meter. Time for circuit of light | > > is | > > 10^-8 sec. Now do a fast turn. | > | > Let's assume 600 rpm, 10 rev per second. | | The passengers would all be DEAD! | George, I am referring to the rotation of the aircraft ref the earth, | which you claim to be able to "time" (the difference in a photon doing | one rev of the attached sagnac machine) when the aircraft is proceeding | straight, and comparing to the "time" of that photon doing one rev when | the plane is changing direction- say 180degrees (half the circumference | of the sagnac) per HOUR! | Whatever your sagnac animation is doing, it is NOT comparing measured | times of photon circuits. | > | > > How much did the 3m alter, | > | > 3m * 10^-8 = 300nm, or 10^-15 sec | > | > > and how good | > > is the watch that differentiated between periods stable and rotating. | > | > Yellow light has a frequency of 5 * 10^14 Hz so 0.1 | > of a fringe shift is 2 * 10^-16 sec. I have used | > interferometers and worked to a tenth of a fringe by | > eye without too much trouble. Electronics is far | > better. | > | > > Hint; Your clocks (time) are trying to measure the difference between | > > the flight of a photon over 3m, and 2.999999999999999999999999999m | > | > 3.0m versus 3.0000003m and we can measure to better | > than 0.00000006m. | > | > > The time is NOT measured to change! We do not posses the technology to | > > get anywhere near that accuracy. | > | > In fact the technology is much better than the example | > given above. If you had read the web sites on iFOGs we | > were talking about, the best can measure a few tens of | > degrees per hour. They can measure the rotation of the | > Earth with a bit of care once properly calibrated which | > is about 100,000 times better than above in a box only | > a few cm across! Ring lasers are even better. You don't | > seem to realise just how powerful modern technology has | > become. | > | > >>It is ASSUMED! | > | > So how does the commercial kit know how fast it | > is rotating if we humans only assume it? Where | > do the numbers on the dial come from Jim? Why | > don't the planes fall out of the sky? | | Q: If the machine is set at 600rpm grounded, how many rpm is it doing | when the airframe to which it is attached is doing 1rpm | (Hint: either 601 or 599) | > | > >> As for your stuff on the galaxy and a merry-go-round, the | > >> correct analogy is that you make the measurement not against | > >> the horses head but using a gyroscope (or you could say a | > >> distant mountain if you were on a non-rotating planet). | > > | > > Nope. Sirius IS the distant mountain as far as our markers for | > > direction go. | > | > Wrong Jim, find out before speaking. Look up "ICRF" | > and learn. In particular look up the defining source | > details and find the average red shift (z factor). | > | > >> Astronomers are well aware of the local proper motion of | > >> stars. That's why you need to learn how astronomy is done | > >> before criticising. | > > | > > It will be 12 billion years before we know what is happening NOW at the | > > limit of our present vision. Might as well shop local! | > > | > > BTW: Do YOU think it likely that the Milky Way has only revolved 60 | > > times? | > > It seems much more stable than that. | > | > Why do you think stability is related to the number | > of turns? I can't see why you think there would be | > a connection. | > | > Anyway, to add a bit of education, a galaxy isn't | > rigid so stars at different radii have completed | > different numbers of revolutions. The place is very | > dynamic, the Sun was only created 4.6 billion years | > ago and will die in a few more. The arms are shock | > waves that move round at a different speed to the | > stars in them, so saying "the Milky Way has only | > revolved 60 times" is an oversimplification. What | > I would say is that by using small radio sources | > billions of light years away as a reference (the | > 'mountain') we can now _measure_ the rotation of | > the galaxy (around Sag A*) directly using VLBI, and | > the value is the same as that obtained by measuring | > the Doppler shift of other parts of the galaxy | > relative to us. It's about 220 million years at | > the distance we are from the centre (about 28kly) | > and we also "bob up and down" through the plane | > roughly every 80 million years IIRC. These are not | > contentious figures Jim, I don't understand why you | > are sceptical. | | So now the poor old sun has only managed 4.6 / .22 = 20 revs | around the galaxy :-( .....hardly seems fair......... | | Jim Hey Jim! Let him have enough rope to hang himself. This is Sagnac: Light starts at A, goes in opposite directions to mirrors at B and C, meets itself at D. + A--\C | | B\--D As it does so, the system revolves. + D--\B | | C\--A So on the turntable, the light went from A to D On the page it went from the top left, where the '+' is, to the top left, where the '+' is. Speed of light on the rotating turntable, c. Speed of light on the page, zero clockwise, 2c counterclockwise. Let him have his time slow down, the observer on the page is not allowed to see the speed of light be anything but c, so it is his watch that slows down and stops. Be careful not to look at fast Sagnac devices, your heart will stop. Androcles. |
From: George Dishman on 8 Oct 2005 08:44 "Henri Wilson" <H@..> wrote in message news:ph6fk1hmlf1hfm5ddp8ai3a1totfk0a1rt(a)4ax.com... > On Fri, 7 Oct 2005 23:34:40 +0100, "George Dishman" > <george(a)briar.demon.co.uk> > wrote: > >> >>"Henri Wilson" <H@..> wrote in message >>news:lgpdk1p5mbj1dipuqa52n434e94li2hhtn(a)4ax.com... > >>>>> George it is the vector speed of the source wrt the next mirror that >>>>> matters. >>>>> >>>>> That is ZERO. >>>> >>>>No it isn't Henri, it is the vector speed of >>>>the LIGHT wrt the next mirror that matters. >>>>You aren't bouncing one mirror off the next! >>> >>> Your basic physics is sadly lacking George. >> >>If you think one mirror hits the next, it >>is your understanding of the apparatus that >>is sadly lacking Henri. > > George, let me explain. Good idea, it helps to flush out any misunderstandings. > You are claiming that the speed component that a photon gains due to the > movement of its source relative to an observer is c+v, where v is the > speed of the observer relative to the source. No. What I call the "lab frame" is an inertial frame (not rotating) defined such that the central point of the turntable is at rest. The easy way is to take that point as the origin. I have always said that the speed of the light in the lab frame is the vector sum of the velocity of the source and a vector describing the emission. The vector sum points in the direction of the point where the light must reflect off the first mirror so that it eventually reaches the detector because only light that hits the detector affects the output of the detector (you seem to think that light that misses the detector defines the output, a view I have never understood). The magnitude of the resultant can then be determined by trigonometry. > In the rotating frame...which you love....the source's speed > is at right angles to the first mirror. > Its speed component towards the mirror is zero. In the rotating frame, the source's speed is zero, period! The light is emitted at c from the source but will then vary along the path as the radius varies between source and mirror. For Ritzian theory, you can convert between those two frames using the transforms of Galilean Relativity. For an iFOG which has a circular light path, the analysis is trivial in the rotating frame, the speed is c/n regardless of rotation therefore the output cannot vary with rotation. QED. All others frames must give the same result. >>>>> Where did Ritz ever say that sagnac should give a null result. >>>> >>>>Do the calculation yorself. That's the thing about >>>>a published theory, anyone can apply it to anything. <snip to clarify> >>No "explanations" Henri, show the maths that >>gives you the predicted output. > > Just resort to LET and you will get the Einsteinian version. Perhaps you lost the plot, the question was what does Ritz predict for Sagnac. The answer is a null result. >>> that the source is moving normally to the next mirror IN THAT >>> MIRROR'S FRAME. >>> The 'v' in 'c+v' is zero in that mirror's frame. >> >>No it isn't. If you insist on using the second >>mirror frame for all your calculations (a rather >>odd choice but any consistent choice of frame is >>as good as any other), then the speed of the light >>is the vector sum of c in some direction (to be >>determined) and v perpendicular to path. That >>isn't zero Henri, remember Pythagoras. > > Every component is moving normally wrt the next IN THE FRAME OF THE NEXT. If that is to be your approach, you have to analyse the first leg from source to first mirror in the frame of the first mirror, then do a transform into the frame of the second mirror before analysing the second leg, etc.. You haven't accounted for the transform effects. At the end of the day, the result can be no different from either of the two methods we discussed above - a null result. > The 'c' part remains c because the beam is not perfectly parallel. The bit > that > hits the centre of the mirror during rotation is not the same as when it > is > still. And you know from personal experience that moving the beam sideways does not alter the fringes. You said you had seen this when you used a interferometer. Henri, we have been over all this before. >>>>>>Then it's up to you to show how you get a non-null >>>>>>prediction, and you need to start by identifying >>>>>>how BaT differs from Ritz. >>>>> >>>>> George, you have been trying to find a decent explanation for the >>>>> sagnac effect for years. >>>> >>>>Trivial Henri, the speed of light is c in the >>>>lab frame does it perfectly. >>> >>> In a gaseous atmosphere, that might be true. >> >>Nope. The speed is c in vacuo for SR and for >>Maxwell's equations but in anything other than >>a vacuum it is reduced by the refractive index. >>That's basic physics Henri, you must know that. > > Maxwell couldn't measure his two constants in a pure vacuum because the > act of measuring would have disturbed the vacuum Irrelevant Henri, the speed is c in the lab frame in SR hence SR gives the correct prediction. Whinge all you like, you cannot change that. > As Androcles says, the values of permitivity in completely empty space is > zero. Then he is an idiot, that would mean the speed of light would be infinite in ANY medium. >>>>> I have given you my opinion. Light has a built-in gyro in the form of >>>>> an 'axis' >>>> >>>>Ritz doesn't have a "built-in gyro" in the theory and >>>>you said BaT was the same as Ritz. Anyway, as I have >>>>pointed out, photon spin is known and is related to >>>>polarisation, and commercial iFOGs use elliptical >>>>cross-section fibre to prevent changes of polarisation >>>>reducing the accuracy so think again. >>> >>> Ritz died prematurely. >> >>His theory is what it is and still predicts >>a null result. > > Like Newton, he didn't have a chance to bring it up to date. > I'm trying to do that for him. Then that will be your "BaT" theory not his. Ritz's theory predicts a null result. George
From: bz on 8 Oct 2005 13:24 H@..(Henri Wilson) wrote in news:pjodk1hp01816bqaj639orkc2k05fnuat2(a)4ax.com: > On Fri, 7 Oct 2005 19:01:12 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> > wrote: > >>H@..(Henri Wilson) wrote in >>news:kuv5k15e65jjb9f44egkok6qht68k537c0(a)4ax.com: >> >>> Oh, there could be. The brightness curves would be just about the >>> same. The main difference is that the one involving an eclipse is dead >>> flat between the troughs. >> >>That is assuming 'uniform brightness' of the star being eclipsed (which >>isn't true because of the geometry of a spherical radiatior) and no >>gravity lensing. > > That sounds like the argument of a desperate person. That doesn't even sound like an argument based on science. Ad hominem attacks are the last refuge of desperate people. When you make such attacks, you put yourself into that catagory. Download starlight pro from http://www.physics.sfasu.edu/astro/binstar.html and play with it a bit. You will quickly find that the way you can get 'flat between the troughs' is by making the stars spherical. If you want the troughs flat bottomed, turn off limb darkening and make sure the plane of the orbit allows total or annular occultation to take place. >>> ..unlike Algol's , which has a distinct >>> concavity....just as the BaT predicts. >>> -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: The Ghost In The Machine on 8 Oct 2005 15:00
In sci.physics, H@..(Henri Wilson) <H@> wrote on Sat, 08 Oct 2005 10:05:12 GMT <m36fk11abperks4bmbcgr0ot9a7550b2np(a)4ax.com>: > On Sat, 08 Oct 2005 04:00:04 GMT, The Ghost In The Machine > <ewill(a)sirius.tg00suus7038.net> wrote: > >>In sci.physics, H@..(Henri Wilson) >><H@> >> wrote > >>>>epsilon_0? >>>>mu_0? >>>>c? >>>>k? >>>> >>>>> >>>>> Next, you accelerate at 0.0001 c/sec2 for 1000 seconds. >>>>> What values do you now get for the two constants? >>>>> What do they imply? >>>> >>>>This experiment cannot distinguish between SR and BaT. It >>>>*can* distinguish between LET and SR or LET and BaT. >>>> >>>>All four constants remain the same. >>> >>> You don't know that. No such experiment has ever been performed. >> >>Probably not, but both theories predict the same thing AFAICT. >> >>In any event, the Earth is moving around in a circle at a speed >>of about 10^-4 c (or 30 km/s). > > And it is rotating with the galaxy Very slowly, though the actual speed might be 10x faster. The good news about the Earth's revolution is that we know the period -- it's 1 year. Any variation of lightspeed relative to that period should show up fairly readily. > >> >>> Anyway, the answer would be the value of the universal constant 'c'. >> >>For all four constants? > > How do you know the readings would be the same? I don't, but I don't see why they wouldn't be. > . >>>Why wouldn't they apply? And what equations *do* apply? >>>>>> >>>>>>In any event, space isn't truly empty, though intergalactic >>>>>>space is probably pretty desolate. >>>>> >>>>> Probably below the 'Wilsonian threshold density', where >>>>> strange things happen to light. >>>> >>>>OK, dumb question #2: what value/quantity/units is the >>>>"Wilsonian threshold density"? >>> >>> Somewhere between 10^-20 and 10^-100 kgm/m3 >> >>Hm...well, the density of interstellar space is estimated to >>be 0.1-1000 atoms per cubic centimeter, which, if every atom >>is a neutral hydrogen atom, translates into >>1.673 * 10^-21 to 1.673 * 10^-17 kg/m^3. > > That's within the galaxy. Yes. > Estimates are much smaller in intergalactic space. ....10^26 -10^-29 > > These are all guesses anyway. > >>http://hypertextbook.com/facts/2000/DaWeiCai.shtml >> >>This would suggest that a star the size of our sun (1.9862 * 10^30 kg) >>would require a spherical volume of diameter 0.64 light years, at >>this density, to form. (It's of course a lot smaller now, :-) but >>still big enough to dominate the Solar System.) >> >>For the entire Universe, a report suggests 3 * 10^-27 kg/m^3: >> >>http://www.space.com/scienceastronomy/astronomy/universe_density_010307.html > > Just guesses really. No way to know without a lot of work and exploring. We can make some guesses by establishing G = 6.674215*10^-11 m^3/(kg s^2) and trying to weigh the Earth, then the Sun -- but there's a lot of unknown stuff out there, not the least of which is "dark matter". Presumably, that's what's being done here. > > If you want to use my redshift program to see how light is redshifted as it > escapes a star or galaxy, you can plug in any density you like. > > www.users.bigpond.com/hewn/redshift.exe If I wanted to use your redshift program I'd rewrite it in Java. :-P And even then, there's the issue of the Eolas patent, which basically precludes, among other things, applets and objects without a license. http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='5838906'.WKU.&OS=PN/5838906&RS=PN/5838906 [.sigsnip] -- #191, ewill3(a)earthlink.net It's still legal to go .sigless. |