Post by thread:[OT] : Challenging...(another thought)

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'[OT] : Challenging...(another thought)'
2004\06\25@035827 by reinaldo

Wow! this must be good stuff i'm smoking! Imagine this.... there's a limited number of pixels in any monitor, yet it can display any image, so, if you wrote a program to set pixels at every possible colour intensity combination in sequence, eventually you'll get real images!! it could be anything, things that already happened and things that will happen!!and ofcourse a lot of made up things, like a photo of me and john lennon drinking coffe together, it'll be there. what's even more scary, what happens when this sequence eventually runs out? it means any possible and even impossible event that could or could not happend, has already been in the sequence... it means nothing else can happen, you'd think that was infinate, BUT the number of pixels is limited, and so are all possible combinations of this... wierd hey. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\06\25@044920 by Daniel Chia

Well, the problem presents itself in that there are many, many combinations. Lets say we take 24bit colout, Red 8, blue 8, green 8 combination. thats 512 possible colours per pixel. now lets say we have an avg resolution of 800 x 600. now that works out to 512^480000 combination. no small no. I am a competitional programmer in school and computers normally hit about 100,000,000 loops per second.. So generating all the permuations is kinda hard. ------------------------------------------------------------------------ Daniel Chia "Genius is one percent inspiration and ninety-nine percent perspiration." - Thomas Edison E-mail: spam_OUTdanielcjhTakeThisOuTyahoo.com.sg MSN: .....danstryder01KILLspam@spam@yahoo.com.sg ------------------------------------------------------------------------ {Original Message removed}

2004\06\25@045956 by William Chops Westfield

On Jun 25, 2004, at 1:55 AM, Daniel Chia wrote: > > Lets say we take 24bit colout, Red 8, blue 8, green 8 combination. > thats 512 possible colours per pixel 24 bits is 16million possible colors... Reminds me of a physics book I had in college that attemped to demonstrate "impossible" by applying actual analysis to the "lots of monkeys at lots of typerwriters" problem... BillW -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\06\25@050617 by Hopkins

So how long would it take? ************************************************* Roy Hopkins :-) Tauranga New Zealand ************************************************* {Original Message removed}

2004\06\25@052107 by Daniel Chia

Ah yes my bad. i took 8^3 rather thank 2^8^3 which is 16777216 about 16 million. And hmm. how long will it take. Not worth waiting.. Its an exponential algorithm and these things are notorious for the slow speed. ------------------------------------------------------------------------ Daniel Chia "Genius is one percent inspiration and ninety-nine percent perspiration." - Thomas Edison E-mail: danielcjhKILLspamyahoo.com.sg MSN: .....danstryder01KILLspam.....yahoo.com.sg ------------------------------------------------------------------------ {Original Message removed}

2004\06\25@062901 by William Chops Westfield

Let's be nicer and use a 256x256 display ("poor" TV quality) with 8 bits of color (256 values.) That's "only" 256^65536 possible combinations. There are about 10^79 electrons, atoms, and neutrons in the universe. BillW -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\06\25@065842 by Peter van Hoof

maybe you can generate 100,000,000 images a second but even the best of monitors can only display 200 different ones a second and even the best of humans can view at most a few a second Peter {Original Message removed}

2004\06\25@073415 by Robert B.

In attempting to carry out similar calculations and convert to years, Matlab keeps returning "infinity" as the answer. So I guess that solves it! {Original Message removed}

2004\06\25@081025 by Daniel Chia

Hahaha maybe you should get better software. =P just kidding. anyway mathematic returns me no of years which has about 160000 digits roughly. Wow. what a small no ------------------------------------------------------------------------ Daniel Chia "Genius is one percent inspiration and ninety-nine percent perspiration." - Thomas Edison E-mail: EraseMEdanielcjhspam_OUTTakeThisOuTyahoo.com.sg MSN: danstryder01spam_OUTyahoo.com.sg ------------------------------------------------------------------------ {Original Message removed}

2004\06\25@100713 by Russell McMahon

Various thoughts on this thread. 1. The inter-star bending rod is subject to the "laws" of relativity and will not allow peturbatuions greater than light speed to travel along/through it. Alas. 2. Look at waves hitting a beach or ripples hitting the edge of a pool etc. If the wave front is slightly off square, watch what happens to the contact point as the wave hits the edge or shore. Whiel nothing on the wave moves faster than wave speed, the contact point is related to the arctan of the contact angle. For very small angles, the contact point can travel at speeds of 100's of kilometres per hour when the wave is travelling under 10 kph. Nothing physical is actually moving this fast but the motion can be very clearly observed. (The cutting point on a pair of scissor blades does the same thing but with a multiplier of only a few times). Now take a light wave meeting a surface at a small angle ... :-) 3. Beyond monkeys and pictures on a screen there is the number of locations in the universe. Space is quantised in units of Planck length (PL) and time in Planck time (PT). The total possible number of locations in a universe of dimension L (whatever that may actally mean) is about (L / Planck_length)^3. While this number is large it is finite. Similarly you can define all possible locations in space and time for a universe of age T by (L / PL)^3 x (T/PT). The universe has a finite number of possible locations in time and space ;-). Now set your monkeys to work to do something useful with that. 4. The two (arguably) major competing theories for the formation of the universe are i. that it was creating by an external pre-existant entity (where eternal and pre-existant are meaningless terms because neither time or space existed prior to their existing :-) ) OR ii That it was created out of nothing by nothing. Both theories have their problems, but I find the second requires far more faith to believe than the former :-) 5. Did John Lennon drink coffee ? 6. Nothing of Einstein's forbids travelling faster than light. Just AT the speed of light. Hawkings has shown (and it may or may not be true) that, even though NOTHING can escape from a black hole, BH's radiate because particles can "tunnel" across the Shwarzchild radius / event horizon. (There are other ways of looking at this feat but tunneling is as valid (or not) as any.) Tunnel diodes also operate by quantum tunneling where an energy barrier is passed through without being crossed over. So, IF it is possible to tunnel the light speed energy barrier, all sorts of interesting things happen. Energy gains a sqrt(-1) term whose significance is as yet (and may always be) unknown. BUT Plotting 0.5 m x V^2 and allowing for relativistic mass shows that energy required DECREASES past light speed to a minimum about (AFAIR) 10 x light speed and then again increases towards infinity. IF you can tunnel light speed there are TWO equal energy points you can jump to. One is slightly above light speed and the other about 10 or more times light speed. You can't get to either until you are travelling at (AFAIR) about 0.9C and odds are that to tunnel you need your "'ship" to be at around 0.999C +, so we aren't going to see this any time soon. But non zero-rest-mass particles MAY be able to be persuaded to play these games. Now, go and write that science fiction story .... 7. Quantum Mechanics says (rightly or wrongly) that causality is broken at the foundational level. If you build something on an insecure foundation it is necessarily insecure. While you may be able to take many steps to shore it up, the basis of causality is lost if the foundation is non causal. But it still all seems to hang together and work very nicely anyway. Interesting. 8. There are ABOUT as many grains of sand on the beaches of earth as there are stars in the universe (around 10^21 give or take). But, Abraham knew that :-) RM -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\06\25@120835 by Robert Ussery

{Quote hidden}>-----Original Message----- >From: pic microcontroller discussion list [@spam@PICLISTKILLspamMITVMA.MIT.EDU] >On Behalf Of KILLspamreinaldoKILLspamIHUG.CO.NZ >Wow! this must be good stuff i'm smoking! >Imagine this.... >there's a limited number of pixels in any monitor, yet it >can display any image, so, if you wrote a program to set >pixels at every possible colour intensity combination in >sequence, eventually you'll get real images!! it could be >anything, things that already happened and things that will >happen!!and ofcourse a lot of made up things, like a photo >of me and john lennon drinking coffe together, it'll be >there. what's even more scary, what happens when this >sequence eventually runs out? it means any possible and even >impossible event that could or could not happend, has >already been in the sequence... >it means nothing else can happen, you'd think that was >infinate, BUT the number of pixels is limited, and so are >all possible combinations of this... >wierd hey. d00d, lay off the stuff... ur scarin' me! LOL... :O) - Robert -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\06\25@131720 by Dipperstein, Michael

{Quote hidden}> -----Original Message----- > From: pic microcontroller discussion list > [RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU] On Behalf Of spamBeGonereinaldospamBeGoneIHUG.CO.NZ > > Wow! this must be good stuff i'm smoking! > Imagine this.... > there's a limited number of pixels in any monitor, yet it > can display any image, so, if you wrote a program to set > pixels at every possible colour intensity combination in > sequence, eventually you'll get real images!! it could be > anything, things that already happened and things that will > happen!!and ofcourse a lot of made up things, like a photo of > me and john lennon drinking coffe together, it'll be there. > what's even more scary, what happens when this sequence > eventually runs out? it means any possible and even > impossible event that could or could not happend, has already > been in the sequence... it means nothing else can happen, > you'd think that was infinate, BUT the number of pixels is > limited, and so are all possible combinations of this... wierd hey. > Unfortunately, capturing an event in space-time and rendering it as a 2D image on even the best monitor is a lossy compression. There are many pieces of information that are lost. What appears to be you drinking coffee with John Lennon, would look exactly like: - A picture of you drinking sewer water John Lennon - A picture of you drinking coffee with a well costumed space alien dressed as John Lennon - A picture of John Lennon drinking coffee with a well costumed space alien dressed as you - A picture of a well costumed space alien dressed as you drinking brownish alien liquid with a well costumed space alien dressed as John Lennon - A picture of any of the above in the company of the invisible man - A picture of a picture of any of the above Then there's the loss of time and locational information too. What you would get though is every possible image that could be displayed on the monitor that you used. If you want to put the recording industry out of business, you can create and copyright every single bit pattern recordable on a CD. Every time they release a CD, you can sue them, because you already have a copyright on that bit pattern. If they release recordings on another media, you can digitize the recording and put it on a CD, find the matching CD and sue them for transmitting and reproducing your copyrighted material without your express written consent (and the consent of Major League Baseball). -Mike -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\06\25@203722 by William Chops Westfield

On Jun 25, 2004, at 7:07 AM, Russell McMahon wrote: > 2. Look at waves hitting a beach or ripples hitting the edge of a > pool > etc. If the wave front is slightly off square, watch what happens to > the > contact point as the wave hits the edge or shore. Whiel nothing on the > wave > moves faster than wave speed, the contact point is related to the > arctan of > the contact angle. For very small angles, the contact point can travel > at > speeds of 100's of kilometres per hour when the wave is travelling > under 10 > kph. Nothing physical is actually moving this fast but the motion can > be > very clearly observed. There's a similar phenomena for EM/etc; either the 'group velocity' or 'phase velocity' of the waveform corresponding to something like a fundamental packet; (IIRC, it goes something like this. A particle is like a wave, right? but you apply forier analysis to get something that looks like the discontinuous waveform of a particle, and the individual frequencies involved have to have propagation velocities faster than C. Unfortunately, you can do anything useful with those parts...) BillW -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\06\26@115637 by John Ferrell

So how much delay is there in a hydraulic system? My intuition is telling me it is faster that a sonar signal. John Ferrell http://DixieNC.US {Original Message removed}

'[OT] : Challenging...(another thought)'
2004\07\25@232947 by Robert B.

A bit of googling found this: 5000 m/sec: speed of sound in structural steel 1500 m/s : speed of sound in water (temp. dependent) 1600 m/s : speed of sound in hydraulic fluid/oil 330 m/s : speed of sound in air (STP) 3e8 m/s : speed of light in a vacuum However, I seem to recall reading some theory in which electrons in a wire are viewed as "marbles in a tube", and thus electricity can apprear to move faster than the speed of light. The theory went that since the "tube" was already full of "marbles", putting one in the end spits one out the other end instantaneously, though no single "marble" really moves that fast. I don't remember the source, but I'll poke around some of my old electronics books and see if I can find it. {Original Message removed}

2004\07\25@234023 by Anthony Toft

> 3e8 m/s : speed of light in a vacuum All though this is considered the speed limit of the universe by most. I read somewhere that royalty exceeds it, the heir to the throne becoming King the moment the former King died. Pratchett I think it was -- Anthony Toft <TakeThisOuTtoftatEraseMEspam_OUTcowshed.8m.com> -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

2004\07\26@021717 by Jinx

> I'll poke around some of my old electronics books and > see if I can find it Just Google for "marbles in a tube" ;-) !! http://www.physicsforums.com/archive/t-5367 -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@040107 by Russell McMahon

> 5000 m/sec: speed of sound in structural steel > 1500 m/s : speed of sound in water (temp. dependent) > 1600 m/s : speed of sound in hydraulic fluid/oil > 330 m/s : speed of sound in air (STP) > 3e8 m/s : speed of light in a vacuum > > However, I seem to recall reading some theory in which electrons in a wire > are viewed as "marbles in a tube", and thus electricity can apprear to move > faster than the speed of light. The electrons do indeed move slower than the "signal", but the signal speed does respect the laws of Physics as we presently know them ie it's always slower than the speed of light in vacuum. The electron speed is referred to as the "drift velocity" and can be calculated from the charge required to be transferred in unit time, the charge on an electron (which together gives electron flow per unit time) and physical characteristics of the system (the fatter the "pipe" the slower the flow). In all such ponderings the principle of TAANSTAAFL almost always applies. An interesting effect occurs when you inject particles/electromagnetic waves from eg a vacuum into a medium where the normal propagation speed is lower. For gamma waves (super energetic photons) the result is "Cherenkov radiation" - this occurs when gamma rays enter the atmosphere and is used as a major means of detecting incoming gamma rays. It is also seen as a bluish white glow when radioactive material is stored under water. An excellent intuitive graphical explanation of the phenomenon may be found here http://physics.csufresno.edu/akira/SR/Cherenkov.html RM -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@041143 by Russell McMahon

Commenting on my comment - > The electrons do indeed move slower than the "signal", but the signal speed > does respect the laws of Physics as we presently know them ie it's always > slower than the speed of light in vacuum. The electron speed is referred to > as the "drift velocity" and can be calculated from the charge required to be > transferred in unit time, the charge on an electron (which together gives > electron flow per unit time) and physical characteristics of the system > (the fatter the "pipe" the slower the flow). The drift velocity is the effective electron speed, which doesn't mean that that is the speed that they travel at when they do "travel". Electrons ALWAYS travel slower than the speed of light as they have "rest mass". No particles with rest mass can travel AT the speed of light. ALL particles with no mass must travel at the speed of light. As far as we know :-) RM -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@100238 by Mike Hord

This is more of a question of the speed of transfer of information, kind of like Russell's "marbles in a tube" question. The marble isn't travelling faster than light, but the information that marble has been added to the tube is. Maybe. Theoretical physics is not my strongest area. I just thought I'd comment on the "Speed of Royalty" (not to be confused with the "Speed of Goverment" which is markedly slower.) Mike H. > > 3e8 m/s : speed of light in a vacuum > >All though this is considered the speed limit of the universe by most. I >read somewhere that royalty exceeds it, the heir to the throne becoming >King the moment the former King died. Pratchett I think it was > >-- >Anthony Toft <RemoveMEtoftatTakeThisOuTcowshed.8m.com> _________________________________________________________________ FREE pop-up blocking with the new MSN Toolbar get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/ -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@101322 by Jake Anderson

you are mixing up 2 things the information can travel faster than the speed of the particle in the tube. however the marbles cant travel faster than the speed of light. so the marbles will compress at their local speed of sound (in the marble material itself) > {Original Message removed}

2004\07\26@101736 by D. Jay Newman

> you are mixing up 2 things > the information can travel faster than the speed of the particle in the > tube. Yes, but according to the currently accepted theories, the information cannot travel faster than the speed of light. Yes, I'm hoping that there are some new discoveries that allow for FTL travel, but for now there isn't even an FTL radio. > however the marbles cant travel faster than the speed of light. > so the marbles will compress at their local speed of sound (in the marble > material itself) Yes, physical objects compress at their speed of sound. -- D. Jay Newman ! DCX - it takes off and lands base down, jayEraseME.....sprucegrove.com ! as God and Robert Heinlein intended. http://enerd.ws/robots/ ! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@102326 by Jake Anderson

afaikr theres nothing that says information cant travel faster than light. nothing says *we* cant travel faster than the speed of light. you just cant go from below the speed of light to above it ;-> i wonder what the affect on luminal matter (ie stuff below C) would be from superluminal matter (ir stuff travelling FTL) ignoring the mechanics of getting there for the time being. methods of detecting this are left as an exercise for the reader. what i find interesting also is apparently for a fair while after the big bang the local speed of sound exceded the speed of light(based on the density of material). > {Original Message removed}

2004\07\26@102934 by Robert B.

Yeah that seems more right, I was confusing it in my head. BUT... it's still hard to believe that if I had a tube about 2km long full of marbles, and a really big sledge-hammer to cram another one in, that it would take a full second after a forceful insertion on the one end for one to pop out the other end. I suppose it's true, but perhaps one day if I get rich and infamous I'll verify it personally, just for kicks. ----- Original Message ----- From: "Jake Anderson" <EraseMEgrooveeeOPTUSHOME.COM.AU> To: <RemoveMEPICLISTEraseMEEraseMEMITVMA.MIT.EDU> Sent: Monday, July 26, 2004 10:14 AM Subject: Re: [OT] : Challenging...(another thought) > you are mixing up 2 things > the information can travel faster than the speed of the particle in the > tube. > > however the marbles cant travel faster than the speed of light. > so the marbles will compress at their local speed of sound (in the marble > material itself) > > > > {Original Message removed}

2004\07\26@103141 by D. Jay Newman

> afaikr theres nothing that says information cant travel faster than light. Physics? There are some theories that certain things happen faster than light, especially in quantum mechanics. However, there is no way to extract information from these things. This is the accepted wisdom *now*. Hopefully this will eventually be changed, but for now, I'd study a bit more physics and less SF. > nothing says *we* cant travel faster than the speed of light. Again, this is physics. This says that we can't travel faster than the speed of light. There *may* be some promising loopholes, but they are only speculative now. > you just cant go from below the speed of light to above it ;-> This is an extremely common plot concept in science fiction. Please do not confuse this with currently accepted physics. > what i find interesting also is apparently for a fair while after the big > bang the local speed of sound exceded the speed of light(based on the > density of material). Again, that is theory. If there was a big bang (and this seems probable) then the basic constants of the universe were in flux during an extremely short period. The speed of light may have been much higher at that point. -- D. Jay Newman ! DCX - it takes off and lands base down, RemoveMEjayspam_OUTKILLspamsprucegrove.com ! as God and Robert Heinlein intended. http://enerd.ws/robots/ ! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@103746 by D. Jay Newman

> BUT... it's still hard to believe that if I had a tube about 2km long full > of marbles, and a really big sledge-hammer to cram another one in, that it > would take a full second after a forceful insertion on the one end for one > to pop out the other end. I suppose it's true, but perhaps one day if I get > rich and infamous I'll verify it personally, just for kicks. You'd have to use strong marbles and get somebody really strong to do the hammering. Two km of marbles will have a lot of inertia and something will probably break. A better experiment would be to take a long metal rod that is restricted to only move in one dimension. Then hit one end and measure when the other end moves. With precision timing you don't need that long a rod. -- D. Jay Newman ! DCX - it takes off and lands base down, RemoveMEjayTakeThisOuTspamsprucegrove.com ! as God and Robert Heinlein intended. http://enerd.ws/robots/ ! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@104146 by Robert B.

The currently accepted physical equations are undefined *only* at the speed of light. They work out to real solutions for speeds both above and below the speed of light. So I assume thats what he meant by "you just cant go from below the speed of light to above it", because it would require passing through that undefined point, speed of light. Of course its all really theory anyhow. {Original Message removed}

2004\07\26@104746 by D. Jay Newman

> The currently accepted physical equations are undefined *only* at the speed > of light. They work out to real solutions for speeds both above and below > the speed of light. So I assume thats what he meant by "you just cant go > from below the speed of light to above it", because it would require passing > through that undefined point, speed of light. Of course its all really > theory anyhow. Sorry, but these equations are Einstein's Special Relativity. General Relativity removes this loophole, as does quantum mechanics. Strangely enough, the equations work very well if you just set c (the speed of light) to infinity. It simplifies a lot of things. I did this in college because a prof claimed it would never work and I wrote out a self-consistent set of equations. (By setting c to infinity, I don't mean that everything happens simultaniously, but that the definition of the theory made c the fastest possible velocity in a given medium.) -- D. Jay Newman ! DCX - it takes off and lands base down, EraseMEjayspamspamBeGonesprucegrove.com ! as God and Robert Heinlein intended. http://enerd.ws/robots/ ! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@104957 by Jake Anderson

perhaps my reading of "the" book by the man (relativity) was off but i'm pretty sure that what he said was to move physical mass at c would take infinite energy. Nothing was said of traveling faster than c being impossible. (in fact if i read it right you would need infinite energy to slow down to c if you did happen to excede it) the problem is to go from traveling at < c to > c without being = c. > {Original Message removed}

2004\07\26@105617 by D. Jay Newman

> perhaps my reading of "the" book by the man (relativity) was off but i'm > pretty sure that what he said was to move physical mass at c would take > infinite energy. Nothing was said of traveling faster than c being > impossible. (in fact if i read it right you would need infinite energy to > slow down to c if you did happen to excede it) Yes, Specific Relativity has these equations. They are only a simplification of General Relativity. > the problem is to go from traveling at < c to > c without being = c. Yes, the equations in Specific Relativity do that. However, that is just one part of the picture. When you add the other parts in, going faster than c is (according to these theories) impossible. Now, it does seem that certain information *does* travel faster than light (perhaps even instantaniously). However, this information is on a level that we can't make use of. For example, if you produce two particles of opposite spin (this happens from certain collisions) and measure one, the other becomes the opposite. On the other hand, this could merely be quantum mechanics strangeness that only happens to make the theories look good. -- D. Jay Newman ! DCX - it takes off and lands base down, RemoveMEjayKILLspamsprucegrove.com ! as God and Robert Heinlein intended. http://enerd.ws/robots/ ! -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\26@174252 by William Chops Westfield

On Jul 26, 2004, at 7:01 AM, Mike Hord wrote: > This is more of a question of the speed of transfer of information, > kind of like Russell's "marbles in a tube" question. The marble isn't > travelling faster than light, but the information that marble has been > added to the tube is. No, in an electrical circuit, the electrons themselves move quite slowly; it's the information that travels at about c (0.7c or so for most wire.) In a tube full of marbles, the individual marbles move very slowly and the info moves at the speed of sound (in marbles.) Certain waveforms have certain component velocities higher than c, but the info transfer is still c... BillW -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

2004\07\27@174359 by Peter L. Peres

>BUT... it's still hard to believe that if I had a tube about 2km long >full of marbles, and a really big sledge-hammer to cram another one in, >that it would take a full second after a forceful insertion on the one >end for one to pop out the other end. I suppose it's true, but perhaps >one day if I get rich and infamous I'll verify it personally, just for >kicks. How about a drum of coax cable, a signal generator, and a two channel scope ? You can substitute fiber if you like. Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@175021 by David VanHorn

> >How about a drum of coax cable, a signal generator, and a two channel >scope ? You can substitute fiber if you like. I've seen this done at the SF Exploratorium. They have a big mechanical chopper, and a drum of fiber. The chopper blocks the transmit end, and the receive end at the same time. If you turn the crank fast enough, you start getting light out the end of the fiber, that was put into it a half-cycle ago. Of course an AVR at 16 MHz can turn an LED on and off before the first light from the LED reaches your eye. :) -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@182959 by Jinx

> Of course an AVR at 16 MHz can turn an LED on and off before > the first light from the LED reaches your eye. :) The Scenix user might ask if you could even see such a LED from so far away ;-P -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@183207 by David VanHorn

At 05:30 PM 7/27/2004, Jinx wrote: >> Of course an AVR at 16 MHz can turn an LED on and off before >> the first light from the LED reaches your eye. :) > >The Scenix user might ask if you could even see such a LED from so >far away ;-P Yes, but I still have nice peripherals. He's too busy emulating a timer. :-P -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@185036 by Mark Jordan

On 27 Jul 2004 at 17:33, David VanHorn wrote: > At 05:30 PM 7/27/2004, Jinx wrote: > > >> Of course an AVR at 16 MHz can turn an LED on and off before > >> the first light from the LED reaches your eye. :) > > > >The Scenix user might ask if you could even see such a LED from so > >far away ;-P > > Yes, but I still have nice peripherals. He's too busy emulating a timer. > :-P > I doubt a SX @100MHz would be faster than the new AVR @24MHz... Mark Jordan -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@191152 by Russell McMahon

> I doubt a SX @100MHz would be faster than the new AVR @24MHz... Overall maybe not. For some individual operations and groups of operations, definitely so. AVR & SX can both do some things at 1 cycle time so SX can be 4 times faster for some things. RM -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@191158 by Russell McMahon

> > Of course an AVR at 16 MHz can turn an LED on and off before > > the first light from the LED reaches your eye. :) > > The Scenix user might ask if you could even see such a LED from so > far away ;-P I'll take that query literally :-): nS = light foot. Say on and off in 1 cycle = 1/16 MHz =~60 nS LED would need to be 60 feet / 20 metre away. Many ultra-bright LEDs seeable at that sort of distance. Using a high speed peripheral gated with PLL clock may allow much faster switching. RM -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@192441 by David VanHorn

At 06:07 PM 7/27/2004, Russell McMahon wrote: >> > Of course an AVR at 16 MHz can turn an LED on and off before >> > the first light from the LED reaches your eye. :) >> >> The Scenix user might ask if you could even see such a LED from so >> far away ;-P > >I'll take that query literally :-): > >nS = light foot. >Say on and off in 1 cycle = 1/16 MHz =~60 nS >LED would need to be 60 feet / 20 metre away. >Many ultra-bright LEDs seeable at that sort of distance. > >Using a high speed peripheral gated with PLL clock may allow much faster >switching. Whoops. I must be tired, somehow I got 1.6' out of that. It seemed slow.. Light in water? :) -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@194555 by Howard Winter

Russell, (Pedantic mode: ON) On Wed, 28 Jul 2004 11:07:01 +1200, Russell McMahon wrote: > nS = light foot. I think you mean: Light nS = Foot ? (Pedantic mode: OFF) :-) Cheers, Howard Winter St.Albans, England -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\27@203632 by Russell McMahon

> > nS = light foot. > I think you mean: Light ns = Foot ? To be pedantic, neither, quite. Or both. * Just a shorthand summary stored in my brain along with many other such for the "fact" that light travels (about) 1 foot in 1 nS in vacuum ie V = 3E8 m/s so in 1E-9s it travels 3E-1m =~~ 1 foot. RM * If you said Vlight x ns = feet then I'd agree as the units then work OK. Maybe I should say ns = light_foot as no multiplication is accidentally implied. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\07\28@084129 by John Ferrell

> Light in water? :) I think this is covered under the topic "refraction". I need more cofee to think more on this subject! John Ferrell http://DixieNC.US {Original Message removed}

2004\07\29@150353 by jsand

Hello Jay & PIC.ers, > >A better experiment would be to take a long metal rod that is restricted >to only move in one dimension. Then hit one end and measure when the other >end moves. With precision timing you don't need that long a rod. >-- This can be made really easy too. Hang any old length of off-cut material (steel, copper rod) horizontally on a couple of strings. When you knock one end of the piece longitudinally with a hammer, the impulse sends it away from the hammer head. This appears to be `instantaneous' but there is a delay due to the need for the impulse to reach the far end of the strike-ee rod, change phase 180degree and reflect back to the hammer. Once it gets there, the two metal pieces separate for the first time. The time delay can be measured by closing a circuit (hammer / rod) and monitoring by scope. Voila, speed of sound in metals. best regards, John email from the desk of John Sanderson. JS Controls, PO Box 1887, Boksburg 1460, Rep. of S. Africa. Tel/Fax 011 893 4154, Cell 082 741 6275, web http://www.jscontrols.co.za Manufacturer & purveyor of laboratory force testing apparatus & related products & services. -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestSTOPspamspam_OUTmitvma.mit.edu

2004\07\29@165428 by Win Wiencke

<jsand wrote> > Hang any old length of off-cut material (steel, copper rod) horizontally > on a couple of strings. When you knock one end of the piece longitudinally with > a hammer, the impulse sends it away from the hammer head. > This appears to be `instantaneous' but there is a delay due to the need > for the impulse to reach the far end of the strike-ee rod, > change phase 180degree and reflect back to the hammer. > Once it gets there, the two metal pieces separate for the first time. > > The time delay can be measured by closing a circuit (hammer / rod) and > monitoring by scope. Voila, speed of sound in metals. Great teaching demo Wonder if a PIC could clock it from contact to rebound. Probably too fast.though. Thanks! Win Wiencke Image Logic Corporation -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestSTOPspamEraseMEmitvma.mit.edu

2004\07\30@083226 by John Ferrell

I think you just described a sonic delay line. IBM was using these for storage in the late 60's with lengths up to about 500 ms. That size was touchy, the 50 ms units were rock solid. John Ferrell http://DixieNC.US {Original Message removed}

'[OT] : Challenging...(another thought)'
2004\08\01@112017 by Howard Winter

John, On Fri, 30 Jul 2004 08:33:03 -0400, John Ferrell wrote: > I think you just described a sonic delay line. IBM was using these for > storage in the late 60's with lengths up to about 500 ms. That size was > touchy, the 50 ms units were rock solid. I think you're wrong there - I believe they were filled with mercury, so were anything but solid! :-) Cheers, Howard Winter St.Albans, England -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

2004\08\01@113054 by Sergio Masci

----- Original Message ----- From: Howard Winter <KILLspamHDRWspamBeGoneH2ORG.DEMON.CO.UK> To: <EraseMEPICLISTEraseMEMITVMA.MIT.EDU> Sent: Sunday, August 01, 2004 4:19 PM Subject: Re: [OT] : Challenging...(another thought) > John, > > On Fri, 30 Jul 2004 08:33:03 -0400, John Ferrell wrote: > > > I think you just described a sonic delay line. IBM was using these for > > storage in the late 60's with lengths up to about 500 ms. That size was > > touchy, the 50 ms units were rock solid. > > I think you're wrong there - I believe they were filled with mercury, so were anything but solid! :-) > I have seen some delay lines that consisted of a coil of wire. The coil was about 8" diameter and only had a few turns (which did not touch each other). I belive the wire was a nickel alloy. Regards Sergio Masci -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

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