The Double Slit Experiment With A Laser Pointer
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From: PD on 19 Jan 2010 15:16 On Jan 19, 1:37 pm, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > On Jan 19, 6:57 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jan 19, 10:22 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > On Jan 19, 6:08 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jan 19, 2:52 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > > > On Jan 18, 7:47 pm, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > On Jan 15, 1:00 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > On Jan 14, 8:02 pm, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > > On Jan 13, 11:17 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > > On Jan 13, 10:39 am, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > > > > It is alleged in a few forum threads that visible interference > > > > > > > > > > patterns can be produced with an inexpensive laser pointer. Is this > > > > > > > > > > true? How do you easily create a suitable 3-line diffraction grid with > > > > > > > > > > the ideal spacing? Has anyone here actually tried the famous double > > > > > > > > > > slit experiment with a low cost laser pointer? > > > > > > > > > > Yes, it's pretty easy. > > > > > > > > > The easiest way to obtain a diffraction grating is to order one. > > > > > > > > > They're cheap. > > > > > > > > > The only diffraction gratings I see in the science education catalogs > > > > > > > > that I know about, Nasco, Fisher Scientific, Carolina Science and > > > > > > > > Math, have 100's of lines per mm. What company sells a diffraction > > > > > > > > grating for a standard double slit experiment? > > > > > > > > > > You can also make one with a trio of single-edge razor blades taped > > > > > > > > > together, scratching parallel lines on a microscope slide painted > > > > > > > > > black. > > > > > > > > > That's too much trouble. > > > > > > > > Really? It takes an hour and is cheap. > > > > > > > > > I want to buy an optimized double slit for > > > > > > > > the typical red laser light pen. Where can I get it? > > > > > > > > The ones with hundreds of lines per mm ARE optimized for the typical > > > > > > > red laser pen. Buy those. > > > > > > > Seriously, here's how you tell. > > > > > > > Red light has a wavelength of 650 nm, which is about half a thousandth > > > > > > > of a mm. > > > > > > > The angle in radians between the central and first side spots is > > > > > > > roughly the ratio of the wavelength to the line spacing. > > > > > > > So if you have a line spacing of a half a hundredth of a mm, then you > > > > > > > will have an angle of about a tenth of a radian or five degrees. > > > > > > > > You haven't checked Edmund Scientific, Wards, or any of a number of > > > > > > > scientific *toy* catalogs that school teachers use. The good news is > > > > > > > that this is used in 4th grade classes sometimes, so you'll find > > > > > > > plenty if you stop looking in professional grade catalogs. > > > > > > > > > Here's a great video on the double slit experiment using pencil leads, > > > > > > > > but I suspect that the presenter, Jack Maxwell, is using a powerful > > > > > > > > laser and who knows how long he had to play with it in front of the > > > > > > > > camera to get it right. Time is valuable to me. I certainly don't want > > > > > > > > to waste time fiddling around during a physics lecture.http://www.youtube.com/watch?v=UANVMIajqlA > > > > > > > Thank you Paul but there is still a mystery that I don't understand. > > > > > > > If the double slit experiment is the central mystery of physics, why > > > > > > is it that no one manufactures a precisely crafted single double slit > > > > > > that is optimized for the very popular low-power red laser light pen? > > > > > > > As you know, Richard P. Feynman said: > > > > > > > We choose to examine a phenomenon which is impossible, absolutely > > > > > > impossible, to explain in any classical way, and which has in it the > > > > > > heart of quantum mechanics. In reality, it contains the only > > > > > > mystery. > > > > > > > As I see it, creating a diffraction pattern with a diffraction grading > > > > > > that has hundreds of lines per mm doesn't seem so mysterious. > > > > > > ------------------ > > > > > the mystry is only becuase of ignorance!! > > > > > QM peoole pose as if they know andunderstand > > > > > everything by their crippled supermarket theory > > > > > AND IN MANY CASES WRONG INTERPRETATIONS !! > > > > > > it starts with the illusion that we know really > > > > > what is a photon > > > > > and worse of that > > > > > WhaT IS REALLY * A SINGLE PHOTON* > > > > > > i claim that : > > > > > > A a single photon is not represented by > > > > > hf > > > > > (nature does not know what is a second!!... > > > > > a second is a human arbitrary definition of time !!.) > > > > > > hf represents MANY SINGLE PHOTONS !!!!! > > > > > Ever seen a photomultiplier tube? > > > > > > ATB > > > > > Y.Porat > > > > > ------------- > > > > no > > > so what about it ?? > > > anyway > > > i am sure that the real **single photon is so tiny > > > that it has no chance to make ant mark] > > > Then you certainly haven't seen a photomultiplier tube. > > Single photons are easily detected. > > > > on a screen > > > y.porat > > > ---------------------- > > just tell me how do you know > waht is a single photon > > why on earth it is defined > BY NATURE by the energy that is emitted in one second It ISN'T. I can't help if if you don't have the foggiest idea what a photon is, or what a photomultiplier tube is, or how we can tell when there is just one of something as opposed to several. > what does nature know about your > second The photon IS NOT the energy delivered in one second. Good heavens, Porat. If I drop something from a plane and it experiences an acceleration of 9.8 m/s/s, does this mean that it takes one second for it to fall to the ground? If I drive to work at 40 miles/hour, does this mean that it takes me an hour to drive to work? Are you really this dense? > why not nanosecond why not billion times smaller than a > nanosecond ??? > Y.Porat > ---------------------
From: Inertial on 19 Jan 2010 20:21 "Y.Porat" <y.y.porat(a)gmail.com> wrote in message news:b5dc1f6b-f8d1-4bf8-9fa2-e27dca2ccb58(a)34g2000yqp.googlegroups.com... > On Jan 18, 7:47 pm, Shubee <e.shu...(a)gmail.com> wrote: >> On Jan 15, 1:00 pm, PD <thedraperfam...(a)gmail.com> wrote: >> >> >> >> > On Jan 14, 8:02 pm, Shubee <e.shu...(a)gmail.com> wrote: >> >> > > On Jan 13, 11:17 am, PD <thedraperfam...(a)gmail.com> wrote: >> >> > > > On Jan 13, 10:39 am, Shubee <e.shu...(a)gmail.com> wrote: >> >> > > > > It is alleged in a few forum threads that visible interference >> > > > > patterns can be produced with an inexpensive laser pointer. Is >> > > > > this >> > > > > true? How do you easily create a suitable 3-line diffraction grid >> > > > > with >> > > > > the ideal spacing? Has anyone here actually tried the famous >> > > > > double >> > > > > slit experiment with a low cost laser pointer? >> >> > > > Yes, it's pretty easy. >> > > > The easiest way to obtain a diffraction grating is to order one. >> > > > They're cheap. >> >> > > The only diffraction gratings I see in the science education catalogs >> > > that I know about, Nasco, Fisher Scientific, Carolina Science and >> > > Math, have 100's of lines per mm. What company sells a diffraction >> > > grating for a standard double slit experiment? >> >> > > > You can also make one with a trio of single-edge razor blades taped >> > > > together, scratching parallel lines on a microscope slide painted >> > > > black. >> >> > > That's too much trouble. >> >> > Really? It takes an hour and is cheap. >> >> > > I want to buy an optimized double slit for >> > > the typical red laser light pen. Where can I get it? >> >> > The ones with hundreds of lines per mm ARE optimized for the typical >> > red laser pen. Buy those. >> > Seriously, here's how you tell. >> > Red light has a wavelength of 650 nm, which is about half a thousandth >> > of a mm. >> > The angle in radians between the central and first side spots is >> > roughly the ratio of the wavelength to the line spacing. >> > So if you have a line spacing of a half a hundredth of a mm, then you >> > will have an angle of about a tenth of a radian or five degrees. >> >> > You haven't checked Edmund Scientific, Wards, or any of a number of >> > scientific *toy* catalogs that school teachers use. The good news is >> > that this is used in 4th grade classes sometimes, so you'll find >> > plenty if you stop looking in professional grade catalogs. >> >> > > Here's a great video on the double slit experiment using pencil >> > > leads, >> > > but I suspect that the presenter, Jack Maxwell, is using a powerful >> > > laser and who knows how long he had to play with it in front of the >> > > camera to get it right. Time is valuable to me. I certainly don't >> > > want >> > > to waste time fiddling around during a physics >> > > lecture.http://www.youtube.com/watch?v=UANVMIajqlA >> >> Thank you Paul but there is still a mystery that I don't understand. >> >> If the double slit experiment is the central mystery of physics, why >> is it that no one manufactures a precisely crafted single double slit >> that is optimized for the very popular low-power red laser light pen? >> >> As you know, Richard P. Feynman said: >> >> �We choose to examine a phenomenon which is impossible, absolutely >> impossible, to explain in any classical way, and which has in it the >> heart of quantum mechanics. In reality, it contains the only >> mystery.� >> >> As I see it, creating a diffraction pattern with a diffraction grading >> that has hundreds of lines per mm doesn't seem so mysterious. > > ------------------ > the mystry is only becuase of ignorance!! > QM peoole pose as if they know andunderstand > everything by their crippled supermarket theory > AND IN MANY CASES WRONG INTERPRETATIONS !! > > it starts with the illusion that we know really > what is a photon > and worse of that > WhaT IS REALLY * A SINGLE PHOTON* > > i claim that : > > A a single photon is not represented by > hf > (nature does not know what is a second!!... > a second is a human arbitrary definition of time !!.) > > hf represents MANY SINGLE PHOTONS !!!!! Then you're an idiot. Read up on the experiments that led to the discovery of E = hf.
From: Inertial on 19 Jan 2010 20:23 "PD" <thedraperfamily(a)gmail.com> wrote in message news:c762c1ab-2691-43a3-b9d8-2e668eed6ffc(a)a15g2000yqm.googlegroups.com... > On Jan 19, 1:37 pm, "Y.Porat" <y.y.po...(a)gmail.com> wrote: >> On Jan 19, 6:57 pm, PD <thedraperfam...(a)gmail.com> wrote: >> >> >> >> > On Jan 19, 10:22 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: >> >> > > On Jan 19, 6:08 pm, PD <thedraperfam...(a)gmail.com> wrote: >> >> > > > On Jan 19, 2:52 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: >> >> > > > > On Jan 18, 7:47 pm, Shubee <e.shu...(a)gmail.com> wrote: >> >> > > > > > On Jan 15, 1:00 pm, PD <thedraperfam...(a)gmail.com> wrote: >> >> > > > > > > On Jan 14, 8:02 pm, Shubee <e.shu...(a)gmail.com> wrote: >> >> > > > > > > > On Jan 13, 11:17 am, PD <thedraperfam...(a)gmail.com> wrote: >> >> > > > > > > > > On Jan 13, 10:39 am, Shubee <e.shu...(a)gmail.com> wrote: >> >> > > > > > > > > > It is alleged in a few forum threads that visible >> > > > > > > > > > interference >> > > > > > > > > > patterns can be produced with an inexpensive laser >> > > > > > > > > > pointer. Is this >> > > > > > > > > > true? How do you easily create a suitable 3-line >> > > > > > > > > > diffraction grid with >> > > > > > > > > > the ideal spacing? Has anyone here actually tried the >> > > > > > > > > > famous double >> > > > > > > > > > slit experiment with a low cost laser pointer? >> >> > > > > > > > > Yes, it's pretty easy. >> > > > > > > > > The easiest way to obtain a diffraction grating is to >> > > > > > > > > order one. >> > > > > > > > > They're cheap. >> >> > > > > > > > The only diffraction gratings I see in the science >> > > > > > > > education catalogs >> > > > > > > > that I know about, Nasco, Fisher Scientific, Carolina >> > > > > > > > Science and >> > > > > > > > Math, have 100's of lines per mm. What company sells a >> > > > > > > > diffraction >> > > > > > > > grating for a standard double slit experiment? >> >> > > > > > > > > You can also make one with a trio of single-edge razor >> > > > > > > > > blades taped >> > > > > > > > > together, scratching parallel lines on a microscope slide >> > > > > > > > > painted >> > > > > > > > > black. >> >> > > > > > > > That's too much trouble. >> >> > > > > > > Really? It takes an hour and is cheap. >> >> > > > > > > > I want to buy an optimized double slit for >> > > > > > > > the typical red laser light pen. Where can I get it? >> >> > > > > > > The ones with hundreds of lines per mm ARE optimized for the >> > > > > > > typical >> > > > > > > red laser pen. Buy those. >> > > > > > > Seriously, here's how you tell. >> > > > > > > Red light has a wavelength of 650 nm, which is about half a >> > > > > > > thousandth >> > > > > > > of a mm. >> > > > > > > The angle in radians between the central and first side spots >> > > > > > > is >> > > > > > > roughly the ratio of the wavelength to the line spacing. >> > > > > > > So if you have a line spacing of a half a hundredth of a mm, >> > > > > > > then you >> > > > > > > will have an angle of about a tenth of a radian or five >> > > > > > > degrees. >> >> > > > > > > You haven't checked Edmund Scientific, Wards, or any of a >> > > > > > > number of >> > > > > > > scientific *toy* catalogs that school teachers use. The good >> > > > > > > news is >> > > > > > > that this is used in 4th grade classes sometimes, so you'll >> > > > > > > find >> > > > > > > plenty if you stop looking in professional grade catalogs. >> >> > > > > > > > Here's a great video on the double slit experiment using >> > > > > > > > pencil leads, >> > > > > > > > but I suspect that the presenter, Jack Maxwell, is using a >> > > > > > > > powerful >> > > > > > > > laser and who knows how long he had to play with it in >> > > > > > > > front of the >> > > > > > > > camera to get it right. Time is valuable to me. I certainly >> > > > > > > > don't want >> > > > > > > > to waste time fiddling around during a physics >> > > > > > > > lecture.http://www.youtube.com/watch?v=UANVMIajqlA >> >> > > > > > Thank you Paul but there is still a mystery that I don't >> > > > > > understand. >> >> > > > > > If the double slit experiment is the central mystery of >> > > > > > physics, why >> > > > > > is it that no one manufactures a precisely crafted single >> > > > > > double slit >> > > > > > that is optimized for the very popular low-power red laser >> > > > > > light pen? >> >> > > > > > As you know, Richard P. Feynman said: >> >> > > > > > �We choose to examine a phenomenon which is impossible, >> > > > > > absolutely >> > > > > > impossible, to explain in any classical way, and which has in >> > > > > > it the >> > > > > > heart of quantum mechanics. In reality, it contains the only >> > > > > > mystery.� >> >> > > > > > As I see it, creating a diffraction pattern with a diffraction >> > > > > > grading >> > > > > > that has hundreds of lines per mm doesn't seem so mysterious. >> >> > > > > ------------------ >> > > > > the mystry is only becuase of ignorance!! >> > > > > QM peoole pose as if they know andunderstand >> > > > > everything by their crippled supermarket theory >> > > > > AND IN MANY CASES WRONG INTERPRETATIONS !! >> >> > > > > it starts with the illusion that we know really >> > > > > what is a photon >> > > > > and worse of that >> > > > > WhaT IS REALLY * A SINGLE PHOTON* >> >> > > > > i claim that : >> >> > > > > A a single photon is not represented by >> > > > > hf >> > > > > (nature does not know what is a second!!... >> > > > > a second is a human arbitrary definition of time !!.) >> >> > > > > hf represents MANY SINGLE PHOTONS !!!!! >> >> > > > Ever seen a photomultiplier tube? >> >> > > > > ATB >> > > > > Y.Porat >> > > > > ------------- >> >> > > no >> > > so what about it ?? >> > > anyway >> > > i am sure that the real **single photon is so tiny >> > > that it has no chance to make ant mark] >> >> > Then you certainly haven't seen a photomultiplier tube. >> > Single photons are easily detected. >> >> > > on a screen >> > > y.porat >> > > ---------------------- >> >> just tell me how do you know >> waht is a single photon >> >> why on earth it is defined >> BY NATURE by the energy that is emitted in one second > > It ISN'T. > > I can't help if if you don't have the foggiest idea what a photon is, > or what a photomultiplier tube is, or how we can tell when there is > just one of something as opposed to several. > >> what does nature know about your >> second > > The photon IS NOT the energy delivered in one second. > > Good heavens, Porat. If I drop something from a plane and it > experiences an acceleration of 9.8 m/s/s, does this mean that it takes > one second for it to fall to the ground? If I drive to work at 40 > miles/hour, does this mean that it takes me an hour to drive to work? > Are you really this dense? Yes .. he is.
From: Y.Porat on 20 Jan 2010 01:11 On Jan 19, 10:16 pm, PD <thedraperfam...(a)gmail.com> wrote: > On Jan 19, 1:37 pm, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > > On Jan 19, 6:57 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > On Jan 19, 10:22 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > > On Jan 19, 6:08 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > On Jan 19, 2:52 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > > > > On Jan 18, 7:47 pm, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > On Jan 15, 1:00 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > On Jan 14, 8:02 pm, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > > > On Jan 13, 11:17 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > > > On Jan 13, 10:39 am, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > > > > > It is alleged in a few forum threads that visible interference > > > > > > > > > > > patterns can be produced with an inexpensive laser pointer. Is this > > > > > > > > > > > true? How do you easily create a suitable 3-line diffraction grid with > > > > > > > > > > > the ideal spacing? Has anyone here actually tried the famous double > > > > > > > > > > > slit experiment with a low cost laser pointer? > > > > > > > > > > > Yes, it's pretty easy. > > > > > > > > > > The easiest way to obtain a diffraction grating is to order one. > > > > > > > > > > They're cheap. > > > > > > > > > > The only diffraction gratings I see in the science education catalogs > > > > > > > > > that I know about, Nasco, Fisher Scientific, Carolina Science and > > > > > > > > > Math, have 100's of lines per mm. What company sells a diffraction > > > > > > > > > grating for a standard double slit experiment? > > > > > > > > > > > You can also make one with a trio of single-edge razor blades taped > > > > > > > > > > together, scratching parallel lines on a microscope slide painted > > > > > > > > > > black. > > > > > > > > > > That's too much trouble. > > > > > > > > > Really? It takes an hour and is cheap. > > > > > > > > > > I want to buy an optimized double slit for > > > > > > > > > the typical red laser light pen. Where can I get it? > > > > > > > > > The ones with hundreds of lines per mm ARE optimized for the typical > > > > > > > > red laser pen. Buy those. > > > > > > > > Seriously, here's how you tell. > > > > > > > > Red light has a wavelength of 650 nm, which is about half a thousandth > > > > > > > > of a mm. > > > > > > > > The angle in radians between the central and first side spots is > > > > > > > > roughly the ratio of the wavelength to the line spacing. > > > > > > > > So if you have a line spacing of a half a hundredth of a mm, then you > > > > > > > > will have an angle of about a tenth of a radian or five degrees. > > > > > > > > > You haven't checked Edmund Scientific, Wards, or any of a number of > > > > > > > > scientific *toy* catalogs that school teachers use. The good news is > > > > > > > > that this is used in 4th grade classes sometimes, so you'll find > > > > > > > > plenty if you stop looking in professional grade catalogs. > > > > > > > > > > Here's a great video on the double slit experiment using pencil leads, > > > > > > > > > but I suspect that the presenter, Jack Maxwell, is using a powerful > > > > > > > > > laser and who knows how long he had to play with it in front of the > > > > > > > > > camera to get it right. Time is valuable to me. I certainly don't want > > > > > > > > > to waste time fiddling around during a physics lecture.http://www.youtube.com/watch?v=UANVMIajqlA > > > > > > > > Thank you Paul but there is still a mystery that I don't understand. > > > > > > > > If the double slit experiment is the central mystery of physics, why > > > > > > > is it that no one manufactures a precisely crafted single double slit > > > > > > > that is optimized for the very popular low-power red laser light pen? > > > > > > > > As you know, Richard P. Feynman said: > > > > > > > > We choose to examine a phenomenon which is impossible, absolutely > > > > > > > impossible, to explain in any classical way, and which has in it the > > > > > > > heart of quantum mechanics. In reality, it contains the only > > > > > > > mystery. > > > > > > > > As I see it, creating a diffraction pattern with a diffraction grading > > > > > > > that has hundreds of lines per mm doesn't seem so mysterious. > > > > > > > ------------------ > > > > > > the mystry is only becuase of ignorance!! > > > > > > QM peoole pose as if they know andunderstand > > > > > > everything by their crippled supermarket theory > > > > > > AND IN MANY CASES WRONG INTERPRETATIONS !! > > > > > > > it starts with the illusion that we know really > > > > > > what is a photon > > > > > > and worse of that > > > > > > WhaT IS REALLY * A SINGLE PHOTON* > > > > > > > i claim that : > > > > > > > A a single photon is not represented by > > > > > > hf > > > > > > (nature does not know what is a second!!... > > > > > > a second is a human arbitrary definition of time !!.) > > > > > > > hf represents MANY SINGLE PHOTONS !!!!! > > > > > > Ever seen a photomultiplier tube? > > > > > > > ATB > > > > > > Y.Porat > > > > > > ------------- > > > > > no > > > > so what about it ?? > > > > anyway > > > > i am sure that the real **single photon is so tiny > > > > that it has no chance to make ant mark] > > > > Then you certainly haven't seen a photomultiplier tube. > > > Single photons are easily detected. > > > > > on a screen > > > > y.porat > > > > ---------------------- > > > just tell me how do you know > > waht is a single photon > > > why on earth it is defined > > BY NATURE by the energy that is emitted in one second > > It ISN'T. > > I can't help if if you don't have the foggiest idea what a photon is, > or what a photomultiplier tube is, or how we can tell when there is > just one of something as opposed to several. > > > what does nature know about your > > second > > The photon IS NOT the energy delivered in one second. > > Good heavens, Porat. If I drop something from a plane and it > experiences an acceleration of 9.8 m/s/s, does this mean that it takes > one second for it to fall to the ground? If I drive to work at 40 > miles/hour, does this mean that it takes me an hour to drive to work? > Are you really this dense? > > > why not nanosecond why not billion times smaller than a > > nanosecond ??? > > Y.Porat > > --------------------- ok if you insist on not giving me some idea in a few lines i will look for your ' photomultiplier tube' and we will see why understands the basics of physics better ...... as it was proven many times in past ... Y.P ----------------------------
From: Y.Porat on 20 Jan 2010 01:24
On Jan 20, 8:11 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > On Jan 19, 10:16 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jan 19, 1:37 pm, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > On Jan 19, 6:57 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Jan 19, 10:22 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > > > On Jan 19, 6:08 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Jan 19, 2:52 am, "Y.Porat" <y.y.po...(a)gmail.com> wrote: > > > > > > > > On Jan 18, 7:47 pm, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > > On Jan 15, 1:00 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > > On Jan 14, 8:02 pm, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > > > > On Jan 13, 11:17 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > > > > On Jan 13, 10:39 am, Shubee <e.shu...(a)gmail.com> wrote: > > > > > > > > > > > > > It is alleged in a few forum threads that visible interference > > > > > > > > > > > > patterns can be produced with an inexpensive laser pointer. Is this > > > > > > > > > > > > true? How do you easily create a suitable 3-line diffraction grid with > > > > > > > > > > > > the ideal spacing? Has anyone here actually tried the famous double > > > > > > > > > > > > slit experiment with a low cost laser pointer? > > > > > > > > > > > > Yes, it's pretty easy. > > > > > > > > > > > The easiest way to obtain a diffraction grating is to order one. > > > > > > > > > > > They're cheap. > > > > > > > > > > > The only diffraction gratings I see in the science education catalogs > > > > > > > > > > that I know about, Nasco, Fisher Scientific, Carolina Science and > > > > > > > > > > Math, have 100's of lines per mm. What company sells a diffraction > > > > > > > > > > grating for a standard double slit experiment? > > > > > > > > > > > > You can also make one with a trio of single-edge razor blades taped > > > > > > > > > > > together, scratching parallel lines on a microscope slide painted > > > > > > > > > > > black. > > > > > > > > > > > That's too much trouble. > > > > > > > > > > Really? It takes an hour and is cheap. > > > > > > > > > > > I want to buy an optimized double slit for > > > > > > > > > > the typical red laser light pen. Where can I get it? > > > > > > > > > > The ones with hundreds of lines per mm ARE optimized for the typical > > > > > > > > > red laser pen. Buy those. > > > > > > > > > Seriously, here's how you tell. > > > > > > > > > Red light has a wavelength of 650 nm, which is about half a thousandth > > > > > > > > > of a mm. > > > > > > > > > The angle in radians between the central and first side spots is > > > > > > > > > roughly the ratio of the wavelength to the line spacing. > > > > > > > > > So if you have a line spacing of a half a hundredth of a mm, then you > > > > > > > > > will have an angle of about a tenth of a radian or five degrees. > > > > > > > > > > You haven't checked Edmund Scientific, Wards, or any of a number of > > > > > > > > > scientific *toy* catalogs that school teachers use. The good news is > > > > > > > > > that this is used in 4th grade classes sometimes, so you'll find > > > > > > > > > plenty if you stop looking in professional grade catalogs.. > > > > > > > > > > > Here's a great video on the double slit experiment using pencil leads, > > > > > > > > > > but I suspect that the presenter, Jack Maxwell, is using a powerful > > > > > > > > > > laser and who knows how long he had to play with it in front of the > > > > > > > > > > camera to get it right. Time is valuable to me. I certainly don't want > > > > > > > > > > to waste time fiddling around during a physics lecture.http://www.youtube.com/watch?v=UANVMIajqlA > > > > > > > > > Thank you Paul but there is still a mystery that I don't understand. > > > > > > > > > If the double slit experiment is the central mystery of physics, why > > > > > > > > is it that no one manufactures a precisely crafted single double slit > > > > > > > > that is optimized for the very popular low-power red laser light pen? > > > > > > > > > As you know, Richard P. Feynman said: > > > > > > > > > We choose to examine a phenomenon which is impossible, absolutely > > > > > > > > impossible, to explain in any classical way, and which has in it the > > > > > > > > heart of quantum mechanics. In reality, it contains the only > > > > > > > > mystery. > > > > > > > > > As I see it, creating a diffraction pattern with a diffraction grading > > > > > > > > that has hundreds of lines per mm doesn't seem so mysterious. > > > > > > > > ------------------ > > > > > > > the mystry is only becuase of ignorance!! > > > > > > > QM peoole pose as if they know andunderstand > > > > > > > everything by their crippled supermarket theory > > > > > > > AND IN MANY CASES WRONG INTERPRETATIONS !! > > > > > > > > it starts with the illusion that we know really > > > > > > > what is a photon > > > > > > > and worse of that > > > > > > > WhaT IS REALLY * A SINGLE PHOTON* > > > > > > > > i claim that : > > > > > > > > A a single photon is not represented by > > > > > > > hf > > > > > > > (nature does not know what is a second!!... > > > > > > > a second is a human arbitrary definition of time !!.) > > > > > > > > hf represents MANY SINGLE PHOTONS !!!!! > > > > > > > Ever seen a photomultiplier tube? > > > > > > > > ATB > > > > > > > Y.Porat > > > > > > > ------------- > > > > > > no > > > > > so what about it ?? > > > > > anyway > > > > > i am sure that the real **single photon is so tiny > > > > > that it has no chance to make ant mark] > > > > > Then you certainly haven't seen a photomultiplier tube. > > > > Single photons are easily detected. > > > > > > on a screen > > > > > y.porat > > > > > ---------------------- > > > > just tell me how do you know > > > waht is a single photon > > > > why on earth it is defined > > > BY NATURE by the energy that is emitted in one second > > > It ISN'T. > > > I can't help if if you don't have the foggiest idea what a photon is, > > or what a photomultiplier tube is, or how we can tell when there is > > just one of something as opposed to several. > > > > what does nature know about your > > > second > > > The photon IS NOT the energy delivered in one second. > > > Good heavens, Porat. If I drop something from a plane and it > > experiences an acceleration of 9.8 m/s/s, does this mean that it takes > > one second for it to fall to the ground? If I drive to work at 40 > > miles/hour, does this mean that it takes me an hour to drive to work? > > Are you really this dense? > > > > why not nanosecond why not billion times smaller than a > > > nanosecond ??? > > > Y.Porat > > > --------------------- > > ok > if you insist on not giving me some idea > in a few lines > i will look for your > ' photomultiplier tube' > and we will see why understands the basics of physics better ...... > > as it was proven many times in past ... > > Y.P > ---------------------------- ok i looked at the Viki for 10 seconds and it told me that you are a parrot !! here is a quote: ": The photomultiplier provides extremely high sensitivity and ultra-fast response. Photomultiplier tubes (PMT) have high bandwidth and noise- free gain on the order of a million. This makes them ideal for the detection of extremely low light or short pulses of light. Photomultipliers can be used to detect photons from 115nm to 1700nm. A typical Photomultiplier consists of a photoemissive cathode (photocathode) followed by an electron multiplier and an electron collector (anode). end of quote ------------------ see above it is locating (detecting) photons from 115 to 1700 nm !! who on earth told you that it is a ***single photon defined by NATURE ???*** ie the smallest possible photon !! 2 i will now go on learning more about it Y.Porat ------------------------ |