The rotation of a fan creates a blocking path for visible light. 1

A moving fan with my 2 MP mobile-camera

A moving fan with my laptop builtin webcam (compare with cellular pic)


The "auto" mode Canon PS


The "nigh shot" mode Canon PS


The "sports" mode Canon PS (see the reverse motion of pattern)


The other modes of Canon PS of a moving fan "shutter spped and aperture priority, custom etc"


The "manual" shot of a Canon PS of a moving fan

The webcam (above) produces exactly 3 smeared out regions of a moving fan. It is much more prominent when you see with the webcam instead of taking the pic because the cam is low res. The cell with much better resolution and faster speed perhaps, does not make this clear atall, there is only 1 complete circle with the cellular cam. This is what I had described in the article below written 2 weeks ago. I took the pic only today. Also see the very interesting patterns of the Canon PS a 8 MP, 12 optical, 6.0 – 72.0 mm lens. The last pic above is dark but if you inspect clearly you will see something. WE don’t need this for our analysis. Check that with a shutter-speed priority (and some other modes) you see a statonary picture of the moving fan (unbelievably sharp) One needs the details of how these things work before one can say exactly why we see these pattern. But the semi-qualitative analysis I had done prior to taking these pics.

YOU can produce a dark room, note everything you about your experimental setup and by obtaining desirable patterns calculate the exact Uncertainity equation value from these (eg you may use calibrated sources of light color and shutter speed etc )

a week or two or three ago, I wrote an article where I said “quantum mechanical phenomena corresponds to classical world and gave two example, one of a rotating fan and I asked you to count it’s blades, the other was rotating a bicycle wheel when your bike man is fixing it for you”.

First of all correspondence is like an effect moving up the ladder to a different scale and despite of their legitimacy in current understanding a lot of bad understaning and philosophy has blocked their way from popular knowledge.

Secondly it may have raised your eyebrow so much you might have consulted your eyedoctor for a check up. I take full responsibility for that but you have to call your insurance not me. I did a little notebook calculation and here is the reason.

Consider a fan with 3 blades of 40 cm length and consider it making a 10 rpm motion. 10 rotations per minute. Oh thats sucking, consider it 10 rps, rotations per second. It gives us an angular frequency of w. vv/R = wwR (v=Rw). Then v = 2pi.R.10 m/s = 62.8×0.4 m/s = 25.12 m/s that is 25 Hz-m.

First of all this is a great speed. Your airplane moves only 250 m/s. Your car moves at 25 m/s (90 km/hr) Most of the energy of your fan is just wasted in keeping it in circle. Now 25 Hz along a meter length is like 25×10^9 Hz for a 10^-9 meter that is 25 GHz for a nanometer deflection. Or 25/500 GHz for a 500 nanometer deflection. 0.05 THz for a wavelength of visible light.

SO at the distance-scale of wavelength of light the time window available for the photon is inverse of that frequency. that is 1/delT = 0.05 THz. This means delT = 5 nano-seconds. This is the time statistically available to the photons of 500 nm to get reflected and give us a good picture so we can see or count the rotating fan’s blade. I intended an Uncertainity relation explanation hence denoted T with delT but now I see that I do not need a mathematically explicit explanation for that.

(remember that the camera shutter has the same principle, it allows certain adjusted time window, if it is higher it won’t work, if it is lower it intereferes in various ways with the process of picture taking and sometimes gives you funny picture such as a fuzzy face who you can realize who he or she is but not recognizable to a 3rd party. The rotating fan also creates a time window as it is moving really fast from one point to the next)

If you are to understand this process in a way in which technology is really really not playing a role consider a camera-obscura. (a pinhole camera, I played these a lot in high school, as an 11 year old, that and the immersion water heater I made using connecting two “blades”, razors that we use for shaving etc etc were my favorite science gadgets. I also had a soap making story which was a disaster that I will never forget. I also thought of making salt from acid and base, from stuff taken away from lab and popular bases/alkalines available such as baking soda, cannot say: stealing from the lab tho. I checked the formula of these from textbook also, this was probably when I was 13 years old, or was it, it may as well be when I was 15 or 16 years old, but I don’t recall exactly when I studied Chemistry with formulas in high school ) But now that I thought hard about it I recall that I might have had some chemistry textbook with formulas during early high-school (8th standard=13 yrs age)

This following article here calculates circular motion parameters using a ceiling fan rotation of 0.5 rps, 20 times lesser than what I have taken here;

(per him/her the table top fan moves much faster and I “javen’t” reviewed exact speeds of fans, but a factor of 10 will only reduce the available time window by the same factor, hence we’ll have 50 nano-seconds for a slow moving fan.)

Now the 500 nm (you can take an average for all wavelength in optical range, how do we do that?) light quantum has an energy proportional to it’s frequency and ~400 to 750 nano-meter lights (all of visible light) has a frequency of 400 – ~ 800 THz. So we do not need additional calculations here.

Our 0.05 THz frequency allows a time window that allows the visible light to pass through. But a variation of these parameters make it easy to see that lights are allowed to be reflected and passed through in a statistical way, with various probabilities. If all lights were to be reflected we would probably see images of only 3 blades with very dark shades and a rotating disk of light-flash. Also the distribution of intensity in various angles makes a more complex geometry to consider.

By varying your fan-speed and intensity of your room light (eg by making it really dark that is switching off scattering) you are capable of seeing a very slow moving image of the fan-blades where you can count the number of these dark shades resembling the actual blades and a disk of rotation characterized by light which signifies no light or much lesser intensity of light was being blocked by the blades.

In other words in an optimized situation we see that the probabilities of light reflected or passing through has really separated. It is also possible to see a reverse motion of the image of the fan blade. All these effects are not explainable by classical wave-mechanics. May be from the latter we understand that OK light passes sometimes and does not sometimes (but why? light wavelength is so small, it’s size is so small, it is just a quantum) but the detailed behavior is much more complicated than the knowledge of classical mechanics can explain.

You can be very strict about the speed of fan and wavelength of light but you must be careful what exact situation you have observed. With a camera you can take picture in an optimally prepared dark room with light sources and you will see the picture never gives you 3 stationary blades. In-fact with very slow motion a blurried picture is produced but that is because the time-window of the camera flash has meant additional relative motion between the target and it’s image, explainable by quantum-mechanics.

And waves as we understand now is fully explanable by quantum-mechanics which has in it the idea that light moves relativistically. The equations are only a result of such understanding and needs to be used careully and only by someone who has the confidence he understands them. Basic Physics is misused without even quantum mechanics and Relativity so it is really a hard job to get your physics right. Do not take this lightly and do not laugh at ideas that you do not understand. But if you really understand something welcome to find loopholes and criticize but don’t forget that for every loophole you think you have found you might have found 4 to your account and the lesson that you are the one who did not understand what was being described. But then take it like a sports as long as you have the sportive shirts on your chest.

Nothing in classical mechanics will ever explain these effects completely (ofcourse you can say we have a camera, we have an object and we take a picture and that is all that matters, but I do not welcome such pickers or cynical people to discuss my Physics ideas)

One comment

  1. Pingback: Multiverses are not string theoretic ideas, they are plain quantum mechanics « Information Radar

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s