How does light split into colors?

[OmCheeto]

As far as I can tell, those lines are indistinguishable from parallel, so the source was not close. This suggests that sunlight was being temporarily redirected and refracted through some distant object, perhaps across the road, producing a continuous spectrum, which was split into lines by the blind. Of course, looking through the blind from low down would have revealed the source.

I don't think the rays are from refraction. One thing I missed up until now, is that the OP said:

When I rotate the shutters as you can see from the pictures, the colors changed.

Which is indeed true:

I was working with image #2, and completely ignored image #1.
The spacing of the colors, along with the anomalous white ray(s, and pinkish one that I didn't include), indicates to me that the rays are not the product of refraction, nor diffraction, but could only be the result of light reflecting off of a multicolored surface.

ps. I suspect the entire problem is photo-shopped*, but given that this is a delightful test of math skills, I really don't mind.

*The orange line is a bit too "crisp", IMHO.

 

[DrStupid]

Of course, looking through the blind from low down would have revealed the source.

The location of the source could also be identified with another picture taken from the same position as the first one but with the window open.

 

[mfb]

Is it repeatable? If yes:

What happens if you cover the dome?
As asked already: What happens if you open the blinds more?
Can you put an object close to the blinds to see where its shadow appears? This gives an estimate for the vertical angle of the light.

 

[RPinPA]

I don't think the rays are from refraction. One thing I missed up until now, is that the OP said:View attachment 233320

I was working with image #2, and completely ignored image #1.
The spacing of the colors, along with the anomalous white ray(s, and pinkish one that I didn't include), indicates to me that the rays are not the product of refraction, nor diffraction, but could only be the result of light reflecting off of a multicolored surface.

This image says to me that the beams are arriving at different vertical angles, that there is refraction happening in both the horizontal and vertical planes.

I love this entire discussion and think it would make a good exercise for a physics class.

 

[DaveC426913]

Man! That is one cool effect!

 

[lightarrow]

yes, but when the light is going through the lens. in the OP's case the light is being refracted/reflected off the surface of a curved dome that is not a lens

Light doesn't go through the dome? Then it's not the dome which generates the colours and even mention it in the discussion would be misleading.

--
lightarrow

 

[DAH]

Great pics
I'm no expert on light but it looks like the effects of light passing through a diffraction grating. Maybe the material of the blinds itself are acting like the small spacing of diffraction grating, if so there would probably be 1st and 2nd orders of diffraction somewhere else in the room.
Just a thought but I'm probably wrong.

 

[Jonathan Scott]

I don't think the rays are from refraction.

It's certainly not something simple like a prism. I agree that the strength of the effect suggests an alternative of something like reflecting from a brightly coloured surface, or from a reflective surface with a "holographic" type finish which gives a rainbow effect. However, I've seen a striking display of rainbow colours from sunlight striking old glass objects in a shop window, where the colour wasn't just a simple spectrum but rather a series of coloured curves, presumably caused by a combination of refraction and reflection, and that might just about account for it. The sharpness of the lines certainly suggests a small distant source.

 

[davenn]

Light doesn't go through the dome? Then it's not the dome which generates the colours and even mention it in the discussion would be misleading.

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lightarrow

unfortunately, it's become obvious that you are missing the point of the whole discussion

you need to go back to the beginning of the thread and catch up on the bits you have missed
particularly the post #8 by the OP. Then you will understand why the discussion of the dome was involved

 

[Dadface]

To me those lines don't resemble anything that you would expect to see due to reflection, refraction or diffraction due to the combined optical arrangement of the systems outside and inside the house. They do look like projected lines, very similar to laser lines. Laser line marking seems to be a growing technology. There is one photo I find a little bit puzzling and that is picture one in post eight where there is a squiggly white line which seems to be obscuring the top of the table on the right side of the picture.

 

[davenn]

There is one photo I find a little bit puzzling and that is picture one in post eight where there is a squiggly white line which seems to be obscuring the top of the table on the right side of the picture.

seriously ?

tis obvious he has probably erased some personal stuff on the table rather than having that info spread across the internet

 

[Dadface]

seriously ?

tis obvious he has probably erased some personal stuff on the table rather than having that info spread across the internet

I suppose that is a possibility but note that something black is projecting from the edge of the table. Now try googling laser line markers. I think it's possible that YeeHaa is having a joke and obscured most of the table top as a clue.

 

[Tom.G]

Naah. Peeking out from the left edge of the table is what looks like the handle of a skillet complete with the nicely shaped hole for hanging it on a hook. Way back on the table top near the chair is something that looks like the edge of a dinner plate with perhaps a place mat under it.
(inspection done at 350% magnification)

 

[Dadface]

Naah. Peeking out from the left edge of the table is what looks like the handle of a skillet complete with the nicely shaped hole for hanging it on a hook. Way back on the table top near the chair is something that looks like the edge of a dinner plate with perhaps a place mat under it.
(inspection done at 350% magnification)

Could well be but if that's all there is why did YeeHaa want to obscure it? Why not just move it out of the way? Anyway, whatever is on the table may well be irrelevant. But those lines lines still look like projected lines.

 

[lightarrow]

unfortunately, it's become obvious that you are missing the point of the whole discussion

I have a bit of suspect that many of us, here, are missing the hole point, since:
1. we don't know if the OP is cheating us or not ,
2. we still don't know which is the source of the coloured lines,
3. in post #8 the OP wrote: "Even if it is the dome causing this, I would still love to know how to lines became this discrete/high intensity" so he didn't exclude this possibility,
4. we don't know how that "dome" is made (maybe this kind of structures is common where you live but it's not usual for me)
5. in post #15 I expose a doubt on the single coloured beams because they seemed too much collimated to me, like laser beams and I haven't received a clear answer to it.
But if you have more clear ideas you can write them.

--
lightarrow

 

[YeeHaa]

Hello all,

Wow! thank you for the huge amount of replies.
In a lot of replies I read some doubt about my sincerity but believe me (on my pretty blue eyes): no photoshop, no cheating. The pictures were taken with my Galaxy S8 phone and were uploaded straight to this forum (shared via mail).
I will make some more overview pictures when I get the chance.

There were also comments as to why I blanked out the table. Simply because it was not relevant and I considered that as my own private (mess) ;-).

I had some discussion at work (I am an opto-mechanical engineer) and were also on the path of "the blinds are shading part of the coloured spectrum"... But no solutions (yet).

Just for the fun of it, I uploaded the third picture I took that day so you can see I am not cheating ;-)

 

[Tom.G]

Using the most recent photo that @YeeHaa posted:
Using the much lower distortion of that photo, I get the parallelism of the color rays as within 2.3°, well within the measurement error of being parallel. Even if the 2.3° is accurate, that puts the source distance at 25 tiles away (50ft. or 15m.).

Question for YeeHaa: Is that effect reproducible enough that you can visually sight along one of those rays to determine the source?
I hope so. You have a whole bunch of us VERY curious as to the cause.

Cheers,
Tom

 

[DennisN]

Hi Yeehaa,

I will make some more overview pictures when I get the chance. [...] I had some discussion at work (I am an opto-mechanical engineer) and were also on the path of "the blinds are shading part of the coloured spectrum"... But no solutions (yet).

I think mfb gave some good suggestions:

Is it repeatable? If yes:

What happens if you cover the dome?
As asked already: What happens if you open the blinds more?
Can you put an object close to the blinds to see where its shadow appears? This gives an estimate for the vertical angle of the light.

Also, you could try the following:
Ask another person, perhaps a friend, walk outside the blinds while you observe the lines to see if and when they disappear depending on where the person is. That can give you (and us!) a clue from where the light originates.

 

[Herman Trivilino]

How often are these lines seen?

When they are seen, is it during some circumstance that is not routine?

 

[YeeHaa]

I have never seen these lines, the blinds are installed for approx. 4 years now. It is the only time I saw this.
I will get back to sending more pictures!

"Question for YeeHaa: Is that effect reproducible enough that you can visually sight along one of those rays to determine the source? I hope so. You have a whole bunch of us VERY curious as to the cause"
I have not tried this at that moment...

Can I make the summary that this is dispersion of light caused by an accidental position of the light source due to the time of day & object which is refleting the light (dome?), where the blinds are causing the dispersion and at the same time are shadowing part of the color gradient? Hard to de-duct from all responses what the general consensus is!

 

[Tom.G]

Perhaps around the same time on a Sunny day, you could go outdoors and see if there is a spectrum projected on a nearby wall or anything else nearby. If so you can probable get a good idea as to where it is coming from.

Cheers,
Tom

 

[DaveC426913]

Using the most recent photo that @YeeHaa posted:
Using the much lower distortion of that photo, I get the parallelism of the color rays as within 2.3°, well within the measurement error of being parallel.

No way.
They definitely converge closer than the horizon.

Look a the truly parallel rays of the tiles. They converge at infinity.
The light rays definitely converge within metres of the window.

 

[Tom.G]

The Yellow shows the vanishing point of the Red lines relatiing to the floor tiles.

 

[DaveC426913]

The Yellow shows the vanishing point of the Red lines relatiing to the floor tiles.

Yes. That'll be the horizon, same as Omcheeto showed in post 16.
The light rays do not converge at the horizon, but much closer.