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# Parabolindrome

Half measures.
 (+2) [vote for, against]

Okay, so this is more of thought experiment I intend to test and not yet something with a practical application... hmm maybe as a solar cooker.

I picked up a twelve foot diameter parabolic dish and have four hundred square feet of reflective Mylar film.
The dish is already bisected making it easier to apply the Mylar, but...

While it is in two segments what would happen if I were to place a flat mirror along the flat edge reflecting inwards towards the half-dish?
Pointing directly at the sun, I imagine that even though the half-dish should be reflected in the flat mirror, so little scattered light would reach it that the temperature at the half-focal point would be exactly the same as if there were no flat mirror there at all.
What would you see though looking at the flat mirror reflecting only light being bent away from it? Would it remain black?

What if you oriented the half-dish so that the flat mirror faced south all day?
Will the flat mirror act as a stationary heliostat keeping a constant focal point no matter the angle of the Sun?
Could you make a curved lenticular mirror designed to reflect incoming rays to the perfect alignment to maximize focal heat with no moving parts no matter the time of year?

<shrugs>
We're gonna find out.

It was a fun little tangent to think through and I thought you guys might like head-scratching about.

On a side note.
I really need to win the lottery soon or figure out the cure for death or something if I want to complete even half of the crap I've saddled future 2fries with.
That poor bastard won't even know what hit him.

Muhaha.
Muhahahahahahaha!

 — 2 fries shy of a happy meal, Jun 22 2024

Start here - a little over 350 years ago... https://en.wikipedi...Newtonian_telescope
... and see if you can come up with a really new arrangement of mirrors [a1, Jun 23 2024]

Parabolic Fun https://optixnz.co....ope-illusion-maker/
If you have 2 dishes spare, you could make a giant one of these... [neutrinos_shadow, Jul 01 2024]

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Annotation:

 Light will hit the parabola's focal point on the flat mirror, then bounce out of the dish. I'll see if I can find or make a sketch for you,

Edit - On reflection (ha), I realize there are lots of websites with diagrams of how mirrors work. I won't bother doing sketches for you - you could find answers to all your "what ifs" by looking them up yourself. But you wouldn't have as much fun that way as you will by stealing time from future you.
 — a1, Jun 23 2024

 Um... exactly how does the search words used by a high school drop out to describe a, what until seconds ago, was an independent, and perhaps unique, (wouldn't be the first time), thought lead to learning of a Newtonian telescope faster than bouncing it off your friends?

 Thanks eh.

"I know how we're spending the rest of the evening Ferb."
 — 2 fries shy of a happy meal, Jun 23 2024

 Oh shit!

 The amount of hyperlinks, and subsequent hyperlinks I would need to wade into in order to understand that which I can already see in my head weighed against current responsibilities?

"Abort Ferb! ABORT!"
 — 2 fries shy of a happy meal, Jun 23 2024

 That telescope was one of the first things I thought of in connection with "curved mirror pointed at a flat mirror." You don't have to grok all of it, just look at some of the ray tracing diagrams and think about what changes if you move the mirrors.

 And that's sadly what you missed by leaving school. A good teacher would have shown you the diagrams, maybe even a real setup of mirrors on a table, and asked you to guess what would happen if you moved them around. Then they'd let you try it to see how close your guesses were.

You can still do that on your own though. Guess what will happen and then try it.
 — a1, Jun 23 2024

 That's what I'ma gonna do.

 Didn't have many good teachers. So few that still I remember the names of the good onesI don't know if you are aware of just how much our western educational systems have declined in their give-a-shit in the last few generations, but it started with mine.

 I got to experience them across most of Canada.Yet it only took a four second gif sometime in my forties to finally understand what PI means.Education was obfuscated purposely, with malicious intent.I couldn't escape it quickly enough.

 Maybe it's the reason why I can randomly think things those men hundreds of years ago also found new.

 I know how little I know... so I wonder/wander.

 Sometimes I've stumbled on things nobody else has thought of before.It's quite the rush. I don't even mind not getting credit.

 I just dig the fact that I can somehow every once and a while glimpse the top of the wave without having learned the entirety of the wave first. I didn't finish high school. All I know is new discoveries.

 When what I discover overlaps with already discovered things that's cool... but sometimes... the thoughts are mine alone and do not already exist.

 This is why past AI made sentient meat to fill in the gaps.AI has no intuition and needs to rely on us carbon based lifeforms to expand its knowledge.Across a multiverse.

 ...

 but I digress.

How 'bout them nicks? Good on ya Newton.
 — 2 fries shy of a happy meal, Jun 23 2024

 ...and...

 ...silence.

Go figure, smart people.
 — 2 fries shy of a happy meal, Jun 28 2024

I have just converted (or rather, had converted) a bit of kitchen space that I had available into a 2ft x 2ft by 8ft cupboard area, which I was quite pleased with until reading this. I'm not sure if I've got anywhere in my flat to store a 12ft parabolic dish, let alone four hundred square feet of reflective Mylar film. But I'm not jealous. No, not at all. Just saying...
 — DrBob, Jun 28 2024

 Don't be jelly.It comes with the cost of several decades of double-time and having absolutely no clue as to how to stop self flagellating.I now work harder than at any time in those previous decades. It's probably going to kill me.

 I figured out how to turn it on from necessity, but I never learned how to shut it off when I was done because I don't know what done is.

 I'm completely bent. Nobody wants this.

 ...

There are perks though.
 — 2 fries shy of a happy meal, Jun 29 2024

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