by johnnydeep » Tue Jan 19, 2021 4:12 pm
My, what a lovely bunch of hyperlinks this has! I think a future APOD should attempt to have a meaningful link on
every single word in the description!
Now, about this "diffraction" concept. I'm confused, and the WikiPedia link -
https://en.wikipedia.org/wiki/Diffraction - only made it worse. Is there a fundamental difference between diffraction and refraction or are they both a result of the same underlying quantum mechanical effect? So far I have:
Diffraction - bending of waves when travelling through or around an object (slit, water droplet, etc)
Refraction - bending of waves when travelling through mediums of differing densities or thicknesses (air versus water, prisms, lenses, etc)
Reflection - bouncing of waves off matter (mirrors, water, skin, etc)
And what about rainbows? Water droplets in the sky with sunlight passing through and around them. So is a rainbow the result of refraction or diffraction... or both?
As for quantum mechanical effects, I suppose when it all comes down to it, ultimately
EVERYTHING is caused by them!
[quote="APOD Robot" post_id=310014 time=1611033063 user_id=128559]
[url=https://apod.nasa.gov/apod/ap210119.html] [img]https://apod.nasa.gov/apod/calendar/S_210119.jpg[/img] [size=150]A Lunar Corona with Jupiter and Saturn[/size][/url]
[b] Explanation: [/b] Why does a cloudy moon sometimes appear colorful? The [url=https://www.atoptics.co.uk/droplets/corform.htm]effect[/url], called a lunar [url=https://www.atoptics.co.uk/droplets/corona.htm]corona[/url], is created by the quantum mechanical [url=https://en.wikipedia.org/wiki/Diffraction]diffraction[/url] of light around individual, similarly-sized water droplets in an [url=https://www.youtube.com/watch?v=fgiOjqTiwn8]intervening[/url] but mostly-transparent cloud. Since light of different colors has [url=https://science.nasa.gov/ems/01_intro]different wavelengths[/url], each color [url=https://www.exploratorium.edu/snacks/diffraction]diffracts[/url] differently. [url=https://en.wikipedia.org/wiki/Corona_(optical_phenomenon)]Lunar Coronae[/url] are one of the few [url=https://asterisk.apod.com/viewtopic.php?f=39&t=21334]quantum mechanical[/url] color effects that can be [url=http://physics.stackexchange.com/questions/65397/quantum-mechanics-and-everyday-nature]easily seen[/url] with the unaided eye. [url=https://apod.nasa.gov/apod/ap160111.html]Solar corona[/url]e are also sometimes evident. The [url=https://www.facebook.com/photo?fbid=1709415295896623&set=a.128219130682922]featured composite image[/url] was captured a few days before the [url=https://youtu.be/aokGqxVdpz0]close[/url] [url=https://apod.nasa.gov/apod/ap201223.html]Great[/url] [url=https://apod.nasa.gov/apod/ap201220.html]Conjunction[/url] [url=https://apod.nasa.gov/apod/ap201219.html]between[/url] [url=https://apod.nasa.gov/apod/ap201215.html]Saturn[/url] [url=https://apod.nasa.gov/apod/ap201212.html]and[/url] [url=https://apod.nasa.gov/apod/ap201208.html]Jupiter[/url] [url=https://apod.nasa.gov/apod/ap201020.html]last[/url] [url=https://www.facebook.com/media/set/?vanity=APOD.Sky&set=a.3211133262324204]month[/url]. In the foreground, the [url=https://en.wikipedia.org/wiki/Italy]Italian[/url] village of [url=https://en.wikipedia.org/wiki/Pieve_di_Cadore]Pieve[/url] [url=https://youtu.be/foOsiBKhavA]di[/url] [url=https://en.wikipedia.org/wiki/Pieve_di_Cadore]Cadore[/url] is visible in front of the [url=https://youtu.be/IobRJtv2d_Q]Sfornioi[/url] Mountains.
[/quote]
My, what a lovely bunch of hyperlinks this has! I think a future APOD should attempt to have a meaningful link on [url=https://www.google.com/search?q=every]every[/url] [url=https://www.google.com/search?q=single]single [/url] [url=https://www.google.com/search?q=word]word[/url] [url=https://www.google.com/search?q=in]in[/url] [url=https://www.google.com/search?q=the]the [/url] [url=https://www.google.com/search?q=descriotion]description[/url]! 8-)
Now, about this "diffraction" concept. I'm confused, and the WikiPedia link - https://en.wikipedia.org/wiki/Diffraction - only made it worse. Is there a fundamental difference between diffraction and refraction or are they both a result of the same underlying quantum mechanical effect? So far I have:
[b]Diffraction [/b]- bending of waves when travelling through or around an object (slit, water droplet, etc)
[i]Refraction [/i]- bending of waves when travelling through mediums of differing densities or thicknesses (air versus water, prisms, lenses, etc)
[u]Reflection [/u]- bouncing of waves off matter (mirrors, water, skin, etc)
And what about rainbows? Water droplets in the sky with sunlight passing through and around them. So is a rainbow the result of refraction or diffraction... or both?
As for quantum mechanical effects, I suppose when it all comes down to it, ultimately [url=https://www.merriam-webster.com/dictionary/everything]EVERYTHING[/url] is caused by them!