the sun has output basically the same spectrum as long as humanity
Last time I checked, human output was brown.
We perceive the sun as white. That’s a fairly important distinction.
The reason we perceive the sun as white is surely because the sun has output basically the same spectrum as long as humanity (and a great deal of humanity’s precursors) has existed. We evolved with our eyes considering the spectrum the sun kicks out as fully white light, comprised of the sum total of electromagnetic frequencies we’re able to receive with our eyeballs.
There is no such thing as objective color of any light. Our understanding of color is completely based on our perception of it. If the sun’s peak output were in the 590–625nm range (what we currently perceive as orange) for all that time rather than in the green part of the spectrum it is in reality (500–565nm), we undoubtedly would have evolved to see that particular spectrum combination as white light instead.
All of the above notwithstanding, if the spectrum output of the sun changed overnight like OP’s idiot friend is suggesting, it would be immediately apparent to everyone who isn’t literally blind.
Zwuzelmaus@feddit.org 6 hours ago
Holytimes@sh.itjust.works 4 hours ago
And if it’s not someone should check in with humanities veterinarian…
Evil_Incarnate@sopuli.xyz 12 hours ago
Ok. Devils advocate here. If it did change, and did it gradually, would we notice? And if it changed suddenly wouldn’t we adjust and soon see things as we always have?
dual_sport_dork@lemmy.world 12 hours ago
The question is how gradually. Over the span of 10,000 years, probably not. Over the span of a month, absolutely. Remember that the hue of sunlight already changes significantly throughout the day based mostly on the sun’s proximity to the horizon (and thus how much thickness of crap in the atmosphere it has to plow through to get to your location) and we can definitely detect that easily.
kuberoot@discuss.tchncs.de 1 hour ago
One point on perception - doesn’t the sun appear somewhat yellow because the blue light has a stronger tendency to scatter, meaning that the roughly white light of the sun is less blue, with all the blue color of the sky being taken away from the color of the sun?