You don't know what you're talking about. The reason the light is "redder in the fall is because the earth is moving away from the sun. This stretches or lengthens the light waves and creates a red shift. As we get closer to the sun in the spring and early summer, this wave becomes compressed and creates a "blue shift". That is why a bluer spectrum is better for vegging and a redder spectrum is better for budding.
Anyone using Ceramic Metal Halide bulbs yet?
- Thread starter OldMedUser
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also, CRI has nothing to do with the true spectrum of the sun, it has to do with our visible light spectrum. What we see. the whiter the light the more "we" see. We don't see ultra violet light or the opposite side of the spectrum, but the sun still produces lots of it. Plants could care less about CRI, the just want lots of blues and reds.
But... In Autumn, we are moving towards the sun. It's the angle (of inclination? I've been up like three days straight and worked my eight plus a few OT today, lol) that changes (causing Winter to be... Winter. Which is why when we have Winter, the opposite point on the planet has Summer, and why the equator has tropical weather most of the time). Err... I didn't state that well, but we're closest to the sun in deepest Winter.
If the planet is moving towards/away from the sun, it's going to be the whole planet - not just half of it - so that red-/blue-shift would be the same planetwide.
I was also under the impression that this phenomenon was best measured (without instrumentation, I mean, such as that perceivable by the eye as far as visible light - for example - is concerned; obviously that's how radar guns work) in velocities approaching the relativistic. A 1% redshift corresponds to 1% of the speed of light (relatively speaking, lol). Also in LARGE distances. Often extra-galactic, and when the terms of "local" and "nearby" observations are mentioned, they generally mean "within the Milky Way Galaxy."
Oh yeah, there's something that I'm missing (the answer), but I'm wiped.
Tyrone Hamilton
New Member
With all due respect, I'm pretty sure the doppler effect does not cause a red shift or blue shift of the sun's spectrum. We'd have to be traveling a significant fraction of the speed of light towards the sun to see a blue shift... and we'd all be toasted in the meantime.
On the other hand, you can certainly observe the red shift of starlight depending on how far away the stars are - in fact, as Hubble proved, you can tell how far away stars are by the degree of red shift - the expansion of the universe causes all non-local systems to move away from each other, like the raisins in a baking muffin, or dots on the surface of an inflating balloon... so, the further away an object is, the faster it's moving away from us, and the further the light redshifts.
Ok - sorry I went off on that tangent... but a CMH bulb spectra just gets me going...
Those who are curious about CMH bulbs might find this thread to be of use:
Ceramic Metal Halide vs HPS
Ceramic Metal Halide vs HPS
