Most likely because development cost of red and green/blue semiconductor diode lasers have been paid for by other applications, and those devices are available cheap. Selling laser pointers probably does not generate enough profit to develop their own laser technology.

Optical data storage used to be pretty big, and paid for development of semiconductor lasers. CDROM used AlGaAs/GaAs/AlGaAs thin film 'stack' which emits in red spectrum. BlueRay uses GaN/InGaN/GaN stack, which emits green or blue depending on In content in the middle layer. So these lasers were/are produced in volume.

You can get yellow/orange LED (light emitting diodes), but not lasers. Old LEDs used to be doped GaP, which are pretty dim. More recent ones are AlInGaP layer wafer-bonded to GaP substrate. These are frequently used in traffic lights, and very bright.

The reason data storage lasers skipped yellow/orange is because timing of invention of green/blue lasers. Shorter the wavelength (red > yellow > green > blue), higher the data density on the storage disk. Green/blue lasers were invented before red-laser CDROM had gone obsolete. So when the time came for data storage industry to move to a shorter wavelength, they decided to put development money into green/blue.

Hexane extraction using fractjonal distillation was a common method for vegetable oil production. So yes in part the oil will be boiled. It's not what a pot on your stove would look like, and takes into account vapor pressures differences, but it boiled would be an accurate description.

Signed, a Chemical Engineer.

That lack of mixing is actually a feature for fiber optic communications. There are optics that use four lasers with different wavelengths to send four data streams simultaneously down the same fiber line.

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Because neither red nor green, in terms of frequency/wavelength, are yellow. The colour wheel is about visual perception.

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But each time they bump into each other they bounce apart with shared energy. So the energy is still conducted but not by the original molecule which began with it.

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Consumer lasers aren't going to be powerful or well calibrated enough for this to be an issue. The main phenomenon is Rayleigh scattering, the same thing that causes blue sky/red sunset, so red would travel farthest, and a hypothetical yellow would travel farther than green. There are some other less common factors like air pollution that could change how this plays out.

Indeed, the diodes for cyan and yellow are very expensive and have only very recently been publicly available

The only hourglass shaped lake I know of is Warm Mineral Springs in FL. It has that shape due to a sinkhole when ocean levels were lower. With a hotspring erosion setting off the process. https://en.m.wikipedia.org/wiki/Warm_Mineral_Springs_(spring)#:~:text=Warm%20Mineral%20Springs%20is%20a%20sinkhole%20formed%20in%20carbonate%20rock,metres%20(236%20ft)%20across.

You can definitely still create tones while whispering. Its not quite as a easy but I was just testing it and I was still able to make tones. Why wouldn't they be able to? Tones don't mean volume, they are pitch. Volume and Pitch are not the same thing and tones can be easily expressed in whisper.

I don't know why everyone else is talking about context.

Yellow also just doesn't travel as far. Which is why from far away, tress on mountains appear blue, not green.

Or at least that's what I've always heard.

I don't know why I need this but I will install it anyway.

Additionally, the “yellow gap” is a thing that exists in semiconductor physics. We just don’t have a good junction diode with a band gap that produces photons around 580nm, which is that “banana yellow.” The way we solve that for LEDs is using phosphors, but that’s useless for producing coherent laser light.

They definitely do not boil the oil to refine it as the smoke point is so much lower it wouldn't make any sense. They heat the oil to like 180f and add an alkaline substance. There are some steaming processes later on but they stay about 100f (400-450f steam temp) below the actual boiling point of the oil and this process deodorizes the oil.

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> how do they convey tone information without using their vocal cords?

The same way English speakers convey the difference between the [s] and [z] sounds while whispering - through context.

When you whisper the sentence Sue went to the zoo, the first and last words begin with the exact same sound. This is because the only difference between the [z] sound and the [s] sound is that the first is voiced and the second is unvoiced, and all sounds produced while whispering are unvoiced. Nonetheless, it’s not hard to understand what words are intended, because of sentential context.

Similarly, speakers of tonal languages use context to understand whispered utterances.

"Boiling" for water is when the vapor pressure of the liquid, equals the ambient air pressure. Water at any pressure has a vapor component, it just happens to be a lower pressure typically than ambient pressure. That's why you can leave a glass of water out, and eventually it will evaporate.

Oil's have a vapor pressure also, it just happens to be much higher than water. We boil oil all the time, as this is typically how it is refined and processed, even vegetable oils. However some oils decompose, before they get to their boiling point.

Frying as others have said is when you boil water out of food, using hot oil.

If you put water under a high enough vacuum, even at room temperature the vapor pressure will equal the ambient temperature and it will boil. In cities like Denver you have to adjust baking and cooking because water actually boils lower than the typical 212F/100C

And an extra note to point out that gas cannot actually possess either. 0 pressure means no gas and gases tend to become liquid under sufficient pressure, and in the scenario of gas in the sun, something much more interesting happens.

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Well, gas has a hard time sitting still to "conduct" heat - convection and advection is inevitable.

And you have to be additionally precise in your setup.

More pressure means more gas matter or less gas volume, or somewhere in between.

But take it to its logical extremes: Almost 0 matter means a vacuum and not heat transfer from "conduction," and infinite pressure means infinite matter needs to be heated up, thus no "conduction."

But if convection is permitted, then generally higher pressure makes it easier to transfer heat between molecules

Not a direct answer to your question, but an important addition for consideration: the lecture in this video describes the important differences in how our bodies treat calories derived from different source molecules. The key comparison starts at 45 minutes in, but the whole thing is worth watching.

True, but the thing that makes lasers lasers and not just tiny flashlights is that they are a single coherent beam of uniform light. This is what allows them to behave reliably for engineering purposes and stay together over long distances, etc.

If I were to build a yellow laser by having a green laser and a red laser, it would be hard to get them to converge on exactly the same point. Or put another way, getting them to converge at a particular distance would be easy, but as soon as you moved slightly closer or further the dots would probably misalign and you'd end up with a red and green dot near each other. Even if the two beams were mirrored into the same trajectory, it's possible they'd refract while traveling due to their different wavelengths and end up as two dots at the end anyway.

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