Recent comments in /f/askscience

abeinszweidrei t1_j7fjtda wrote

Reply to comment by zerpa in Why are green and red laser pointers so cheap and available, but yellow ones not so much? by SurprisedPotato

Good question, I don't know. Sounds like it could work. A quick search only gave me some single wavelength yellow ones though. My guess is that they are just more expensive. You'll need two lasers, and also optics compensated for the chromatic shift and suitably coated. That's straightforward, but probably just makes it too expensive for normal laser pointers. But yeah, i don't see a fundamental reason not to make it like this

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SgtSchabing t1_j7fiqcn wrote

Reply to Why are green and red laser pointers so cheap and available, but yellow ones not so much? by SurprisedPotato

Laser diodes are made from a semiconducting material. We have different materials available, and the choice of material determines the colour. We have good working and widely used materials available for red and blue, but not for the space inbetween (green, yellow, cyan, orange). As someone else described, it is relatively easy to produce green from infrared. For the other colours, we do not have materials available for home consumer use. There are some, but they are not in high demand which is why they are not as cheap and widely available.

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bionic_human t1_j7fg4kq wrote

Reply to comment by open_reading_frame in Did the 2009 H1N1 outbreak in the US increase the incidence of type 1 diabetes in adolescents? by legendary_kazoo

I would expect it to occur with any virus that causes metabolic disruption. I haven’t seen any statistical analysis on timing of new diagnoses, but many T1s report getting diagnosed around holidays, during which virus transmission (even asymptomatic) naturally spikes.

I’d imagine to even begin to get a feel for it, you’d need a huge sample size and accurate medical record coding to mine for. KP and other large health systems would be the most likely to have the necessary data, but someone would have to see enough value in the research/potential results to actually fund the analysis, even if you had access to the data.

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_GD5_ t1_j7fdzu1 wrote

Reply to Why are green and red laser pointers so cheap and available, but yellow ones not so much? by SurprisedPotato

Cyan and yellow solid state lasers exist. They are not common or cheap though.

Red and blue lasers technology was driven by the CD and DVD industries. A lot was invested to make them fast and cheap. Green was pushed later to make RGB displays and because humans are very sensitive to that color. Green pointers are perceived as very bright. There hasn’t been much invested in yellow or cyan.

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Cyber_Fetus t1_j7fdg54 wrote

Reply to comment by KBoxter in Do tonal language speakers understand each other while whispering? by Paulix_05

Cot-caught merger. It covers a good chunk of the US and Canada, so I wouldn’t exactly call it a “weird way of speaking”. But regardless, it was just an example so if you pronounce them differently I’d hope you can manage to come up with two different words that are pronounced the same in your accent.

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abeinszweidrei t1_j7fajh1 wrote

Reply to comment by ellipsis31 in Why are green and red laser pointers so cheap and available, but yellow ones not so much? by SurprisedPotato

This, but I think there's even more to it: When checking a plot of wavelengths vs color, (eg https://www.gentec-eo.com/media/3583/commercial_laser_lines.png ) one can see that the region of wavelengths perceived as yellow or cyan is rather narrow compared to red, green, or blue. So if you want a yellow laser, you need a laser running pretty exactly at the desired wavelength, so when frequency doubling around 1140-1180 nm. It is doable, but red or green is just much easier as its a wider range (and suitable lasers have been lon established, e.g. Nd:YAG at 1064nm to be frequency doubled to 532nm, which is a great green).

And I think another point comes into play: yellow is just really not convenient as a laser pointer, when most slides have a bright background. Red and especially green can just be seen mich easier also with low power.

So I think in the end it's a combination of harder/more expensive to engineer and just little demand for it.

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CrustalTrudger t1_j7f927z wrote

Reply to comment by bullwinkle8088 in Is there a term for lake bottoms that "hour glass" (temporarily becomes wider following a "shelf" as the depth increases ) , how do bathymetric maps depict this, and does this have a common affect on turbidity, thermoclines, or other characters? by Irisgrower2

Right, I understand what an hourglass looks like, the point is that this type of question probably stemmed from a particular example and so providing that example would help narrow down specifically what OP is asking about.

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SolasHealth t1_j7f7jnb wrote

Reply to When does the body store fat? by fappie6

That's a good question. Your idea is also admirable. However, the fact is not as you assumed. When you consume fat, it is stored in your cells. These cells stores energy in the form of glycerides.. Later, these glycerides degraded and released energy when required. When the number of fat storage cells increases , a person gains weight. This is an ongoing process. Storing fat is not going to happen overnight.

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