Recent comments in /f/todayilearned
NerdyKirdahy t1_j7mjgt4 wrote
Reply to comment by wufnu in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
This is why the Dreamcast failed—orange light.
rockmsedrik t1_j7mhh8p wrote
Reply to comment by zed857 in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
For the few of us that lack a separate office for our equipment, some of us need to live in one room, I use my computers to render video, and to render 3-D projects while I sleep, it’s crazy that I have to black out all the LEDs just to keep them quiet.
Typical_Balance3892 t1_j7mgc3v wrote
Reply to comment by 4Blu in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
Hikaru
Ok-disaster2022 t1_j7mdrk1 wrote
Reply to comment by Splice1138 in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
It's frustrating that the headlights from heall are more blue tinted, so no only ate they brighter, but the person using them can't see as well, so they make them even brighter.
Ok-disaster2022 t1_j7mdka0 wrote
Reply to comment by strangr_legnd_martyr in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
However there's an issue with emergency signage. Red is the color of danger, stop, while green is safe, go. Exit signs in areas of low literacy are green and green are becoming more common in the US to be more inclusive of people who can't read.
Rosy2020Derek t1_j7mc1zz wrote
Reply to TIL about Rob McKuen, the bestselling poet in American history who sold 60 million books and 100 million records but is all but forgotten today by SAT0725
Idk he was the “ best” Who decided that? I don’t like his stuff
macdon74 t1_j7ma5fq wrote
Reply to TIL about Rob McKuen, the bestselling poet in American history who sold 60 million books and 100 million records but is all but forgotten today by SAT0725
"It's not who you love or how you love, Just that you love"
Jackieirish t1_j7m95ia wrote
Reply to comment by rks404 in TIL about Rob McKuen, the bestselling poet in American history who sold 60 million books and 100 million records but is all but forgotten today by SAT0725
The poem and song were a translation of a Belgian song Le Moribund.
mobugs t1_j7m8zo0 wrote
Reply to TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
I remember a physics professor in highschool being very excited about the blue led telling us it would allow for white light LEDs.
WillTFB t1_j7m8r6y wrote
Reply to comment by planoavid in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
Ah thank you, that make sense.
[deleted] t1_j7m7rck wrote
planoavid t1_j7m6nu8 wrote
Reply to comment by WillTFB in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
The lens and cornea of the human eye absorbs shorter wavelengths (blue) better than longer wavelengths (red) so less blue lights reach the retina.
The cones the retina uses to see longer wavelengths are active over a wider array of wavelengths vs the blue cone.
So it is easier for your eye to sense longer wavelengths of light than the blue light.
wufnu t1_j7m5dw1 wrote
Reply to TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
First bright blue LED I ever saw was on the PS2. I got a week to play with it pre-release due to work. Before and after gaming sessions at night, that piercing blue light felt like the goddamned future.
Splice1138 t1_j7m56uj wrote
Reply to comment by TrumpterOFyvie in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
You might be a more extreme case, but human eyes can't focus on blue light as well, period. I know this first hand (and second, and third) from calibrating three tube RGB projectors back before LCD/DLP.
I also read about it being used in image compression. If you split an image into R, G, and B channels, you can save the B at half resolution and the difference is nearly imperceptible to human eyes, whereas it is easily seen if you do that with R or G.
zed857 t1_j7m37rh wrote
Reply to comment by rockmsedrik in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
Connect that stuff to a power strip with an on/off switch and turn the whole lot off when you go to bed. Apart from your phone charger it's not like you'll be using those other electronics when you're sleeping.
WillTFB t1_j7m36pp wrote
Reply to comment by TrumpterOFyvie in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
Wonder what the science behind this is
TheLyingProphet t1_j7m2u18 wrote
Reply to comment by HPmoni in TIL about Rob McKuen, the bestselling poet in American history who sold 60 million books and 100 million records but is all but forgotten today by SAT0725
nope they are forgotten all the same
Kipsydaisy t1_j7m1lrh wrote
Reply to comment by askmeaboutmysciatica in TIL about Rob McKuen, the bestselling poet in American history who sold 60 million books and 100 million records but is all but forgotten today by SAT0725
No. But the poetry wasn't the dealbreaker. I don't think the poem was good, though.
4Blu t1_j7m197x wrote
Reply to comment by undefined7196 in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
I was at UCSB when Nakamura won. He was apparently pretty stoked he didn’t have to teach anymore.
Jaksmack t1_j7m0gsb wrote
Reply to TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
In 98 or 99, blue LED's we're still so expensive that I bought 1 to replace the green LED on my PC's power light. I was going to put them all over the PC case, but instead went with some cold cathode tubes.. the tubes and power supply was still cheaper than buying 1 LED. If I remember right, the LED's were like 25$ each..
Thelgow t1_j7m0bd7 wrote
Reply to comment by strangr_legnd_martyr in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
That too because lord knows what happens when the tape falls off my optical to rca adapter. Why this thing has a Batman spotlight built into it, I'll never know.
strangr_legnd_martyr t1_j7lzy1d wrote
Reply to comment by Thelgow in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
Red LEDs do require less power. The forward voltage on a red LED is about 1.8V at 20mA. The forward voltage on a blue LED is about 3.6V. That's 36mW of power for red vs 72mW of power for blue.
Blue light has more energy than red light (higher frequency/shorter wavelength).
I think they generally favor red over blue for emergency systems, though, because red light has less effect on low-light vision. So if the power goes out, your red-lit emergency signs don't blind you in the dark.
neoplastic_pleonasm t1_j7lzl7u wrote
Reply to comment by rockmsedrik in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
Nail polish is good too. You can use it to make them dimmer but still visible.
RockItGuyDC t1_j7mnjkg wrote
Reply to comment by rockmsedrik in TIL the first Blue LED wasn't commercially available until 1989 and bright blue LEDs weren't available until 1993. by j-merc23
I understand that it's not always possible for everyone, but this is exactly why I have zero electronics in my bedroom (aside from my phone charging on my bedside table, but that doesn't have an always on LED).
That plus blackout curtains have really improved my sleep!