Ask Lemmy
A Fediverse community for open-ended, thought provoking questions
Please don't post about US Politics. If you need to do this, try !politicaldiscussion@lemmy.world
Rules: (interactive)
1) Be nice and; have fun
Doxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them
2) All posts must end with a '?'
This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?
3) No spam
Please do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.
4) NSFW is okay, within reason
Just remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either !asklemmyafterdark@lemmy.world or !asklemmynsfw@lemmynsfw.com.
NSFW comments should be restricted to posts tagged [NSFW].
5) This is not a support community.
It is not a place for 'how do I?', type questions.
If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email info@lemmy.world. For other questions check our partnered communities list, or use the search function.
Reminder: The terms of service apply here too.
Partnered Communities:
Logo design credit goes to: tubbadu
view the rest of the comments
Lighthouses.
They were quite important for a long time. We used them for thousands of years, and they're often unique in form, iconic. And they're a good subject for photos and paintings, and I think that the light effect from them is neat. Lots of books and such using them, like ones on remote rocks, to get an isolated setting ("the lone lighthouse keeper").
But the past few decades of technological advancement have probably closed the end of their era.
Narrator: and that is how the great solar storm of 2027 wiped out the entire naval shipping and logistics industry.
Let's hope not...
On a modern container ship, by the time you'd see the light, it's already to late to avoid running aground.
Similarly, at airports they had these alternating white and blue lights that would sweep the sky for miles around. When we were on the road at night I used to know where we were based on that. I loved it.
Flight instructor here. That is called a beacon, and airports still have them. And none of them have ever been blue. It may appear blue from the ground but the beam is actually green. The colors actually encode what kind of airport they're at.
At a normal civilian airport that has runways, the beacon will be green and white.
At a military airfield, the beam will flash green and then two whites.
At a heliport with only helipads for helicopters, the beacon will be green, yellow, white.
At a seaplane base, the beacon will be white and yellow.
The beacon will operate from sunset to sunrise, and also during daylight when instrument conditions prevail.
Bonus airport light fact: some smaller, less busy airports like your typical county airport probably does not turn all of its surface lights on all of the time. It'll run the beacon to help pilots find the airport, but the runway and taxiway lights will remain off. Pilots are able to turn them on from the air by tuning their radios to the airport's UNICOM frequency and pushing the PTT key several times in rapid succession. Quite often the brightness is controllable whether you press the key 5, 7 or 9 times. This is called Pilot Controlled Lighting. It's an energy saving system that's been around for decades now, and a fun magic trick for private pilots to pull on their friends lucky enough to be invited on a night flight.
I've witnessed the lights getting turned on for a landing when driving past my local airport before. That's neat to know it might be pilot controlled!
It's possible to look that up in a document called the Airport Facility Directory (which they now call Chart Supplements apparently) but if you don't speak pilotese you're not going to make heads or tails of it. Here's the line that instructs pilots that there's pilot controlled lighting at the first airport I ever landed at:
That expands to "Activate Medium Intensity Approach Light System for runway 5, Runway End Identifier Lights for runway 23, Precision Approach Path Indicator for runway 5 and 23, High Intensity Runway Lights on runway 5 and 23 on the Common Traffic Advisory Frequency." It's actually weird to me the PAPI is pilot controlled; usually those are constantly on because they're useful even during the day.
Drag doesn't like light pollution. Imagine living in the light path of a lighthouse. Every minute your bedroom lights up like Christmas then goes dark again.
I think if you lived near a lighthouse you would invest in some blackout curtains.