I'd assume that the engineers would have performed some form of stress tests for these installations that were actually meant to afford wind resistance and that the noise should have been noticed. Does anyone know how these conditions are tested in a simulated large structural engineering lab?
New slats make the Golden Gate Bridge sound like a David Lynch movie
181–190 of 344 posts
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#182I'm just glad they identified the source of the hum, many people are impacted for years by unexplainable sounds, and it is maddening. It took me and my neighbours a month to find the source of a hum that was resonating with our windows. It was torture, with midnight walks and lurking around potential sources, mapping nearby industrial sites, and questioning our sanity, while our windows were vibrating without a stop.…
A couple years ago I got moved to a new office where I could hear an awful humming noise from the light ballasts in the ceiling when the lights in a showroom/lobby downstairs were turned on. None of other dozen people in my office could hear it. I feel like I wasted a bunch of perfectly good political capital at work in my fight with building management to get them to fix the lights. They finally replaced them with b…
Same thing happened with me and getting a full spectrum light for a windowless office. I left the job not too long after due to an abusive manager. Certainly wasted political clout on the push for health.
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#183I'm just glad they identified the source of the hum, many people are impacted for years by unexplainable sounds, and it is maddening. It took me and my neighbours a month to find the source of a hum that was resonating with our windows. It was torture, with midnight walks and lurking around potential sources, mapping nearby industrial sites, and questioning our sanity, while our windows were vibrating without a stop.…
Two unrelated anecdotes: 1. A few years ago I spent some time in Falmouth, MA and there was an ongoing battle over newly installed wind turbines. The humming sound was getting to people, including to the point where they were getting headaches. Some people heard it and others didn't. The locals were going to war with the initiative. This article reminded me of that and I checked in on the ordeal. Looks like they shut…
1. Very funny to be reading this. I grew up in Falmouth, and lived there until 2014 when I graduated highschool. I obviously wasn't incredibly attuned to this issue, but as I recall, the only people opposed to the installation of the turbines were a very small, very vocal, and very, very, wealthy minority of people who owned mind-bogglingly expensive beach houses and lived there two months out of the year. I'm fairly certain a lot of the more reasonable-sounding complaints they threw at the project were simply cover-up for their real gripe, that the turbines ruined their view over the bay. I recall an unintentionally hilarious piece of mockup art that was drafted up, comparing the horizon over the water with and without turbines, side by side. They were barely distinguishable blips. It was an interesting phenomenon. Woods Hole, a tiny community on what is essentially a peninsula near Falmouth, is both a center for oceanographic science (WHOI, USGS -- disclaimer, I've worked at both), and a summer home for the insanely rich. The scientific community was largely in support of the turbines, but all anyone ever heard about was how the turbines would be a huge disaster. As I recall, many of the noise complaints ended up being somewhat unfounded.
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#184Earlier quoted context omitted.
Just across Buzzards Bay from Falmouth was the original Marconi transmitting station for transatlantic communication to a receiver in Norway. My great-grandfather helped build it in 1914! At the time it was the most powerful transmitter in the world at 300 kW. There were 14 440-foot towers in a grid, and it was so powerful that apparently anywhere in town you would get zapped while hanging out the laundry on a clothe…
Very interesting. Maine also has a significant transmitter array in Cutler with 30 or so antennas around 900 ft tall apiece. https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler I wonder what it's like to try to pull a signal up there. Your comment brings up memories of Lighthouse Beach in Chatham, which has a ton of warnings about Great White Sharks due to the prevalence of seals in the waters. Beautiful place. If t…
Picking up TV and other RF signals near there should not be a problem. Modern transmitters are much different than in Marconi's time. Then they used a spark gap to generate RF, which have a DC to daylight kind of output that GP described. Much like a bad ground on a car ignition system can make a lot of RF noise that really gets around, a spark gap transmitter puts out a signal EVERYWHERE. Which is why it affected so much.
Modern transmitters are tuned and filtered so they can coexist with everything else.
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#185Did we just make the golden gate bridge more epic?
What makes it epic compared to other bridges? Well except being in many films so more people knows about it.
It's universally considered to be a beautiful bridge. Compare and contrast with the old eastern span of the bay bridge.
https://en.wikipedia.org/wiki/San_Francisco%E2%80%93Oakland_...
You have to admit the old eastern span was just ugly.
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#186Earlier quoted context omitted.
When I lived in Nob Hill, there was a quiet long beeping sound that could be heard every couple of minutes - imagine a quiet booooop and you're pretty much there. Definitely sounded electronic. The weird thing was I could actually hear it on quiet days in a large radius in Nob Hill. It didn't seem to be localized on my house. I was never able to identify it, and searching online gave me nothing.
I hear this all the time. I was just talking to someone about it. It’s not everyday but it’s frequent. I hear it mostly in the morning and at night. It’s always the same length, about a second. It’ll come in pulses of 2 or 3 usually. Spread out a few minutes a part. It definitely sounds like an electronic sound. Almost like a sci fi satellite sound but deep in the water far away. Or maybe a far away whale mourning or…
Power companies transmit a signal at certain times of the day through the lines. This controls devices that can switch between day and night mode. My ceiling fans will buzz when it's happening. Sounds almost like the old SMS interference you'd get with FM radio.
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#187Earlier quoted context omitted.
Get an audio spectrum analyzer app for your phone, and enable its log-X scale. Very useful for this sort of thing. The FFT will reveal sounds you don't hear yourself.
They are indeed cool, but no math magic can help you if your microphone is not picking up the signal. I don’t have datasheets for mobile phone microphones but lets look at some professional ones. The Senheiser MD 46 goes down to 40hz. The Behringer MC8000 goes down to 15hz. These are just two random samples I looked at to illustrate that its not obvious that a microphone will even have a good response down to 10hz.
Those ratings are 3-dB points, not brick walls. It doesn't need to have a good response down to 10 Hz (and it's safe to say that it won't).
The main drawback is that you may have to wait a while between updates.
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#188Earlier quoted context omitted.
I forgot about the part where you would have a phone and can call for help! Why is the landing part hard, is it about maneuvering and slowing?
In the marinas you have limited maneuvering space and with sails you are limited in which directions you can go - directly against the wind is not possible, you need to zig-zag. Slowing is also a bit more difficult. To add to trouble, marines are often built in places with less wind (of course) and wind might change direction during landing. Note that it's still quite possible, just more challenging, risky too I gues…
Thanks for the explanation, appreciate it!
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#189This is very similar to an Aeolian Harp, also known as a wind harp. https://en.wikipedia.org/wiki/Aeolian_harp https://www.youtube.com/watch?v=CtzSm76ppS4 They are pretty cool art installations. The Golden Gate bridge may now be the largest such installation ever built!
Ok, I'm on board here. This is really cool. Yes, it cannot be a 24/7 thing, the harp/bridge is too loud. Also, putting resonances into a suspension bridge is likely to be unsafe. That said, like the chiming of church bells in a village, it may be used selectively. I can imagine some Burners quickly putting up an adjustable mechanism to have the bridge sing/chime. Something that can point into the wind correctly (to s…
I joked with a friend today that with San Francisco being San Francisco, someone will have a system for making it play Carol Of The Bells by next week.
Re: New slats make the Golden Gate Bridge sound like a David Lynch movie
#190I tried making a spectrogram: https://twitter.com/nibot/status/1269347206445756416 I tried using baudline[1] (a 20-year-old program!) but it didn't work out-of-the-box on my current Linux installation. Instead I found something called Sonic Visualizer[2], which, while not real-time, worked out of the box. Using Pulse Audio 'pavucontrol' it was easy to configure Sonic Visualizer to use as its input the 'monitor' chann…
every musician ever: A440 PROVEN BY THE BRIDGE
A440 is not as universal as you’d think. Tunings as low as A435 and as high as A466 are in use even today.