A broken cable smashed a hole 100 feet wide in the Arecibo Observatory | Hacker News Reader

A broken cable smashed a hole 100 feet wide in the Arecibo Observatory

businessinsider.com

132 pointsdjsumdog65 comments

I always assumed that the bottom of the dish was made out of concrete, but apparently it's relatively thin and floats above the ground.

Also, the pictures in that article made me feel nostalgic playing Golden Eye on the N64.

My immediate thought was that of the "Rogue Transmission" map in BF4.

Its made of panels of thin perforated aluminium. See these photos https://www.researchgate.net/figure/A-close-view-of-the-perf... and https://www.localguidesconnect.com/t5/Share-Your-Photos-and/...

... and designed to let enough sunlight through that the plants underneath continue to flourish, preventing soil erosion

Huh. I live about 40 miles south of it and I always wondered about that.

> Also, the pictures in that article made me feel nostalgic playing Golden Eye on the N64.

Recently a mate and I plugged in an n64 to play Golden Eye and spent way too long messing with the cables before realising that it was displaying correctly and that the graphics just weren’t that great. A 15 inch CRT hid a lot too.

We still had a great time - no Oddjob usage per house rules. Using him is cheating.

Glad to hear others used the same house rule. It's definitely cheating.

Our rule was you could pick Oddjob, but if you did everyone got to punch you in the arm.

You'll be glad to know some modders are remaking the game using the Unreal Engine

https://www.youtube.com/watch?v=R55y17rXdt4&feature=emb_titl...

About 10 years ago I regularly played a multiplayer only source engine remake that was ok.

I'm guessing that was an earlier manifestation of Golden Eye: Source?

https://geshl2.com

No - Goldeneye 25 was a completely different project, focusing on singleplayer. Just a couple of days ago it had a takedown notice and its twitter feed is now gone:

https://twitter.com/007GoldenEye25/status/129309061086227251... (the tweet announcing it)

They are now Spies Don't Die, and are making it a 90s-themed shooter that will be reminiscent of, but not a remake of, Goldeneye: https://twitter.com/spiesdontdie

The comment I replied to said they were playing a multiplayer-only version. I'm not sure you're responding to the right comment?

I think I misread the replies, thinking the Source engine remake comment was referring to its parent comment (which was Goldeneye25, not Source.)

Gotcha. Hadn't heard of the projects you linked or the parent. Had no idea there were so many!

Seems likely. And did I really regularly play it? I don't think I actually did. Maybe I just did for like a week and remember it well.

Unfortunately, everything surrounding this remake implies that the project is dead and gone. The Twitter account and the IndieDB entry have both been deleted.

They were forced in to a rebrand a week ago due to legal threats on using the 007 licence. Dev work is still continuing though.

From the photos it surely looks like Alec fell through the dish...

> I always assumed that the bottom of the dish was made out of concrete

Probably because you watched Goldeneye :). In that movie the dish looks like it's concrete:

https://www.youtube.com/watch?v=FtKJpr7N1qc

https://www.youtube.com/watch?v=wGmDAjRRNXs

https://www.youtube.com/watch?v=jp9tENRDVzA

Here's a bigger picture of the cable: https://www.sciencealert.com/images/2020-08/5f32fb9b2618b96b...

Thanks to article on sciencealert.com: https://www.sciencealert.com/a-broken-cable-smashed-a-huge-h...

That's.. The same article (with credit given, even -- "This article was originally published on business insider" at the bottom)

How do radio telescopes track asteroids? I don't imagine that asteroids would be emitting radio waves, and their small size wouldn't seem to be an advantage either (though, a few miles across might be plenty to interrupt/reflect radio wavelengths? I dunno)

Just like with radar, it's an active process. The telescope emits radio waves, they are reflected by the object, and the telescope receives the reflected waves.

With clever tricks they can then get a hint of the size or other parameters of the object from the shape of the reflected signal.

> Relying upon high-powered terrestrial radars (of up to one MW[3]), radar astronomy is able to provide extremely accurate astrometric information on the structure, composition and movement of Solar System objects.[4] This aids in forming long-term predictions of asteroid-Earth impacts, as illustrated by the object 99942 Apophis. In particular, optical observations measure where an object appears in the sky, but cannot measure the distance with great accuracy (relying on parallax becomes more difficult when objects are small or poorly illuminated). Radar, on the other hand, directly measures the distance to the object (and how fast it is changing). The combination of optical and radar observations normally allows the prediction of orbits at least decades, and sometimes centuries, into the future.

https://en.wikipedia.org/wiki/Radar_astronomy

Indeed, the fact that Mercury is not tidally-locked with the Sun was discovered using the Arecibo radar telescope. If I remember correctly, they used the Doppler shift imparted to the radio wave --which expresses differently across the width of the rotating planet -- to learn this.

"The rotation of Mercury was not discovered until 1965. Until then the most widely accepted theory had Mercury tidal locked to the Sun. Soviet scientists bounced radar signals off the planet’s surface in 1962 verifying that the planet rotated, but it wasn’t until scientists using the Arecibo Observatory verified the planet’s sidereal rotational period of 58.647 day."

(From: https://www.universetoday.com/14008/rotation-of-mercury/)

The same way your eye tracks an object that is illuminated by light. They just do it with a different part of the EM spectrum.

I had to look this up on Wikipedia[1], it can apparently transmit as well as listen the way that most radio telescopes do and in at up to 20 TW too. I had frankly thought the most powerful radars in the world were in the 10s of MW range and this thing has got a dish 305m in diameter compared to the 10-50m I'm used to for radars tracking satellites in orbit (I used to do software for that professionally).

I wouldn't have thought doing active radar scans of an astroid out in space was possible given that radar returns fall off as the 4th power of range. But given that power and dish size, given that these are large objects being tracked, and given that they move slowly compared to the radar cone I guess it's possible after all. But then again one of the first ballistic missile defense radars accidentally mistook the rising Moon for an attack and almost caused WWIII[2] so I guess there's precedent, even though the Moon is much larger and closer. I'm seeing references to it tracking asteroids in the Apollo group, so relatively nearby[3] and plates which are much larger. I'd guess that even the biggest asteroid in the main belt, 1 Ceres, would be too dim for it to see but I'm curious.

[1]https://en.wikipedia.org/wiki/Arecibo_Observatory

[2]https://blog.ucsusa.org/david-wright/the-moon-and-nuclear-wa...

[3]https://en.wikipedia.org/wiki/Apollo_asteroid

If anyone's transmitting at TW powers, it is in a short pulse. You might be comparing it with more-continuous systems.

> But then again one of the first ballistic missile defense radars accidentally mistook the rising Moon for an attack...

They are in good company; like 90% of UFO sightings are just people seeing the Moon and mistaking it for something else (or rather, not immediately identifying it, leaving them with impressions like "there was a bright light following me down the road" or "there was a glowing orb behind the trees").

Regarding the 20TW from the Wikipedia page, that's referring to the EIRP - effective isotropic radiated power. This is the amount of power that you would need to radiate from a theoretical antenna with a perfectly spherically symmetric power distribution. The Arecibo antenna has a fairly narrow beam. The 20TW EIRP transmitter appears to operate at 2.38GHz. Plugging that frequency and the 270m diameter, a beamwidth calculator gives me a gain of about 75dBi. So, yes, it's like a 20TW transmitter, but only one tiny narrow little slice of it. At 75dBi gain, that's one (10^7.5)th of the total sphere, about 1 part in 30 million. Or, you could say, if the antenna were radiating the same power in every direction as it does in it's peak direction, that would be 30 million times as much power. So, dividing to find the power in that narrow beam, we get "only" about 600kW radiated in the direction it is pointing. Add in cable losses and other inefficiencies, and the power output at the amplifier is probably close to a megawatt.

I used to work for NRAO. Arecibo is a transmitter, which illuminates the asteroid with very high powered radio waves. The asteroid reflects some of the radio waves, which is received back on the ground at Arecibo or at other radio telescopes like Greenbank or the Very Large Array.

I don't know why the scrolling on businessinsider.com is broken for me, but this worked: https://apnews.com/668bb0219afcc086376c9d56685ab9d0

This can happen on sites where you have an adblocker removing modal overlays elements but there are still an invisible part or other CSS means limiting scrolling.

Some sites block scrolling with CSS (usually on body): overflow: hidden;

For me they blurred the images because of my ad blocker. Or probably because I have cookies blocked.

the images loaded in for me, I think it's lazy loading

lazy internet can't be bothered to deliver the images...

You expect me to believe this wasn't the aliens?

I grew up visiting the Observatory all the time.

Before Trump made my home island famous, Arecibo Observatory was the one place I could point to mainland American friends so they recognized Puerto Rico (since it's famous, used in scifi movies, etc.)

Hope the government assists in reconstructing the dish.

Given HUD still hasn't released the relief funds for Maria in 2017, I'm not holding my breath on any other help coming here.

There was an episode of Agents of S.H.I.E.L.D. set in San Juan, though. So now there's something else mainlanders have heard of.

Ha, indeed..

Seems like such a strange break. I feel like there's supposed to be a dramatic piece of video in slow-mo showing one strand breaking, then the additional stress causing the next one to snap, until the final 'plink' before the whole thing comes crashing down.

I hope this wasn't due to underfunding. Old stuff breaks, but it should last when it is being maintained properly.

Not only underfunded, but also damaged in Hurricane Maria in 2017. https://skyandtelescope.org/astronomy-news/arecibo-observato...

I always say that 99% of my IT issues are bad cables.

Looks like that applies here, as well...

That first picture reminds me of a level in a team-based FPS I played briefly. Can't remember the name. You can send drones out and stuff.

First picture? There's only one picture, and it's blurred so much I can't make anything out of it at all.

YOu have to allow JS to view the images and load the actual text of the article too! How did we get to this stage where you can't even just view a images and text without JS.

Because the people who put ads and paywalls on their sites are in an active war against adblockers and dynamically loading all the content is an effective countermeasure for not allowing JavaScript?

As another comment points out, probably "Rogue Transmission" in Battlefield 4?

That looks very similar, but this one was an older game. I'd look it up but I was playing it on XBOX Live free trial and I let my subscription lapse..

"Frontlines: Fuel of War" perhaps? It does have a satellite dish in one level, and the gameplay prominently features drones as far as I can remember.

https://oyster.ignimgs.com/mediawiki/apis.ign.com/frontlines...

Source: https://www.ign.com/wikis/frontlines-fuel-of-war/Mutliplayer...

Interesting to me that everyone is calling this a "cable".

It might be the combination of climbing/sailing/rigging/nerd ... but I'd never call that structural element that broke a cable.

The only cables I can think of either carry electrons, photons, or signal wires (say, a clutch cable). I'm being maybe pedantic, curious what others think, esp in industry.

It's a very common term: https://www.mcmaster.com/steel-cable

What would you call it, then?

On a suspension bridge, what are the catenary pieces called?

Or even.....a cable stayed bridge.

I don't understand how you can be a sailing/rigging nerd and say that isn't a cable.

Last time I checked nautical cables do not carry photons or signals. Arresting cables, bowden cables are also cables that do not do so.

I would call it wire rope, or a support line. If I worked with it often enough, I'd probably refer to it by size or construction (EHS, 7x7, etc)

I'd argue that a Bowden cable (eg a clutch cable) is primarily carrying a signal... really though, just thinking through what defines a cable.

By contrast, rope and line are terms with fairly specific meanings.

"the Arecibo Observatory, which searches for aliens"

It seems clear what happened here. Aliens.

The abbreviation for the time zone, ET, caused me to pause.

wow, I feel like "Smashed a hole" isn't quite doing that carnage justice. Good luck to them on the repairs :(

Illuminati preventing us from hearing signals. Aliens Confirmed!!

Dupe of https://news.ycombinator.com/item?id=24127343

Insert not saying it’s aliens meme

Reply on news.ycombinator.com