
Obligatory Beatle referance
".. Are you sure he's earthed..?
I wonder if copper conductors from the cable body, direct to ground would have mitigated some of the induced potentials?
The collapse of the 305-meter telescope at Arecibo Observatory in 2020 is being attributed to zinc creep – slow deformation due to stress – in the telescope's cable spelter sockets, according to a committee report from the National Academies of Sciences, Engineering, and Medicine. This effect may also have been accelerated by …
> trying to desperately pretend it was anything but that
It sounds indeed like that. Because (AFAIK) most of the time Arecibo was used as just another passive radio telescope, so most of the time there was no "unique powerful electromagnetic radiation environment", not any more than at the George Washington bridge. Besides we would had noticed by now if strong radar radiation destroys metals...
Why did it fail despite a safety factor above two? Much likely because of potential initial building defects, and the lack of maintenance: The tropical environment is very aggressive.
To me Arecibo is a monument to what's wrong with the modern world.
A great instrument bequeathed to us. But we failed to maintain it because science is now run by bureaucrats.
And have we fixed it? No. Instead we are opening a BS educational centre: The name speaks for itself:
"NSF Arecibo Center for Culturally Relevant and Inclusive Science Education, Computational Skills, and Community Engagement "
There was a major problem with maintaining it, as the towers and cables that the dish was suspended from hadn't been designed with maintenance in mind. It was impossible to remove even a single cable to replace it, as that would increase the load on the remaining cables beyond a safe margin. The towers themselves were also crumbling. It would have needed a vastly expensive engineering solution to support the dish while the cables and towers were replaced, well beyond the likely cost of building a replacement from scratch, and there was no budget for that.
Yes, that was pretty much my understanding, that any actual repair would involve rebuilding anchor towers around it and rebuilding the central antenna.
Aside from maybe beamcasting messages at various stars, there are much better ways of doing the same thing now.
I am almost certain that there was a German punk band named 'Electroplasticity' back in the day. Although I may just be misremembering pieces of Japanese electro-punk brutality. The zinc in my memory sockets has probably been oozing out over time. There's nothing for it. Wouldn't be surprised if it all comes crashing down soon.
I was having an argument with a colleague last week - as she wanted to play Christmas music in the office. I said you can only play a Christmas tune if it's 'Merry Christmas Motherfucker'. A "song" I had invented on the spot. But curiousity got the better of me, and so I checked to see if someone else had had the idea first. A quick check on Apple Music suggests that at least 8 bands had beaten me to it.
Also, if you need Christmas metal - you need Christopher Lee (link to Youtube
Christopher Lee made a metal album, aged 91. Followed it up with a Christmas single, and another metal album the year after.
The telescope isn't going to be rebuilt. No scientist is ever going there again. It's too far out of the way to be a tourist destination.
They presumably need to keep some sort of 'science facility' there to keep the lease/avoid remediation costs
So put up a birdbox and call it a wildlife habitat
“No scientist is ever going there again.”
I wouldn’t be too sure. For example: I recently read a contemporary review of Darwin’s earthworm treatise, and am genuinely pleased to see on Google Earth that his sloped stony field behind the house is all still there pretty much as he had described.
(Makes one curious for a visit and dig around amongst the buried rocks for some of them Darwin Worms, best baiters ever. Perhaps next springtime?)
https://books.google.ca/books?id=GiIDAAAAMBAJ&printsec=frontcover&rview=1&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
And then there's the new president asshole elect ... (fixed the spelling for you)
He is so fond of Puerto Rico.
You do remember that Trump had over 5 million more votes than Harris, won more than twice as many states, and 86 more electoral votes than Harris.
One good indicator of how voters did not want her as president was that Trump took the early lead and Harris never came close.
Wow. Science needs to be Culturally Relevant and Inclusive? Science just is.
Science has always been incredibly politicised, because humans are politicised. It is true that just as 2+2 = 4, so the world will get on and science will happen without us. Humans do not need to believe evolution or gravity for it to be true.
Nonetheless, it is a fallacy to believe that science as done by humans is neutral, objective or apolitical - the canonical extreme example being the pseudoscience of the Nazi's Racial Theories, which claimed (via many papers and journals) to have observed a strict and scientific hierarchy of the human race. Or the historic persecution of "unacceptable" science by the Vatican. The Catholic Church was always a major patron of science and engineering - provided you didn't challenge religious orthodoxies (like the Earth being the centre of creation). Such persecution resulted in self-censorship and the suppression of research.
Or we could consider the way in which women have been traditionally excluded from the sciences - forced to publish under male pseudonyms, or having credit taken by male colleagues. Not to mention the inherent racism in mid-20th century science where European and American scientists ignored science from Asia or Africa as being inferior, despite there being a deal of seminal work done. The Jantar Mantar astronomical park in Jaipur was easily on a par with 18th century European naked eye astonomy (notwithstanding that they didn't have the lens grinding technology for telescope astronomy).
And now we're about to watch Trump implement Schedule F for any civil servant whose face doesn't fit, defund NOAA, privatise the National Weather Service, "drill, drill, drill" in the Arctic and generally inhibit any science he doesn't like.
The fact that this center is in the buildings that formerly supported a world-leading scientific instrument which was allowed to fall into disrepair by political indifference should surprise noone (the fact that it's collapse was not met by immediate and bi-partisan calls for rebuilding in Congress is a damning indictment of US discourse. Someone should tell Trump that China has a better one - that might get his interest!).
I agree entirely though that even if what you're doing is outreach to kids and encouraging participation by minority groups - particularly in environmental sciences (highly culturally relevant to small Caribbean islands) and "human-centered computing and data science", it's a fucking dreadful name. Utter word soup.
"Science has always been incredibly politicised, because humans are politicised."
VIEWS surrounding science are politicized, but science itself aims at getting to core truths. Governments can argue all day long about the value of Pi or the law of gravitation, but whatever they have to say doesn't change the science one whit.
"The Catholic Church was always a major patron of science and engineering"
Only when that science can be used to reinforce revealed doctrine. If that science is counter to their beliefs and traditions, people will be made to suffer. Those old stone cathedrals are amazing echo chambers.
I was reading that trying to spot the acronym :o)
then, upon discovering no such thing, MY mind went instantly to the ElReg acronym of choice - T.I.T.S.U.P.
T - elescope
I - n
T - he
S - and
U - nusual
P - ractice
=====
T - he
I - nternational
T - elescope
S - topped
U - ploading
P - ictures
This post has been deleted by its author
"Electric current flowing through zinc "
Well there goes my high school science education. I'm pretty sure the teacher said the current flows on the outside of the conductor.
=====> That's me off to go and rewire the plugs on my appliances in the wake of new scientific discoveries.
"Generally only applies with RF rather than DC, as was probably the problem here."
High currents will flow more towards the outside of a conductor. I sat down with a college prof after a class and he ran me through the math. I have done a lot of work in audio and the "audiophiles" believe a lot of strange things about "skin-effect" which has zero science behind those beliefs.
There can be tiny current flows that change material properties over time which is why sacrificial anodes are used in water heaters and marine applications. Was the Arecibo antenna transmitting? I can't even remember the sorts of science that was done there. If they were just receiving, I wouldn't see RF being an issue. The signals would have been so small.
Skin depth depends on conductivity. It is significantly deeper on steel wires than on copper conductors. In this case, they are talking about cable termination, so the current would be flowing through the cast-zinc layer: even if it only causes migration of the skin, that might have caused deep cracks.
They [NSF] really have not read the room, have they?
Culturally Relevant and Inclusive is definitely not going to cut any mustard with the new regime.
The Centre for the Celebration of the Benefits of US Imperialism Investment* (to Puerto Ricans) might garner more support from the mainland.
They could more usefully fill the old dish with water for water sports. ;)
Welcome to the brave sad new world.
* the abolition of the Section 936 federal tax break which encouraged actual investment was on the Clinton administration's watch. Puerto Rico has its own contentious tax breaks which only encourage Americans to move there and push up real estate prices. Perhaps Arecibo could be redeveloped as luxury Condos?
> a unique and powerful radio telescope environment, capable of inducing current in the cables at some level.
What does "a unique and powerful radio telescope environment" even mean? It listened to the faintest of radio signals so they wouldn't induce any meaningful current. It didn't transmit so there is no chance of inducing a current there.
Take that away and you're left with a suspended steel structure, just like many bridges or stadium roofs, and similarly subject to wind, rain and electrical storms.
> It was also a radar, used to image the surface of Venus. Don't know how often it was run in this mode though
Thanks for the correction.
I would like to think that this generated very little current in the structure, simply because that would be a waste of power that could otherwise be used imaging Venus etc. and scientists usually try hard to avoid that kind of inefficiency.
It was used for radar imaging/ranging of asteroids and a few planets. Transmission power was about 900 kW at 2380 MHz before Hurricane Maria downgraded it ~350 kW.
The time used for such was a small fraction of the total telescope time. But we did get a fair amount of data from it, and Arecibo is still missed by the planetary defense community.