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Arecibo telescope, on the brink of collapse, will be dismantled

sciencemag.org

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Re: Arecibo telescope, on the brink of collapse, will be dismantled

#261

Post by kortilla »

nicoffeine wrote: post #223
brnt wrote: post #219

Earlier quoted context omitted.

Now I really want to know what it's like working on the team that repaints the bridge for years or decades on end.

Probably not to different from refactoring the same CRUD applications over and over to keep up with with the other poor bastards who had to do it first. Except you get exercise and fresh air.

That’s a pretty bad analogy because you don’t refactor for maintenance. A better equivalent would be swapping out hard drives in a major storage system or servers in a data center on the scale of Google. It’s mind numbing work but it’s better than many other “pick and place” style manual labor. At least with painting a bridge the scenery is better although the temperature is more harsh.

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#262

Post by watersb »

mumblemumble wrote: post #110
antognini wrote: post #84

Earlier quoted context omitted.

It's been a little while since I dabbled in radio astronomy, but arrays like the VLA use interferometry to produce high resolution images. However, the high resolution is only along the directions between pairs of telescopes. Since you don't have telescopes in all directions, there are some directions with low resolution and others with high resolution. (In the technical parlance they talk about "UV-coverage" and fil…

Could this characteristic be mitigated by arranging the telescopes in a random pattern rather than using simple, regular pattern like the VLA follows? That seems like it might be what's going on with the UV coverage diagrams being demonstrated at the bottom of page 3 in this paper about the ATA: https://www.seti.org/sites/default/files/ATA-memo-series/mem...

It isn't a random pattern, but yes.

A logarithmic expansion of baseline distances seems to be the first thing you want in a sparse array. Ideally you want to be able to look in all directions with about the same amount of sensitivity and angular resolution. But the UV coverage of even an asymmetrical, relatively sparse array like the VLBA is surprisingly good, because as the Earth rotates, the antennas describe sweeping arcs on the sky.

The regular UV coverage of the VLA is great, though, for sensitivity at short duration observations.

But Arecibo was great for pulsar work. :-(

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#263

Post by Retric »

mixmax wrote: post #225
Retric wrote: post #99

Earlier quoted context omitted.

It really depends on the structure. Giant steel objects are much harder to keep intact, to the point where non iconic objects are easier to replace once than maintain for 100+ years.

Not really - steel boats easily last 100 years. A friend of mine lives in one from around 1940 and the steel is in fine shape. As long as it's properly maintained there's no problem.

Yet, Modern ships have a lifespan of 25 to 30 years before corrosion, metal fatigue and a lack of parts render them uneconomical to operate. https://en.wikipedia.org/wiki/Ship_breaking

With smaller boats labor is a higher fraction of construction costs vs raw materials. Going big results in massive increases in efficiency which almost paradoxically shift things to a shorter ship lifespan.

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#264

Post by XorNot »

aylmao wrote: post #257
RhodoYolo wrote: post #132

Earlier quoted context omitted.

Do you have a list or link to any mega projects you are currently excited about?

Three that sound pretty exciting to me are ITER [1], the Extremely Large Telescope [2] and the James Webb Space Telescope. I'm sure there is also more I haven't heard of yet! [1]: https://en.wikipedia.org/wiki/ITER [2]: https://en.wikipedia.org/wiki/Extremely_Large_Telescope [3]: https://en.wikipedia.org/wiki/Extremely_Large_Telescope

James Webb is the one I worry about the most. ITER has a taken a long time, but they're making steady forward progress with it.

Whereas I live in fear that James Webb will suffer a failure during launch or deployment that just turns it into a very expensive explosion.

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#265

Post by perilunar »

HarryHirsch wrote: post #60
MattGrommes wrote: post #37

This is the kind of thing I always hope that one of the billionaire nerds will help with. Seems right up Elon Musk's alley.

This is multigenerational national infrastructure. Imagine a volatile nerd like Musk funding Goldstone or CERN. He'll get into a pissing match with someone who knows what he is talking about damn quick (remember the Thai U-boat story) and then refuse to pay further.

SpaceX was founded 18 years ago, so it's almost a 'generation' old already. Not bad for a 'volatile nerd'. I'm betting it will be around longer than the Arecibo Observatory (the main telescope anyway).

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#266

Post by lambda_obrien »

frob wrote: post #187

Oh Arecibo, how I will miss thee. I had the luck to tour the observatory in the early teens with a physics conference. Someone pulled a few strings and we got the technical tour. It was amazing and full of facts, but two things still stick with me. First, Aricebo as a space observatory was a serendipitous accident. It was originally designed just to be an atmospheric observatory. The original idea and calculations fo…

That's cool as hell and why in the world are we all building stupid AI advertising platforms today?

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#267

Post by jessaustin »

smnrchrds wrote: post #206
ardy42 wrote: post #167

Earlier quoted context omitted.

> Is a GoFundMe campaign outside of the realm of possibility? I know that I'd contribute to such a worthy effort, but only if the rest of the players would pledge to fund current operations. The biggest GoFundMe campaign according to Wikipedia only raised $25 million in 2020 dollars ( https://en.wikipedia.org/wiki/GoFundMe#Notable_projects , Bannon's et al's fraudulent We Build the Wall project). Arecibo cost $9.3 mi…

Wikipedia itself raises more than $120 million per year. I don't think a telescope could attract as much in donations as Wikipedia, but it is interesting to see how high could donations possibly go.

TLAs have lots of money.

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#269

Post by peterwoerner »

aylmao wrote: post #257
RhodoYolo wrote: post #132

Earlier quoted context omitted.

Do you have a list or link to any mega projects you are currently excited about?

Three that sound pretty exciting to me are ITER [1], the Extremely Large Telescope [2] and the James Webb Space Telescope. I'm sure there is also more I haven't heard of yet! [1]: https://en.wikipedia.org/wiki/ITER [2]: https://en.wikipedia.org/wiki/Extremely_Large_Telescope [3]: https://en.wikipedia.org/wiki/Extremely_Large_Telescope

Roman Space Telescope, LISA.

[1] https://roman.gsfc.nasa.gov/

[2] https://lisa.nasa.gov/ , https://www.esa.int/Science_Exploration/Space_Science/LISA

Re: Arecibo telescope, on the brink of collapse, will be dismantled

#270

Post by TylerE »

ardy42 wrote: post #167
rmason wrote: post #157

Earlier quoted context omitted.

Wouldn't it be infinitely cheaper to replace all the cables/fixtures and simply rebuild it? Or have the funders simply lost interest in it? Is a GoFundMe campaign outside of the realm of possibility? I know that I'd contribute to such a worthy effort, but only if the rest of the players would pledge to fund current operations.

> Is a GoFundMe campaign outside of the realm of possibility? I know that I'd contribute to such a worthy effort, but only if the rest of the players would pledge to fund current operations. The biggest GoFundMe campaign according to Wikipedia only raised $25 million in 2020 dollars ( https://en.wikipedia.org/wiki/GoFundMe#Notable_projects , Bannon's et al's fraudulent We Build the Wall project). Arecibo cost $9.3 mi…

It would be way more expensive then that. You can't just inflation adjust.

Construction has a lot more costs these days - have to take care of the environment, not kill your workers...

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