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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

#271

Post by jessaustin »

admiralspoo wrote: post #104
petschge wrote: post #96

Earlier quoted context omitted.

And the US is planning to purchase 2500 of those. Because 2400 are clearly not enough.

The defense budget is tiny compared to the US's welfare state programs.

Welfare programs promote the welfare of USA residents, which is a valid use of public funds. The defense budget is almost entirely wasted. We haven't won a war in 75 years. Our various bumbling military misadventures have killed thousands of Americans and millions of other humans. If we spent a tenth of what we spend, both we and humanity in general would be safer, happier, and more prosperous. The Pentagon is never held to account for its myriad failures, so over time it has evolved to do only one thing well: consume vast resources.

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

#272

Post by jessaustin »

themaninthedark wrote: post #161
throwaway0a5e wrote: post #135

Earlier quoted context omitted.

>There was a time when those ideas weren't so dominant, That was also a time when three news networks controlled everything on TV. Print media had "journalistic integrity" (i.e. was buddy-buddy with existing institutions) so you never got to hear about it when the police kicked in a black guy's skull for no reason or when a construction project turned into a boondoggle handout for someone well connected. It was also…

>"You mean they actually vote for the lizards?" >"Oh yes," said Ford with a shrug, "of course." >"But," said Arthur, going for the big one again, "why?" >"Because if they didn't vote for a lizard," said Ford, "the >wrong lizard might get in. Got any gin?" This view isn't new, right now half the US is celebrating that we have elected a career politician because he is better then the millionaire that was previously ele…

People in the streets are angry because the media is telling them to be angry.

Media may have been something different in years past, but from now on, the only time it will cease telling people to be angry is when it's more profitable to spend all its time telling them to be afraid. It's not as though there isn't reason to feel dissatisfaction with our rulers. [0]

[0] https://wtfhappenedin1971.com/

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

#273

Post by kawfey »

floatrock wrote: post #64

The thing was iconic... even if not everyone watching/playing Goldeneye knew it was a real radio telescope, it was nevertheless one of those science megaprojects that featured prominently in the popular zeitgeist and got more than one young kid excited about what's out there in the stars. But infrastructure ages, and 60 years isn't a bad run. What comes next? Clearly there's going to be a capabilities gap for a while…

I used to work at the VLA as an RF engineering intern. I learned a lot. There is a good technical answer in these comments already, in regards to reception.

But AO was also a transmitter - it could pump out millions of watts to illuminate asteroids, the moon, and other orbiting objects for mono static and bistatic radar measurements. For example, images such as these [0] are created by receiving the reflection of energy emitted from transmitters like AO and Goldstone (I didn’t find an exact image of an AO-VLA measurement but they’re out there).

The AO and VLA had a unique relationship, in that one could precisely measure and image irregularities of any particular VLA dish panel down to a few tenths of a millimeter using bistatic radar of the moon. It’s somewhere in the eVLA library but my google fu is failing me (also google really sucks now).

They also had a few events for ham radio where AO lit up the moon and hams across the world could hear its reflection with basic equipment. [1]

[0] https://m-cacm.acm.org/careers/182810-high-def-radar-images-...

[1] https://youtu.be/SUr1z5XeOE0

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

#274

Post by selimthegrim »

kgin wrote: post #34

When I was 5 years old, I saw a pbs documentary about the Arecibo telescope. During a shot of a huge expanse of the telescope's metal, the narrator said something to the effect of "as one gets closer to the equator the sun's rays are stronger and the metal becomes too hot to touch". This, combined with the fact that I had a globe with a raised ridge around the equator, caused me to assume (for many years) that the eq…

I just remember its appearance in “The Arrival” as “el radio”

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

#275

Post by ashtonkem »

floatrock wrote: post #64

The thing was iconic... even if not everyone watching/playing Goldeneye knew it was a real radio telescope, it was nevertheless one of those science megaprojects that featured prominently in the popular zeitgeist and got more than one young kid excited about what's out there in the stars. But infrastructure ages, and 60 years isn't a bad run. What comes next? Clearly there's going to be a capabilities gap for a while…

60 years in a tropical environment, no less. The humidity there cannot be kind to steel.

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

#276

Post by ashtonkem »

dgr582systems wrote: post #194
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.

Like the (iconic) Sydney Harbour Bridge which requires continuous repainting. It’s very expensive to maintain. https://www.australiangeographic.com.au/blogs/ag-blog/2013/1...

Paint is preventative maintenance. It's a lot cheaper in the long run than not painting at all.

For those that don't know, paint should be considered a non-optional component of most iron or steel objects, since paint serves the important role of preventing rust formation. It's less important in most uses of aluminum, since aluminum oxide tends to form a protective layer instead of flaking away.

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

#277

Post by ashtonkem »

throwanem wrote: post #260
Miraste wrote: post #208

Earlier quoted context omitted.

Those are both made of iron.

Steel is iron, with a carbon content somewhere in the range of about 0.25% to 2%.

No, steel is an alloy of iron, carbon, and other trace elements. Saying that "Steel is iron" is like saying "Bronze is copper".

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

#278

Post by [deleted] »

ashtonkem wrote: post #277
throwanem wrote: post #260

Earlier quoted context omitted.

Steel is iron, with a carbon content somewhere in the range of about 0.25% to 2%.

No, steel is an alloy of iron, carbon, and other trace elements. Saying that "Steel is iron" is like saying "Bronze is copper".

[deleted]

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

#279

Post by samstave »

floatrock wrote: post #64

The thing was iconic... even if not everyone watching/playing Goldeneye knew it was a real radio telescope, it was nevertheless one of those science megaprojects that featured prominently in the popular zeitgeist and got more than one young kid excited about what's out there in the stars. But infrastructure ages, and 60 years isn't a bad run. What comes next? Clearly there's going to be a capabilities gap for a while…

Bezos should build an updated one there for his legacy!

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

#280

Post by [deleted] »

goatinaboat wrote: post #180
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.

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. What about the Eiffel Tower? Or Blackpool Tower. That proves it can be done.

[deleted]
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