[WorkerBee28474]

> Would it be unthinkable to just NOT have bright lights pointed at the sky all night?

That's possible, and directed/shielded lighting is commercially available.

However, the project's critics have already said that no plan the project comes up with will be good enough - “Even if [AES] do a perfect job, using perfect lights that probably don’t even exist and perfect shielding, there will be an impact and that will be significant [0]

[0] https://www.science.org/content/article/chilean-energy-megap...

[aragilar]

The plan of "don't build a major industrial centre 5km from the best site for optical astronomy in the world, build it somewhere else" seems like a perfect viable one to me.

[oefrha]

Well, local people probably care about economic development and don’t give a rat’s ass about astronomy. So the question becomes, who’s going to compensate for the loss of economic development? (By local I don’t mean strictly local, in case of counter arguments along the line that there are no/very few local people to begin with.)

Disclosure: I’m a former physicist and I have personally operated an optical telescope with a 15’ dome, as well as a 60’ radio telescope, which probably puts me among 0.01% of world’s population. So I do know a thing or two and care about astronomy.

[kahirsch]

This is in the middle of the desert at high altitude. There are basically no local people who aren't associated with the telescopes.

https://maps.app.goo.gl/cWgWx1RKjEUjavPn8

Whether the facility is built there or 50 km away, it's going to have to draw people from more than a few km away. The entire Taltal district only has about 11,000 people.

[Enk1du]

At Las Campanas, most of the staff from the cooks to the techs and a number of the researchers were all local. I found quite a bit of interest in the country as a whole as it's a source of national pride being the best location for astronomy.

Allowing this to proceed will affect _all_ future astronomy projects in Chile. No one is going to splash out on a shiny, new 100m optical telescope (OWL) if anyone can come along and park a city's worth of light just down the road.

https://www.eso.org/sci/facilities/eelt/owl/

[aragilar]

My understanding is ESO uses local labour where possible (e.g on building the ELT, maintenance, catering, transport), so it's not like it's one guy in a shed, there are jobs and economic benefits. That's why this seems so confusing to me, I can't see why you can't have both?

[throw5959]

Do you mean that the economical output of astronomy and this industrial project is comparable?

[est31]

If most of the local people are going to move to that location, they could also move to a different location which is a bit further away from where it's planned now.

[WorkerBee28474]

So that would be Mauna Kea. I don't believe there is any industry being built near there.

[aragilar]

I'm happy to be proven wrong, but I though Paranal beat Mauna Kea (and some basic google searches aren't throwing up anything that makes me question it, e.g. https://www.eso.org/gen-fac/pubs/astclim/espas/espas_reports..., though that's from more than 20 years ago, so site quality has likely changed since then). There's also the issue of northern vs. southern sky.

[cubefox]

> That's possible, and directed/shielded lighting is commercially available.

Given the size of the site (over 3000 hectares), even lights purely pointed at the ground will still create large amounts of bounce lighting. The ground reflects light up in the sky.

[ungreased0675]

It’s possible to go more restrictive than shielded lights. What if all outdoor lights must be turned off from 9pm to 5am? If the conditions were something like that, would the developers still want to build?

[justlikereddit]

Have you ever seen a heavy construction site involving land preparation? Like a new road being built?

Dust everywhere. Backhoes with 360 light coverage that makes a lighthouse envious. Trucks, trucks everywhere! Floodlights! String lights! Crane lights! Temporary light poles! Service lights! Warning lights! A dictionary of lights!

Can they work in the dark without producing so much dust? Can a tiger be a vegan?

Also the development is part wind power, this alone causes wake turbulence. So even if regulation demanded complete blackout after sunset on the penalty to of death the observational quality is still permanently degraded.

[II2II]

I suspect the real concern is there would be a push to relax the restrictions once the industrial facility has been built. Astronomical observatories have faced such problems in the past, to the point where research goals had to be fundamentally altered or where they ceased to be research facilities.

That said, if the goal is to reduce the lighting to the point where it has no impact, one has to ask: what is the point of having lighting at all? I suppose lighting could be restricted to indoor use only, but most commercial operations will expect some outdoor lighting.