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Comment by dylan604 | Hacker News Reader

The Tom Scott video linked else where in this thread shows that the existing 4 telescopes have on-prem facilities to resurface the mirrors with a layer of 99% pure aluminum 1000 atoms thick. I'm guessing that quality material fabricated to be installed that precisely is not cheap. The mirrors are moved around on custom built hover crafts. When the 4 scopes are used at the same time, the "plumbing" to get the lights to the instruments at the same time is so precise, it is measured in nanometers.

There is nothing about these facilities that is normal off the shelf components. Everything will have a cost associated that reflects that. What ever back of the napkin math you are attempting doesn't even come close to being accurate.

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The person you are replying to is asking about operating costs, not manufacturing costs.

Well operating a highly custom and very expensive is going to have astronomical operating costs as well.

Resurfacing is an operating cost it needs to be done periodically.

I'm going to need some more info on that, because that doesn't sound right to me.

There's no way they are regrinding and resurfacing the mirror periodically - cleaning, sure. But redoing the surface? I'd like to see more info please.

Just go watch the referenced link. It is a very informative video. It's only the top response of this whole thread, but just to make it convenient[0]. I can only lead you to water. I can't make you drink it. Continuing to refute it after that just let's us know exactly what you're about

[0]https://news.ycombinator.com/item?id=38092084

As requested, I drank, and I saw the part about them refinishing the top surface layer. As I suspected it was not them redoing the glass, rather removing the aluminum and redepositing it.

The perfectly shaped glass is the expensive part - coating it is not the expensive part. So despite drinking, I did not get my answer on how this telescope costs $100million a year to operate.

What part of my comment suggests I was talking about manufacturing costs?

This part: "quality material fabricated to be installed"

But they do this operation every few years. It is an ongoing process of installing the aluminum surface. Applying/Re-applying maybe words better fit for your understanding?

It's nice to change your words after the fact, but taking your words, as originally written, your response to a question about operations was a reply about manufacturing.

Additionally it does not costs millions to operate this resurfacing machine. Building it? Sure, I could see that. But running it? No way.

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