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Comment by jerf | Hacker News Reader

Sorry, what "natural system" exactly are you talking about? The moon doesn't have one in the sense you mean.

I notice a lot of people operate on the unexamined assumption that there's life everywhere. This is a decent assumption for the Earth. It does not hold in space. There is no "environment" to mess up on the moon. It is already a radiation hellscape with no air, no water, and no life. It can't be turned into an ecological disaster, it already is one, of a scope beyond anything you can find on Earth. If you literally dumped a million tons of the worst radioactive waste on the moon, it would would not noticeably affect its characteristics.

If you value the ecosystems of Earth, get as much industry off of it as possible, into places where there is no "environment" to mess up.

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> If you literally dumped a million tons of the worst radioactive waste on the moon, it would would not noticeably affect its characteristics.

But, but... https://en.wikipedia.org/wiki/Space%3A_1999 said so!1!!

>Sorry, what "natural system" exactly are you talking about? The moon doesn't have one in the sense you mean

Whether the moon and the earth are part of a natural or unnatural system is irrelevant, so we can omit the word natural for the purposes of this argument.

The moon and its interactions with the earth are part of a system. Some parts of the system are understood. For example, the moon's effect on the earth's tides.

Mao's sparrows were part of a system. Changing this variable, the sparrow population, impacted one variable that impacted another variable, that impacted another variable. Dead sparrows --> more pests --> less grain --> famine.

We can try to predict and speculate all we want, but the only way to know how a system is affected by a variable change is to change the variable and observe the effects. And it can take a very long time before effects reveal themselves, and sometimes they cannot be easily reversed.

When introducing an unprecedented change to a system, all we have is uncertainty, so before we introduce that change, it's important to proceed very slowly, and with caution.

I dunno, I'd say its effect on earth's tide is a pretty "natural system". Seems odd you can assert such certainty of not having unintended consequences and miss that

Do you have any idea how much material you'd need to remove from the Moon to change its mass enough to get a measurable effect on tides?

I don't. How much? I'd also be curious to compare that number to:

1. How much we have mined on earth

2. Expectations on how much we expect to mine over time

According to Google, the moon's mass is 8.1 x 10^19 tons. According to some random info I found, we mined about 3 x 10^9 tons of metal ore in 2019. If we did that on the moon for a thousand years and brought it all back to earth, that's still 7 orders of magnitude less than the moon's mass, so what is that, 1 ten millionth? Is that significant? Well, the earth apparently gains 4 x 10^4 tons every year from just sucking up space dust, and presumably has been for the entire 4.5 x 10^9 years the moon has been around without obvious issues, so it seems like our moving a bit more mass between them wouldn't do much.

Thanks. That sounds reasonable.

But tides aside, which we kind of understand, and you may be correct about in regards to mass and mining, what other effects does this system have that we don't understand? The unknown unknowns are the important things to consider here.

Did people who started burning coal all those years ago ever think they'd have to worry about climate shift driving their descendants from their homes centuries later because of their actions? Did anyone ever consider that the mass use of disposable plastics would cause these chemicals to persist in our bodies, our water, our food supply? Did any of these people proceed slowly and with caution out of consideration of unknown unknowns?

Unfortunately, no.

There's a certain line you need to draw when considering unknown unknowns. You're suggesting that changing surface features on a remote body in space could somehow affect Earth. Consider that the moon has been hit by very large asteroids in the past which caused disruption on a scale beyond what we could ever do and we don't have any indication that it has affected the Earth other than kicking up some meteor showers. Worrying that we could somehow provoke something more is akin to worrying that driving to the grocery store will trigger an ecological collapse. We have no reason to think it will, we can't even posit something that sounds plausible, but there could be unknown unknowns that make it so.

The mass of the Moon is around 7.35 x 1022 kg.

It would take in the order of 10^6 years to reduce the mass of the Moon by 0.01% if we mined at the rate at which we mine(example: iron) on Earth.

Having said that, it is not about altering the mass of the moon. It is not even about deorbiting. Both of which are enormously difficult to fuck up by our puny efforts. It would also have very little effect on rotational speed or gravitational field.

But that’s not the point. At all. What is the cost of mining the moon/space mining? What is this metal that we are going to mine at astronomical costs that is alleged to magically make all our lives better and ‘save the oceans’.

I couldn’t find that information the article. I think someone simply wants grant money to build a bigger house or fund their children’s college fund. This duck isn’t flying..not walking..not even limping it’s way to the moon to mine anything.

How about the supply chain that would move equipment and labor to and from the moon? How about the debris this would leave behind around both bodies? How long can this be done before the Earth's environment is affected? Will our descendants stop drilling when problems begin? Will they still continue long after the damage has become visible?

Do you have any idea how many problems were created by good intentions?

Which is a gravitational effect, and per original post: "the volume you remove is unlikely to be enough to influence moon gravity"

The amount of mass you'd need to move for that to happen is... well... astronomical. Besides, that's easily offset by sending things back to the moon for recycling/dumping.

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