Hacker News Reader

Comment by lumost | Hacker News Reader

an interesting, albeit unsatisfactory solution to the Fermi parodox would be that we are a rare anomaly of a distant moon of comparable but lesser mass to the primary body, located in the inner solar system, but without tidal locking.

The latter two points might turn out to be extremely rare events.

View on HN

I wouldn't call that a final solution to the paradox, though.

(Put on your tinfoil hats.)

Maybe the Earth-Moon system was engineered. The solar system came together from a nebular cloud 4.6 billion years ago. The great impactor hypothesis points to the mega-collision around 4.5 billion years ago. During the early days of the solar system, the system was very chaotic. By applying tiny-but-very-precisely-calculated forces in that system, you could cause an impact. Sure, it's many orders of magnitude above what humans have accomplished, but the gravity slingshots that got the Voyager missions out of the solar system are the same principle.

Dunno, seems crazy to think we are rare. Based on what exactly? Sure our radio signal has gone out 60-80 light years, which means nobody has replied within 30-40 light years of us.

There could be many 1000s of civilizations in the galaxy. Maybe we aren't that interesting to visit, especially since we always have a few wars going on, and we have nukes. Maybe they are watching us for anti-matter production, fusion, stopping burning fossil fuels, and a century of peace.

Would nukes be a concern to a civilization capable of interstellar travel? They'd almost certainly have access to technology capable of wiping us out. The more likely reason is that space is really big, and making interstellar voyagers is simply not worth the effort for most civilizations, if they do exist.

It seems like the circumstances of our planet's location and the moon and the resulting tides and temperatures are rare. And our evolutionary history seems very dependent on those.

The question is whether or not there are other good ways to end up with an abundance of complex life. We have no idea.

" nobody has replied " "we aren't that interesting to visit, especially since we always have a few wars going on, and we have nukes."

Do you think it's just a bunch of humans out there? That is such an anthropomorphic view

Not sure why you would said that.

Maybe warlike species that destroy their planet are a dime a dozen and considered invasive species by the rest of the galaxy. They have enough interest to keep an eye on us with probes, but have no plans to visit or reveal themselves.

Maybe! Or they could have no concept of weaponry at all. How advanced would that be? I guess natural selection suggests we're most likely to encounter a hostile species, so maybe you are a lot closer to the truth than I imagine

2 trillion galaxies in the observable universe, each with hundreds of billions of stars on average. Those events better be extremely extremely rare.

To me it would be much more mind-blowing if our earth/moon system actually was a one in two hundred sextillion-ish event, than if the universe is teeming with life.

> The latter two points might turn out to be extremely rare events.

Are those events that crucial for life?

No, but they are crucial for the shift from sea to land.

without the moon, earth would likely have become a tectonically dead world a few billion years ago.

Why? Something to do with tidal influence on the core?

I'd also like to know. I supposed there must have been a lot of heat from the initial impact, tides must also happen inside the Earth, but I wonder how different the Earth would have looked like techtonically without the Moon?

No plate tectonics? So perhaps resurfacing event(s) like on Venus?

I suspect this is what the GGP was getting at:

https://www.discovermagazine.com/the-sciences/the-moon-our-s...

Reply on news.ycombinator.com