Getting back out will be a pain in the ass though....

Absolutely, no guess there. It was Brahe and Kepler's astronomical collaboration that led to Kepler's discovery of "the force that moves the worlds" and, thence, Newton's theories of gravitation, motion, continuous mathematical functions, the speed of light, and so on.

So it probably was for everyone who studied the stars carefully. Whenever someone ever said, "I feel like it must be the equinox" and then consulted their astronomical rock markings and learned that, actually, no, irrespective of how they might feel the equinox is not for another 3 weeks.... that was science right there.

I mean we see the "documents" all over, in stone.

Okay maybe not all over all over. But it's no kind of mysterious thing that we can only guess at.

Yeah it is absolutely possible, in terms of celestial mechanics.

In terms of the process of planet formation... it might be a bit improbable. But all that means is that you'd have to look for a while longer through the vast universe before you found it, right?

You could even paint a pretty clear picture by calculating the Earth-Earth Roche limit. Earth is not a rigid body, it is prone to deformation, but we could probably still use the rigid body equation if we give some extra padding. The Earth-Earth rigid body Roche limit is about 8000km so if you say it's ... I don't know... 2 or 3 times that you could probably avoid deforming your Earths too badly as they orbit each other.

In fact if you stick them at about 30 thousand km apart you could (I think...) preserve your 24 hour day, while also having a massive Earth in the sky of each Earth. But only from one part of each planet of course.

For people of this binary world, would be easier to establish a permanent presence in space than for us. But I think it would be harder to get to their Moon. (Assuming you keep our current Moon as it is, with maybe a slightly more wobbly orbit because of the proximity to the binary Earths around which it orbits.)

And of course exploring "the other Earth" would have been a major preoccupation throughout history. With all kinds of speculation and wild tales of what must lie above.

Really cool!

They are saying that there was literally nothing to pay with. No cash.

Well you know it's like the narrator in that one video game says:

Economics.

Economics never changes.

There's another possibility, which is that acquiescence by the private corporation or the cultural mainstream simply represents actual political success. Superficial expression of the "ideas and images" is a form of tribute paid to a victorious political power. Like the banners of subjugated peoples paraded by imperial conquerers.

Yes, like the conquered imperial subject, the restive corporation may remain forever ready to abandon its display of subordination at the first opportunity, its acquiescence is never wholly sincere... but so what? In a sense, all that means is that regular display rituals are proof to an even greater degree of the dynamism of the emerging victorious political force. It commands this power each time anew.

Only a week?? See, now, to me this says that automation is already greatly improving outcomes.

Before face recognition, it would have been 9 years, minimum. >_>

All good news! I'm not sure how much a light hydrofoil is going to contribute to shipping, but every action to defossilize what we do is going to be needed.

Meanwhile there actually is all-electric container shipping going on right now. The application is relatively small scale and the range sucks at the moment, but it's sufficient to handle shipping between iirc Denmark and Norway. And it's very new technology so the hope is that it will improve rapidly.

Defossilization is happening. It's our hand on the lever that controls how fast we get it done.

After 13 days you issue a press release declaring the effort a success, then start a new company... >_>

"Mantle" is the inside, not the outside. I wouldn't think that needs to be explained but here we are.

The advent of repeating rifles probably helped with that.

Right on. We don't hear enough of this kind of constructive critique.

Green hydrogen will be awesome.. when it exists. Until it exists, it's a red herring.

>"The situation was tough: if you stay with your people, then you are a traitor…We asked the government for instructions several times, whether we should stay or evacuate, but we never got a clear response."

Hmm, sounds like Zelensky's tyrannical fascist political dominion isn't all that some people claim. Open criticism of government policy.. public debate.. free expression.. Must be some kind of Nazi trick for sure.

<_<

"The nation must die so that ... so that ... I'll think of a reason later, the important thing is that the nation must die."

(You're absolutely right, I just sometimes think these psychopaths grab the murder stick first and think of the rationale later. If ever...)

No, I'm kind of making fun of you because you are saying the same things I am.

Sounds like you'd enjoy Roger Zelazny's Lord of Light...

So what you're saying is that permanent heavy orbit to orbit shuttles are the application?

Hmm, you want to be "redpilled?" Okay..

What if I told you that you're assuming that every mission that departs from the Moon must necessarily return to the surface of the Earth? What if I told you that you're assuming that there are no missions aside from surface to surface travel? And that as soon as that's not the case anymore, permanent infrastructure starts to make more sense?

The Δv assumptions you have been making have made you a slave. The reality is that the Δv difference is really not that much.

What if you woke up one day and realized you had been assuming that when people talk about supplying a fuel depot they mean entirely from Earth? When actually mining and refining on the Moon itself, coupled with magnetic delivery to cislunar space, would be massively more efficient -- especially if you didn't carry any Earth re-entry capability around with you?

The choice is yours. Take the blue pill, and remain a lunar transit infrastructure skeptic.

Take the red pill.... and find out how far into the cosmos we can go.

I mean paper studies still count as "R" if not "D..."

But leaving that aside. Let's get back to the original point. There is no application for nuclear thermal propulsion right now. Everyone is all about surface-to-surface reusable transatmospheric launchers and low-earth orbit delivery. If we were ready to build something in the 50T range to act as a permanent shuttle between Earth orbit and Lunar orbit, I don't see why we wouldn't happily use NERVA as we had already developed and tested it. It seems already there. In terms of being ready for that application.

I'm all for it if it's true. But from everything I've seen, 40 years of R&D after the original NERVA project netted all of a 5% increase in Iₛₚ. Sure you can make one that's ⅓ of mass, but that doesn't help much if you will still end up needing 3 of them. You know?

I doubt the nuclear thermal concept would have advanced much beyond where they took it in the 1960s. Iirc they had pretty much nailed it. Maybe later designs improved reactor characteristics.

Anyway one of the main issues is scale. Just a single NERVA engine is in like the same mass neighborhood as the entire space shuttle orbiter. And NERVA is only good for orbital maneuvers. So to be economical, you need something ISS sized to move around, and we just haven't had anything like that. That's billions of dollars.

Haha still not dumb. So many people wonder about stuff like that, someone made a graphic. Here's a great way to visualize the answer:

https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/thumbnails/image/all-the-worlds-water.jpg

Basically... it's less water than you think. Because water, being water, tends to spread out flat. And the Earth is actually pretty smooth.

We think of all these tall mountains and deep chasms and stuff but they're only tall and deep from our human-scale perspective. From the perspective of the whole volume of the Earth, they are the teensiest aberrations. The depths are barely deep enough to get wet.

I don't know, ask OP.....

Well, so far the entire concept has been stalled on the question of who would go.

Scientists have calculated that the person would need to be big. And of Scots descent. And come from a line of about 755 predecessors.

So far no one has been found who meets these exacting standards. It has been incredibly vexing and has stalled interstellar exploration completely.

Why, do you know anyone who might qualify?