Can life exist on a planet without a star?

http://en.wikipedia.org/wiki/Nightfall_%28Asimov_short_story...

Los Alamos, Argonne, and Tana Tuva.

Was Tana Tuva a topic of discussion during this time period? I remember Richard Feynman wrote quite a bit about it, too.

This one.

> Most of Earth’s internal heat was delivered by the giant collisions that built the planet, a large portion of which remains locked inside its crust.

In 19th century, Lord Kelvin estimated the age of Earth using this method, arriving at somewhere between 20 and 400 million years[1], much shorter than 4.6 billion years currently accepted. It turns out radioactive decay keeps the Earth's inside warm for a much longer time. (I.e., assuming Kelvin's calculation was correct, without radioactivity the Earth's core would have frozen over within the first 400M years.)

[1] http://en.wikipedia.org/wiki/Age_of_the_Earth#Early_calculat...

Instead, it should be saying:

"The solar energy flux is 3000 times greater than the surface heat flux from interior heat."

https://en.wikipedia.org/wiki/Earth%27s_energy_budget

https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget

Some have decided this means star travel is impossible; I say it just limits how quickly we can do it. We could launch very large ice asteroids with nanotech unmanned fusion stations that construct lasers ("vigorous handwave about magic here") and create ourselves a series of stepping stones to a star. It would take a long time, not least of which is because we would also need to set up the "stepping stones" to stop us on the other end, too! But in theory it seems like it would "just" be a matter of time. Lots of time. But a whole star system on the other end! It's a pretty big payoff for a strapping young Kardashev II civilization.

(Note that "just send information" only works after you deliver a physical package to the other end which would be capable of receiving it and doing something with it, and even nanotech is unlikely to be able to land anywhere to begin its lengthy self-replicating process to bootup civilization on the other end if it's merrily passing through a system at 80% the speed of light relative to the local rest frame.)

If you were lucky enough to stumble on to one of these planets in the way, it would provide a pretty nice shortcut to setting up your bridge by providing you a nice, huge power source (if you can find a lot of hydrogen lying around somewhere, which is a reasonable guess) that's already more-or-less at rest in the galactic frame, allowing you to use it to relatively easily create more stages on the enormous pipeline, and allowing you the ability to relatively easily replenish the stages in the middle. (If that's even desirable... perhaps the stages can be retargeted to other stars or something once the bootstrap package is successfully delivered.)

... of course, the article's starting with "10,000 years in the future" is probably not a terrible guess about all this, as such things go. This is a guaranteed-slow process, trading time for space. Tell your great-grandchildren to ask their great-grandchildren how the initial plans to make the initial plans for all this are going, and say "hi" to the future for you. Saying "we" will do this might very well be considered to be rather impudent of me, much like Napoleon trying to claim some sort of perceptible credit for the Hoover Dam.

Kind of like Flatland in that regard, I suppose, so it's not terrible.