The Universe Within 12.5 Light Years

Sadly, that also means you have to accelerate them hard if you want to get to a decent fraction of c before they're effectively out of range. Which means your solar sail has to be really, really tough while being really, really light.

Why should we believe it will continue to advance exponentially? And even if it does, we many find none of the hypotheticals pans out - perhaps we advance exponentially and there is nothing feasible to reach even 0.01c

But when we observe the universe we see nothing. Therefore either no advanced life exists in the universe besides ourselves, which seems unlikely, or none have spread to space in any significant degree and FTL is either impossible or so difficult no one bothers. There doesn't seem to be a secret third thing that both satisfies our observations and obeys known physics.

Anything that exists within spacetime is bound by this rule. The only odd exception people point to is quantum entanglement, but while the correlations appear instantaneous, they can’t be used to send information faster than light. Sending matter is distant second.

So, if we ever hope to travel faster than light, we wouldn’t do it by "outrunning" gravity. Instead, we’d need to find a way to manipulate spacetime itself, like bending, warping, or reshaping it ... since that, in the first place itself, is what is defining the limits of motion.

Currently focusing on imaginary money crypto schemes and ML chatbots whose data centers use as much power as entire US states, sorry.

(Big IF there, I know)

Physical world is big and getting from one point to other takes lot of energy and involves lot of mass.

“The next step is crucial. The simple organic molecules have to be shielded from the ultraviolet radiation of the primary. That requires a large body of water—an ocean—to protect them. No protection and the molecules break up as soon as they're formed. And oceans of water are … extremely rare.”

…

“But something else is rarer still. The next step in the creation of life is when the amino acids form into long chains.

Left in the ocean, they drift apart as easily as they join together. There has to be a means of concentrating them. Once a certain level of concentration is reached, they'll form long chains, more complex molecules, automatically. Heating isolated bodies of water would help, say tidal pools warmed by hot lava and occasionally replenished by the sea.”

…

“Do you understand, Sparrow? Tidal pools implies tides and that means a moon large enough to raise them—though not too frequently, because you might dilute the pool too much. A combination of the primary and the moon would raise larger tides less often, and that would be a happy medium. What's required, then, is a planet that has land surfaces, oceans, and a large enough satellite to raise suitable tides. The action would concentrate the simple amino acids and they could combine into the longer chains.”

The novel is The Dark Beyond the Stars, and I recommend it highly.

"It is inconceivable that inanimate Matter should, without the Mediation of something else, which is not material, operate upon, and affect other matter without mutual Contact... That Gravity should be innate, inherent and essential to Matter, so that one body may act upon another at a distance thro’ a Vacuum, without the Mediation of any thing else, by and through which their Action and Force may be conveyed from one to another, is to me so great an Absurdity that I believe no Man who has in philosophical Matters a competent Faculty of thinking can ever fall into it. Gravity must be caused by an Agent acting constantly according to certain laws; but whether this Agent be material or immaterial, I have left to the Consideration of my readers."

https://plato.stanford.edu/archives/win2008/entries/qm-actio...

What I was trying to get at is I argue that historically we had no reason to assume magnets to exist until we discovered them. (Sure, today we can explain them in terms of the effects of electrons traveling at relativistic speeds.)

It otherwise seems a safe assumption that we cannot move into a 4th spatial dimension (even if such exists) or do many other outlandish things. I don’t think we can prove them impossible but likely just don’t know how.

But imagine if Newton had been shown an electromagnet and asked to explain it… It would have been witchcraft!

I knew HN would nit my nit, well done!

There's also a different thing that GP might be hinting at, which is that by convention we assume that the speed of light is the same in all directions, but there are other conventions we can use as long as the round-trip speed of light agrees with that which we've measured (and yes, we can only ever measure the round-trip speed of light, FYI). Another convention is that all the light we see takes zero time to get to us but the light we emit goes out at half the speed one would expect with the standard convention (known as the Einstein synchronization convention). So instead of "light we see from Alpha Centauri is 4 years old" or "we see Alpha Centauri as it was 4 years ago" we can say that we see it as it is right now, but this is not a very commonly used convention.

https://booksforkeeps.co.uk/article/visiting-uncle-albert/

The intuition you can develop about special and general relativity from these books is pretty amazing!

Experiencing time and having mass are linked in a very deep way. Objects that experience time, i.e. have some kind of state evolution, must have mass, this is how we know the neutrino has mass even though it's smaller than we can measure, because we measure them oscillating between the various flavours of nutrinos.

This is also how the Higgs mechanism gives rise to "rest mass" in most particles, by constantly exchanging weak hypercharge with them. This oscillation back and forth gives them mass.

The crazy part is that this 3D game was programmed in 68k assembly, ran smoothly on Amiga and Atari ST home computers, and fit on a single 1.44MB floppy. The massive universe with realistic solar systems was almost entirely procedural.

While there's a rough polynomial (v =~ c * w^3, I think) for post-TOS Star Trek warp factors, the only consistent rule: a starship travels at a velocity that helps tell a good story.

It's fun to try mapping Star Trek stories, anyway; it helps you ponder how much time they must have spent in transit. They have to find things to occupy their time.

Estimating time-to-arrival when your destination is also moving at ludicrous speeds is incredibly difficult.

However say red dwarfs with moons of closely orbiting gas giants, and many other combinations could in theory be sustain life easily .

We can learn from history on earth, economics is the reason why cities or outposts form and die, even when they are very hostile or very unsuitable and expensive to make it work.

Space would be no different, people would be happy to setup an outpost on Betelgeuse despite its impending supernova if they can say get away from regulation or it cheaper to make things for some other reason, or there is ideal low gravity planet with the right conditions for growing some thing even it would normally be considered hostile .