Why we are unlikely to ever leave the solar system.

There is a minimum amount of mass necessary for an object to be able to collapse upon itself and form a black hole, such as a large star does when the outward pressure due to the internal fusion reaction stalls.

However, any amount of mass can (in classical theory) be compressed far enough to obtain a Schwarzschild radius, from which light cannot escape. This has only to do with the density, not the total mass: a very small mass can still cause a large curvature of space, though only in a very small region of space.

The survival of your species after your death is not a vested interest (a "special interest in protecting or promoting that which is to one's own personal advantage"). It affects you nil, by definition: you will be dead by then.

What affects you is having children before you retire, because then you'll be fed and survive a lot more than otherwise. Evolution is a conclusion of that, not the other way around.

I too believe we will (unfortunately) never leave the solar system. But for a quite different reason; consumerism. People are much more interested in stuffing burgers into their faces, living comfortably to a very old age while living unhealthy, buying tons of inane crap which they will never use. Downloading ringtones, spending 99% of their working day glued to Facebook, not cooking but ordering in every single day. Having a nicer car and house than the neighbors and getting their education while preferably not spending more than a month a year with their noses in books.

The smart/educated few are not enough to offset the masses and for the masses it's simply not 'comfortable' to work on space travel; why would you, you already have a pool? Maybe poorer countries where people are not comfortable could be of use? Nah; you see around the world; when GDP gets over a certain level, out come the gadgets, mobile phones, ringtones, bentleys and other useless crap.

A very small (fractional) % of humans is busy with the problem of energy and space travel. If it would be a few actual %s of humanity we might stand a chance, unfortunately, the rest of the collective brainpower is spent arguing if the latest X Factor was won fairly.

I don't think we'll ever meet aliens either; after a certain time in the evolution, every race of 'intelligent' beings will invent paid ringtones, after that all chances of interstellar travel are gone.

Oh, the ego, what a marvelous thing!

Believing that what we currently know is applicable to humans in the future, that our current limits are immutable.

We know all the laws of physics, right? We know if the universe is finite or infinite(because we had traveled there and seen the limits), we know what creates gravity and exactly how electromagnetic attraction really works... the same way the people Socrates asked 2500 years ago knew it all, and Socrates himself did not knew anything(in his own words).

The same way people already knew everything about the small things before microscope invention(in their own words it was unnecessary because "why we want to see what we already know smaller?").

That someone develops better ways to control active fission(atom by atom) and fusion reactions, that someone discovers something new about the universe,that someone discovers how to create antigravity because understands what gravity really is, that someone discover the way to crack the code on aging on our DNA, that someone discovers why the light limit on vacuum is what it is and some way of going faster, all of this impossible, because we know it all.

Making predictions grounded in supremely well-tested physics is not egotistical. Making specific predictions about the content of as-yet undiscovered science without any evidence is egotistical. http://lesswrong.com/lw/gq/the_proper_use_of_humility/