Meanwhile, outside of the world of politics and pandmic

[Suff]

No need for aliens,

It has been clear for decades now that continuing on this path means our liveable biosphere will support about 5bn by 2100 and about 2.5bn by 2200.

Of course we will have killed. 99% of the population by then through war and famine and catastrophic sea level rise.

This is not conjecture or some catastrophe planning, this is a ruthless look at what we are doing to the planet and our willingness to stop doing it.

What is left. Two courses. Go on a military footing, drive all of our production towards CO2 mitigation, restrict the population of the world for births, movement and the goods that can be owned, bought and binned. Lockdown in covid? Nothing on Global Warming mitigation action.

Or.

We can send a few to the planets, make sure they survive and hope that the lessons learned in living on a Much less hospitable world will produce a society able to coexist in a sustainable fashion on Earth.

Because the first is never going to happen. Once you let the genie of freedom, wealth and the pursuit of happiness (whatever that is seen to be), out of the lamp, it is almost impossible to stuff it back in.

Spacex is taking a miniscule sliver of world production, resources and effort. Yet it may lead to something much more beneficial for us all. Lunar mined solar cells as vast arrays in orbit, beaming power to earth to avoid carbon fuels? Possible with Starship, impossible with current space technology.

Genetic research tells us that the human species reduced to close to 1,000 people in the last ice age. What is not talked about much in climate change disasters is that if our population collapses CO2 reverses and an ice age comes crashing down on us, along with half the nuclear reactors in the world going out of control and their spent rod cooling areas, containing 10 times as much fuel as the reactors, go on fire;then that 1,000 people are at even less chance of survival. The bushman is screwed every way.

So why not go interplanetary? Sounds more reasonable than hoping for something which is never coming.

Unless you read the DM that is. They hate everyone who is successful and won't apologise for it.

[Workingman]

Planets eh, plural, so that's just the two: Earth and Mars. The gas giants are out, and so are Mercury and Venus.

We are trashing Earth and terra-forming Mars to the extent it could support reasonable sized colonies could take centuries, if ever. We might get a few tens of "Eden" type projects where everything is under a dome and with possibly a thousand or two people in them. But will they, the numbers, allow us to build ships to the stars? I doubt it.

Even if we could build the ships then come the next few problems: distance and time. There are only two Sun types stars out of 11 within 15 light-years from the Sun. Alpha Centauri and Tau Ceti. All of the other stars between them have only about eight planets and not all of them are habitable. The overwhelming majority of the nearest 50 stars are red dwarfs out to about 17 light-years. Barring the magic of worm holes, star gates and warp drives we are not going anywhere. We might as well work with what we have. Or we could go Elysium.

And if we were able to leave what would we do? More of the same? Or would we learn more and more and more till we know everything? Then what? And who empties the bins?

It is a nice dream, or maybe a good book or film franchise, but it is not reality - never has been and never will be.

[Workingman]

BTW the speed of light is about 300,000,000 m per second, the Parker Solar Probe at about 2 m second is our fastest ever spacecraft.

Alpha Centuri is 4.2 light-years away. Do the maths. They don't look too good.

[Suff]

Of course I was talking about immediate interplanetary colonisation.

We have already passed the point where we have created our own potential Dinosoar event yet very few seem to care. So long as we live only on one planet we are one massive catastrophe away from extinction.

Yet those who argue hardest that we have created the catastrophe argue hardest that we don't do everything as a species to evade that extinction.

They cling to the hope that if we just try hard enough, then things will come out OK in the end.

Reality, they won't, not now and not before the rolling disaster is at the door, at which time they will be 100 years too late to stop it.

That is the world we live in today.

So why would we not want to reach as far as we can?

I keep asking the environmentalists that and they have the same mantra "it's wrong".

Go figure.

[Workingman]

I am not for one moment saying reaching for the stars is wrong, but I am saying they are way out of reach with present and the near future's (100 years or so) knowledge, engineering and technology.

The simple truth is that we are decades away from even getting a small colony, a few tens of people, living and functioning long-term on Mars, and they will have to come back at some time because the gravity of Mars is only 0.4 of that of Earth. It is for the few, not the many.

In my dreamscape things will come crashing down before we gain access to the things I mention above, knowledge etc. We could get to the point where in a few hundreds of years there might be fewer than a billion humans roaming the Earth. However, those who are left will be able to use the knowledge from times past (our present) and build on it: Humanity 2.0 can begin. They might get the chance to zoom off, but see my previous about the nearest stars and planets.

The nearest hoped for truly habitable candidate planet is Gliese 667 Cc. Its mass is 3.8 that of Earth but its gravity is only 1.32 times, surface temp is thought to be about 30 °C and it does have an atmosphere thought to contain oxygen..... but it is 22 light-years away. "We" are not getting there any time soon.

Another thing that bugs me about this colonisation game is "How many?" I was reading an article by Frédéric Marin a University of Strasbourg astrophysicist and one by Cameron Smith, an anthropologist at Portland State University in Oregon. Their numbers range from 98, needed for genetic diversity, and 14,000, which is needed for demographic, skills, societal and cultural diversity. Again "We" are not going anywhere.

But never mind, we always have Hollywood and the sci-fi genre in books and comics to keep us hoping.

[Workingman]

Suff I already know that you are miles off regarding interstellar travel, but I also fear that you, and Golden Boy Musk, are underestimating the difficulty of landing the mass of the payloads and the work required to establish even a small colony on Mars.

Yes, I know Elon has plans, I have seen the SpaceX simulation and heard his podcast. Starships launching three times a day each carrying 1000 metric tons. Starship rockets making roughly 1,000 flights per year, launching a total of 100,000 tons of cargo into orbit. “So, every 10 ships yield 1 megaton per year to orbit,” sayeth the man.

And 1,000 Starships could send “maybe around 100k people per Earth-Mars orbital sync,” Musk added on Twitter, referring to the period, every 26 months, when Earth’s and Mars’ orbits are best aligned for an interplanetary journey.

What he does not say is how his spacefarers will survive. Let's see.

The shortest round trip for Elon's Martians will be about two years - see his tweet. During that time they will either be in zero gravity or one of only 38% that on Earth. Nobody really knows the effect that will have on a body's bones, cells and organs. Gravity suits, Elon?

The atmosphere on Mars is only 1% as dense as Earth's and it is mostly (95%) carbon dioxide so it will be a bit difficult to breathe. It is also cold, with a mean temperature of -63 ºC, so they will need to wrap up warm.

And what about the Martian magnetosphere? Well, because Mars does not have a core capable of acting as a dynamo, as is the case with Earth, it doesn't really have one, and that is a big problem. Mars is constantly bombarded by solar emitted particles and galactic cosmic radiation. These nasty little sods can pass through most things killing living cells and unravelling DNA strands and eventually killing things. To stop them will require a thick wall of something. Lead is good but tons of Martian soil / rocks could be used, as could a sort of reverse Faraday cage, electrically charged, to create a magnetic shield. Or a cave!

Then there's the food, water, ablutions, sewage, entertainment, work, keeping sane, communications home, 4 to 22 minutes each way.... If it can happen it will be a multi-generational project needing massive long-term logistical support from..... Earth.

[Suff]

All true WM, but it is not impossible. Nobody thinks it will be a cake walk, most people know it will be a subterranean subsistence. But it will be less hazardous than the moon and more viable to grow food etc than the moon. The more they look for water on Mars, the more they find.

The point is to try. Because the one path which is most surely the longest is the one which never gets a single foot step on it.

I'm realistic. Not in my lifetime for viable colonies, the first colony will probably die out. But it won't stop people trying any more than it stopped the flood to the Americas.

So they should at least try. As SpaceX continues doing things which were deemed impossible, they gain more and more experience with it. All that experience leads to more success.

Two years from now Starship will be a reality. It will be providing earth to orbit logistics, orbit to Moon logistics and, eventually, orbit to Mars logistics. SN6 will hop next, then there will be an alternating cadence between the two until SN8. Then real fun should start. I expect a fireball for the first one to sub orbital. But it doesn't matter. Using steel means less than 10% of the cost of traditional space craft, they can burn down 10 for the price of one carbon fibre one.

When SpaceX was trying to land the boosters Musk wanted to know how close they were. When the team said 6 months for 95% certainty, Musk said "how long to 50%?", They said 2 weeks... So they went for it on 50% certainty. They failed. The data received in failing told them that 6 months later they wouldn't have been 95% they would have been 50%. The rest is history. SpaceX kept on trying until they got it right. What did they have to lose? The boosters were being lost in the ocean anyway.

In order to progress you have to keep trying. Space is the next frontier. The only way we won't make it is if we don't try.