My stepdad had a saying [many actually] when he was alive...
"A wise man can learn even from fools".
Rand has called me a ignorant nonsensical fool when I asked him to name one thing we are ignorant of that would prevent us from colonizing mars. He named nine, eight of which I will respond to in other posts so I can concentrate on just the first: gravity.
Before I start I'd like to point out a few things. Rand claimed (and argued) that I said: "you said there is nothing we don’t know about colonizing Mars" What I actually said was, "Everything we need to colonize mars we’ve already done in other programs." Which is not the same thing at all. My position is there will always be things we are ignorant of until we are not, but that the things we don't know in no way prevents us from starting the colonization process, which will in turn lessen our ignorance. Perhaps there's a better way of saying that, but in no way am I discounting what we don't know. I'm saying we shouldn't ignore what we do know either. We're not exactly entirely clueless about mars. We've been sending landers there since the 70s (almost half a century!!!)
Do we need all the answers up front before we go? That would be impossible so the only reasonable answer is: no. So here's what Rand thinks prevents us from starting mars colonization...
"The long-term effects of partial gravity on human[s, animals and plants.]"
Of course we don't know the long term effects (until we do.) How does that prevent us from starting a mars colony? Humans have experienced long term zero g and had only minor problems (frankly less than my current medical problems, including some like those of zero g, which haven't stopped me.) Then he goes on to say...
"We have zero experience with conception or gestation in free fall, and we have zero experience with anything in Martian gravity."
That's only true of humans. We do have limited studies of other animals in zero g which is why we know gestation could be a problem but not conception. As for martian gravity, he is right so I ask the question again. How does that prevent us from going to mars and learning while starting a colony for others to follow? Can we just not conceive until we're ready?
We will always have questions. Are those questions barriers we dare not cross? Then Rand cuts with this...
"This sort of thing is why no one takes you seriously."
Taking somebody seriously is a choice. But here he presumes to speak for everybody.
I do speculate which is a reasonable thing to do when you only have some of the facts. There is a huge difference between zero g and some g. Some g makes some things possible that are not possible in zero g, even when the g force is tiny. Of course we may need to discover the threshold where some things go from impossible to possible or probable (which is usually more often the case.)
Just to make my position clear: "Mars gravity does not prevent us from starting the colonization process or prevent us from learning more by actually going." I believe this is self evident. Saying this is not true is ignorant. Foolish or nonsense is a subjective issue.