New Mars Forums

Back in September 2002, a few of us here were discussing similar gravity problems with specific regard to the colonisation of Mars. (It was on Page 2 of 'Plans, plans, plans', which is on Page 23 of 'Human Missions'.)

    If any of our newer recruits to New Mars are interested to see what's gone before, they can http://www.newmars.com/forums/viewtopic … 1766]click here.
                                             

    The circular railway device, with gimballed carriages, was suggested by Bill (White) to fend off the deleterious effects of 0.38g but could just as easily be used on any moon or planet to create an artificial 1g environment.
    If a full 1g is not required, then any level of 'gravitational field' between that of the celestial body in question and 1g can be arranged by varying the radius of the circular track and the velocity of the train. (While there is no theoretical limit to the maximum g-force which can be generated, obviously the natural gravity of the moon or planet is the minimum.)

We can't know the absolute effect of low-gravity living on human physiology, without doing the experiments.
    But the relative effects of different gravity fields can be estimated with some degree of accuracy, I think. What concerns me is the effect of moving from Mars to Earth or the Moon to Mars, say. If we're going to be a space-faring race, with many homes on many worlds, won't we want to travel from one to another?
    Just imagine that the blood in your vascular system is suddenly swapped for a liquid which is equally life-supporting but weighs 2.6 times as much as normal blood. What would that do to your heart?
    This thought experiment represents the physiological equivalent of a human, acclimatised to martian gravity over a long period of time, coming to Earth for a holiday or to live permanently. Remember, also, that the heart is not only coping with much heavier blood but also with the added strain of the body working 2.6 times harder to lift anything or even just to stand up!
    Is this survivable?

    Or, assuming humans can adapt to living on Ganymede, say, do we just leave them there - effectively banishing them from Earth and even Mars, forever? (I suppose they could visit Luna and Titan for a vacation, though .. )   ???

You mean a statue of the exotic green dancing girl isn't an automatic inclusion??!!!
                                                     :angry:

Cindy:-

    I've often thought about this very point and wondered whether humans actually need at least some kinds of bigotry, in the form of rigid social structures, in order to avoid a descent into chaos.
    That probably sounds crazy and contradictory in today's developed world, with its tendency toward liberalisation of everything, but maybe our logic is getting ahead of our primate instinct(?).
    For a group to survive as a viable unit, at least in the primate world, there has to be a structure with a pecking order (someone in charge) and a set of taboos. While this certainly sounds like a primitive construct, I sometimes think humans are actually happier and more content in a society with definite boundaries of behaviour.
    The human equivalent of a pecking order used to be social class structure, which, though stultifying and intellectually abhorrent to us today in our enlightened world, did bestow stability on society. People knew where they stood. (I'm not necessarily implying, by the way, that we return to that situation; merely making the point that things have changed.) Another of the bastions of western civilisation was marriage between a man and a woman; a powerful and almost irreversible institution not to be trifled with. Yet another foundation of western society was the grim spectre of severe punishment, including possibly execution, for transgressions against the law. This is by no means an exhaustive list, I'm sure, but should serve to make the point.

    Political liberalisation, while eminently supportable, both logically and emotionally, has surely and consistently undermined these supporting structures of society. I hasten to add, again, that I'm not necessarily denigrating that liberal 'progress', merely pointing it out.
    While, in the past, a suffocating marriage has been a virtual prison-sentence to many a woman - and, in many cases, men too(! ) - it did help to make life more predictable. Men and women who, after a few years of marriage, entered that period of doubt as to whether they'd done the right thing, were essentially forced to see it through. In the great majority of cases, perhaps more as a result of necessity than choice, they were obliged to reconcile and re-establish their relationship. Nowadays, a year or three into a marriage, if everything's not perfect, it's off to the lawyer for a divorce.
    I don't know about America but here in Australia much of the population is aghast at the lenient sentences handed down to criminals. Young men, convicted of vicious assaults against the helpless and the elderly, or perhaps found guilty of aggravated rape, are given community service orders (mow the lawns at the local park every weekend for 6 months) or minimal suspended jail sentences. Much to the chagrin of the people they've attacked, these offenders are frequently back on the streets before the victims leave hospital! If you ask a lawyer why these people aren't given a public flogging or a lengthy real jail sentence, you'll be told flogging is brutalisation of someone who's already disturbed and that stiff jail sentences just produce worse criminals in the end.
    I make no direct comment as to my feelings about this, though I'm sure you'll have little trouble guessing where I stand!  :hm:

    Anyhow, my point is simply to say that it may be possible we're running before we can walk with this personal liberty thing. We seem to be forgetting that every freedom comes with a little price tag with 'responsibility' written on it.
    Am I the only one here who dares utter the heresy that not all men and women have the maturity and judgment to handle the freedoms modern western society has heaped so liberally upon us?

    While I don't necessarily agree with the knee-jerk reactionary behaviour of right-wing people toward concepts such as gay marriage, and while their reasoning may be more visceral than cerebral, there may be an accidental wisdom in their reluctance to shift the boundaries still further.
    The anguish of Cindy and others, including me, at the erosion of civil society, may be an indication we're moving too far too fast(?)
                                                  ???

I'm not American and I don't understand all of what you've been talking about. ("Breck" doesn't compute, for example.)
    But, anyway, I just thought I'd mention a financial seminar I attended, where the speaker mentioned the upcoming U.S. election. Using various indicators from past elections, including how long a particular party has been in power, consumer confidence and spending, employment trends, etc., he reported that President Bush should be re-elected with 58% of the vote.

    The speaker is purportedly seldom wrong about financial and/or political matters, so I'll be watching the situation with some interest come polling day.
                                           

Welcome to New Mars, Pete!
    Wish I could be of some use in answering your question but, alas ...   

    It's good to have you here, though, and I think you'll enjoy many of the topics we discuss.
                                                   

It looks like some kind of exotically engraved or etched pewter to me! (Must be the filters they used that gave it that almost metallic sheen.)
                                       

Thanks, Synthomus, for that interview with Dr. Squyres. 

    I was beginning to get a little frustrated at the lack of any significant information from Mars in recent days but the interview helped me understand the problems faced by the MER drivers.
    It's easier to be patient when you have some idea what's going on in the background.

Hi RobS!
    Cancer is the scourge of the developed world - we all know that. But it still takes some getting used to when people you know, or are close to, come down with it.
    It was disturbing to hear of your wife's recent brush with cancer and I'd like to add my sympathies to those offered by others here. My wife had suspicious breast lumps a few years ago and tissue was removed for a biopsy which, thank God, showed the lumps to be benign.
    You must both have been through a very worrying ordeal. What my wife and I went through was bad enough, but that was nothing compared to your experience.
    I, too, am delighted that the treatment has been successful. Even though she doesn't know me from a bar of soap(! ), please convey my good wishes to your wife.
                                               

I think this Ted Twietmeyer is slightly flaky. His list of problems with the Space Elevator (SE) is full of red herrings and pseudo-science.
    The cable hung from the shuttle developed a large current because it was a conductor moving very quickly in Low Earth Orbit through Earth's stationary magnetic field.
    The SE will be essentially stationary with respect to Earth's magnetic field because it will move only at the same rate as Earth's rotation. Trying to equate the two situations is false science designed to impress people who don't understand basic physics.

    As to the prospect of shorting out the entire ionosphere, I believe this shows a misunderstanding of the density of the atmosphere at these altitudes. While there may indeed be a major electrical potential between the ionosphere and Earth's surface, the number of ions per second that will impinge on the surface of the SE in the ionosphere will be totally insufficient to create the kind of massive electrical current Ted describes.
    In addition, however good a conductor the SE may be, over distances of 100,000 km there will be significant electrical resistance. We can even introduce substances, if need be, to reduce the electrical conductivity.

    Then Ted mentions massive ice build-up on the SE in the upper reaches of the troposphere. Well, which is it? An elevator frozen and heavy with ice? Or an elevator crackling and sizzling hot with mega-Amps of current causing it to glow like an incandescent lamp?!!

    There are more holes in Ted's article than I have time to point out. The guy is a wild-eyed, Luddite, sensationalist with little grasp of the facts.
    Don't lose any sleep over his nonsense.
                                                             

I was very happy to see this news item the other day because it tends to confirm my suspicions that Mars was once very much wetter than even the water-optimists think.
    Actually, I'm surprised we haven't seen more comments on this intriguing paper. The idea of rainfall on Mars for about the first 1.5 billion years of its history is very exciting from a biogenesis point of view, or even from the angle that terrestrial life could easily have gained a foothold there via impact transfer.
    Whether Mars gave rise to life first and it found its way to Earth, or vice versa, this latest information from French scientists gives us a much broader window of opportunity for life to have flourished during Mars' early history.

    This, at least to me, may have a bearing on the activities of Spirit and Opportunity. As I've said before, I haven't given up hope that one of the MERs might serendipitously come across a macroscopic fossil.
    If you accept that the climate on Mars was balmy enough for rainfall up to 3 billion years ago, you must surely give credence to the notion that large colonies of bacteria - along the lines of the large terrestrial 'mats' of blue-green algae - could well have thrived there. Terrestrial bacterial colonies gave rise to the stromatolites we all know and love, which are the best hard evidence we have of very early living organisms here on Earth. They're hard to find on Earth because so much of our crust has been recycled by plate tectonics and weathering over the eons but may be much more common on Mars.
    Spirit and Opportunity might be lucky enough to sidle up to a perfect martian stromatolite any minute now! 

    In any case, it seems to me that it's becoming less and less likely Mars could be sterile. The evidence, while still only circumstantial, is now overwhelmingly against such a notion.
    Look at the evidence:-
1) The chemical signature of life has been found in terrestrial rocks up to 3.8 billion years old (less controversial evidence exists from about 3.1 to 3.4 billion years ago).
2) Two-way impact transfer of essentially undamaged crustal material between Earth and Mars is an almost undisputed fact.
3) Conditions on Mars were conducive to life up to 3 billion years ago.
4) Opportunity has provided hard evidence that open bodies of water existed on Mars - only the depth and the persistence of these bodies is in question.
5) Dr. Gilbert Levin's Labeled Release Experiments on the Viking landers produced results it has proved impossible to duplicate by purely chemical means. The results, while controversial, fit a biological source much more closely than a chemical one. (Incredibly contrived and complex soil chemistry was proposed to explain the results, calling to mind the principle of Occam's Razor ... )
6) Mars is producing methane, which has recently been found in it atmosphere. While a volcanic source is possible, a biological source is seen as very much more likely. (The lack of metabolites in the martian environment was the chief stumbling block to my 'life-on-Mars' hypothesis. This discovery of methane removed nearly all remaining doubt in my mind.)
7) Once bacterial life gets a foothold anywhere, it's an all-but-impossible job to eliminate it. Ask anyone in charge of a hospital Operating Room!

    There's now even less doubt in my mind that Mars harbours a biosphere - if not at the surface, then not far below it. And the odds against finding macroscopic fossils have just shortened considerably, in my opinion.
                                       

It's all well and good to be designing hi-tech solutions to the problem of retaining air on a celestial body with low gravity but I think the low gravity will lead to other, more serious, problems.
    While you might get away with living on Luna, at 0.16g, and avoid debilitating muscle and bone loss (nobody really knows), lower gravity than that must surely cause drastic physiological deterioration, even in the short to medium term.
    And, even if you can live comfortably on the Moon, you'll never be able to visit Earth again, once you've acclimatised to lunar gravity. In fact, I have very grave doubts that anyone who becomes accustomed to living on Mars in 0.38g will ever visit Earth either - at least not without major medical assistance and help of other kinds.
    In addition, a native Lunarian may well find Mars and Mercury intolerable, too, and thus be forever restricted to the Moon and the satellites of the outer planets.

    I think we'll need to address important human physiological limits before we worry too much about forcing a tiny world to retain an atmosphere.
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