New Mars Forums

Bill:-

    Huh?!!  Oh the shame of it all!  :bars:
    All these years I thought I was thinking for myself and now it turns out I've been no more than a puppet of the French. 

    Interesting man that David Brin. He sounds just like you, Bill.
    Hmmm .. Brin.  That's not originally a French surname, is it?  ???     [    ]

   [Brin makes a number of fundamental errors in his assessment, of course; oversimplification of complex and ever-changing world circumstances being the main one.
    Without going into a point-by-point counter-argument, it's obvious, for example, that comparing the Balkans in the 90s with the Middle East in the 00s is a nonsense. Different problem, different continent, different people, different world situation, and not surprisingly a different outcome.
    The other main problem is his spurious assertion that an obviously pre-existing and already expanding militant Islamic movement was somehow brought into existence, or at least exacerbated, by the invasion and liberation of Afghanistan and Iraq. The build-up in the frequency and audacity of Islamofascist attacks on the West, leading up to the Twin Towers attack in 2001, was evident to everyone except Brin, apparently. There's absolutely no proof at all that Islamic terrorist attacks on Western interests since Afghanistan/Iraq are any worse than they would have been - in fact, the reverse is just as possible and there's no way of knowing. Yet Brin's assumptions become 'facts'

    I could go on but there's little point to it. I won't convince anyone of anything, after all.
    Many of Brin's points are good food-for-thought, though, and I like some of his stuff very much. But, as always, we need to sift carefully through the inevitable prejudices and consequent inaccuracies that show up in the work of even astute philosophers like him.    ]

Hi EarthWolf!
    Yes, I believe a Gyr is a billion years.   

    The Celsius scale of temperature, as you probably know already, runs from zero degrees at the melting point of water up to 100 degrees at the boiling point of water, 0 deg.C to 100 deg.C.

    It was found that there is a lower limit to the temperature of a substance. At -273 deg.C, all atomic and molecular movement ceases (apart from some quantum fluctuations); in other words, you can't extract any more energy from the substance and make it colder.
    This is the famous 'Absolute Zero' we've all heard about.

    Somebody (it might have been Lord Kelvin, I can't remember) decided that, for scientific purposes, an absolute scale of temperature was necessary. They set the lower end of the scale at Absolute Zero but used the same degrees as are used in the Celsius scale, and called the scale the Kelvin scale.
    Thus, Absolute Zero became 0 deg.K, with the melting point of water occurring at 273 deg.K, and the boiling point of water at 373 deg.K.
    (Incidentally, you'll notice that there are no 'minus' temperatures in the Kelvin scale.)

    So, if you want to convert Celsius to Kelvin, just add 273 degrees.
    For example, the surface temperature of Titan is about -180 deg.C. Adding 273 degrees gives us the temperature in  degrees Kelvin, i.e 93 deg.K

    It's harder to convert degrees Kelvin into degrees Fahrenheit because a degree in one scale is not the same magnitude as a degree in the other.
    What I do is just use the conversion equation to convert Fahrenheit to Celsius, and then add 273. 

[In case you're unfamiliar with the conversion of Fahrenheit to Celsius:-
  Take the temperature in Fahrenheit, subtract 32, and multiply by 5/9.
   e.g. 50 deg.F - 32 = 18
                18 x 5/9 = 10 deg.C

   In reverse, take the temperature in Celsius, multiply by 9/5, and add 32.
   e.g. 20 deg.C x 9/5 = 36
                       + 32 = 68 deg.F ]

DP:-

    I think I can help you here, DP; I know exactly who these pedophile teachers are.
    They're fully-fledged registrants on the list of the "richly deserving few" ... that's who they are!!  :realllymad:

    The fact that you seem to have doubts about the true nature of these disgusting predators indicates strongly, at least to me, that your understanding of what constitutes a serious threat to society is gravely impaired. Teachers are entrusted with the safety of our children. These teachers have systematically abused that trust, using their positions to harm grievously the very children they were assumed to be nurturing. This is one of the most heinous of crimes and, in my opinion, completely unforgivable. The fact that these contemptible creatures covered up their despicable behaviour by deliberately and slyly assuming the mantle of civilized behaviour while perpetrating their offences, only makes them all the worse - not better!

    This glaring inconsistency on your part, DP, and your inability to see long-term mental torture (even unto death) as no better than swift painless execution, shows the disturbing dearth of logic in your attitude. If you are typical of the people who seem to be in control of the way justice is administered these days, at least here in Australia, it's not difficult to see why the safety of ordinary citizens is being compromised and the rule of law is breaking down.
                                                                           ???

Yes, I've often wondered about our crater-counting method of determining the age of terrain on Mars. If Mars has had intermittent wet epochs, when major erosion has occurred, followed by intervals of atmospheric attenuation and extreme dryness, then counting craters and judging their ages by their state of preservation may be leading us seriously astray.
    It may work on the Moon, where we know there's never been any weathering apart from a continual rain of micrometeorites, but I think Mars' erosional history is probably much too complex.
                                                           ???

Hmmm.
    As more and more information comes to light (at least for me), the complexion of the case changes.

    I thought Terri's family were to foot the bill for her ongoing care, not the taxpayers. Apparently not true.
    All credible authorities seem to think she's in a PVS. Her responses are brainstem activity only.
    There's no insurance policy (motive for skullduggery).

    I'm tending toward euthanasia in this instance, though allowing Terri simply to die of neglect seems cowardly. If she is to die, something it seems likely she would have wanted for herself in these circumstances (not proven, but likely), then let's grasp the nettle and do the job properly.
                                                             

Chat:-

    There are already numerous localized magnetic fields on Mars - some of them quite large and some up to 1/10th as strong as Earth's global field. These are crustal fields and are believed to represent the 'fossil' remnants of Mars' earlier global magnetic field.   
   [See http://sunearth.gsfc.nasa.gov/sunearthd … 4.htm]THIS SITE.]
    We've already discussed establishing settlements in the shelter of these localized fields in another thread here at New Mars somewhere. 

Auras?  ???

Thanks, YLR!
    That last picture was excellent (you were right about the file size! ). 

    Makes you wonder whether we should be switching the Mars Polar Lander to somewhere like this or, better yet, the 'frozen sea' in Elysium. Then we could establish the presence of shallow sub-surface ice and accelerate the crewed expedition timetable.
    (Perhaps even to the point where the first expedition lands before I drop dead .. instead of years afterwards!!!  :realllymad:  )

Dook:-

    Yes, I agree.
    If it can be done that way, it would certainly save a lot of time and effort. We'd still need bulldozers, of course.

    And yes, we're sort of off topic. But creating a thick atmosphere, either in a dome or out of it, is a practical alternative to 'magnetizing Mars'. So, are we that far off?  ???   

Sheesh .. you leave an argument, go get some shut-eye for a few hours, and wake up to find you've been left waaay behind! 
    By the way, as is not uncommon, I find myself in broad general agreement with CC.

DonPanic:-

    This is a noble point of view in many ways and therefore an eminently arguable one. My main point, however, was to highlight the dangers of what I believe is a relatively small group of people imposing their views on an ostensibly democratic system.
    One man's ethics can be another man's debauchery; one woman's morality, another woman's immorality. That's why we have democracy - the rule of the greatest number of people.
    If you have a group of elitist intellectuals who believe their morality is superior to that of the masses, and if those intellectuals contrive to impose their view over and above the democratic system, you can have one of two outcomes. Either their morality is indeed superior, and its imposition leads to the greater good, or it isn't superior and it can lead to increased misery in society. This has been borne out over the millenia with the results of systems like monarchic imperialism - a benign monarch can do enormous good for his/her subjects, often surpassing the best efforts of democratic systems in a similar time frame, but a bad monarch can do equally enormous damage over the same period.

    DonPanic, you believe capital punishment is always unethical and immoral, touting long periods of imprisonment with solitary confinement or other forms of sensory deprivation as an alternative.  CC, Trebuchet and I don't agree; believing there are instances where the death penalty is appropriate.
    You cannot say that your morality is superior to ours, however much it may look that way from your point of view. Every person likes to imagine that their own point of view is special and it takes intelligence and imagination to see things from another person's perspective.

    There is little doubt in my mind that the Australian people (and I'm reasonably sure the same applies in other states and countries) would reinstate the death penalty for certain criminals if given the opportunity.
   What troubles me deeply is the fact that there are forces at work which are determined to deny us the opportunity to express that desire. These forces are not confined to Australia alone; they are well organized internationally-based forces.
    It is the fact that these people have no compunction whatsoever in organizing the imposition of their personal morality on the rest of us, which worries me. And the fact that they actually have the power to implement their personal agenda is even more profoundly disturbing.
    Who are these people and whom do they answer to?
    It's obvious they don't answer to the majority of ordinary people. And that should worry all of us!   ???

Hmmm.  ???
    I think I've just noticed an error in Dr. Zubrin's assessment of how much regolith would have to be moved in digging out a hemisphere of 25 metres radius.
    A hemisphere of that size has a volume of about 32,700 cu.m. In order to reach a mass of 260,000 tonnes, the figure in "The Case for Mars", the regolith contained in that volume  would need a density of 7.94 tonnes/cu.m.
    Even pure iron has a density slightly less than that, at 7.87 tonnes/cu.m!!
    And so, on Earth, a cubic metre of iron would weigh 7.87 tonnes. On Mars, a cubic metre of iron would weigh 'only' 3 tonnes.

    Mars' overall average density, including its iron core, is about 3.95 tonnes/cu.m. From this, it seems reasonable to assume that rocky regolith material might mass no more than about 3 tonnes/cu.m., which would weigh about 1 tonne/cu.m under Martian gravitational acceleration.

    Therefore, digging a hemispherical hole of radius 25 metres, on Mars, requires the shifting of about 32,700 tonnes (weight) of regolith - not 260,000 tonnes.

    I never noticed that error until now.  ???

Flashgordon:-

    No, Flash.
    But I believe scientists have concluded, from the study of what are known as 'banded iron formations', that Earth's atmosphere became oxygen-rich about 2.25 - 2 billion years ago. And I assume an ozone layer would have formed at the same time (?).
    Yet the 'Cambrian explosion' of multicellular life forms didn't occur until about 590 million years ago. We had the oxygen, and presumably the ozone protection against U.V., some 1.5 billion years before this apparently sudden event - so why the delay?  ???
    I think it's still a mystery.