New Mars Forums

All those galaxies!!   

    It's all been said before, I know, but it really is totally beyond our just-got-down-from-the-trees ability to comprehend such vastness.

    It reminds me of that movie scene:-
    "Did he really think his primitive ape-brain could contain the secrets of the Krell?!"  - Dr. Morbius in 'Forbidden Planet'.
    One of my faves!
                                   

    And that Mars and Moon picture is beautiful! But why does Mars look so close?
    It looks like it's only about 10 millon kms away, instead of 56 millon ... God it looks just sooo tantalisingly near and reachable!!
                         

Cindy:-

    Some people regard dreams that lucid as astral travel, an out-of-body experience. My elder son is going through a 'spiritual phase' at the moment and would be quite sure you were in Ireland that night! Or at least he would tell you your consciousness was there, minus your physical self.
    I'm not so sure of everything as to feel confident enough to write off such beliefs. "There are more things in Heaven and Earth, Horatio, than are dreamt of in your philosophy."
                                        :;):

Clark:-

    Many a foolish man has dismissed the Little People with equal abandon. None has ever done so with impunity. Have a care now ... watch your step!
                                         

Lucky Charms cereal?
    LUCKY CHARMS CEREAL, IS IT?!!!!

    Don't be mentioning that filthy sticky breakfast food in the same breath as you speak the proud name of Brian, King of the Leprechauns!
    Much and all as I'm fond of you, Cindy, and hold you in high regard, I cannot long stay the wrath of the Little People if you persist in this reckless folly of disrespect. Say no more now, lest you would invite the same fate upon yourself as awaits that impudent blackguard with the rag-bag rabbit!!! (Or tawdry teddy, or repulsive rodent, or whatever else he thinks it looks like! )
    A dozen wailing screaming banshees will soon decend upon him and his fluffy idol and carry them both off to a place of eternal darkness and torment!
    And don't be telling me you weren't warned!!  :angry:

Hi Clark,
    Unless I misunderstand you, you're talking about a series of vast, carefully spaced 'shutters' orbiting the Sun, which would produce a dimming of the sunlight in a particular pattern.(?)
    This would be an enormous technological challenge because the objects interrupting the light would have to be so big to make an appreciable difference to the Sun's apparent brightness. In addition, since you want these objects to go on producing this Morse-Code-like signal long after our civilisation is dead and gone, their orbits would need to be stable over geological time. For that, you either have to place them at stable Lagrangian Points or you have to equip them with long-lived computer-controlled thruster systems which will constantly monitor and correct the objects' positions.
    The latter is not desirable since technology fails over long periods due to wear and tear. And if you use stable Lagrangian points, then you are no longer at liberty to determine the form of the message since your objects must be placed at points dictated by the vagaries of orbital mechanics. Interruptions to the Sun's light made by objects at such well-known natural positions relative to planetary bodies, could easily be interpreted by an alien civilisation (in another star system) as caused by accumulations of ordinary debris and not a signal of intelligent manufacture.

    Another drawback to orbiting 'signallers' of the kind I think you're suggesting, is that they're only visible at or near the plane of the ecliptic, or whatever plane you choose to orbit them in. I don't know how many inhabited star systems you'll miss out on signalling simply because, from their vantage point, your objects fail to interrupt our star's light.
    On the other hand, I recognise that this will be a problem with any directional signal used by any civilisation.

    As an illustration of the size range we're talking about for your obscuring objects, let's consider Jupiter, which is about 1/10th the diameter of the Sun. Observers in a far-flung planetary system, which just so happens to be on the plane of the ecliptic, will see our Sun dim by just 1% as Jupiter passes between it and them.
    How much dimming is required before an observer is certain it's not being caused by a patch of interstellar dust? How large are you prepared to make your 'shutters'?

    Just a few thoughts.   ???

Cobra Commander:-

    Simple, wise and moving words, CC. 

    I was standing in the street here in Cairns with a guy I know who thinks space is something you place advertising in! He's always ridiculed the concept of space exploration and laughed at my fascination with Mars.
    I casually pointed to Mars, which was nearly at its closest point to Earth at the time, and told him: "Well, there it is. That's Mars .. only 56 million kilometres away. A whole new world waiting for us." (Or words to that effect) I then waited for the usual mocking response.
    But it never came!
    He seemed suddenly interested in Mars, I think because this was the first time he'd seen it with his own eyes and realised it's an actual place. And it didn't seem too far away either because you could make out its tiny circular shape.
    I don't know which of us was more amazed, him with Mars or me with him!!   :laugh:

    It's such a shame Mars doesn't come closer still, and more often too!
    If it did, we might be able to stir more curiosity in more people and persuade them that sending humans there is perhaps a good idea after all. Wouldn't that be grand?
                                         

Hi Dicktice!
    I haven't investigated in detail the actual physical mechanism by which a classical aerofoil shape causes lift. When I was in school, we were taught it was the Bernoulli Effect and since then I have most often heard it called the Venturi Effect.
    My impression has always been that increasing the speed of the airflow over the wing causes a pressure reduction, though I am also familiar with the concept of redirecting a large mass of air in such a way as to give it a significant downward momentum vector, which must result in an equal and opposite upward force vector on the wing. (Newton and all that! )
    Until now, I hadn't heard the name Coanda in relation to this topic. A regrettable display of ignorance on my part, no doubt!

    But, whichever way you care to describe the mechanism of aerofoil lift, I hope it won't detract from the overall thrust of my argument, which was to reassure Dickbill that there is still hope for his winged re-entry vehicle.
                                 

    In response to Cindy's question, I think the two major factors affecting the persistence of dust in the martian atmosphere are the size of the particles and the lack of rainfall, which 'washes' a lot of dust out of our air here at home.
    If you remember the video clips of Apollo astronauts driving their cars on the Moon, you will recall how the dust thrown up by the wheels followed a long slow parabolic path back down to the surface. None of it remained in clouds in the air, as it would on Earth, because there's no air to support it. Gravity is only 1/6th of Earth's but that wasn't the main factor. It was the lack of air which mattered most.
    For fine dust on Mars, there's enough air to keep it suspended for long periods regardless of the fact that gravity there is twice as strong as on the Moon. Again (at least for fine dust), gravity is of little consequence compared to atmospheric density.
    With an atmosphere as dense as Earth's, we would be bedevilled with eternal dust in the air, and lots of it (! ), if not for the vast amounts of water vapour we have. The vapour tends to condense around fine dust particles and form water droplets, which ultimately become large enough to fall as rain.
    On Mars, this 'washing' action doesn't happen, so we have the worst of all worlds in that the air's thick enough to support fine dust but too thin (and cold) to carry enough moisture to get rid of it!!

    So you see, Mars is just too untidy with all that nasty dust everywhere. We really ought to get in there and terraform the place as soon as possible!!
                                          :laugh:

Many thanks, Cindy!
    Those last four posts were very entertaining.
    Especially the instruction manual on how to be a disagreeable bore, by the inimitable Mr. Franklin.  :laugh:

About the Deism thing: I really can't imagine all these amazing phenomena being meaningless.
    The universe is just too incredible, at least to my mind, to be the result of entirely random, mindless chance.
    I have no evidence, no proof, but my own personal opinion is that there has to be some purpose to it Even if there isn't, I don't want to live out my life thinking that!!

[I know, I know ... even if there were no God, man would have to invent Him!
                                     

What gets me about the Moon landings is how the astronauts managed to sleep in hammocks strung up inside the lunar module.
    Remember all those nights when we were kids and we had sleep-overs or slept out in tents or whatever? Remember how excited we were and how we'd talk and laugh and couldn't get to sleep for hours?

    Imagine lying in a hammock in a high-tech tent with a friend on the Moon!! You're 385,000 kms from home, camping out on another celestial body, the walls of your tent are no thicker than canvas, outside is a hard vacuum (not rain! ), there's not another soul on that rock but you and your buddy, and mission control says: "Lights out guys".
    YEAH ... SURE!!!!   

    [Then imagine you're lying there with the soft hiss of the life-support system in the background, and you hear something outside tapping on the walls .... !!! Uh-oh.  ]
                                       :laugh:

Clark:-

    Beware speaking idly of the Little People, you wretched worshipper of stuffed toys!
    King Brian of the Leprechauns is not to be trifled with by idolaters who insult the power of the ancient Celtic spirits with foolish abandon.
    Stay your ignorant arrogant tongue, you spawn of a toad, lest King Brian stuff your stuffed toy up your ... nose .., by way of retribution!

Wow, that's quite an exchange you had going there! At my rate of typing, that's about two weeks worth!   

    For what it's worth, I don't seem to remember dreaming much at all in recent years - busted brain cells, I guess!

    I'm sure tornadoes occur regularly here in Australia but neither my wife nor I have ever seen one and we don't know anyone who has. We remember a T.V. report about a tornado somewhere in Queensland earlier this year but they certainly don't seem to feature in Australian life the way they do in American life, thank God!
    As you hinted, Cindy, most probably occur toward the middle of the country where there is only a very sparse population because of the extreme desert conditions.

    Just touching on that skin cancer thing again, most of the damage is done in the first 10 or 12 years of life and sun exposure then pretty much determines your chances of skin cancer later. I spent a lot of time in the sun as a kid; many weekends at a surf beach at Ballina on Australia's east coast, swimming or leaping off huge sand dunes just for fun. In those days nobody worried much about sunscreen etc. and regarded a tan as healthy.
    Since the age of ten, I lived in cloudy London for 16 years and I've spent almost all my time indoors since then but the damage was locked in all those years ago. There's nothing to be done now except watching, zapping and cutting!!   :laugh:
    Needless to say, I don't spend a lot of time in the sun these days if I can avoid it!

    Byron, your father gave you a wonderful start in life. My Dad was good to me too and there should be more of it!   

    I'm sure your Dad meant well, Cindy, and he was probably just exhibiting loyalty to your mother with the religion thing. Anyhow, from what you've mentioned about him, I've formed the impression he was a nice guy.

Spider-Man, I've neither the linguistic wherewithal nor the slightest desire to become immersed in this seemingly fruitless argument!
    However, might I draw your attention to the pronunciation of the name 'Constanze'?
    Sifting through the ragged remains of what's left of my memory of the German language [    ], I think I would be inclined to pronounce the name as Kon-stahn- tseh.

    A trifling point, to be sure, though one you may care to dispute. If so, I'm prepared to listen.