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If we found another living planet

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13

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    #62
    The lazy rat
    Closed Accounts Posts: 36 ✭The lazy rat


    ScumLord wrote: »
    I guess I should hand back the massive grant I got for starting this thread.

    You can't really develop technology for the future without knowing what the future may bring. We've seen that the likes of Star Trek can inspire people to invent mobile phones.

    The fact is most of the problems of prolonged space travel are exactly the same as the problems we have on earth now. Mainly getting the most out of limited resources.

    Capt'n Midnight wrote: »
    there's an argument that we haven't advanced quantum mechanics since the 1930's




    X-ray tomography has proved very useful in lots of ways , as long as you don't do it on healty people.


    Anyway the key word here is living as in living planet.

    Forget the asteroid that wiped out the dinosaurs , in the grand scheme of things that was a walk in the park compared to the Permian Extinction. Or consider Snowball Earth a time in the past we were lucky to come back from.

    Science and engineering to get us spacefaring capability is the only way we could survive similar extinction events. And by we I don't just mean humans but most higher life forms.

    To get to space we need better materials and to do that we have to understand matter better.



    Also

    It looks like there's liquid water on Ganymede \o/
    and the Juno probe, compete with Lego should arrive there 2016

    *waits impatiently*




    My wisdom has fallen on deaf ears.


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    #63
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    The lazy rat wrote: »
    My wisdom has fallen on deaf ears.
    No, it's just your wisdom seems to be "I don't understand the LHC" and we can't go faster than light. Nobodies really arguing that we can travel faster than light but based on findings about how space behaves we might be able to bend space.

    There are some parts of the galaxy that do seem able to travel much faster than they're supposed to be able to. I think the outside arms of our galaxy are spinning around the centre at impossible speeds. We're finding space has some anomalies that we're going to be able to take advantage of when traveling great distances.


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    #64
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    ScumLord wrote: »
    No, it's just your wisdom seems to be "I don't understand the LHC" and we can't go faster than light. Nobodies really arguing that we can travel faster than light but based on findings about how space behaves we might be able to bend space.

    There are some parts of the galaxy that do seem able to travel much faster than they're supposed to be able to. I think the outside arms of our galaxy are spinning around the centre at impossible speeds. We're finding space has some anomalies that we're going to be able to take advantage of when traveling great distances.

    Not to mention that if you could travel at a significant fraction of C, then time passes more slowly from your perspective. So if you could get your ship moving at 0.99 C (Don't know what energy source you're using mind) you could travel 20 light years out in a year and a half. Of course your family back home would be pretty old when you got home - but if it was a one way trip it wouldn't matter.


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    #65
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    Maximus Alexander wrote: »
    Not to mention that if you could travel at a significant fraction of C, then time passes more slowly from your perspective. So if you could get your ship moving at 0.99 C (Don't know what energy source you're using mind) you could travel 20 light years out in a year and a half. Of course your family back home would be pretty old when you got home - but if it was a one way trip it wouldn't matter.
    It wouldn't although the people on the ship could find that when they reach their destination the people back home are waiting for them because they've developed a new warp technology in the mean time.

    If a ship could travel close to light speed I'd assume it couldn't be communicated with until it slows down.


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    #66
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    ScumLord wrote: »
    It wouldn't although the people on the ship could find that when they reach their destination the people back home are waiting for them because they've developed a new warp technology in the mean time.

    If a ship could travel close to light speed I'd assume it couldn't be communicated with until it slows down.

    I'm not aware of a physical reason why you couldn't communicate with it, although I'd imagine it would be a technical challenge.


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    #67
    The lazy rat
    Closed Accounts Posts: 36 ✭The lazy rat


    Pie in the sky stuff. Enjoy the journey.


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    #68
    sheesh
    Registered Users Posts: 4,080 ✭✭✭sheesh


    jamo2oo9 wrote: »
    Just out of interest, have we made any attempt at terraforming anything, not planet scale but something small like an acre of field or something?

    they have grown plants in powdered moon rock afaik ok maybe moon rock analogue


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    #69
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    Maximus Alexander wrote: »
    I'm not aware of a physical reason why you couldn't communicate with it, although I'd imagine it would be a technical challenge.
    I would assume radio waves wouldn't be able to catch up with the ship if it's moving away from earth and even with some sort of lasers it's going to take them a while to catch up too.


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    #70
    Baked.noodle
    Closed Accounts Posts: 1,014 ✭✭✭Baked.noodle


    I'm not very good at physics but perhaps gravity could one day be used for communication, as I understand gravity doesn't travel but instead it is a field.


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    #71
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    Baked.noodle wrote: »
    I'm not very good at physics but perhaps gravity could one day be used for communication, as I understand gravity doesn't travel but instead it is a field.
    Gravity affects space. Scientists are finding now that the idea of space being empty isn't really true. Gravity bends space which is why people think we might be able to use the same process to travel through space.

    I don't know if gravity is the right word to use when describing how a ship would bend space. Gravity is very weak and we'd need to be generating the mass of planets, stars or black holes to get the kind of pull we need. We also don't actually want to be pulled like gravity would pull something normally because then we're just moving through normal space and have all the same speed restrictions that you'd have in any other propulsion method.


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    #72
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    ScumLord wrote: »
    I would assume radio waves wouldn't be able to catch up with the ship if it's moving away from earth and even with some sort of lasers it's going to take them a while to catch up too.

    Radio waves are a form of light, they travel at C. :) There'd be a delay for sure due to the distances involved. Just as there is a delay in communicating with the rovers on Mars, for example, only over much greater distances.

    You'd have to calculate where your transmission and the ship would intersect, point your dish that way, and transmit. The other issue I see is that when the ship receives your signal, because of time dilation the frequency will be extremely high. But that can be dealt with too.
    Baked.noodle wrote: »
    I'm not very good at physics but perhaps gravity could one day be used for communication, as I understand gravity doesn't travel but instead it is a field.

    Gravity propagates at the speed of light too. :)


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    #73
    tac foley
    Registered Users Posts: 5,504 ✭✭✭tac foley


    Maximus Alexander wrote: »
    Are you active in the field of cosmology/astronomy/physics/mathematics? Because otherwise I don't really know why you'd expect to know their names.

    My post was in the nature of a semi-rhetorical question. AFAIK, the continent of Africa has not actually produced any of the above professions. And no, I'm not active in any of those fields, having only a Masters degree in Remote sensing and Geophysics.

    Names are not necessarily of interest - their actual existence was.

    tac


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    #74
    catallus
    Closed Accounts Posts: 6,106 ✭✭✭catallus


    I thought gravity is space?!


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    #75
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    tac foley wrote: »
    My post was in the nature of a semi-rhetorical question. AFAIK, the continent of Africa has not actually produced any of the above professions. And no, I'm not active in any of those fields, having only a Masters degree in Remote sensing and Geophysics.

    Names are not necessarily of interest - their actual existence was.

    tac

    Top, middle and bottom. Come on, try harder.


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    #76
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    catallus wrote: »
    I thought gravity is space?!
    No they're different as far as I know. You can almost think of space as fluid, it's not but fluids are the closest thing we know about. The planet is a ball suspended in the fluid and as water passes by the ball it compresses and speeds up. Of course space isn't moving like water and it doesn't compress like water but it's something vaguely similar to that sort of effect, I think. :confused:

    Gravity can affect the space around it to the point we can see stars that are technically behind planets because the planet is bending the space and even the light traveling through that space.

    I suppose it might be better to think of space like jelly, if there was a piece of string running horizontally through the jelly to simulate a light beam, then make an incision a centimetre to the left of the string and pushed in wide pen to simulate a planet. It would push the jelly with the string to the side just around the pen. So if you followed the string it would run straight until it got to the pen (planet) go around it and continue on straight, even though the jelly hasn't seemed to have changed shape all that much. In the real world though from the point of view of the light beam it seems like it's always traveling in a straight line.


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    #77
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    catallus wrote: »
    I thought gravity is space?!

    The best way I could describe it is: imagine space as the flat surface of a trampoline. Put a bowling ball in the middle. The curve is gravity.


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    #78
    catallus
    Closed Accounts Posts: 6,106 ✭✭✭catallus


    ScumLord wrote: »
    No they're different as far as I know. You can almost think of space as fluid, it's not but fluids are the closest thing we know about.......

    I suppose it might be better to think of space like jelly, if there was a piece of string running horizontally through the jelly...
    Maximus Alexander wrote: »
    imagine space as the flat surface of a trampoline.

    Now I'm getting more confused!

    What flavour is the jelly?


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    #79
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    catallus wrote: »
    Now I'm getting more confused!

    What flavour is the jelly?
    Well both analogies are trying to demonstrate the effect gravity has on space. I'm confused in my own head about it so I rambled and tried to think of it in 3D.

    The problem is it's difficult to explain it in visual references and language. You'd really need to know maths to get a proper explanation. These are just laymen interpretations of a concept that's beyond normal explanation.


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    #80
    catallus
    Closed Accounts Posts: 6,106 ✭✭✭catallus


    Does light move?


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    #81
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    catallus wrote: »
    Does light move?

    From our perspective, yeah. From its perspective, no.


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    #82
    catallus
    Closed Accounts Posts: 6,106 ✭✭✭catallus


    Maximus Alexander wrote: »
    From our perspective, yeah. From its perspective, no.

    But then how can we be sure it's moving at all, unless we are sure we are not moving?


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    #83
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    catallus wrote: »
    But then how can we be sure it's moving at all, unless we are sure we are not moving?

    It's moving relative to us. There's no such thing as not moving. Everything is moving relative to something.


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    #84
    catallus
    Closed Accounts Posts: 6,106 ✭✭✭catallus


    Maximus Alexander wrote: »
    It's moving relative to us. There's no such thing as not moving. Everything is moving relative to something.

    :( I don't understand. :confused:

    Surely there are some things that don't move relative to anything.


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    #85
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    catallus wrote: »
    But then how can we be sure it's moving at all, unless we are sure we are not moving?
    Well we have cameras that can capture light moving. Before that we could just measure the time that passes between turning on a light and how long it takes to hit a predefined target.

    In this video you can actually see the light particles traveling.


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    #86
    Maximus Alexander
    Registered Users Posts: 13,080 ✭✭✭✭Maximus Alexander


    catallus wrote: »
    :( I don't understand. :confused:

    Surely there are some things that don't move relative to anything.

    Nope - how could that be? Imagine nothing exists at all, except for two golf balls. The two golf balls are getting closer together. How can you tell which one of them is moving?


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    #87
    catallus
    Closed Accounts Posts: 6,106 ✭✭✭catallus


    Ok, but isn't the current knowledge/state of affairs that Earth/Sun/Solar System is at the centre of the observable universe, which is expanding?

    So everything is moving relative to the Earth/Sun/Solar System.


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    #88
    tac foley
    Registered Users Posts: 5,504 ✭✭✭tac foley


    Good points there. Thanks for clearing that up. That's why you are a Mod, and I'm just a scumbag trouble-making interfering old furriner. ;)

    tac


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    #89
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    catallus wrote: »
    Ok, but isn't the current knowledge/state of affairs that Earth/Sun/Solar System is at the centre of the observable universe, which is expanding?

    So everything is moving relative to the Earth/Sun/Solar System.
    No, we're not even close to the centre of anything. The big bang caused everything (at the time) to move away from each other. It's not that everything is moving away from our sun, but everything is moving away from everything else at the same rate. On earth it would seem like everything is moving away from us but if you went to another planet around another sun it would look exactly the same because both planets are heading away from each other.

    Of course gravity has interrupted that process so now there are clumps of galaxies moving together and smashing into each other, but over all everything is still moving away from everything else.

    They use a balloon to demonstrate this, Blow up a balloon halfway, draw some points at different positions around the balloon, then continue blowing it up. You'll see the points move away from each other and that's how galaxies move away from each other.


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    #90
    catallus
    Closed Accounts Posts: 6,106 ✭✭✭catallus


    Yeah, I get all that, big bang, blahblahblah, the answer to a question no-one asked :)

    Is the observable Universe not what we are constrained to? So, from that point of view, we are the centre, no? Even if we can deduct/infer/know that we are not the centre, but for what we can observe we are that centre.

    Anyways, I must think more on your liquid/jelly/gravity analogy, I am most confused but we shall speak further on it!


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    #91
    ScumLord
    Registered Users Posts: 28,789 ✭✭✭✭ScumLord


    catallus wrote: »
    Yeah, I get all that, big bang, blahblahblah, the answer to a question no-one asked :)
    It is the answer to the exact question you asked.
    Is the observable Universe not what we are constrained to?
    No, the observable universe is just the bit we can see. Our telescopes have limits, any observatories we have on earth have the problem of looking through our atmosphere to deal with. The hubble in space is our best telescope and the problem you have with that one is that when it looked at one tiny supposedly empty bit of space for a few weeks it found a couple of billion galaxies. Observable space get's bigger every day, it's just a matter of getting around to observing it.

    So, from that point of view, we are the centre, no?
    No from our point of view we can see that most the things in the universe are moving away from us, but we can also see that everything is moving away from the next galaxy over as well, and so on..
    Even if we can deduct/infer/know that we are not the centre, but for what we can observe we are that centre.
    No, we observe that everything is moving away from everything else.


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