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Thread: Just a thought

  1. #1 Just a thought 
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    Want to share a thought. May be most of us already aware of it...

    When we see an incident happening on a star which is 1 million light years away frm earth, it means that light travelled 1 million years and reached our eyes(earth) at that point of time. Which means, we are seeing something which happened 1 million years ago. (Human species would've not evolved)
    We are seeing the past of that star, present of that star is still future for us. What we see now is Future for another planet far from earth. ie. If we can travel faster than light and reach that planet, we can forcast whats gonna happen in future regarding the incident happened in the Star we witnessed from earth .!

    here is the relation with speed, distance, tense.....
    How crazy this universe is !!!

    'Gods' and 'Godesses' in myths wouldve utilized / controlled these coordinates to travel different planes of universe


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    Common misconception.

    Yes you are seeing " into the past' by looking into distance because of the finite speed of light ( one year, time, per light year, distance ).

    But there is no such thing as simultaneity, nor is light the only thing limited to c, the speed of light, information, all other forces and causal interactions, are all limited to c. Which means that if you look 1 billion light years away, even though you see conditions of 1 billion years ago, that's as close to 'now' as you're going to get.


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    "even though you see conditions of 1 billion years ago, that's as close to 'now' as you're going to get. "

    Please explain this. If my understanding is correct, You say that we see conditions of 1 billion years ago. That means we dont know about the present condition at all. It means we see the past of that star right? How can we say that "that's as close to 'now' as you're going to get. ". It might be 'now' for us..but is a 'past' for that particular star. Correct me if 'am wrong.
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  5. #4  
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    Quote Originally Posted by eldhosepg
    "even though you see conditions of 1 billion years ago, that's as close to 'now' as you're going to get. "

    Please explain this. If my understanding is correct, You say that we see conditions of 1 billion years ago. That means we dont know about the present condition at all. It means we see the past of that star right? How can we say that "that's as close to 'now' as you're going to get. ". It might be 'now' for us..but is a 'past' for that particular star. Correct me if 'am wrong.
    What you see "now" is in the past of the object across the room that you are seeing.

    So what ?
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    Universal Mind John Galt's Avatar
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    Only now do you say that!
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    :-D like it
    beyond the theorems..word weird is apt !!!
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    When you look at the sun today, you are seeing it as it was, and where it was, 8 minutes and 26.6 seconds ago
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    Quote Originally Posted by eldhosepg

    Please explain this. If my understanding is correct, You say that we see conditions of 1 billion years ago. That means we dont know about the present condition at all. It means we see the past of that star right? How can we say that "that's as close to 'now' as you're going to get. ". It might be 'now' for us..but is a 'past' for that particular star. Correct me if 'am wrong.
    Yeah. It's the star's past. Like if you saw an intelligent alien with a radio near that star and you sent a radio signal out, he'd have been dead 2 billion years by the time the signal reaches him.

    But, when you're using relativity, the moment a light signal makes you aware of something is considered to be the moment it "happened" from your perspective. Thinking like that makes it easier to navigate your way through the theory. If you don't think like that, the theory gets confusing really fast.
    Some clocks are only right twice a day, but they are still right when they are right.
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    Sorry, i guess I was kid of vague. What I meant, eldhosepg, is that the 'present' conditions of a galaxy 1 billion light years away, is purely hypothetical as we can never measure any effect from the 'present' of that galaxy. The only valid thing we can talk about is the conditions of said galaxy a billion yrs ago.

    For that matter, as someone else mentioned, the sun we see is the sun of 8 minutes ago. If it goes nova in two minutes, we won't know about it ( and acoording to relativity, cannot know about it ) for another six minutes.
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  11. #10  
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    Quote Originally Posted by MigL
    For that matter, as someone else mentioned, the sun we see is the sun of 8 minutes ago. If it goes nova in two minutes, we won't know about it ( and acoording to relativity, cannot know about it ) for another six minutes.
    And you won't be aware of it six seconds after that.
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    here comes something called Einstein's time machine...travel beyond the speed of light (speed of mind) .. travel from past to future thru presnt and in any direction... it is quite possible.. but we need to travel faster than light crazy thought as it looks like now..who knows it will be possible in near future halt movement in time axis..go in X-Y-Z axis alone..come back n resume time axis..any1 able to imagine things like this without blindly followng theorems and equations??

    years back..Michael faraday was abused a lot when he proposed his discoveries abt electricity , coz the rulers were nt aware of it's use...rt now, imagine a minute without having electric supply.. thats how paradigm shifts..
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  13. #12  
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    Quote Originally Posted by eldhosepg
    here comes something called Einstein's time machine...travel beyond the speed of light (speed of mind) .. travel from past to future thru presnt and in any direction... it is quite possible.. but we need to travel faster than light crazy thought as it looks like now..who knows it will be possible in near future halt movement in time axis..go in X-Y-Z axis alone..come back n resume time axis..any1 able to imagine things like this without blindly followng theorems and equations??

    years back..Michael faraday was abused a lot when he proposed his discoveries abt electricity , coz the rulers were nt aware of it's use...rt now, imagine a minute without having electric supply.. thats how paradigm shifts..
    Look at the Lorentz transformations and time dilation. Superluminal speed does not get you negative time dilation, it gets you imaginary time dilation.

    There is nothing "blind" about understanding the mathematics of the subject. There is some blind, and dumb, about ignoring it.

    Imagination is not fantasy. Vision is not hallucination. An open mind is not an empty head.
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    Quote Originally Posted by eldhosepg
    Please explain this. If my understanding is correct, You say that we see conditions of 1 billion years ago. That means we dont know about the present condition at all.
    Well, it's possible for us to make educated guesses about the present condition of a distant celestial body like a star. Astronomers know a lot about how stars age. They can use extrapolation to determine what's going on with that star at present.

    Let me provide an example. Our sun will go nova in about 5 billion years. If we detect a star like our sun at a distance of 5 billion light years, then it's a good bet that the distant star is now close to the end of its life. It may be exploding in a supernova.

    Closer to home, the images of the other planets in our solar system we see through our telescopes are actually what the planets looked like minutes or even hours in the past. Pluto, for instance, has moved a significant distance along its orbit in the time it has taken the light to reach earth. Nevertheless, thanks to Kepler's Laws of Planetary Motion, we know where Pluto is at present!

    Jagella
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    Quote Originally Posted by MigL
    Sorry, i guess I was kid of vague. What I meant, eldhosepg, is that the 'present' conditions of a galaxy 1 billion light years away, is purely hypothetical as we can never measure any effect from the 'present' of that galaxy. The only valid thing we can talk about is the conditions of said galaxy a billion yrs ago.

    For that matter, as someone else mentioned, the sun we see is the sun of 8 minutes ago. If it goes nova in two minutes, we won't know about it ( and acoording to relativity, cannot know about it ) for another six minutes.
    Can't we make predictions about galaxies from what we know about their evolution? I believe some astronomers can use computer simulations to determine how galaxies change over their lifetimes. Couldn't we just plug that galaxy into a simulation and see what it changes into in 1 billion years? That way we can have a good idea of what it's like at present.

    And for that matter, I believe the sun going nova would not be a sudden event. We could see telltale signs that it is ready to explode long before it goes nova, could we not?

    Jagella
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    Quote Originally Posted by Jagella
    And for that matter, I believe the sun going nova would not be a sudden event. We could see telltale signs that it is ready to explode long before it goes nova, could we not?
    Since nova are the result of material from a close binary falling onto the surface of a white dwarf that forms one of the pair, I see little risk of the sun going nova.

    And suprenovae only occur with star much more massive than the sun, so no risk there either.
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    [quote="Jagella"]
    Quote Originally Posted by eldhosepg
    Let me provide an example. Our sun will go nova in about 5 billion years. If we detect a star like our sun at a distance of 5 billion light years, then it's a good bet that the distant star is now close to the end of its life. It may be exploding in a supernova.


    Jagella
    Sorry, that's not correct. The sun is not massive enough to nova or supernova. It will expand as a red giant, expel much of it's mass, then contract into a smaller cinder that will cool for the rest of the existance of the Universe.

    Edit: Sorry Ophiolite, didn't see your post before I wrote mine. You beat me by a few minutes.
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  18. #17  
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    Quote Originally Posted by Jagella
    And for that matter, I believe the sun going nova would not be a sudden event. We could see telltale signs that it is ready to explode long before it goes nova, could we not?
    Quote Originally Posted by Ophiolite
    [Since nova are the result of material from a close binary falling onto the surface of a white dwarf that forms one of the pair, I see little risk of the sun going nova.

    And suprenovae only occur with star much more massive than the sun, so no risk there either.
    and
    Quote Originally Posted by MeteorWayne
    Sorry, that's not correct. The sun is not massive enough to nova or supernova. It will expand as a red giant, expel much of it's mass, then contract into a smaller cinder that will cool for the rest of the existance of the Universe.

    Edit: Sorry Ophiolite, didn't see your post before I wrote mine. You beat me by a few minutes.

    Progress !!

    Jagella has moved forward from utterly loopy to merely wrong.
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