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Thread: Light from distant galaxies: How?

  1. #1 Light from distant galaxies: How? 
    Administrator KALSTER's Avatar
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    How is it that we can see an object that is 10 BY + away from us? If you draw lines to represent the paths of the photons, a very small percentage would reach us. I mean only photons with a very narrow margin of error would be able to reach us, wouldn't it? So the photon density should be extremely small.


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  3. #2 Re: Light from distant galaxies: How? 
    Moderator Moderator Janus's Avatar
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    Quote Originally Posted by KALSTER
    How is it that we can see an object that is 10 BY + away from us? If you draw lines to represent the paths of the photons, a very small percentage would reach us. I mean only photons with a very narrow margin of error would be able to reach us, wouldn't it? So the photon density should be extremely small.
    We use very long exposure times. The Hubble can spend weeks or months pointed at a given area, slowly collecting photons a few at a time to form an image of a distant object.


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    I would imagine that the telescope would have to be VERY steady in relation to the object studied. How does it track (if that is the correct term)? How large a part do computers play in sharpening, filtering, contrasting and such to get a good picture relative to technology of a few decades ago? How do you distinguish between imperfections and dust and digital noise and the real deal?
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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  5. #4 Re: Light from distant galaxies: How? 
    Forum Professor sunshinewarrior's Avatar
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    Quote Originally Posted by KALSTER
    So the photon density should be extremely small.
    That's what I'd assume too. But given that the dark adapted eye can detect, on occasion, even a single photon, I presume modern radio telescopes don't so too badly.
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    The universe never ceases to amaze .
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    The Hubble Space Telescope, orbits the planet. It has no ability to increase or decrease speeds in these orbits. The James Webb, hoped to launch in 2013, will be a million miles out in space and have a two tennis court size shield to dim the light effects from our sun...by he way, the Hubble, could ends its life (orbit) in 2011, if estimates are correct.

    Time exposures in seconds, is what gives, the said images from distant objects. The most distant observation to date, 2004. I am saying 'said', because in the 1995 and 2004 observations of deep field images are 'artist creations' of whats suggest the collected light could be.

    Photons collected from distant objects (13 bly) are received at a rate of ONE PHOTON per minute, compared to millions per minute from near by galaxy.

    The 2004 observations were taken during 400 orbits, 2 exposures per orbit with an average 17 seconds per. The 800 exposures produced 11.3 days of viewing time and a suggested 10k galaxy.

    This summery was taken from; Hubble Deepest View, News Release
    STScl-2004-7...

    One point, I have tried to make over years, has been very simple; What photons we receive from our sun, compared to what is received from near by light source and that of 10-13 billion light years out continually decreases and logically at some point, we could not receive enough to determine anything. I would also suggest, none of this has to do with curved space or gravity effects on energy and throw in dark energy. Any of these factors, if true, would make any observations from distant objects, unachievable, IMO.

    In arguing opposition to BBT, light sources did not exist pre BB is not the why we cannot observe, but that light waves received are limited and should be non-existent at some point for observation. The James Webb, will be equipped to observe nearly all energy from a sources, which could reveal the consistency of energy/source in the Universe I feel is probable. This only means energy received from all the sources required to produce that energy is/was consistent (must have existed to produce) in those years the JW is effective. In all cases however, we will always be limited to receiving ANY energy from a determinable source, for lack of photons from a particular source.
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    Good post :wink: . So if I am understanding this correctly, the 13.7 billion LY limit is not necessarily (or at all) a result of the age of the universe, but as a direct result of the sheer distance involved? So then how was the age of the universe arrived at? By reversing expansion? Was the expansion rate determined by comparing the relative red shift of distant galaxies? I am starting to think that if the 13.7 billion LY observational limit is a direct result of the distance, that if the age of the universe is independantly calculated to be 13.7 billion years, that it would be an extraordinary coincidence :?
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    The age of the Universe, in 1916 (when Einstein determined relativity to it) was thought to be 3- 4 BYO, based on observable space (known universe). Later it was revised up, as newer telescopes found light further out and now rest at 14.2 (NASA's latest estimate 2007). BB proponents have accepted the Universe may be much larger, suggesting 156 BLY across at this time, but that what we can see at distances are what was, after that expansion began, not what is today. That is even under BBT, the Universe in todays time is much like it is near by. Opponents of BB, especially during these times have suggested that limited power to observe and that regardless of size, our limited ability to observe has given a distorted view of what actually was 8-10 or those 14.2 billion years ago.

    There is a recorded history (images) of these observances, as technology improved. What was said to be 5 billion years ago in about 1950, is very much like what Hubble has observed in both 1995 and 2004. I can only conclude as a guess, our ability to observe will increase to these distances
    with clarity, but to the limits of what can be observed. Remember, we are limited to short exposures today. James Webb or future telescopes, could well make exposures into hours, even days, giving unimaginable clarity to objects that existed 10-15 or 30 Billion years ago. Any image of a formed galaxy over 10 billion ly in distance, will make BBT suggest an older universe, which would keep that theory alive. If they focus on an area thought to pre exist BB and find light, with those long exposures, will also just increase that said Universal age.

    As said in my last post, consistence of energy (all) should not be the same, even if calculated to distance. Something has to create energy and many forms should not have existed, if the Universe formed from an expansion 14.2 or 20BY ago.
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    Wow,

    That is the simplest explanation of astrophotography I have ever heard. Simple and to the point and easy to understand.

    I love it we people put out the facts and do not cloud the issue with mainstream theory. Theory is good but it is just that theory.

    Imagine what we will see when we are able to block out the photon noise from the sun.

    Vincent
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    You fail to see the forest from the trees, the sun from the stars.

    You talk about stars, and what is emitted, no?

    When you see what's around you with amazing clarity, you merely see a reflection, with all things considered, from the light of this sun: this is how our mind, our perception, has been conditioned to observe things, "reflected light"......our condition of evolution, until recently, it would seem.

    When we see the stars, the respect we owe to our perception is that we see, ideally, an endless reflection of the light of our own sun.

    (did any of that make sense?)

    .......unless of course we were brought up by star light itself, prove me wrong.
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  12. #11  
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    Quote Originally Posted by theQuestIsNotOver
    You fail to see the forest from the trees, the sun from the stars.

    You talk about stars, and what is emitted, no?

    When you see what's around you with amazing clarity, you merely see a reflection, with all things considered, from the light of this sun: this is how our mind, our perception, has been conditioned to observe things, "reflected light"......our condition of evolution, until recently, it would seem.

    When we see the stars, the respect we owe to our perception is that we see, ideally, an endless reflection of the light of our own sun.

    (did any of that make sense?)
    Yes, I understand what your saying but its a bit more complicated.

    Visual conception is from eye/brain reaction to energy as it hits an object.
    It is limited to to certain frequencies/wavelengths of energy and varies from one person to another (minor) and to larger degrees in different species. Cheetah's, Eagles and some species see clearly to distances, probably through long periods of evolution, where mankind is limited, possibly from recently evolving. Mankind however has invented means to substitute and enhance perception, giving us the ability to observe what no man will ever see directly. Eye glasses, lens to many forms of telescopes.

    Energy is a product created by mass. Once spent from a source its an independent product, until absorbed by mass and all said to move through a vacuum at C speed. (186,200 m/p/s). What our telescopes see or what we see in the night sky are these by products, not the actual objects. In fact a good share, may no longer exist.

    "When we see...an endless reflection from our own sun", is extremely mis-leading if your inferring our suns energy is reflecting light (as it does off the moon) off those distant objects. I'll pretend this was not the intent, but explain one point. Even the most devoted theologian, would admit energy is limited to travel time. They would also admit most objects are at rather long distances to the Earth and that our sun is probably less than five billion yeas old. Any sense of math would not support such a notion, nor would any rational understanding emitted energy allow for such a theory...
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    Quote Originally Posted by jackson33
    Quote Originally Posted by theQuestIsNotOver
    You fail to see the forest from the trees, the sun from the stars.

    You talk about stars, and what is emitted, no?

    When you see what's around you with amazing clarity, you merely see a reflection, with all things considered, from the light of this sun: this is how our mind, our perception, has been conditioned to observe things, "reflected light"......our condition of evolution, until recently, it would seem.

    When we see the stars, the respect we owe to our perception is that we see, ideally, an endless reflection of the light of our own sun.

    (did any of that make sense?)
    Yes, I understand what your saying but its a bit more complicated.......

    "When we see...an endless reflection from our own sun", is extremely mis-leading if your inferring our suns energy is reflecting light (as it does off the moon) off those distant objects. I'll pretend this was not the intent, but explain one point. Even the most devoted theologian, would admit energy is limited to travel time. They would also admit most objects are at rather long distances to the Earth and that our sun is probably less than five billion yeas old. Any sense of math would not support such a notion, nor would any rational understanding emitted energy allow for such a theory...

    I am not inferring that the star light is actually our sun reflected off distant objects. The point I was making was that when I stand back from this planet and look at it, all I see is reflected light. If I pointed a telescope from space at Earth, all I see is reflected light from the sun. If I pointed the hubble at planet earth, I would see amazing clarity, but all of what I see would be reflected light. Everything. I then think about the stars and consider that the beauty and clarity is similar, yet that what I see of earth is more brilliant than the stars, and it is all reflected light.

    I wonder though, in using a computer simulation, what a theoretical reality would look like, the one you thought I proposed, one where the light from a strong source is endlessly reflected in a type of solar system mirror. Let's say there is a type of very distant mirror beyond the radius of pluto, and light is somehow bent back to us. Well, I wonder what that would look like, as a computer simulation, while also appreciating that the refelcted light itself would then become re-reflected, and so on and so forth. Do you know of any such computer simulations? I am guessing a type of fractal pattern of point sources of light would develop, an eerie looking Universe. What do you think? Surely the physics astronomical community has considered this?

    What if we could prove that our position in the universe represents a type of "balanced" position of reflected light and emanated light, theoretical reflected light that also happens to mimic emanated light presumably from stars. Would that be a unique reference to harbor life?
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    When looking at earth from near by space, your mind (eye/brain) is seeing a result of energy on matter. Its really has nothing to do reflection, such as a mirror. For instance a dog, would see a black & white circle with virtually no clarity. The sun which appears orangeish surrounded by blue, from space appears as a white object surrounded by black as does the moon or any object visible in space. A telescope picking up an object, in our solar system, relays a white object, which is solar energy acting on that objects mass. Energy produced by all mass (other than solar), and all mass produces energy, has no luminosity to our limited visual capacity.

    If other life forms exist, I think they do and some intelligent, then there systems for recognition (sight) may and are likely not like ours. IMO, ours could be from a lack of evolving OR more important a rejected mutation which would cause all kinds of problems if sight were to all or much more energy.

    You inadvertently, have suggested an idea, which could be more effective than say our 'radio wave' attempts to look for life elsewhere. Some kind of relay of solar energy from space into space, with a pulsating pattern of lens and magnified into concentrated beam. Some how this could be configured to span per sequence of the pattern cycle. In reverse, if life elsewhere did that, in frequencies above and/or below their sight, we should be able to pick up, much easier than radio waves. A mirror reflection alone, again to our limited technology, would get lost in the maze of light energy, generally around all galaxy, likely homes to civilizations. There are many working on laser beams for such things as transporting matter, to accelerating sails attached to a craft, so some of this may be in the planning, but I have only had a few minutes to come up with an idea, incorporating your thoughts...
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  15. #14  
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    Interesting as the preceding discussions are the casual reader should be aware that Jackson and theQuestisNotOver hold wholly non-standard views on the nature of the Universe.
    Absorb their wrtings with caution.

    And Vincent, stating "Theory is good but it is just that theory." makes you sound like a creationist. In science it doesn't get any better than theory, so to make a remark like that suggests you haven't quite grasped that important distinction between theory as used in everyday speech and theory as used in science.
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  16. #15  
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    Quote Originally Posted by Ophiolite
    Interesting as the preceding discussions are the casual reader should be aware that Jackson and theQuestisNotOver hold wholly non-standard views on the nature of the Universe.
    Absorb their writings with caution.
    "wholly"???....would you explain. A rather strange observation, from a person who thinks our existence came by chance from some distant galaxy....even creationism makes more sense.....IMO.

    Pendragon put it best..'Talk to people, don't talk about them'.

    Visual perception is a much mis-understood concept...

    Even you have said, intelligent life COULD exist elsewhere...

    My reply to 'The Quest', was on a hypothetical search for that life in distant places, other than say 'making radio contact' ie, searching for irregularities which intelligence could pass on. Just what is the STANDARD on that issue...
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    And Vincent, stating "Theory is good but it is just that theory." makes you
    sound like a creationist. In science it doesn't get any better than theory, so to make a remark like that suggests you haven't quite grasped that important distinction between theory as used in everyday speech and theory as used in science.


    Good to have a response. I should have said mainstream theory. I have a problem with visible data not matching the current model.

    If we get to the part were Goldie locks meets the bears, they should be some bears.

    That’s right

    Vincent
























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  18. #17  
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    The reality is those boys were discussing Cosmic images. They keep changing. As we see further the world changes.

    How many photons you need to understand?

    Lets make the exposure longer. Everything changes. Artwork

    Vincent
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    Looks like it is exposure time. I is a scientist lets get down. Photons what a concept.

    Vincent
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    Looks like it is exposure time. I is a scientist lets get down. Photons what a concept.

    Vincent
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