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Thread: Light, Gravity, and that Einstein guy

  1. #1 Light, Gravity, and that Einstein guy 
    Forum Freshman FractalMind's Avatar
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    Firstly, I don't believe in Einstein's theories of relativity. However, it does explain some things, like the way light behaves.

    Einstein says that a mass distorts/dents spacetime, right? The mass like a bowling ball denting a bed sheet. objects that pass into this dent while moving by roll along the contour of the spacetime sheet and change course/collide with the other object; aka gravity.

    I don't really believe too much in time as a universal constant or a material 'dimension' which destroys the concept Einstein's of spacetime. The only thing left is light. If light has NO MASS it should not be influenced by gravity's force! Yet it does sucumb to gravity around large sources of the force like the sun and black holes (hence the name).

    Just for a sec pretend you don't agree with Einstein and humor me please. Or maybe you don't as is. What else could explain this oddity?


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    Why would light not have mass? I mean, regardless of how small it is, its displacement has to account for something. And, I am skeptical about the THEORY that space time is like a sheet which can be influenced by matter. I do not think there needs to be a form of universal scale; like the way we look at gravity on earth. I see space as a void, and that is all. I think that gravity, rather than bending space, is just a field of un-nameable particles that grip the objects in their circulating field, and spin them around due to the object of mass spinning. Gravity is the anomaly, not space. Space is the neutral state of the universe, gravity is just an odd compilation of physics that present themselves in that form.

    Hell, I could be wrong, but it only seems logical.


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    Quote Originally Posted by Cold Fusion
    Why would light not have mass? I mean, regardless of how small it is, its displacement has to account for something. And, I am skeptical about the THEORY that space time is like a sheet which can be influenced by matter. I do not think there needs to be a form of universal scale; like the way we look at gravity on earth. I see space as a void, and that is all. I think that gravity, rather than bending space, is just a field of un-nameable particles that grip the objects in their circulating field, and spin them around due to the object of mass spinning. Gravity is the anomaly, not space. Space is the neutral state of the universe, gravity is just an odd compilation of physics that present themselves in that form.

    Hell, I could be wrong, but it only seems logical.
    That's pretty much what I was getting at. The point, though, is that light (photon) is typically regarded as something without mass because it would theoretically take an infinite amount of energy to propel to the speed of light. Anyway, IF light doesn't have mass (as said, it is a common thought agmonst some of the regarded thinkers), then WHY does gravity effect it without a bending of 'spacetime'? That's what bothers me. I would like to know if light has mass or if gravity is not like Einstein's idea.

    Like I pointedly said, I do not believe spacetime to be 'real' either. I think it was an idea that merely sufficed to explain a few things better than other ideas at the time. Needless to say, I don't follow Einstein here.
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    Why would there be energy needed to propel it? From the quantum theory reaction, you could see the photon being given Vo at that instant, and that there is just very little in the universe that cause resistance to it. But what about back round radiation in space? For things like the air, light is in fact reacting, hence the blue sky, but wouldn't the radiation in space cause some resistance to light?
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    Quote Originally Posted by FractalMind
    Quote Originally Posted by Cold Fusion
    Why would light not have mass? I mean, regardless of how small it is, its displacement has to account for something. And, I am skeptical about the THEORY that space time is like a sheet which can be influenced by matter. I do not think there needs to be a form of universal scale; like the way we look at gravity on earth. I see space as a void, and that is all. I think that gravity, rather than bending space, is just a field of un-nameable particles that grip the objects in their circulating field, and spin them around due to the object of mass spinning. Gravity is the anomaly, not space. Space is the neutral state of the universe, gravity is just an odd compilation of physics that present themselves in that form.

    Hell, I could be wrong, but it only seems logical.
    That's pretty much what I was getting at. The point, though, is that light (photon) is typically regarded as something without mass because it would theoretically take an infinite amount of energy to propel to the speed of light. Anyway, IF light doesn't have mass (as said, it is a common thought agmonst some of the regarded thinkers), then WHY does gravity effect it without a bending of 'spacetime'? That's what bothers me. I would like to know if light has mass or if gravity is not like Einstein's idea.

    Like I pointedly said, I do not believe spacetime to be 'real' either. I think it was an idea that merely sufficed to explain a few things better than other ideas at the time. Needless to say, I don't follow Einstein here.
    Hi Fractalmind

    I hope you see the problem for 'real' physicists here? You claim, for whatever reason, that you do not 'believe in' what Einstein says (as though it were a matter of faith) and, having decided you will not listen to the best, in fact only, explanation that we have (empirically borne out by observation) for the curvature of light around massive bodies, you then proceed to say that you want an explanation, any explanation but the one we use every day.

    You are hardly likely to get a scientist to respond to this one. Perhaps you are trying to make a point about creativity or your arguments from personal incredulity or some such. If, however, that is the case, then this thread belongs in the pseudoscience forum.

    Regards

    shanks
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  7. #6 Re: Light, Gravity, and that Einstein guy 
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    Quote Originally Posted by FractalMind
    Firstly, I don't believe in Einstein's theories of relativity. However, it does explain some things, like the way light behaves.
    Or the way time slows down as velocity increases, which has been experimentally demonstrated many times.
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  8. #7 Re: Light, Gravity, and that Einstein guy 
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    Quote Originally Posted by Scifor Refugee
    Quote Originally Posted by FractalMind
    Firstly, I don't believe in Einstein's theories of relativity. However, it does explain some things, like the way light behaves.
    Or the way time slows down as velocity increases, which has been experimentally demonstrated many times.
    What, you mean on something as speedy as an airliner? Man, I'm sorry, but the way I see time is merely as a concept to understand and patternize motions. Atomic clocks run by observing the radiation decay of atoms. Though it finely segements the actions of the radiated particles, it is still dependant on motion. I think a millionth of a nano second hardly counts for time 'slowing down'. That time should be more like the margin of error in the consistancy of the clock.
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  9. #8  
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    Well hi Sunshinewarrio,

    So it is typically accepted. Yes, I agree with that. Does it make it right? You decide *cough*. Ask me how Einstein came to his conclusion or look it up yourself. Im hardly the first person to question Einstein's ideas. Einstein's ideas currently don't co-exist with quantum mechanics so gemme a break will ya?
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  10. #9 Re: Light, Gravity, and that Einstein guy 
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    Quote Originally Posted by FractalMind
    Atomic clocks run by observing the radiation decay of atoms. Though it finely segements the actions of the radiated particles, it is still dependant on motion. I think a millionth of a nano second hardly counts for time 'slowing down'. That time should be more like the margin of error in the consistancy of the clock.
    1. A millionth of a nano second definitely counts as time slowing down if the margin of error in the clock your using is well below a nano second.

    2. Relativity theory is necessary for GPS systems to work because the satellites are further away from the earth's gravity creating a time difference.

    3. Most units like the second are now defined in terms of some natural event to help maintain consistency.
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  11. #10 Re: Light, Gravity, and that Einstein guy 
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    Quote Originally Posted by FractalMind
    Firstly, I don't believe in Einstein's theories of relativity.
    Actually, you have no choice. Apart from the rather nice fact that the math all works out, there are countless experiments that prove the two theories
    Einstein says that a mass distorts/dents spacetime, right?
    Forget Einstein, the math says it!

    I don't really believe too much in time as a universal constant
    Good, I don't think anyone else does.
    If light has NO MASS it should not be influenced by gravity's force! Yet it does succumb to gravity around large sources of the force like the sun and black holes (hence the name).
    Well, first be careful talking about "gravity's force", this is where your problem lies.

    Second, the fact that light has no mass (within experimental error), and yet can have it's path deflected by a massive stellar object, as shown by experiment, simply proves that light's path is influenced by something other than the "gravitational force" of that object.

    Einstein's field equations reveal that this is spacetime curvature in the vicinity of a massive stellar object. It all works. Get used to it.
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  12. #11 Re: Light, Gravity, and that Einstein guy 
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    Quote Originally Posted by FractalMind
    What, you mean on something as speedy as an airliner? Man, I'm sorry, but the way I see time is merely as a concept to understand and patternize motions. Atomic clocks run by observing the radiation decay of atoms.
    No, that's not how atomic clocks work.

    And as someone else pointed out, they have to make a significant time correction for GPS satellites because the satellites are traveling so quickly. It’s kind of a strange coincidence that the correction that gives you good GPS coordinates happens to work out to exactly what is predicted by relativity, isn’t it?
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  13. #12  
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    Wow, ok. So I come to a conclusion based on what I know and I get proverbially beaten for it. It's one thing to give one's take on something. It's another to present it as the absolute truth and those without it are morons.

    So GPSs need to be corrected by the time difference. I never heard of such a thing. Never. Doesn't mean I won't investigate this and think you are all morons (like you treat me), just means I was without any knowledge that such a notion even existed. Pardon an inquisitive mind. For Pete's sake, does everyone here think they can verbally stomp anyone just because their existance here is merely text?

    Alright, you guys obviously are fierce proponents of spacetime. What is it composed of? Is time physical if it can alter light's trajectory as water in a glass does? And how does one come to light having no mass when it obviously posseses momentum? Solar sail's anyone?

    Explain please, and please do so with tact. I believe that those in possesion of knowledge are smart enough to compile a tactful reply. Did I offend you guys or something? If so, Im sorry and that wasn't my intentions. I MERELY stated my stance scientifically. I NEVER infringed on anyone's intelligence but my own.
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    I don't think I said anything which tore you to shreds at least that wasn't my intention. However, it was my intention to show you that relativity theory is backed up by many different experiments of which the easiest to understand is the GPS example.

    I have no problem with anyone questioning commonly accepted theories ( i honestly think it is what helps keep the best theories at the forefront) but you do not have any evidence for anything you just seem to point out things you do not understand. In contrast relativity theory has the math and experiments to back it up, common sense should tell you something about it is correct.
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    Quote Originally Posted by Supernothing
    I have no problem with anyone questioning commonly accepted theories ( i honestly think it is what helps keep the best theories at the forefront) but you do not have any evidence for anything you just seem to point out things you do not understand. In contrast relativity theory has the math and experiments to back it up, common sense should tell you something about it is correct.
    Ok, as I previously asked, what is spacetime composed of? What medium is there to be bent? Time is relative to the observer and space is a void. It is merely a decuction based on what other objects are doing. No one, to my knowledge, has yet pinned down spacetime. It's very much like the graviton or dark matter. You can only see what 'it' is influencing so far.
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  16. #15  
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    Quote Originally Posted by FractalMind
    Wow, ok. So I come to a conclusion based on what I know and I get proverbially beaten for it. It's one thing to give one's take on something. It's another to present it as the absolute truth and those without it are morons.
    On a quick skim, I see nobody calling you a moron.

    But if you make assertions like this
    I don't believe in Einstein's theories of relativity
    you really ought to have some seriously heavy-duty arguments to back them up.

    Otherwise, I'm sorry, but you won't be taken seriously.

    Now, if you ask a question, that's a different matter....
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    Quote Originally Posted by Guitarist
    Quote Originally Posted by FractalMind
    Wow, ok. So I come to a conclusion based on what I know and I get proverbially beaten for it. It's one thing to give one's take on something. It's another to present it as the absolute truth and those without it are morons.
    On a quick skim, I see nobody calling you a moron.

    But if you make assertions like this
    I don't believe in Einstein's theories of relativity
    you really ought to have some seriously heavy-duty arguments to back them up.

    Otherwise, I'm sorry, but you won't be taken seriously.

    Now, if you ask a question, that's a different matter....
    Look, I made the mistake of assuming there would be more people that would be in the process of questioning spacetime. My ONLY question was to see if gravity could (a) effect things regardless of mass or (b) if light had mass. I asked about it BECAUSE I question Einstein. Maybe this is entirely old news to you folks that have already seen the seasons fly by in these parts, but tis not for me.

    And I never accused anyone of calling me a moron. I simply gather that many are writing in a condecending yet passive way to protect themselves from direct a retort/ goad people on.

    Please. Read the topic if you haven't. It sure seems that many have been offended due to my skeptisism of Einstein and felt upset as they agree with him for what have you. And in their blind irritation just flew over the topic's main point I had attempted to build up to.
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  18. #17  
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    [quote="FractalMind"][quote="Guitarist"]
    Quote Originally Posted by FractalMind
    My ONLY question was to see if gravity could (a) effect things regardless of mass or (b) if light had mass.
    Gravity effects thing regardless of "mass", because gravity also couples with energy.

    A second point that should be made.

    If you assume that light has mass, and that it is just this mass-mass attraction which causes light to bend around the Sun, you can predict how much a particular light ray passing a particular distance from the Sun will bend, by using Newton's laws of gravitation.

    If you, on the other hand, assume that light bends around the Sun due to an altered geometry of spacetime near the star, as per Einstein, you can also make a like prediction.

    The point is that the second assumption leads to a predicted deflection twice that of the first assumption, and when we actually make the measurement, the deflection we measure matches the prediction of the second assumption and not the first.
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    Well, I guess I need to study more lol. I looked for the GPS time alteration, but found nothing on it. I want to see hard evidence. The light trajectory comparison is very interesting and merits further investigation as does the others simply for the sheer amount of people in contast with my limited view.

    Spacetime always seemed like a concept and it was alway always presented to me as such! I feel like an nimrod or fresh from the stone age. If someone could direct me to such evidence (GPS or light trajectory) via link, I would be very happy. I want to know what is right even if it means my original stance is dead wrong.
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  20. #19  
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    Okay. So riddle me this. Light has no 'rest' mass yet it has a motion mass. This motion mass is frequency dependant. UV light has more motion mass due to its energy content whereas visible light is less. Anyway, can motion mass be affected in the same or similar nature to rest mass?

    [EDIT] Here's a quote from a user of a different sci forum:

    In one sense, any definition is just a matter of convention. In practice, though, physicists now use this definition because it is much more convenient. The "relativistic mass" of an object is really just the same as its energy, and there isn't any reason to have another word for energy: "energy" is a perfectly good word. The mass of an object, though, is a fundamental and invariant property, and one for which we do need a word.


    Do you like terminology? If so, could you please give me the definition of "bend"? Imagine an object. Any object... Let's say a remote control. The remote control takes up some spots of the space and others not. It's bend is obvious. That's the definition of "bend". There isn't any geometry which supports limits between space and non space. So, where does the space bend???


    quote "On the other hand, the "relativistic mass" of photons is frequency dependent. UV photons are more energetic than visible photons, and so are more "massive" in this sense, a statement which obscures more than it elucidates."


    I didn't say anything different. The photon's mass is h*f/c^2 , where f is frequency. Apparently, UV photons are more massive than visible photons. I don't think that spacetime bend is less obscure.


    quote "So, a photon's path near a massive object isn't a Newtonian "G" relation; the path curves because the photon is following the straight line/path of curved spacetime."


    I'm sorry, but I'm not ready to erase the whole Physics in order to accept a theory (General Relativity). I read your links and the main argument was that there isn't any experiment where the light is in rest. To be honest, I didn't expect that kind of argument because I can easily reverse it to you. Which experiment proves that the spacetime curves??? If there isn't any experiment, then you shouldn't claim that light curves because of the curved spacetime.

    Between the two answers I think that light curve because of gravity makes less "damage".
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  21. #20  
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    Quote Originally Posted by FractalMind
    I looked for the GPS time alteration, but found nothing on it.
    You must not have looked very hard. I typed in "GPS Relativty" into Google and this was the first this listed:

    http://www.astronomy.ohio-state.edu/...Unit5/gps.html
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  22. #21  
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    The time correction could be due to times zones on earth. Navigation works on basis degrees, but also minutes an seconds as well.

    GPS satellites will be hovering above regions with different clock times, at the same moment.

    Steve
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  23. #22  
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    Quote Originally Posted by Steve Miller
    The time correction could be due to times zones on earth. Navigation works on basis degrees, but also minutes an seconds as well.

    GPS satellites will be hovering above regions with different clock times, at the same moment.

    Steve
    I can't tell if this is supposed to be serious or not.
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  24. #23  
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    The (shortest ) distance of the satellite from earth must be known to determine the position of an other object on earth (with the help of two
    or more other satellites ), I think. It's being like a geostationary position for the satellite in the moment of measuring, anyway.
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  25. #24  
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    You should read the link posted by Janus.
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  26. #25  
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    Yes, I should indeed. Thank you.
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    If gravity bends space, then light would follow that bend, light doesn't directly get effected by gravity, or so my physics teacher says, lol.
    Reinforced Carbon/Carbon <3
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    Gravity is not a force, its just geometry. If a photon didn't have mass it would still be affected by gravity because it is just following the curves of spacetime. Yet the photon has momentum and that means that it might not follow spacetime curves as another object would.

    For example (this is going to sound really strange). Push your finger into your stomach so a curve is made, then get the other finger of you other hand and start from the bottom at the edge of the dent (either the far left or right of it) going up and don't correct yourself when it starts to move., you won't end up at the top of the dent in your stomach, you'll end roughly above the middle of the hole.

    Its the same with Earth. If myself and say Ophiolite were to travel north-he started in America and I stated in the middle east, we would both encounter and bump into one another eventually, what mysterious force brought us together? None, it's just geometry (the Earth is a sphere), as spacetime acts spherical, depending on the mass.
    "If you wish to make an apple pie from scratch, you must first invent the universe". - Carl Sagan
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  29. #28  
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    Quote Originally Posted by Kasc
    If gravity bends space, then light would follow that bend, light doesn't directly get effected by gravity, or so my physics teacher says, lol.
    An interesting and a very good point I think. Doesn't he want to be shot with the next or the
    shooting after?

    lol
    Steve q:-)
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