6 ms·

Oh, I can prove it with evidence. The only thing that can change the direction of motion of a particle is a force. Photons have zero mass and zero charge, there

Oh, I can prove it with evidence. The only thing that can change the direction of motion of a particle is a force. Photons have zero mass and zero charge, therefore no force (including gravity) can act on light (strong and weak interactions are not applicable here). Therefore light will always travel in a straight line. When light appears to 'bend' it is not because the light itself changed direction in its reference frame, but because the space the light is traveling thru in is warped. Any physics professor will understand precisely what i'm saying, and all agree. Someone who has only read a few articles online will not. I've understood this since 1986. I'm very old and wise you little child.

lutusp 10y ago
> The only thing that can change the direction of motion of a particle is a force. Quite false. You're overlooking the fact that photons are the carrier particle of the electromagnetic field, which takes the form of waves in space -- waves that change direction without the application of forces. An optical lens changes the direction of photons without exerting a force. So does curved spacetime. These are examples of hundreds of things about physics that contradict your outlook. Also, masses respond to gravity by changing direction, and gravity is not a force: http://curious.astro.cornell.edu/physics/140-physics/the-theory-of-relativity/general-relativity/1059-if-gravity-isn-t-a-force-how-does-it-accelerate-objects-advanced http://curious.astro.cornell.edu/physics/140-physics/the-the... Again, at 1.5 times the radius of a black hole, looking tangentially, you would see the back of your own head. So even in this local frame of reference, light has taken a curved path along with curved spacetime. In other frames of reference, light is obviously not traveling in straight lines. In fact, it can be argued that light never travels in straight lines -- that would be true only in a universe without any mass at all. You could argue that water always travels along straight lines inside a pipe and never changes direction, and in the case of the pipe itself changing direction, you could argue that the water is always traveling in a straight line from its own perspective inside the curved pipe, but having said that, people would see your ideas for what they are. > Any physics professor will understand precisely what i'm saying, and all agree. You appear to have forgotten I have already disproven this with my John Wheeler quote: "Mass tells space-time how to curve, and space-time tells mass how to move." As with masses, so with photons. If masses could travel at c, they would take the exact path photons do -- curved ones.
- ClayFerguson 10y ago
  If you're calling light interactions with other particles (like mirrors, lenses, or even edges of things) your 'bending' then that is a complete 'context switch' you have made, and is not the kind of light bending we are discussing. I've been talking about light freely traveling thru open space passing thru any force field you can imaging. Period. Full stop. It never bends. The space bends. BTW, none of those 'waves in space' (you mentioned) ever involve an actual anything changing its direction of propagation thru space. That is a 'classical view' of it that is completely wrong. The wave-equations of quantum mechanics are indeed sinusoidal, but there is nothing that traverses a sinusoidal path. It's merely an oscillating 'potential'. It tells you where you are likely to find a particle at any given time, in terms of the probability of that location, but even if you do look and FIND the particle there, it doesn't mean the space from its last position was actually 'traveled thru'. So trying to use duality of light as an example of light changing direction is wrong from about 10 different ways I could explain it.
  - lutusp 10y ago
    Rhetoric is not physics. If you should ever learn physics, post again.
    - ClayFerguson 10y ago
      ...and this from a guy who thinks the wave-function of light is describing a path of motion.
    - dang 10y ago
      We've banned that account—for obvious reasons, given how it behaved in this thread. Unfortunately, several of your comments were also uncivil. Please err on the side of civility when posting here. Also, please don't engage in flamewars on HN. A good-faith discussion about how someone is wrong is fine, but at the point when good faith dries up, such discussions become tedious tit-for-tats, which amounts to mutual trolling. We definitely don't want those kinds of threads here.

lutusp 10y ago

> The only thing that can change the direction of motion of a particle is a force. Quite false. You're overlooking the fact that photons are the carrier particle of the electromagnetic field, which takes the form of waves in space -- waves that change direction without the application of forces. An optical lens changes the direction of photons without exerting a force. So does curved spacetime. These are examples of hundreds of things about physics that contradict your outlook. Also, masses respond to gravity by changing direction, and gravity is not a force: http://curious.astro.cornell.edu/physics/140-physics/the-theory-of-relativity/general-relativity/1059-if-gravity-isn-t-a-force-how-does-it-accelerate-objects-advanced http://curious.astro.cornell.edu/physics/140-physics/the-the... Again, at 1.5 times the radius of a black hole, looking tangentially, you would see the back of your own head. So even in this local frame of reference, light has taken a curved path along with curved spacetime. In other frames of reference, light is obviously not traveling in straight lines. In fact, it can be argued that light never travels in straight lines -- that would be true only in a universe without any mass at all. You could argue that water always travels along straight lines inside a pipe and never changes direction, and in the case of the pipe itself changing direction, you could argue that the water is always traveling in a straight line from its own perspective inside the curved pipe, but having said that, people would see your ideas for what they are. > Any physics professor will understand precisely what i'm saying, and all agree. You appear to have forgotten I have already disproven this with my John Wheeler quote: "Mass tells space-time how to curve, and space-time tells mass how to move." As with masses, so with photons. If masses could travel at c, they would take the exact path photons do -- curved ones.

ClayFerguson 10y ago
If you're calling light interactions with other particles (like mirrors, lenses, or even edges of things) your 'bending' then that is a complete 'context switch' you have made, and is not the kind of light bending we are discussing. I've been talking about light freely traveling thru open space passing thru any force field you can imaging. Period. Full stop. It never bends. The space bends. BTW, none of those 'waves in space' (you mentioned) ever involve an actual anything changing its direction of propagation thru space. That is a 'classical view' of it that is completely wrong. The wave-equations of quantum mechanics are indeed sinusoidal, but there is nothing that traverses a sinusoidal path. It's merely an oscillating 'potential'. It tells you where you are likely to find a particle at any given time, in terms of the probability of that location, but even if you do look and FIND the particle there, it doesn't mean the space from its last position was actually 'traveled thru'. So trying to use duality of light as an example of light changing direction is wrong from about 10 different ways I could explain it.
- lutusp 10y ago
  Rhetoric is not physics. If you should ever learn physics, post again.
  - ClayFerguson 10y ago
    ...and this from a guy who thinks the wave-function of light is describing a path of motion.
  - dang 10y ago
    We've banned that account—for obvious reasons, given how it behaved in this thread. Unfortunately, several of your comments were also uncivil. Please err on the side of civility when posting here. Also, please don't engage in flamewars on HN. A good-faith discussion about how someone is wrong is fine, but at the point when good faith dries up, such discussions become tedious tit-for-tats, which amounts to mutual trolling. We definitely don't want those kinds of threads here.