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Thanks for answering guys, pleased to meet you! Hi Mathew, do you mean that, to your opinion, light is not bent by gravitation?
Hi Mathew, do you mean that, to your opinion, light is not bent by gravitation?
....you will see that the two light rays travel in the same direction once they start traveling nearby together at the sun's perimeter. Being independent from the body where they come from at this point in space and time, do you see any reason why they should experiment a different bending?
in my opinion, based on experimental evidence, gravity has no effect on electromagnetic waves
The light rays you show in your diagram would be affected differently because they spend different amounts of time in the gravity field.
However, in principle it is possible to imagine 2 rays that do end up parallel but there are some issues to consider. On the sun the effect is exceedingly small
if you use a neutron star as your example it is much easier to consider that your diagram would be correct
... Anybody thinks that the rays coming from the sun should also be curved by the gravitation of the sun?
One minor problem with this argument is that it assumes that a photon emitted near the limb of the solar disk could reliably reach the Earth. The light is emitted from the visible disk of the Sun because the temperature of the Sun is sufficiently high; but at these temperatures, the Sun's atmosphere is effectively opaque to visible light.
As an example, a neutron star would be more difficult to imagine than the sun, because it doesn't produce visible light and because it has no measurable diameter.
Quote from: Le RepteuxAs an example, a neutron star would be more difficult to imagine than the sun, because it doesn't produce visible light and because it has no measurable diameter.I think that this latter comment was referring to a black hole, rather than a neutron star.A newbielink:http://en.wikipedia.org/wiki/Neutron_star#Structure [nonactive] has a definite surface, and a very compressed atmosphere (perhaps μm thick).They are very hot (at least initially), and will produce visible light as well as X-Rays.
Sun will appear very slightly bigger because of gravitational-lensing ... newbielink:https://van.physics.illinois.edu/QA/listing.php?id=21717&t=gravitational-lensing-of-the-sun [nonactive]
Light refraction of plasma medium is a conventionally accepted physical phenomena...Example: newbielink:http://journals.aps.org/pr/abstract/10.1103/PhysRev.162.117 [nonactive]Or, is the San disobeying the low of refraction?
Light refraction of plasma medium is a conventionally accepted physical phenomena...
The way I understand it, gravitation from the sun during an eclipse is affecting the position of all the stars that we observe at that moment, which means that most of them appear far away from the sun's perimeter, so that their light doesn't have to go through the sun's atmosphere to be bent. If it is so, then refraction wouldn't affect those rays, so how would you explain their bending?
...the refractive index of a plasma is frequency dependent, but observations show the bending to be frequency independent.
Good observation Collin!
You mean that you observed a refraction phenomenon when the source was near the sun? That some of the frequencies vanished?
Rainbow effect is internal to planets atmosphere just like we see at sunset...
And what about my proposition that the rays might get curved the same way aberration curves them, but by the acceleration of the earth towards the sun instead of its inertial motion around it?
To better understand what I mean by that, you may refer to my thread on inertial motion:http://www.thenakedscientists.com/forum/index.php?topic=53171.msg467891#msg467891
Interesting idea though.
However, I think you'll find that the rays should be bent towards the center, but the effect is so small that they still reach us here on earth causing the sun to appear infinitesimally larger.
I think I found a way to test my point!If the sun's light was really curved by its own gravity, it follows that a spiral galaxy light would also be, which means that its apparent diameter would also look larger than it really is. In the case of galaxies, the measure of their rotational speed made at different heights would thus be attributed to larger heights than the real ones, which could explain the lack of gravitational pull that we attribute to Black Matter. Anybody wants to help me with the maths?
let's work out an example and see if this is even feasible. We'll assume a galaxy 100,000 light years across with a mass of 100,000,000,000 solar masses which is 1 billion light years away.The light from a source behind this galaxy and just skimming its edge, would by gravitational lensing be deflected by 0.258 sec of arc. Since 1/2 of this deflection occurs on the inbound path, the most we can expect light coming from a star at the edge to be bent on its outward path to us is 0.129 sec of arc.At a distance of 1 billion light years, this equates to an apparent displacement of ~625 light years ( meaning the galaxy would appear to be 50,625 light years in radius instead of 50,000.)Calculating the difference in orbital speed at 50,000 vs. 50625 light years produces orbital velocities of 167 km/sec vs. 168 km/sec.If we work out how much extra mass it would take to make that 1 km/sec difference at a fixed radius of 50625 light years, it works out to a difference of ~1.2%, or far short of the amount of dark matter needed to make up for the missing mass according to the actual orbital velocities we measure.In addition, gravitational lensing in fact gives us additional evidence for dark matter. Because of the extra mass due to DM, the light passing galaxies bends more than and differently from what we would expect from just the matter we see.On top of that, we have the case of the Bullet Cluster, in which dark matter has been "knocked loose" from the visible matter in a collision between galaxy clusters. In this situation we see gravitational lensing of objects behind the cluster where there is no visible matter to cause it.Galaxy rotation curves may have set us on the road to dark matter, but there has been a great deal of other supporting evidence uncovered since the first step on that path.
Yes, in my opinion, based on experimental evidence, gravity has no effect on electromagnetic waves, photons, magnetic fields and electric fields...But it does affect the frequency of all oscillating structures including pendulum and atomic clocks...
Quote from: mathew_orman on 28/09/2015 08:16:12Yes, in my opinion, based on experimental evidence, gravity has no effect on electromagnetic waves, photons, magnetic fields and electric fields...But it does affect the frequency of all oscillating structures including pendulum and atomic clocks...What? Electromagnetic waves ARE an oscillation. A photon is comprised of an electric component and a magnetic component, both of which oscillate. Magnetic and electric fields are actually comprised of photons.