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we know that the position in which we view the suns light, is not the position that the sun is in at the precise moment that we are viewing the light we view. But if we were able to view the light of the sun instantaneously, would we observe a blue shifted streak from the position that we observe the light of the sun to be in, streaking across the sky to the position that the sun is now in?(given that it all wasn't so damn blindingly bright that is...(chuckle) )
Ok then - let's have a look at our closest light source, the sun, for simplicity.The picture depicted in the link below states itself as vastly out of scale, but it does not state itself as geometrically incorrect. Is it?https://en.m.wikipedia.org/wiki/Gravitational_redshiftThe light will redshift away from the sun, but when it comes under the influence of Earth's gravitational field, it will start to blueshift...And... as both bodies of mass are moving relative to each other, we know that the position in which we view the suns light, is not the position that the sun is in at the precise moment that we are viewing the light we view. But if we were able to view the light of the sun instantaneously, would we observe a blue shifted streak from the position that we observe the light of the sun to be in, streaking across the sky to the position that the sun is now in?(given that it all wasn't so damn blindingly bright that is...(chuckle) )
If you could observe the sun "instantaneously" c would be infinite by definition and no relativistic corrections would apply to anything. And any photon leaving the sun will be red shifted from the point of view of an observer in a lower gravitational field, as shown experimentally by Pound & Rebka.You don't need the sun or any other celestial body to play with red and blue shifts. As you have pointed out, the 57Fe mossbauer photon is entirely adequate for measurements in a terrestrial laboratory.
Where the gravitational field becomes progressively weaker, light will redshift, and where the gravitational field becomes progressively stronger light will blueshift.
Can we agree that there is nothing relativistic about this?
Thank you Puppypower for your dialogue. I think it worth pointing out though, that the purpose of 'this' discussion, at present juncture, is to dissect 'observation' of redshift, via experimental evidence, with respect to parallax method.
If you move your head really fast left and right to keep in time with the animation in the link, the background moves at the same speed, just an observation note for you.
Quote from: Thebox on 21/02/2016 22:38:41If you move your head really fast left and right to keep in time with the animation in the link, the background moves at the same speed, just an observation note for you.And... it is also possible to totally obscure a full moon with your thumb!(That's not Cockney rhyming slang btw )Very good evening to you box!
Quotethe origin of the wavesThis week's show asked about how the direction of the source was determined.The unfortunate answer is that it was not determined very accurately at all. It is constrained to within a total area of about 600 square degrees, which is a fair swathe of the sky (the Moon occupies about a quarter of a square degree). [ Invalid Attachment ] CalculationThe time of arrival at the two detectors differed by about 6.7 ms over a distance of around 5000 km.The source could not have been on a straight line between the two detectors, as that would mean that it exceeded the speed of light, which physicists think is impossible.Assuming that the gravitational wave traveled at the speed of light (as predicted by Einstein), you can deduce that the wave originated at a point in the sky which is at a certain angle to the line joining the detectors. This would inscribe a circle in the sky. Due to uncertainties in the measurements, this circle is about 10 times the width of the Moon in the sky.There was additional (phase?) information which they drew on to further limit it to less than a quarter of this candidate circle around the sky Finding the SourceIt was suggested that astronomers could point their telescopes at the source and see a black hole. They certainly tried.Unfortunately, 600 deg2 is not a small enough region to know where to point a big optical telescope, which typically cover a very small area of the sky, much smaller than the Moon. This event was so distant that it would need long exposures on a large telescope. Radio and gamma ray telescopes have less resolution, so they can cover larger areas of the sky.Black holes are particularly hard to see - astronomers now have a good idea of the location and mass of the black hole in the center of our galaxy - but only because they have spent the past 15 years observing the paths of about a dozen stars that are in close orbit around it. The black hole itself is practically invisible - and this one is only 25,000 light years away, not 1,000,000,000 as estimated for this gravitational wave source.Fortunately, by the time they have 3 or 4 operational gravity wave detectors (in 4 or 5 years), they will be able to narrow down the source to an area in the sky that is perhaps no larger than the Moon. That is still a large area to search, but if the source were the merger of two neutron stars within our own galaxy, that may produce a burst of visible, radio and X-Rays radiation that is easily visible on Earth.Unfortunately, the merger of two otherwise isolated black holes is unlikely to produce much visible radiation.This paper shows more details on the analysis: http://arxiv.org/pdf/1602.03840v1.pdfThis paper is expected to appear soon (for now it is just the diagram above): https://dcc.ligo.org/public/0122/P1500227/006/placeholder.pdf
the origin of the waves
I suppose Stoke might win... and the odds are pretty good, aren't they? Not that I'm a betting woman - nor overly interested in football!
Is that so...? I was actually rooting for the Villa myself, having somehow found my way back to good old familiar Coventry, so it would seem...whereas I know my way on to Birmingham quite well from there.Box... I notice you also make diagrams! Did you know that in posting on forums, you retain the ownership rights on intellectual property, such as an idea - particularly if that idea is an idea that is easily distinguishable from other idea's in its genre - but that the copyright on anything you post publicly to the forum becomes the property of the site owners?Actually it's a little more 'grey' than I'm perhaps portraying, but only because no-one has yet taken such a case to court. This being, I think, because the general opinion is - that if you wish to retain full copyrights to any artworks, writings, or poetry you create, it would be foolish to post it to a public forum. If you do in fact actually want it out there on the net, better to create your own page. Even then your work will not be entirely safe. My artwork was ripped off from my webpage a few years back for the launch of a new car series, produced by an exceedingly prominent car manufacturer. I had to write and tell them that I was expecting my free car to be arriving imminently! They subsequently took it down, much to my disappointment! (chuckle)Anyway - I notice box that you are indeed posting your rather interesting diagrams to the forum, so... just thought I'd point these facts out to you!