Superfastman88 Posted March 25, 2017 Share Posted March 25, 2017 If the supermassive black hole that was knocked out of its galaxy recently was 8 billion light years away then how could it have happened 1-2 billion years ago? This was listed on multiple articles but the main article in reference is: http://www.spacetelescope.org/news/helc1706/ The only 2 conclusions that I can come up with are that a)the information was wrong or b)our galaxy is moving directly away from the light coming from the debris outside the event horizon of the supermassive black hole in question.... which i'm no mathmatician but light travels about 670,616,629 mph and our galaxy travels at about 515,000 mph which doesent seem to add up. Could someone please help explain this to me? Link to comment Share on other sites More sharing options...
Endy0816 Posted March 25, 2017 Share Posted March 25, 2017 Probably looking at Expansion. The present distance can now be greater than that which the light had to cross. Link to comment Share on other sites More sharing options...
Superfastman88 Posted March 25, 2017 Author Share Posted March 25, 2017 How fast is the universe expanding? Is there an estimate and/or an analogy that could make sense to someone that isn't a physics or math major? And from what I understand you're saying because of this expansion the light from 8 billion light years away only happened 1-2 billion light years away because space has been expanding and caused it to take that long? only happened 1-2 billion years ago* Wait... So in reference to expansion... the Earth and where this happened at 8 billion light years away... At the point light emitted from this body shouldn't it still reach us at the same time? If something is say 1 light year from earth shouldn't it have happened 1 year ago? Roughly? Link to comment Share on other sites More sharing options...
Endy0816 Posted March 25, 2017 Share Posted March 25, 2017 Wikipedia is probably the clearest source here(and has a nice math-free example): Two views of an isometric embedding of part of the visible universe over most of its history, showing how a light ray (red line) can travel an effective distance of 28 billion light years (orange line) in just 13 billion years of cosmological time. Hubble's Constant: H0 = 67.15 ± 1.2 (km/s)/Mpc. For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second.[8][9][10] https://en.wikipedia.org/wiki/Metric_expansion_of_space#Measuring_distances_in_expanding_space Not as good as the Wiki's but here's an example I came up with of a photon making constant progress while the starting point grows increasingly distant as time passes. Earth--------Photon-Start Earth------Photon----------------Start Earth----Photon--------------------------------Start Earth--Photon----------------------------------------------------------------Start Link to comment Share on other sites More sharing options...
Strange Posted March 25, 2017 Share Posted March 25, 2017 I don't think expansion is enough to explain the difference between these numbers. I can't find the published paper to see exactly what they are saying but I think when the say "when" the event happened, they are describing it relative to what we see now. So we see the black hole "now" being 35000 light years from the galaxy, and it was expelled 1-2 billion years before "now". But, in reality, by now it has had an extra 8 billion years (or more) to move and so will be much further away. But we can't see that yet. BTW, the original link didn't work for some reason, so here it is: http://www.spacetelescope.org/news/heic1706/ 1 Link to comment Share on other sites More sharing options...
goldglow Posted April 19, 2017 Share Posted April 19, 2017 (edited) If the supermassive black hole that was knocked out of its galaxy recently was 8 billion light years away then how could it have happened 1-2 billion years ago? This was listed on multiple articles but the main article in reference is: http://www.spacetelescope.org/news/helc1706/ The only 2 conclusions that I can come up with are that a)the information was wrong or b)our galaxy is moving directly away from the light coming from the debris outside the event horizon of the supermassive black hole in question.... which i'm no mathmatician but light travels about 670,616,629 mph and our galaxy travels at about 515,000 mph which doesent seem to add up. Could someone please help explain this to me? Only guesswork, but could it be that the black hole was already 6 or 7 billion light years distant when it was ejected, or is that too simple a solution? Edited April 19, 2017 by goldglow Link to comment Share on other sites More sharing options...
imatfaal Posted April 19, 2017 Share Posted April 19, 2017 Here is the paper http://www.spacetelescope.org/static/archives/releases/science_papers/heic1706/heic1706a.pdf I think Strange is correct and their phrasing is extremely sloppy. What they mean is that the event took place 1.2billion years prior to our present observation - which of course is not 1.2billion years from now but much much longer (8.24 Gly I think) Based on the morphology of the host, we estimate that a major merger be tween two galaxies both containing an SMBH occurred roughly 1.2 Gyr ago. I think this means "1.2Gyr before the situation we are currently observing" Link to comment Share on other sites More sharing options...
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