My son shared this video by Vertasium on the black hole pic, https://www.youtube.com/watch?v=zUyH3XhpLTo I thought it was nice. and this, https://www.youtube.com/watch?v=S_GVbuddri8 Amazing stuff. George H.
OT black hole pic.
Started by ●April 11, 2019
Reply by ●April 11, 20192019-04-11
On Thu, 11 Apr 2019 10:42:18 -0700 (PDT), George Herold <gherold@teachspin.com> wrote:>My son shared this video by Vertasium on the black hole pic, >https://www.youtube.com/watch?v=zUyH3XhpLTo > >I thought it was nice. > >and this, >https://www.youtube.com/watch?v=S_GVbuddri8 > >Amazing stuff. > >George H.It's always hard to tell real pictures from animations and "artists conceptions." There should be a convention to identify unreal images. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●April 11, 20192019-04-11
John Larkin wrote...> > On Thu, 11 Apr 2019, George Herold wrote: > >> My son shared this video by Vertasium on the black hole pic, >> https://www.youtube.com/watch?v=zUyH3XhpLTo >> >> https://www.youtube.com/watch?v=S_GVbuddri8 > > It's always hard to tell real pictures from animations > and "artists conceptions." There should be a convention > to identify unreal images.These images have been called pictures, i.e., photographs, and I think that's a fair name. They're created from a 200GHz, "telescope" with a diameter of the whole earth. Made from data from multiple simultaneous radio telescope images, in perfect phase synchronization. The more you read about it, the more you'll agree this is a real image. -- Thanks, - Win
Reply by ●April 11, 20192019-04-11
In article <q8oo590a0m@drn.newsguy.com>, Winfield Hill <hill@rowland.harvard.edu> wrote:>> It's always hard to tell real pictures from animations >> and "artists conceptions." There should be a convention >> to identify unreal images. > > These images have been called pictures, i.e., photographs, > and I think that's a fair name. They're created from a > 200GHz, "telescope" with a diameter of the whole earth. > Made from data from multiple simultaneous radio telescope > images, in perfect phase synchronization. The more you > read about it, the more you'll agree this is a real image.The full set of papers which make up this report (there are six of them) go into a lot of detail about the processing that was done. If I recall correctly, there were no less than four independent teams, working with several different sets of data-processing "pipelines", working on the data, blinded to one anothers' results until the last. I'm only partway through the reading, and I don't pretend to understand all of the math (or even more than a fraction of it) but it's a worthy learning effort nevertheless! Any form of image which is based on interferometry is necessarily somewhat synthetic - the image which results is a best-fit result generated from the data. There are, necessarily, interpolations made in the process (that is, the data is "under-constrained") because the interferometric relationship between any two of the radio telescopes "sweeps out" only a limited set of parts of the image field during any single recording pass. The teams seem to have gone to a lot of effort to make sure their analysis process resulted in image data corresponding to "what was there" rather than "what we expected to see". They tested the analysis pipelines with synthetic image data first, artifically generating this based on various models of what the emission source might "look like", and confirming that the computed images actually matched up to the models that generated the test data.
Reply by ●April 11, 20192019-04-11
On Thursday, April 11, 2019 at 8:31:01 PM UTC-4, John Larkin wrote:> On Thu, 11 Apr 2019 10:42:18 -0700 (PDT), George Herold > <gherold@teachspin.com> wrote: > > >My son shared this video by Vertasium on the black hole pic, > >https://www.youtube.com/watch?v=zUyH3XhpLTo > > > >I thought it was nice. > > > >and this, > >https://www.youtube.com/watch?v=S_GVbuddri8 > > > >Amazing stuff. > > > >George H. > > It's always hard to tell real pictures from animations and "artists > conceptions." There should be a convention to identify unreal images. >Well it's all radio waves. 1.2 mm or something. I like the pic of the black hole in the center of our galaxy. George H.> > -- > > John Larkin Highland Technology, Inc > picosecond timing precision measurement > > jlarkin att highlandtechnology dott com > http://www.highlandtechnology.com
Reply by ●April 11, 20192019-04-11
On Thursday, April 11, 2019 at 9:24:11 PM UTC-4, Dave Platt wrote:> In article <q8oo590a0m@drn.newsguy.com>, > Winfield Hill <hill@rowland.harvard.edu> wrote: > > >> It's always hard to tell real pictures from animations > >> and "artists conceptions." There should be a convention > >> to identify unreal images. > > > > These images have been called pictures, i.e., photographs, > > and I think that's a fair name. They're created from a > > 200GHz, "telescope" with a diameter of the whole earth. > > Made from data from multiple simultaneous radio telescope > > images, in perfect phase synchronization. The more you > > read about it, the more you'll agree this is a real image. > > The full set of papers which make up this report (there are six of > them) go into a lot of detail about the processing that was done. If > I recall correctly, there were no less than four independent teams, > working with several different sets of data-processing "pipelines", > working on the data, blinded to one anothers' results until the last. > I'm only partway through the reading, and I don't pretend to > understand all of the math (or even more than a fraction of it) but > it's a worthy learning effort nevertheless! > > Any form of image which is based on interferometry is necessarily > somewhat synthetic - the image which results is a best-fit result > generated from the data. There are, necessarily, interpolations made > in the process (that is, the data is "under-constrained") because the > interferometric relationship between any two of the radio telescopes > "sweeps out" only a limited set of parts of the image field during any > single recording pass. > > The teams seem to have gone to a lot of effort to make sure their > analysis process resulted in image data corresponding to "what was > there" rather than "what we expected to see". They tested the > analysis pipelines with synthetic image data first, artifically > generating this based on various models of what the emission source > might "look like", and confirming that the computed images actually > matched up to the models that generated the test data.It's very cool. I read that there was so much data, they transported it on planes, by wire would have taken too long. We should put a dish on the moon. :^) George H.
Reply by ●April 12, 20192019-04-12
On 12/4/19 11:54 am, George Herold wrote:> On Thursday, April 11, 2019 at 9:24:11 PM UTC-4, Dave Platt wrote: >> In article <q8oo590a0m@drn.newsguy.com>, >> Winfield Hill <hill@rowland.harvard.edu> wrote: >> >>>> It's always hard to tell real pictures from animations >>>> and "artists conceptions." There should be a convention >>>> to identify unreal images. >>> >>> These images have been called pictures, i.e., photographs, >>> and I think that's a fair name. They're created from a >>> 200GHz, "telescope" with a diameter of the whole earth. >>> Made from data from multiple simultaneous radio telescope >>> images, in perfect phase synchronization. The more you >>> read about it, the more you'll agree this is a real image. >> >> The full set of papers which make up this report (there are six of >> them) go into a lot of detail about the processing that was done. If >> I recall correctly, there were no less than four independent teams, >> working with several different sets of data-processing "pipelines", >> working on the data, blinded to one anothers' results until the last. >> I'm only partway through the reading, and I don't pretend to >> understand all of the math (or even more than a fraction of it) but >> it's a worthy learning effort nevertheless! >> >> Any form of image which is based on interferometry is necessarily >> somewhat synthetic - the image which results is a best-fit result >> generated from the data. There are, necessarily, interpolations made >> in the process (that is, the data is "under-constrained") because the >> interferometric relationship between any two of the radio telescopes >> "sweeps out" only a limited set of parts of the image field during any >> single recording pass. >> >> The teams seem to have gone to a lot of effort to make sure their >> analysis process resulted in image data corresponding to "what was >> there" rather than "what we expected to see". They tested the >> analysis pipelines with synthetic image data first, artifically >> generating this based on various models of what the emission source >> might "look like", and confirming that the computed images actually >> matched up to the models that generated the test data. > > It's very cool. I read that there was so much data, they transported > it on planes, by wire would have taken too long. > We should put a dish on the moon. :^)It's hard to beat the bandwidth of a jumbo jet full of disk drives. Some of the radiation used to make that picture came from the Earth... 110 million years ago, and bent right around the black hole and back to us. If we could increase the resolution a lot(*), we could get video of live dinosaurs! (*) Quite a lot. In fact, a lot a lot alot! Clifford Heath.
Reply by ●April 12, 20192019-04-12
On Thu, 11 Apr 2019 18:54:27 -0700 (PDT), George Herold <gherold@teachspin.com> wrote:> >It's very cool. I read that there was so much data, they transported >it on planes, by wire would have taken too long. >We should put a dish on the moon. :^)This has been used for decades in VLBI. Previously each radio telescope recorded the signal and clock sync on tape and the tapes were flown to the correlator site, The different tapes were synchronized and run through the correlator.So apparently they now use disks instead of tapes. It is surprising that they still use disks, since for at least a decade there has been a protocol for transferring very high data rate interferometric data. Standard TCP/IP is useless, since the transmission window would be filled, before the acknowledge frame would be received from intercontinental distances. You might need hundreds or thousands parallel TCP/IP tubes to fully utilize the available bandwidth (up to 800 Gbit/s on a single DWDM fibre).
Reply by ●April 12, 20192019-04-12
On 11 Apr 2019 18:03:37 -0700, Winfield Hill <hill@rowland.harvard.edu> wrote:>John Larkin wrote... >> >> On Thu, 11 Apr 2019, George Herold wrote: >> >>> My son shared this video by Vertasium on the black hole pic, >>> https://www.youtube.com/watch?v=zUyH3XhpLTo >>> >>> https://www.youtube.com/watch?v=S_GVbuddri8 >> >> It's always hard to tell real pictures from animations >> and "artists conceptions." There should be a convention >> to identify unreal images. > > These images have been called pictures, i.e., photographs, > and I think that's a fair name. They're created from a > 200GHz, "telescope" with a diameter of the whole earth. > Made from data from multiple simultaneous radio telescope > images, in perfect phase synchronization. The more you > read about it, the more you'll agree this is a real image.It is definitively a false color (black / red / yellow) image :-) The recording was done on a single 1.3 mm wavelength. Anyway, even optical astronomical raw pictures are heavily processed to make published pictures more beautiful.
Reply by ●April 12, 20192019-04-12
On 11 Apr 2019 18:03:37 -0700, Winfield Hill <hill@rowland.harvard.edu> wrote:>John Larkin wrote... >> >> On Thu, 11 Apr 2019, George Herold wrote: >> >>> My son shared this video by Vertasium on the black hole pic, >>> https://www.youtube.com/watch?v=zUyH3XhpLTo >>> >>> https://www.youtube.com/watch?v=S_GVbuddri8 >> >> It's always hard to tell real pictures from animations >> and "artists conceptions." There should be a convention >> to identify unreal images. > > These images have been called pictures, i.e., photographs, > and I think that's a fair name. They're created from a > 200GHz, "telescope" with a diameter of the whole earth. > Made from data from multiple simultaneous radio telescope > images, in perfect phase synchronization. The more you > read about it, the more you'll agree this is a real image.I meant the other animations of the black hole that are mixed up with the actual, very fuzzy radio telescope image. But more generally, the silly artists' conceptions that are not always identified. I've seen versions of that actual image that are zoomed or otherwise manipulated to look like movies. It sure was a ton of extended hype over that one fuzzy image. -- John Larkin Highland Technology, Inc lunatic fringe electronics
