Magnetic Fields around a Black Hole

[The Admiral]

I came across this link on work to map the magnetic field lines around the black hole at the centre of our galaxy. I must say that I am always amazed at the abilities of modern science. Back in the day, the resolution of radio telescopes was far poorer than their then optical equivalents, but here I read that the Event Horizon Telescope (EHT) will have a resolution of 15 micro-arcsecs. Incredible!

https://www.cfa.harvard.edu/news/2015-28

Ian

[Tiki]

I came across this link on work to map the magnetic field lines around the black hole at the centre of our galaxy. I must say that I am always amazed at the abilities of modern science. Back in the day, the resolution of radio telescopes was far poorer than their then optical equivalents, but here I read that the Event Horizon Telescope (EHT) will have a resolution of 15 micro-arcsecs. Incredible!

https://www.cfa.harvard.edu/news/2015-28

Ian

Incredible. It says in the article that at 15micro-arcseconds you could resolve a golf ball on the moon!!!

[Stub Mandrel]

If you compare the aperture of the Arecibo radio telescope, or even the Jodrell Bank scopes with any optical scope, that's a big increase in resolution.

Now they use an array of radio telescopes along huge baselines to synthesise apertures measured in kilometres.

Perhaps one day they will work out how to make huge arrays of optical scopes.

[Tiki]

Here is a nice little page http://www.eventhorizontelescope.org/science/general_relativity.html that explains something  about the Event Horizon Telescope's mission. There can never be enough strong-field gravity experiments.

[acey]

If you compare the aperture of the Arecibo radio telescope, or even the Jodrell Bank scopes with any optical scope, that's a big increase in resolution.

 

Now they use an array of radio telescopes along huge baselines to synthesise apertures measured in kilometres.

 

Perhaps one day they will work out how to make huge arrays of optical scopes.

Interferometry was used at optical wavelengths before it was applied to radio astronomy. Michelson was able to determine the diameter of Betelgeuse as 0.05 arcseconds in 1920.

[Stub Mandrel]

thanks for the clue, I found this:

https://en.wikipedia.org/wiki/Astronomical_interferometer

[nameunknown]

There are, I think, two golf balls on the Moon. On Feb. 6, 1971  (was it really that long ago!)-- Alan Shepard pulled out a makeshift six-iron he "smuggled" on board Apollo 14 and hit two golf balls on the lunar surface, becoming the first -- and (so far as we know) only -- person to play golf anywhere other than Earth. Now that we can potentially find these balls, I expect that Donald Trump sees some great commercial possibilities here if he gets control of the NASA budget

P