I thought this was worth a thread not just because it's historic and never been achieved before, but because it's worth sharing what a monumental undertaking this was.
The researchers used a global network of very specific radio dishes. The astronomers could only see the black hole using millimetre wavelengths in order to penetrate the dust clouds and gases at the black hole and get back to Earth. These were the ones extremely high up in mountains so that any excess moisture in the atmosphere would be lessened. In addition to linking these together, they had to ensure that the weather in 7 different locations was clear for long enough to get an exposure. Doing this alone took months and many nights were lost when a single node of the network dropped out due to a cloud drifting in or some such weather problem. The dish network is so sensitive that it could perfectly shoot an image of a golf ball on the Moon.
Eventually they connected them at just the right time and pointed it at the supermassive black hole at the centre of the galaxy for 5 consecutive days. This created 500 terabytes of data at each location which has to be processed - that's half a million Gigabytes each, full of what is essentially text files. There's no way to actually send this over the internet in any real amount of time so each dish has to disconnect a bunch of their hard drives and send them into a central point. This also means the image can't be properly completed until October because the dish in Antarctica won't be able to fly in or out due to their winter blizzard months.
The data has to be synced together with perfect accuracy - organisations has to use atomic clocks that were accurate down to the nanosecond to ensure that they received the same data at the same time - this included calculations based on curvature of the Earth and the billions of a second more that the signal had to travel to South America than North America to ensure they were perfectly synced.
Once all these hard drives come together then an international super computing effort will attempt to get all of this data and process it, removing any deviations due to atmosphere or location, to attempt to compress all of it down into a single 10MB image of an event horizon of the black hole.
Obviously the image isn't available yet and won't be for a few months but it's worth a mention due to how cool the process was. I remember when NASA crashed an object the size of a washing machine into a comet and some were remarking how I wasn't really impressed by it. That's not exactly easy but it IS simple physics to get it right, the execution/project management is where the talent lies there. This project broke new ground in several places and was one of the most difficult science projects I've read about for an awfully long time. The amount of things that all needed to go right and all needed to be perfect otherwise it would be a complete failure was immense.
More on the story here:
https://phys.org/news/2017-04-astronomers-piece-image-black-hole.html
The researchers used a global network of very specific radio dishes. The astronomers could only see the black hole using millimetre wavelengths in order to penetrate the dust clouds and gases at the black hole and get back to Earth. These were the ones extremely high up in mountains so that any excess moisture in the atmosphere would be lessened. In addition to linking these together, they had to ensure that the weather in 7 different locations was clear for long enough to get an exposure. Doing this alone took months and many nights were lost when a single node of the network dropped out due to a cloud drifting in or some such weather problem. The dish network is so sensitive that it could perfectly shoot an image of a golf ball on the Moon.
Eventually they connected them at just the right time and pointed it at the supermassive black hole at the centre of the galaxy for 5 consecutive days. This created 500 terabytes of data at each location which has to be processed - that's half a million Gigabytes each, full of what is essentially text files. There's no way to actually send this over the internet in any real amount of time so each dish has to disconnect a bunch of their hard drives and send them into a central point. This also means the image can't be properly completed until October because the dish in Antarctica won't be able to fly in or out due to their winter blizzard months.
The data has to be synced together with perfect accuracy - organisations has to use atomic clocks that were accurate down to the nanosecond to ensure that they received the same data at the same time - this included calculations based on curvature of the Earth and the billions of a second more that the signal had to travel to South America than North America to ensure they were perfectly synced.
Once all these hard drives come together then an international super computing effort will attempt to get all of this data and process it, removing any deviations due to atmosphere or location, to attempt to compress all of it down into a single 10MB image of an event horizon of the black hole.
Obviously the image isn't available yet and won't be for a few months but it's worth a mention due to how cool the process was. I remember when NASA crashed an object the size of a washing machine into a comet and some were remarking how I wasn't really impressed by it. That's not exactly easy but it IS simple physics to get it right, the execution/project management is where the talent lies there. This project broke new ground in several places and was one of the most difficult science projects I've read about for an awfully long time. The amount of things that all needed to go right and all needed to be perfect otherwise it would be a complete failure was immense.
More on the story here:
https://phys.org/news/2017-04-astronomers-piece-image-black-hole.html
