Creating the EHT was a formidable challenge which required upgrading and connecting a worldwide network of eight pre-existing telescopes deployed at a variety of challenging high-altitude sites. These locations included volcanoes in Hawai`i and Mexico, mountains in Arizona and the Spanish Sierra Nevada, the Chilean Atacama Desert, and Antarctica.
The EHT observations use a technique called very-long-baseline interferometry (VLBI) which synchronises telescope facilities around the world and exploits the rotation of our planet to form one huge, Earth-size telescope observing at a wavelength of 1.3 mm. VLBI allows the EHT to achieve an angular resolution of 20 micro-arcseconds — enough to read a newspaper in New York from a sidewalk café in Paris.
50 years ago on Christmas Eve (Dec 24, 1968), the astronauts aboard Apollo 8 took an amazing series of photos of the rising earth behind the limb of the moon, while in orbit. The first photo was black and white, and subsequent ones (with the earth having risen farther from the moon horizon) were color, and now with some digital magic, these are combined into one image. Glorious.
“Oh my God, look at that picture over there! There’s the Earth comin’ up. Wow, is that pretty!” — Astronaut Bill Anders, Apollo 8
America has the means to reduce traffic and connect people to where they want to go in less time — but solving these problems entails politically difficult choices to shift travel away from cars and highways. Any high-tech solution that promises a shortcut around these thorny problems is probably too good to be true.
I can’t help but see an echo of the wishful thinking surrounding the EMDrive in the Hyperloop marketing campaign. Maybe I’ll be proven wrong.
Here’s the original white paper PDF from Elon Musk, and here’s a rather detailed critique by mathematician and transit analyst Alon Levy. Anyone who takes Hyperloop seriously should read both.
We must resist the usurper Pi! Tau is the true constant, the real savior of mathematics. The above image is essentially all the proof you need, but for those indoctrinated by the 2,000 year old cult of Pi, watch this short video: