Why we need an Earth-sized telescope

21:34want to do radio. um wavelengths and we want to image um a donut on the moon. Okay, we can calculate okay that's uh we want to image at the level of like single arc single micro arc seconds um plug that into the theta of the rally criterion the lambda is 1.3 mm so how big should my diameter be the diameter be turns out to be 10,000 kilometers [laughter] that's it's quite large >> quite large um what it's saying is in order To image a donut on the moon with radio

22:16wavelengths, I need a detector, a radio telescope the size of the Earth. >> 10,000 km. Take it or leave it. That's what physics says. >> Let's get a Dyson sphere going, baby. [laughter] >> Well, these guys created like a like a telescope sphere around the Earth effectively. Okay. The next video shows you how they did it. They said, "Okay, this this is what it is, right? We need a telescope the size of the Earth. >> Yes, >> we can't build a single telescope. What we're going to do is rig up a bunch of radio telescopes all across the globe and they're all going to communicate with each other and take independent images of this thing. Now, our light gathering power is not going to be that

22:57high because the detector is not the size of the Earth. Right. >> Right. But our resolution capacity is going to be the size of the earth because I'm able to take light from this part of the detector and this part of the detector. So there's um there's um two detectors in Chile, there's one in um Tucson, there's one in Hawaii, there's one in northern Africa, and as the Earth rotates, you use the Earth's rotation to image the black hole. >> Isn't that sick? And and and so this is