Jason Jorjani

And the mass of the galaxies closer to us bends the light of the galaxies that are far from us. So based on how, at what angle the light is bent as it reaches our telescopes from distant galaxies, we can estimate the weight, the mass of the galaxies that are closer to us. You follow?

And the mass of the galaxies closer to us bends the light of the galaxies that are far from us. So based on how, at what angle the light is bent as it reaches our telescopes from distant galaxies, we can estimate the weight, the mass of the galaxies that are closer to us. You follow?

And the mass of the galaxies closer to us bends the light of the galaxies that are far from us. So based on how, at what angle the light is bent as it reaches our telescopes from distant galaxies, we can estimate the weight, the mass of the galaxies that are closer to us. You follow?

You've got galaxies that are far, far from us, right? We're trying to look at them.

You've got galaxies that are far, far from us, right? We're trying to look at them.

You've got galaxies that are far, far from us, right? We're trying to look at them.

The light coming from them is bent by the galaxies that are closer to us.

The light coming from them is bent by the galaxies that are closer to us.

The light coming from them is bent by the galaxies that are closer to us.

It's like they're going around the rim of a black hole. It bends the light, right?

It's like they're going around the rim of a black hole. It bends the light, right?

It's like they're going around the rim of a black hole. It bends the light, right?

So they observe this and they say, wait, this doesn't make any sense. We know the mass of such and such galaxy. It's bending the light much more severely than it should based on what we think that galaxy weighs. So then they did a third observation where they said, okay, well, maybe there's gas. Maybe there's a bunch of gas in these galaxies that's giving them more mass than we can see. Okay.

So they observe this and they say, wait, this doesn't make any sense. We know the mass of such and such galaxy. It's bending the light much more severely than it should based on what we think that galaxy weighs. So then they did a third observation where they said, okay, well, maybe there's gas. Maybe there's a bunch of gas in these galaxies that's giving them more mass than we can see. Okay.

So they observe this and they say, wait, this doesn't make any sense. We know the mass of such and such galaxy. It's bending the light much more severely than it should based on what we think that galaxy weighs. So then they did a third observation where they said, okay, well, maybe there's gas. Maybe there's a bunch of gas in these galaxies that's giving them more mass than we can see. Okay.

So they looked at the same galaxies with spectrometers that can detect gas and estimate the masses of gas. Nope. Doesn't account for anywhere near the amount that this light is bent by.

So they looked at the same galaxies with spectrometers that can detect gas and estimate the masses of gas. Nope. Doesn't account for anywhere near the amount that this light is bent by.

So they looked at the same galaxies with spectrometers that can detect gas and estimate the masses of gas. Nope. Doesn't account for anywhere near the amount that this light is bent by.

So putting these, and these observations were all made in the 70s. The first one in the early 70s, the second in the mid to late 70s. Putting all three of these together, they came to the conclusion that there's a ton of mass around these galaxies that we can't see. It's not electromagnetically detectable. And yet it has massive gravitational effects. Okay? What does that mean?

So putting these, and these observations were all made in the 70s. The first one in the early 70s, the second in the mid to late 70s. Putting all three of these together, they came to the conclusion that there's a ton of mass around these galaxies that we can't see. It's not electromagnetically detectable. And yet it has massive gravitational effects. Okay? What does that mean?