So this is what we've got here is this count of the number of galaxies that we have, of brighter galaxies on the x-axis to fainter galaxies sort of in that origin. And then we have on the y-axis the number of galaxies we're seeing of all those different types.
So you see there's a lot of natural variation in the star. It gets brighter and fainter over time. The camera is operating at the edge of its performance.
So in that kind of a universe, you'd be looking at the galaxies, you'd be lying on your back. They're getting fainter and smaller with time. You would say it's a good universe.
And in that process of going supernova, you could actually disrupt the entire galaxy altogether and essentially tear it apart. And therefore you would have far fewer fainter galaxies in the simulations if you included that process in it. And if you include it, it starts to match observations again.
Here's the new image. And the measured brightnesses were fainter than expected.
It has this universal speed limit that nothing can go faster than it at 30 million meters per second. And so it means that as we see more distant and fainter things, we're seeing what the universe looked like when the light left that object, say 13 billion years ago, the closest to a time machine we're probably going to get in our lifetime, so let's put it
That's the sample that's going to allow us to calculate the fraction of stars in our galaxy that host small, potentially habitable planets. Afterwards, the fainter planet also comes into view.
That's the sample that's going to allow us to calculate the fraction of stars in our galaxy that host small, potentially habitable planets. We can now see objects more than a billion times fainter than the star.
What we're really measuring is the structure of the density of stars as you get further away from the Galactic Center, and as you get further away So it's going to image the sky to fainter apparent magnitudes.
You've calibrated how bright the headlights of a car of known distance are. And you look at cars whose headlights are fainter , and you figure out their distance. If you're not very good at doing this almost intuitively, you shouldn't be driving at night.
a percent. Because it's a darker surface that's replacing the very hot surface on the star, so less energy reaches the earth. And we can time how long it's getting fainter along the edge and that gives us the radius of the planet. So we have the mass of the planet from using Newton's laws and the velocities. And we have the radius of the planet, so that's gives us a density. And we're able to get a few other clues as to the properties of
As you can also see by the varying shades of the bars, the uncertainty is also quite huge. So these shades there, and the fainter part, that represents the uncertainty, the intervals, that we should probably rationally have based on the studies. So the uncertainty is huge, but we can also see that, despite this uncertainty, which we should of course factor in, the expected differences in impact
at some nearby star and take a picture. And what you might hope to see is the star at the center of the picture and then a few fainter dots surrounding the star that would represent the planets.
is confined to just one pixel in the image. But because of all sorts of practical problems, the starlight spills over many pixels in the detector, thereby spoiling our view of the much fainter dots, the planets that might be underneath. So this this so-called direct imaging method of just taking a picture and looking for planets is very
star, so far away that it only looks like a point of light in the sky, we might be able to tell that it's happening because when the planet goes in front of it, the star appears to get slightly fainter . The planet blocks a small fraction of the starlight.
brightness versus time. And I want to impress upon you the numbers here on the vertical axis. These are very tiny changes in brightness that we are now capable of measuring. So this particular star got fainter . You know, a few numbers in the fourth decimal place. The brightness went down by just this tiny little amount. That tells us we're dealing with a roughly Earth-sized
conditions. So that's the Mustafar like planet from uh from that third Star Wars And during the transit, as expected, the star gets fainter . In this case, by a little more than 2%. But this was what
It looks one-sided because this side is actually aimed towards us, and therefore appears brighter. The other side is aimed away from us, and therefore is fainter . If you look at it at radio wavelengths, it looks very, very different.
This is a graph made with a school light meter, which records the total brightness of the sun. And you can see that when Venus is in front of the sun, it appears slightly fainter . Astronomy's a really simple science.
And that's, of course, like launching something at a speed greater than Earth's escape speed. In that case, the galaxies would continue to get fainter and smaller in the sky forever, albeit at a progressively decreasing rate, because there is some gravity acting upon them.
"There is no music, no cues at all. The game world is silent but for your footsteps and the sound you now realize that you have been set upon this path to encounter. "You panic and run down to the other end of the hall, the feasting sound growing fainter , only to find two locked doors. "No choice then, you walk-not run-back toward the hallway corner and stop and go to a sub-screen to check your inventory. Your pistols ammunition reserves are paltry and you curse yourself
that they don't reflect much energy as seen from earth. I mean, they can easily be a million to ten million times fainter than the star. So the best analogy is like trying to see a firefly just outside of a searchlight as you're looking into the searchlight. So he came up from this from pure thought.
conditions. So that's the Mustafar like planet from uh from that third Star Wars microns, those are the orange dots, it goes deeper. the star gets fainter .
So for our Earth, it is 100 times smaller than our Sun. It's also 100-- I think that number might be wrong, but 100,000 times less massive and 10 billion times fainter than our Sun. So if I was going to ask you which technique would you pursue to find another Earth, would it be one that has to do with size
Or you could say, Big Bang, "gnab, gib," which is Big Bang backwards. And so if you were in this universe and lying on your back looking at the galaxies, they would look progressively fainter and smaller. And you would say, yes, I live in a good universe.
And these typically take some number of hours, these transits. So for a certain number of hours, you'll see the star just get a little bit fainter . And then, if it's an Earth-like planet in an Earth-like orbit, it might be a year later you'll see the same event for a few hours, and then again a year later.
And he found-- next, please-- that the relatively nearby galaxies had small red shifts for their spectra. And-- next slide, please-- the more distant galaxies, which typically appear smaller and fainter in the sky had bigger red shifts. And this can be interpreted in terms of a motion.
And most measurements of the matter density suggested that we live in a universe that's only 30% of this critical density. So if that's the case, and you're lying on your back and looking up at the galaxies, they'll keep on getting fainter and smaller forever, all right? And that's a very different fate compared with the Big Crunch.
Here's the new image. And that argument is correct, but the point is, they look fainter than they had any right to be.
I said we've found 95% of the 1 kilometer or larger, and we've had an amateur help with that. The difficulty, though now, is that as you get smaller, they're fainter . They're moving fast. And to expect the amateur community to help us with detection is really not very realistic at this point.
Along our line of sight to this star, the planet's orbit just happens to go right across the face of the star. So when it goes across the face of the star, we can monitor the brightness of the star. And as the planet goes across, the star just gets ever-so-slightly fainter . You know on the order of a percent or a half a percent. Because it's a darker surface that's replacing the very hot surface on the star, so less energy reaches the earth.