Time for this week's questions show.
Your questions, my answers, as always, wherever you are on the Youtube channel, if some idea
or question pops into your mind, just type it in.
Whether it's on the general channel on the video.
Whether it's about what the video's about, whether it's not, it doesn't matter.
I see them all, I see everything.
I wanted to remind you that we do this videos in 4K.
Now obviously for the questions show, you're just staring at my face in great detail, it's
not that useful.
but for the regular guide to space videos.
All those animations, all those pictures, we try to make it as much in 4K.
If you've got a 4K TV, which I don't have, you should totally watch them in 4K, it's
awesome.
All right, let's get on with the first question.
Andrea Pisani - Hi Fraser, I'm a patron.
Can you explain to me why everybody says that the kilonova explosion is so important to
understand how heavier elements form?
I thought that supernova can produce elements like gold.
Maybe quantity matters?
First, thanks for being a Patron, that's why I put your question to the top.
Now, we've got a whole episode coming out about the discovery.
But again, you used the word Patron, so I just had to put your question to the top of
the queue.
Here's the thing that's important about this discovery.
These two neutron stars collided, and astronomers were able to see gold and platinum in the
wreckage coming out of this explosion.
Astronomers thought that maybe, probably, gold was formed in supernovae, but they couldn't
kind of make the physics and the math and the models explain what we saw.
And so, it was, really, supernovae were the way they thought that gold was formed, but
it wasn't good enough.
So the other idea was that maybe when neutron stars collided, that would do the trick.
And so with this kilonova explosion, they actually saw the cloud of gold confirming
that theory.
Which blows your mind when you think about the fact that all of this gold, all around
us, all of the platinum, all of these heavier elements were formed from two neutron stars
smashing into each other that were caused by two supernovae explosions, and these things
whirled around each other for billions of years and then seeded the solar nebula.
It's amazing, and it's an incredible discovery, definitely the big discovery of the year so
far.
And I can't wait to see what happens next.
Mister Doctor - Hey Baby, I hear the blues a callin.
Tossed salad and scrambled eggs.
I see what you're doing there: Frasier Crane, my name is Fraser Cain.
Congratulations, you're the first person to ever notice that.
No, obviously, I've known since the first time that guy, Kelsey Gramer's character showed
up on Cheers, and he took my name.
I had the name first, I was born in 1971.
There was no Cheers, there was no idea of Cheers.
In 1971, when my parents gave me my perfectly fine, Scottish name.
So, Kelsey, give me my name back, please.
Lari588 - Would a location right at the edge of even outside of the solar system be an
even better location for a space telescope and such?
I know what you're thinking, with that question, or I think I know what you're thinking.
If you put a space telescope outside of the Solar System, or really far away from the
glare of the Sun, you'd have a really nice dark view of the night sky.
Eh, it wouldn't really be much better.
But man, there's something really cool for why you should put a telescope out at the
very edge of the Solar System.
When you get 550 Astronomical Units away from the Sun.
So 550 times the distance of the Earth to the Sun, the Sun itself acts like a gravitational
lens that distorts the light from directly behind it.
And so if you put a telescope at that point, it would use the Sun as a lens.
Now the problem is that the Sun is right there where the lens is and it's super bright.
So you have to go farther away, you have to go 1000 astronomical units or 2000.
If you can actually go that far away, you'll get the Sun, and you'll get this Einstein
ring around the Sun.
This distortion of light.
And you could see objects with a powerful telescope.
You'd only have to be looking at that distance away.
You're looking at this distorted light around the Sun.
And you rebuild it into a picture.
And the capability of that is that you could see objects on extrasolar planets 30 light
years away the size of a kilometer, which is mind bending.
You could see features and structures and mountains and rivers and oceans, 30 light
years away.
So there is a really terrific reason why we should get a telescope out that far.
There's an idea in the works called the FOCAL mission.
But the problem is getting a telescope 2000 astronomical units from the Sun.
That's hard, that's far.
And would require some engineering that we really haven't worked out yet, but it would
be the best place for a telescope.
Crazysquirrel - Brown dwarfs fuse deuterium right?
So can brown dwarfs turn into white dwarfs after they fused all of their deuterium?
No, a white dwarf is the core of a star like our Sun that has gone through the full main
sequence stage of its life.
So it starts out fusing hydrogen into helium at its core, puffs up as a red giant, reaches
the end of its life, and then runs out of hydrogen in its core, starts cooking helium,
runs out of helium, starts creating carbon, and then that's as far as a star like our
Sun can go.
And then it cools down, and you've got this ball of carbon, the Universe's biggest diamond.
And then that will cool down, and then that will turn into a white dwarf which is very
hot, into what's called a black dwarf.
That'll take trillions, quadrillions of years for it to finally cool down, eventually becoming
the background temperatures of the Universe.
While a brown dwarf, right, is a failed star, a star that's not big enough to actually get
fusion of regular hydrogen in its core.
Only deuterium, so it does deuterium for a while, but then it can't go any further than
that.
So it just runs out of usable deuterium, cools down, and just dies.
And then it would cool down to the background temperature of the Universe, as a ball of
hydrogen.
Like a big planet, really, like Jupiter, like when Jupiter finally stopped with compression,
temperature in its core.
When everything cools down, it'll just be a cold ball of hydrogen.
So that's what brown dwarfs will become.
That's what the Earth will become, but made of rock.
Martijn Schuman - What happens if the black hole in the center of the galaxy disappeared.
Will everything be the same as it is right now?
Or will we fly away in a straight line till another galaxy catches us?
The black hole, the supermassive black hole at the heart of the Milky Way is about 4.1
million times the mass of the Sun.
That sounds like a lot.
But actually, it's less than 1%, it's a fraction of the total mass of the Milky Way.
And the thing that's actually holding the Milky Way together is the mutual mass of all
the stars and dust and planets.
But also this huge halo of dark matter that surrounds the Milky Way and acts like an anchor.
So if someone came and just disappeared the supermassive black holes at the middle, you'd
have a bunch of these stars which are orbiting around the black hole, kind of like comets,
actually.
They would lose their gravitational center.
There might be some other stars that are kind of jostling around a little.
But for us, we wouldn't even feel it.
So it wouldn't have any real impact on the stability or the structure of the Milky Way.
It's not like that black hole is the anchor of the Milky Way, and if we lose it, everything
flies away.
The Goat - Hi Fraser, just wanted to point out that a docking ring would be stationary.
Once the shuttle has docked to the ring, the ring would then slowly start turning to match
the rotation of the station.
Just saying.
So this was based on last week's questions show, and someone wanted to know how a spaceship
would dock with a rotating space station.
I clearly need to do an episode on rotating space stations, that is in the queue.
And I think you're right.
You would have some kind of space station that's rotating, and maybe it's got a docking
ring that's attached to the end of it.
And the space station can make that docking ring stop compared to the rest of the rotation.
So the docking ring that's there, and the spaceship comes up and docks to the side of
the docking ring, and then, the brakes are removed or applied and the ring starts to
rotate with the rest of the space station.
and then you've got this spaceship that's going around and around, and then the astronauts
start to feel the gravity, and then they go out their door and now they're the space station.
So that sounds like a pretty good way to do it, unless your docking ring breaks.
When you think about it, there's this great big wheel and then there's this other wheel's
got to slow it down and stop it from turning.
There's a lot of pieces involved.
No matter what happens, there's going to need to be a way to get people from a spaceship
that's going to be docking to a rotating space station to match the rotation of the space
station.
And the best way to do that, I'm sure that hasn't been completely figured out.
I wish we'd got to a place where people are trying to engineer the best kind of way to
dock space ships to rotating space stations.
That would be an awesome problem to have.
Ernie Simpson - What about mining the far side of the Moon to preserve our view of it.
I got this response a bunch of times, and this was sort of like, I gave you the ethical
question of: should we dismantle the Moon, is it ethical for us to wreck this thing,
even if it's dead.
So that it's gone, or that it doesn't look disfigured for our own purposes.
We mine it, we chisel away at it.
And I got this response from a bunch of people.
The Moon is tidally locked to the Earth, it's only showing us one face.
So let's put all that heavy industry on the far side of the Moon, the side that we can's
see.
So we can look up in the sky and we see the beautiful Moon that we always did, and we
know that the far side is being dismantled and torn apart.
It's a great solution.
It would make it so we didn't have to see the Moon being taken apart, but it would still
be happening.
Anyway.
I got that response a bunch of times, and I kind of like the idea.
SnowToad - Is time infinite.
Whoa.
Which direction do you want to go?
So, if you want to go back to the beginning of the Universe, 13.8 billion years ago, it
appears that time has a finite beginning.
That the the Universe and time, and spacetime, and all this stuff started with the Big Bang.
So you can imagine on the one side, you've got this boundary, that time began.
But if you go the other way, if you go forward into the future, right now, from what we can
tell, the Universe is going to be expanding and expanding forever.
And so time will go on forever into the future.
There's no reason to think that time will come to an end.
You can imagine that it's a line with one point at the beginning and it just goes on
forever.
Now there are a couple of things.
There's one idea called eternal inflation, I've got a special guest coming and we're
going to talk all about it.
How there could be other universes popping up within this Universe, so the concept that
there's one time in the Universe doesn't make a lot of sense.
The other idea is this idea.
And this is way out there, but, quantum mechanics says that everything around us, all the particles,
all the parts of our body, it's a probablistic function that says that I'm going to be here,
that all the air is going to happen to be here.
It could, through quantum mechanics, be teleported somewhere across the Universe.
So there's this other idea, that quantum mechanics says that particles are actually wave functions,
and the position of where a particle is, is a probablistic situation, and so if you wait
long enough, for trillions, quadrillions, for a long long time, particles can appear
in different locations.
And if you go long enough, that more complex objects will literally form, pop, into the
Universe because of the probablity that the Universe rearranges little chunks of itself.
And in fact, if you wait long enough, and it's a ludicrous amount of time.
The probablity is that you'll get an entirely new Big Bang, that the matter in the Universe
will rearrahge itself into a new singularity, and you'll get a new Big Bang.
Assuming that the Universe is finite, if it's infinite, all best are off.
And then time will begin again, so that's a weird thing that's out there right now.
But like I said, we've got an episode on eternal inflation coming, and we'll go into more detail
on that later.
Markle2k - Isn't L4/L5 stability a double-edged sword?
There should be a lot of crap that got itself stuck there for a while.
That might cause a hazard for a telescope.
Well, yes and no.
You are going to have objects in the L4 L5 Lagrange Points.
These are the stable Lagrange Points.
Asteroids, debris, rocks, comets, stuff.
They call them Trojans that are located around Jupiter, and there are probably similar Trojan
objects that are located around the Earth.
And so if you put a telescope, it's going to be jostled around by all these objects.
So you would need to go and map out the density of a Trojan system.
And actually NASA is working on a mission that may go and explore the Trojan asteroids
of Jupiter.
And so send the mission out to this area, and kind of sit in the middle of the Trojan
area as objects jostle around and bring themselves close to your telescope.
We don't know what dangers it will face until we go and actually do it.
If we put a human colony there, we're going to want to deal with the other objects that
are located in the L4 or L5 point.
But that's a problem for a Type 1 civilization.
James Brownlie - Would the best way to explore Mars actually be by helicopter drone or some
other ultralight flying vehicle?
And to what extend has Mars already been explored and mapped?
Mars has been explored in incredible detail.
The spacecraft, all the spacecraft, especially the Mars Reconnaissance Orbiter, which is
the most powerful telescope that's ever been installed on another world, has mapped the
planet in incredible detail.
And there are some great resources where you can see the Curiosity Rover crawling across
the surface of Mars, where the Beagle 2 impacted.
You can see their aeroshells, you can see the parachutes that are on the surface of
Mars.
It been mapped in incredible detail, and people are still poring through information on this.
Would airplanes and other ultralight things work there?
Yes, there are some great ideas of drones or gliders and helicopters and things like
that that could work on Mars.
They need to have a very big wingspan, but the low gravity on Mars makes them work.
And you can imagine in the future Mars rovers with some kind of drone on top.
The drone takes off, maps the area, returns to the rover.
And then the scientists on Earth look at all that map data, pick some targets for the rover,
and moves to the next position.
And then the drone takes off again.
Where that would work even better is Titan.
Titan is the best place for us to send some kind of flying explorer, so that's where I'd
like to see wings.
Garland Garrett - Could the SpaceX BFR or similar boost the International Space Station
to the Deep Space Gateway Lagrange point to be used as the first blocks to build the Gateway?
The problems is that the International Space Station contains an enormous amount of mass.
And to move it to another location, you'd need to attach rockets.
You'd need a tremendous amount of energy to move it to this location.
So that's one problem, it would just take a lot of energy, lots of rockets.
Not one BFR, but several.
But also, it's not built to protect human beings away from low Earth orbit.
So it doesn't have a lot of shielding, because it's got the Earth's magnetosphere around.
The reality is that the Deep Space Gateway will need to be some kind of custom built
outpost designed for the environment of this cis-lunar orbit.
James Smyth - Who gets to name Planet 9 when it's found?
What do you think it should be called?
In general, the International Astronomical Union is the one that provides the names of
things, like planets.
So when Planet 9 is discovered, they'll be the ones to name it.
That said, the discoverer gets to propose names, and then they may accept or reject
them.
And so Mike Brown, for example, the person who discovered Eris.
He pitched the name Eris, originally he called Xena.
He pitched the name Eris, and they liked that name and they went with it.
So the person who discovered it will get a pretty good chance to suggest a name, and
the IAU may or may not accept it.
All right, that's it for this week's questions show.
So wherever you are on my channel, if you've got a question about space and astronomy or
characters from Cheers, just type it in and I'll answer it here.