Welcome to our weekly questions show.
As you see, we're not outside, we're inside the house because it's been pouring rain with
non-stop storms here on Vancouver Island.
So we're on the set of the Weekly Space Hangout, which is also my office, which is also the
living room of my house.
So, as always wherever you are on my channel, go ahead, ask any question, I will gather
them all up and I will answer them here.
Let's get started.
FrogLungs - you think people in the Andromeda galaxy are saying the Milky Way galaxy is
hurtling towards them?
Absolutely, well for starters, I love your avatar, I laugh every time I see it.
Absolutely, when you think about it, the mass of Andromeda is far greater than the mass
of the Milky Way, so really it's not that Andromeda is coming towards the Milky Way,
we are falling into Andromeda.
We're the ones that are really being affected the most by this interaction between Milky
Way and Andromeda.
We're going to fall into Andromeda and it's going to tear the Milky Way apart and then
the two galaxies are going to merge together.
The supermassive black hole at the heart of the Milky Way is 4.1 million times the mass
of the Sun.
The supermassive black hole at the heart of Andromeda is 100 million times the mass of
the Sun, so Andromeda is a much bigger, more massive galaxy, and it's the one that's really
calling the shots here.
Daneel Buchner - What's the maximum speed you could achieve using a gravitational slingshot
around a black hole?
Right so you're trying to figure a way that you could use black holes to speed up your
spacecraft.
And before we talk about black holes, let's talk about a second how a gravitatational
slingshots work.
When the Voyagers spacecraft or New Horizons used the giant planets in the Solar System
for a gravity speed boost, you kind of imagine the spacecraft falling into the planet and
it picks up velocity, but then as it moves away from the planet, it's being pulled back
by the planet so that velocity decreases.
What a gravitational slingshot does is that it lets you take advantage of the orbital
momentum of the spacecraft.
So for example, Earth is going 30 km/s around the Sun, so you try to do a gravitational
slingshot around the Earth, you would fall into the Earth's gravity well and you'd gain
speed and then fly back out and then you would lose speed.
But you would steal some of that 30 km/s of orbital velocity.
In fact, you would slow the Earth down.
That's how gravitationtal slingshots work, it's not about the falling in or falling out,
it's about you essentially raising to the orbit of the orbit of the object that you
are chasing.
So could you do that with a black hole?
Absolutely, a black hole is merely a massive object that orbits the center of the Milky
Way, just like all the other stars.
You could do that with a star, you should do that with a black hole, you could do that
with anythign.
The thing with a black hole is that you get very close, and so by getting a lot closer
that you could with a star, then you could get more of the black hole's orbital velocity.
But the problem is that if you try to get close to a black hole and you're going to
get torn apart by the tidal forces, the radiation that's coming from the area around the black
hole and if you crossed the event horizon, you go in.
In theory, it should be possible to go up to relativistic speeds by using multiple black
holes, each time stealing a little more orbital velocity.
But once you go faster the speed the black hole is orbiting the center of the Milky Way
there going to be stealing velocity from you.
You're going to be speeding them up.
So really, you're not going to be able to use black holes than you could use any object
that you'd be getting in the Milky Way.
The problem as well is the massive amounts of time that are going to happen to let you
get from one location around one star to another star.
But when you look at how fast the objects are going around the Milky Way you could in
theory gain a lot of that velocity by stealing orbital velocity from those objects as you
go faster and faster.
DocWolph - So could you not have an Earth-sized Trojan planet riding along in the Lagrange
Point of a sufficiently large main planet?
Most like captured there and not in this star system.
So the trick with Lagrange points, and you know we've done episodes and people like this
topic.
The Lagrange points are these 5 stablish points that are connected to two objects of mass.
So you've got the Sun and you've got the Earth and that creates 5 Lagrange points.
The 3 unstable Lagrange points, the ones that are in line between the Earth and the Sun.
And you've got the two stable Lagrange points, the ones that are ahead and behind the Earth
in orbit.
So the question is could you have the Sun and Jupiter and then could you have a fairly
large planet in one of those stable Lagrange points.
And the answer is no, you need to have an object that is essentially insignificant mass
compared to the planet.
And so and Earth-sized planet, even though it's 100th the mass of Jupiter, would still
be too massive to remain for any period of time in that Lagrange point.
You need to have something that's tiny asteroid size or spaceship size, or awesome L4 rotating
colony size, but nothing that's the size of a planet.
Put a planet in there it would just drift away.
SubnetMask - Hey Fraser, what's your day job and what are your hobbies?
Who do you live with?
And what kind of music do you listen to?
It's funny to me that there are people who watch the YouTube videos and they don't know
what my dayjob is.
And there are people who know what my day job is and they don't know that I do YouTube
videos.
So I am a science and space journalist, and I have been doing that for close to 20 years.
You know when we start the episode, maybe Chad will do it right now, I'm the publisher
of Universe Today, which a space and astronomy news website which I've been running since
March of 1999.
And for the first 10 years all I did was report on launches and new images from the Hubble
Space Telescope and discoveries in cosmology and I got to interview astronauts and so on.
And then about 10 years ago I started doing this podcast called Astronomy Cast with Dr.
Pamela Gay who is a PhD astrophysicists.
We just wrapped up 430 episodes of Astronomy Cast, and then it's only been in the last
4 or 5 years, 4 years?
That I've been doing these videos here on YouTube, and really it's just that I knew
there was lots of stories that I wanted to be able to tell, lots of concepts that I wanted
to be able to get across, that video was the best thing.
So if you go back to the beginning of this Guide to Space series, that is me trying to
learn how to do video coming from a background in print and podcasting.
So really my job is that I am a science journalist.
And what I do here is a tiny part of my larger job is that I manage the team that reports
on all this space news.
What are my hobbies?
Video games, mountain biking, traveling, probably in that order.
Who do I live with?
I have two kids and I also have my wife who also operates the camera?
What kind of music?
I listen to a lot of music, mostly because I really love podcasts.
I like music, but if I'm walking around or doing housework, I'm listening to podcasts
because I love that knowledge so much.
And I can't listen to any kind of music when I write, while I do any kind of work, so I
have to have silence while I'm writing.
And so I don't really get a chance to listen to any music.
But while I'm driving in the car and my kids are with my, they're playing music so I'm
kept abreast of all the music coming out these days.
So there you go, that's me.
Gally - Could a redwood tree that's grown on Mars or the Moon get so large that it could
be a living building?
Assuming that the tree is in a building.
Redwood trees could almost be buildings right now here on Earth, but the maximum size of
a redwood tree, I think is like 100 meters tall, like 300+ feet tall.
They're really at the theoretical limit of how tall a tree could grow in Earth's gravity
and envirnoment.
If you build a big enclosed dome on Mars and grew a tree there, you could definitely get
a tree that would get bigger than this limit of how big a tree can get on Earth.
Because and thanks to the lower gravity, the question is how theoretically big it could
get, and the answer is we don't know until we grow a tree on Mars.
Because the scale of living things is not only dependent on just how well a tree for
example can bring water up to its branches while fighting gravity.
There could be all kinds factors, like how well it could pull carbon dioxide or how well
it could expend it, or what is the possible strength it could hold itself in the soil.
So this is one of the things that we're just going to have to plant plants and see what
that lower gravity does to the biology of these plants and these crops.
But it would be amazing, right, if the force of gravity on Mars is 1/3rd of what it is
on Earth, could you imagine a tree that is 300 meters tall, that's 1,000 feet tall as
tall as some of the tallest buildings in the world.
Imagine one on the Moon, where it's 1/6th, so imagine a tree on the Moon that's 600 meters
tall, that's just mindblowing, that's crazy.
But really, there could be so many factors, that we don't know which one is going to cause
it.
Quintin Riekert - Why do you sound so negative about SpaceX
I gave that example, I should have grabbed another two that said, why do you gotta be
such a SpaceX fanboy.
And so this is on a video that we did a couple of weeks ago about SpaceX's new plans with
the BFR and how they're going to be going to Mars in like 2024.
And it's funny to me that people hear out of me exactly what they want to hear.
So in other words, so what I said was that, on the one hand, SpaceX makes rockets land
on their launch pads.
It is one of the most amazing accomplishments in the history of spaceflight that people
have been trying to do for a long time.
And the fact that they now do this regularly, it's a routine, we expect it to happen and
now they're using these rockets again.
Where they land, they can refurbish them and within a few months, they're able to launch
the rocket again.
That is an amazing amazing accomplishment.
At the same time, 2024 is only 7 years away and we've seen enormous delays with both the
original Falcon and with the Falcon Heavy, so it's not unreasonable to expect that there
will be delays with the BFR.
It's just as Elon Musk himself said, these are aspirational timelines.
If everything goes well, then they'll have the BFR flying by 2022 and send the first
spacecraft to Mars by 2024, but delays happen, there are challenges that come up that will
be unforseen and so me, the aspirational timeline is fine, but if takes another 10 years, 20
years, it's fine, it's good.
To create a completely reusable spacecraft top and bottom will change everything and
decrease launch costs by a factor that we don't even know what we're going to be able
to do, so where do I stand on SpaceX?
I am a fanboy and I am skeptical, and I'm excited and I'm nervous, and my mind boggles
at the potential for what we could do for this kind of thing to happen, but I'm also
not a huge fan of sending humans to Mars because I think it's kind of dangerous there and think
there are a lot of challenges that need to be figured out.
I have a lot of thoughts about this.
But I'm neither 100% skeptical or 100% fanboy.
I am all those things and so that's why I find it so funny that people see into my videos
almost what they want to see or something, anyway, so, that's all I have to say about
that.
But I'll keep reporting it because I'm incredibly excited about it, but I'm also a realist.
Radar Blue - How come neutron stars, composted of neutrons have a magnetic field at all.
Are neutrons central to magnetism?
The neutrons are usually portrayed as "no electric charge" unlike the proton and electron.
Neutron stars are the remnants leftover from supernova explosions.
The supernova goes off and the layers compact down inside and the protons and electrons
are mashed together into neutrons.
So you've got this ball made of neutrons.
But it's not only neutrons, it's mostly made of neutrons but it's also surrounded by other
protons and electrons farther out to the outside of it.
So you've got these rotations of this object and these different layers and that's what
leads to these powerful magnetic fields.
Silt Strider - Are the "planetary planes" in our galaxy random or do they have a tendency,
like to be at a similar angle as our galaxy?
I modified your question, I think this is what you're asking.
You've got the Milky Way galaxy and you've got all these different kinds of orientation
or all they kind of lined up, like little spinning plates inside this larger spinning
plate of the galaxy.
And the answer is that they're random, they're totally random, they don't match the plane
of the Milky Way itself and that tells you something about the way these different solar
systems formed.
If the solar systems formed within the galaxy and you got the galaxy had one axis of rotation,
and all of the solar systems had that same axis of rotation, you would think that they
all formed in a chain of events in the same way that the planets formed with the Sun in
our Solar System.
Everything is lined up in the plane of the ecliptic.
But what we see in the Milky Way is that all of these solar systems are arranged completely
randomly and that means that they had a completely different separate formation event from the
formation of the galaxy itself that they're embedded within.
And you can confirm this for yourself.
If you go out and look at the night sky, you're able to know where the Sun and the Moon pass.
I'm pointing where they go compared to my house.
For me the Sun rises over there and then heads all the way over there and then sets over
there to the West.
But the Milky Way starts over there, kind of to the north and goes across the sky and
goes over to the south.
And so you can see that they form this X, they're not lined up, and that's the way that
you can tell for yourself, that we don't live lined up with the Milky Way and none of the
Solar Systems out there do.
Vectorlover3 - I have a question.
Given the cost of launching infrastructure, the idea of retiring the iSS and the idea
of the Deep Space Gateway, could we not move and repurpose the ISS? if not to lunar orbit
then only for a one-off mission to Mars?
Thanks.
I get this question quite a bit, which is, why build new stuff when we've got the International
Space Station, and we saw Valerian and the 1000 worlds or something, and they kept adding
to the ISS to make a bigger and bigger space station and eventually they had to move it
away from Earth because it was just too close to the gravity well, for science reasons.
Anyway, I'm not going to debunk that movie.
But the point is the reason why you don't keep using the International Space Station.
There's a bunch of them, one is that ISS was designed to be close, within the magnetosphere
of the Earth.
And so it doesn't have the kind of protective shielding that you would want if you're farther
away from the Earth than just in low Earth orbit.
So that's the first one.
In other words to make it safer, you would need to up-armor it to be a more protective
place, while these new space stations that are being developed and the Orion spacecraft,
they're purpose built with the kind of radiation shielding that would be better protective
when you're outside the magnetosphere.
The second thing is that ISS really massive, it is enormous, it is complicated, has a lot
of moving parts and to try and move it away from the Earth would actually require a lot
of energy to do that.
And then the third reason is that it's getting kind of old.
I'm just reading this great book called Endurance from astronaut Scott Kelly.
And he was saying they now spend a good chunk of their time on the International Space station,
just maintaing it.
The various parts were built back in the 90s.
They're still maintaining those parts, the CO2 scrubbers, their toilets, their water
makers, all these things are wearing down to a point where the amount of time spent
maintaining the Internationla Space Station is just too long.
So does it make sense to build a purpose built spacecraft for a mission to Mars or a purpose
built spacecraft for lunar orbit.
They're expecting they're going to be deorbiting the International Space Station by 2028.
My guess is they won't, they're going to keep on extending the lifespan of it.
The same way they're extending the lifespan of the Hubble Space Telescope.
As long as they're getting science out of it, they're going to keep it going for longer
and longer.
It's just not the right spacecraft to take to the Moon and definitely not the right spacecraft
to take to Mars.
Fun4uitstrue - Hey Fraser, I know you did a video on what space actually looks like,
but it was mostly concerning false color images.
What I'm wondering is what space ACTUALLY looks like from the naked eye.
Say if I teleport to between the orbits of Earth or Mars or even into interstellar space
and if I open my eyes, what would I see?
You would see kind of what you would see from here on Earth.
So in other words if you opened up your eyes, you would see the Milky Way, you would see
bright stars in the sky, you would see bright stars that were the planets.
What you wouldn't see, you wouldn't see the atmospheric shimmering, every star that you
would see would be this perfect pinpoint of light that wouldn't be moving around in the
way that they are.
But you wouldn't see, you would still be able to see Andromeda is this hazy fuzzy bit over
there, like I said you'd see the Milky Way, you might see some other fuzzy nebulae and
other things like that, but you wouldn't see those nebulae that we see in the pictures
from Hubble Space Telescope and partly as I mentioned in that video is that stuff is
done with false color.
They take images using three separate filters and then they combine the images together
and they produce a false colour image of what it would look like.
But it's just that a camera can record photons for a long period of time.
Your eyeballs, your meat cameras flush out the photons they receive every couple of seconds,
so you'll never gather enough photons to build up a really pretty picture in your eyes.
Even if you were really close.
If you moved right beside the Orion Nebula, and you looked at it, you wouldn't get this
bright vivid thing with all the colors and all that.
You would still just see this fuzzy hazy bit and that's all it would look like.
Now if you just took your regular camera but you could do a really long exposure while
you were out in space, then you could produce astrophotographs that looked better that anything
here on the Earth with the same camera.
Being outside the atmosphere of the Earth really helps with how good of a picture you
can take.
But you're still just limited to the fact that our eyes can't gather the photons over
that long period of time that a telescope can.
And so every picture of space that you see is done really using the technology of the
camera to produce that image.
AnotherGlenn - Has anyone been developing equipment for processing raw materials in
space?
We'll need clean water?
What about the energy and the chemicals needed for the processes?
What will we have to bring with us?
What can we use that's already onsite?
So the term for what you're talking about is called in situ resource utilization, in
other words, using the resources of space on site to be able to support your exploration.
And this is something that explorers have done forever.
When you're exploring some new place back in the 1600s or 1500s, you hunted and you
gathered food from where you were and you built shelter out of the trees that you cut
down.
That you didn't bring all that stuff with you.
So that concept, that technology makes sense.
When we go to Mars, for example, we're going to be able to make methane fuel right out
of the atmosphere of Mars by pulling in the carbon dioxide atmosphere, mixing it with
the hydrogen gained from the water deposits on Mars and be able to produce methan fuel.
People are going to be able to use the regolith of Mars to grow crops if that's what they
want.
There's going to be all kinds of uses for these materials that are out there.
And over time as our technology, as our ability 3D print, as our ability to draw in these
resources gets better and better.
You can imagine more and more of the technology used for space being maintained out in space.
And the great thing is that out in space, you're already outside of the gravity well
of Earth.
Trying to get material from the gravity well of Earth out into space is the worst.
But out in space, you're already there.
And you've got enormous resources, there's metals and water and rock and the materials
that you would need to be able to produce pretty much almost anything.
Lots of energy with solar radiation, it's just a matter of building up bit by bit the
techologies to be able to do this.
Stu niverse - As the Sun heats up over these millions of years, since Mars' global temperatures
goes up, would that mean that Mars' state could be a little more comfortable for life?
The Sun is outputting more radiation and over time, the amount of radiation is going to
be increasing.
But the problem is that the Sun is blasting away anything that is, any atmosphere that's
trying to build up around Mars.
And so one of the really cool ideas that I've heard is that you could build this artifical
magnetic shield and you put it at the L1 Lagrange point between the Sun and Mars and it acts
like a cone that protects Mars itself from the solar radiation that's coming from the
Sun and that would let the volcanic outgassing build up the strength and thickness of the
Martian atmosphere.
And over time it would warm up and you'd get the polar icecapse to melt and that would
thicken up the atmosphere even more.
So this is the challenge you're always going to face.
The reality is that Mars is dead and it lost its atmosphere a long time ago.
And really unless we get in there and come up with a solution to help rebuild the thickness
of that atmosphere, Mars will really ever come back.
All right, another week, another set of your questions.
Thanks to everyone for asking their questions.
As always, wherever you are, wherever you are on my channel, just type in your question.
It doesn't matter if it's about the episode, or whether it's just some random thought that
just came into your brain, I'll gather them up and I'll answer them here.
I'll see you next week.
For more infomation >> Family member shares story about mother's tragedy - Duration: 1:43. 
For more infomation >> Learn Colors for Kids With Wooden Toys Numbers 1 to 10 Education Video for Kids Children Toddlers - Duration: 10:27. 
For more infomation >> Muerte fatal de un hispano por defender a su hijo | Al Rojo Vivo | Telemundo - Duration: 2:28. 
For more infomation >> Video: how funds are spent under review by school officials - Duration: 1:54. 
For more infomation >> Perturbador video de maltrato a unas vacas en una granja | Al Rojo Vivo | Telemundo - Duration: 2:31. 
For more infomation >> Tomó foto de su esposa muerta y luego la desmembró | Al Rojo Vivo | Telemundo - Duration: 0:42. 
For more infomation >> Hai Loại Trái Cây Dùng Để Giảm Cân 3-5 Kg Trong Vòng 1 Tuần Hiệu Quả Nhanh Nhất - Duration: 5:40. 
For more infomation >> Veteran allegedly targeted by firefighter who police say robbed bank - Duration: 1:29. 
For more infomation >> Video: High school senior kicks for cancer - Duration: 1:37. 
For more infomation >> Conmovedor drama de niños que tienen a sus padres presos | Al Rojo Vivo | Telemundo - Duration: 4:22. 
For more infomation >> Drug firm founder pleads not guilty to opioid conspiracy - Duration: 1:50. 
Không có nhận xét nào:
Đăng nhận xét