Hello again, thanks for joining us on Space Nuts Q and A Andrew Dunkley
here your host. Going to have your company and great to get a whole
bunch of questions in from various members of the audience who want to know about
supernovae. It's a question that's come in from David and Peter Is because Fred
Fred's written books about telescopes or one in particular, Peter is asking Fred's opinion
of three D printed telescopes. That's a new thing. James wants to know
about the voyage of space probe missions, and Zay is he's come up with
an interesting idea on how to do particle collision. That's all coming up on
space nuts Q and a fifteen second is in channel ten nine ignition sequence space
nuts or three two space nuts as when I report it, Neil's goods and
back again to answer all of those questions and probably a lot more is Professor
Fred. What's an astronomer at large? Hi? Fred, Hell there,
Andrew, very good to see you, looking hale and hearty. Yes,
I wish no, we're going all right. We're going all right? Shall
we get stuck straight into it? I think that's a good idea. Yes,
all right. Our first question comes from David Hey, Brendan Andrew.
This is David Fellows Flee in Texas. Question about supernovasplodes. Why doesn't it
blow away the gravitational field? And how does it stay intact to become a
new front star? Why doesn't it? And it does? Thanks m.
We've had questions about supernova before and we did actually refer to them in the
last episode the standard Candle. Why do they not blow away the gravitational field?
And how does a neutron star developed as a consequence of a supernova?
Yeah, it's a good question, and you know, we think of an
explosion as blowing stuff away and gravity is a bit more robust than that.
Though it's not something you can blow away. It's always associated with mass and
that's where really the answer to David's question comes in, because what happens when
a super and over explodes is it's just the outer envelope of the star.
So what you've got is a star which has got a core where all the
action is taking place, exactly as our sun has. And then on top
of that, you've got this mantle or envelope of hot gas where lots of
things happen. Magnetic fields do their thing and convection does its thing. When
a super and Over explode, basically the energy of the explosion goes into that
envelope of material, so it does blow stuff away. And you know,
David said, why doesn't he just blow blow into dust? And in a
sense it does. We find all over the sky and there's a beautiful new
picture of one at the moment called the Villa Super and Over Remnant. We
find these remnants of supern Ova, which is the gas and dust that's been
expelled by the explosion. There's a new image from the Dark Energy Camera has
been released to show what the Villa Super and Over Eminent looks like. If
if any of our listeners want to check it out, I think you're doing.
That's an amazing picture. Yeah, just to add to that, one
of the first pictures of that super over eminence, certainly the first in color,
was taken by my conic David Merlin back in the probably early nineteen eighties,
because he was the man who worked out how you could take true color
images of celestial objects, and that was one of his first targets and it
is very, very spectacular. The new image taken with a one point three
gig pixel camera I think shows a lot more detail. It's taken on the
telescope about the same size actually as the Australian telescope that David used, but
on a better site. So the detailing very very spectacular. That's not part
of the story, but that's just to let you know and let David know
that he can go off and find pictures of exactly what he said. All
the DU's being blown away. It's gas as well, gas and other stuff.
But the bottom line is that gravity wins. Gravity overcomes the outward force
of an explosion and pulls the core of that star down to the size of
a neutron star, so that gravity is all concentrated, if I can put
it that way at the middle, and it wins out. That's basically what
causes the explosion. The fact that gravity wins out, the core collapses,
and because of basically momentum considerations when the course collapsing, all this other stuff
is being blown out into space. I used to do for schools Andrew a
demonstration with a ping pong ball which is very light and one of those really
solid rubber bouncy balls that bouncees really well. And if you hold the two
together and then drop them, the bouncing ball transfers some of its momentum to
the ping pong ball. The ping pong ball flies up, usually hits the
ceiling quite often hit me in the eye, which always went down well with
schools. Occasionally hit the teacher at the back of the hall. That went
down well as well. But it's just that transfer of the momentum, the
energy from one to another. So I used to say this is the heavy
rubber ball is an iron atom, the lightweight pink pong ball is a hydrogen.
To put them together, because they are together, drop them. What
happens. The iron atom goes down, the pink pong ball goes up very
quickly. Indeed, it's a good demonstration to do, actually, And so
that's what's happening. But the bottom line is gravity always wins. And the
only thing that stops the neutron star crushing being crushed into a black hole is
the outward pressure of the neutrons themselves, and that's the You know that that
is enough to stop that gravitational pull. Okay, just as a bit of
a side note, you mentioned one point three gigapixel camera. If you were
to lay out a photograph from a one point three gigapixel camera, it would
be eighty by thirty inches. Okay, yeah, I wanted to know how
big a photo would be if it was one point three gigapixel. That's big,
that's too many. Yeah, it's a pretty big photo. I've seen
them, some of the big photographs put to full size on a computer screen
and you'll see like just a chunk of it. Yes, I have to
scroll, stroll and scroll is to get the whole photo. But of course
you can cram them into the screen these days. But yeah, they're quite
amazing. Thanks for your question, David. We've got a text question now,
Fred. This one comes from Peter. He said, I'm new to
astronomy and just found a three D printable telescope, the Hadley. I've not
used a telescope before. What do you think about this project? Is it
a good place to start? Named Peter from Peter, I had look quickly
at the website he sent about printable or printables dot com is the website,
but it also shows this printable Hadley telescope. Did you have a chance to
have a look at that thread? I did yes, it's really interesting.
Actually so what you're fabricating other mechanical parts, and it actually looks pretty well
done. It's a modest sized telescope one hundred fourteen millimeters that they're talking about
for the aperture that's getting on for five inches. That's a usable size and
it's cheap. There will be a lot of fiddling around with because you've got
a three D print the components, and there are a few components you've got
to buy, and certainly the optical components. You can't three D print the
ips and the mirror of the mirrors, so you can buy your screw and
mirror kits and you can then do the three D printing of the mechanical bits.
To be honest, I think as a beginner that you might be better
buying a cheap off the shelf telescope such as adopsonian, which is the kind
of telescope that sits, you know, on what we call an altatimuth mount.
It's just basically a box with cutouts in it so the telescope can sit
in it and you can move it up and down. The printable telescope is
that kind of telescope, but you're kind of starting from scratch, and you
might not really know what all these bits and pieces are for. So my
estimate, if your a rank beginner, would be to save up a little
bit more and buy a small Dopsonian telescope, which are very readily available.
Probably wouldn't cost you that much more than the three D printed one either.
Okay you are. I was going to suggest that maybe a three D printable
telescope would be a lot cheaper, but maybe not. But five inch five
inch mirrors pretty well, lens is pretty Yeah, it's pretty decent in terms
of starting point. It's bigger than mine for four and a half inches.
Yeah, I think this. You know, tell uscope making is an art
in itself, and you're still doing that, but you're just, you know,
rather than sawing bits of wood up and things of that sort of drilling
holes in metal, you're actually three D printing. So yeah, if you
if you're into three D printing, give it a try. But yeah,
my bat is you'll find it easier to get into astronomy by buying one.
I'm not I haven't tried any three D printing. My son bought a three
D printer and used it for a while. And I think he built his
his son, my grandson a racing car with it or something. But it's
it's extraordinary technology. But it shouldn't surprise us that three D printed telescopes are
a thing. Thanks Peter Lovely to hear from you. This is space nuts.
Andrew Duncley here with Professor Fred Watson. Okay, we tech vote space
nuts. Next question comes from an old friend, James, mister Duckley Prester
Watson exchanged from Cincinnati, USA, and I've got questions relating to the Voyager
mission. I recently read where Alan Cummings, who worked on the mission for
five decades, said the spacecraft should last one billion years. My questions what
star systems are the spacecraft going to encounter and how close Where might it end
up after one billion years? Based on the size, I imagine it will
be incredibly unlikely any ets out there would detect either craft. If an alien
version of Voyager came as close to our son as either spacecraft are predicted to
encounter and other star systems we be able to detect it. Good question.
Thanks James Lovely to hear from you. You know James has been I was
wondering that James the other day. I haven't heard from him in a long
time, but theory is, and I've still got my Cincinnati Jersey. Thank
you, James. I adore it. Voyages. Yeah, where will they
be in a billion years if they survive, and it's every probability they will.
Yeah, that's right, it's you know, i'd say probably longer than
a billion years. So I don't know the you know, the the exact
number of objects or solar systems that are on their current trajectories. There are
two of them, of course, the two voyages. Voyas are one of
the most distant human made objects, Voyager two not very far behind it,
but in a different direction. I don't think either of them are going to
pass near any star systems, you know, within any kind of human lifetimes.
But because I think their veloses in the region of twenty kilometers per second,
and well you can divide a billion years by twenty kilometers per second to
get how far they'll go, it's still within our galactic neighborhood. But I
think the more interesting question that James raises is could they be spotted by,
you know, somebody on the planet in extraterrestrial intelligence on a planet as these
things drift by, and the answer is yes, they could if they were
near enough to the Earth. Both the voyagers would be detectable from Earth.
If they were whizzing through our solar system, it would depend on the trajectory.
If they were on the other side of the Sun, we'd never see
them. They'd be too small, you know, they're just a few meters
in size. But they will shine by reflected sunlight or in the case of
the Earlien version, reflected starlight. And if you've got big enough telescopes and
you're sufficiently adept at scrutinizing the sky, you might well see them. And
then you might do what we'd love to have done with the interstellar asteroid chase
after it, with rockets or laser propelled sales with cameras on board, just
to find out what it was. So that's I guess the old thing at
fate of the voyage of spacecraft is maybe to be captured into orbit around another
star, maybe to collide, although collision, because space is so big,
a collision is actually a lot less likely. It's more likely that they might
be captured and maybe even spiral in towards something down the track, which I
guess will be a collision, but we don't know. And that's what makes
them. I find them completely intriguing, these voyagers, and in fact the
other three space that are leaving the Solar System, because they'll probably outlast our
species. Uh and yes, effectively go on forever they've you know, they
will they will keep going. They won't keep operating. The nuclear batteries will
die, but they will be still artifacts on a trajectory away from the Solar
System. Yes, And of course one of them is carrying that recording of
the sounds of Earth. So the two voyages, yeah, they both got
that. Yeah, all right, I didn't read one interesting Oh that's right.
Yeah, I did read one interesting theory is that they could reach a
star that doesn't exist yet in one or two billion years, So you go,
yeah, that's food for thought. Yes, indeed, so there's there's
all sorts of possibilities. Could they you know, is it possible that one
or both of them could be captured into a planetary orbit. Yes, and
when we've captured a couple of pseudo moons, haven't we. That's right.
That was one of the outcomes that I mentioned that I probably didn't say it
was being captured into an orbit. But that will be what would happen,
and it's captured by the gravity, and it would remain in orbit, maybe,
as you say, forming an artificial moon of a of a distant world
around a distant planet. Wouldn't it be amazing if it just happened to stumble
across an occupying planet? Yes, yeah, yeah, And they eventually achieved
space travel and went up there and went, hang on a minute, what's
this? What is the first? Yeah? Yeah, I never say never.
Thank you, James. And our final question today comes from Zaane.
Hey, space nuts, this is a name from Moment, Australia. I
hope everyone is doing good. I've been listening for ages. I love the
show. Now I've had this idea of the years and it's on the topic
of particle gliders, like a large hadron glider, which, don't get me
wrong, is an awesome piece of engineering. Also hop it we build these
things in space and from what I understand, the particles are guided along their
journey by electromagnets and I'm guessing the bulk of what makes up these machines are
those super conducting electromagnets and that would cost a lot to send up to orbit
even once starship is up and running. But would we even need them?
Couldn't we just shoot these particles off in opposite directions in the same orbit and
wait for them to meet up. And I guess the speeds with forests like
far exceed the scapebod see if anything else all system. So I suppose we'd
need to do it around something really big, black, hot, or something
might of the wait a long time idea. It's an idea, and I'd
love to hear what friend Andrew you boys have to say that. So have
a good one. Thank you, Zay, and thanks for being a long
term listener. By the way, particle colliders, okay, we've got Yeah,
we've got the large hadron collider on Earth, and I think they're building
a bigger one. They've fred but taking it off shore, you know,
maybe using the planet as a particle collider, using the natural gravity effect.
I don't know how you would target something so minute in opposite directions to meet
on the other side with precision. That's the that's the quandary I find in
this question. Yeah, there's a number of issues. Zam's right though,
that a large children collider is it's us quite modest in its size. The
tube is about a meter across, which is what is it twenty seven kilometers
if I remember rightly, around the perimeter of the of the large Adrin collider,
So it's a meter that that contains the electromagnetics and cryogenic cooling liquid even
liquid helium. I can't remember what the coolant is, but all that those
magnets are exactly as Zaine said about precisely guiding particles along around the accelerator.
So that guiding has to be very, very precise. And you're right in
what you said, Andrew, in that you know, the precision that you
need to get too protons to collide is pretty high considering how small they are,
But the problems bigger than that. And Zen's actually hit on it the
figure quite a lot of times. It's been at the large Hundrd collider,
but I've been there several times and in fact went down into the bowels of
it to one of the detectors, the compact new on solaroid, where you
see the ends of these tubes that do the acceleration. The velocity is if
I remember rightly, they're accelerated to ninety nine point nine nine eight percent of
the speed of light, So they're traveling at the speed of light, so
they're above the escape velocity of anything that you could think of putting at the
middle, with the exception of a black hole. As Zain said, we
know that black holes do focus the light around them. They actually, you
know, the light travels around a black hole because of the gravitational distortion of
space. But you're not trying to make particles collide around a black hole.
So maybe with a black hole it could be done. You've still got the
difficulty of getting one particle to hit another by the end of it, by
the end of its orbits around the black hole. I think it's going to
be much easier and much more cost effective and much more realistic to keep doing
things here on Earth with our standard particle colliders guided by electromagnetism. Indeed,
yeah, I like his idea, and maybe one day they'll find a way
of doing it off the planet. At this point in time here probably beyond
our capabilities and certainly beyond our bank balance twenty six point seven kilometers the larch
hedron collide said twenty seven. So not that rounding up is always a good
thing. In astronomy unless it's the hubble tension. Andrew, if you're around
those numbers, they both come out to seventy and the hubble tension disappears.
So wheneber you hit you fit on the answer. That what we were talking
about last time with the tension. Yes, thanks to your question, Zaan.
Always good to hear from you, and a reminder, if you do
have questions for us, please send them through via the website. We always
love to hear from you. It's a simple process of jumping on to space
Nuts podcast dot com or spacenuts dot io and just click on the AMA link
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and if you want to tell us where you're from, that is nice as
well. We do love to know where you're from. So yeah, send
us your questions. We will try and answer them in our Q and A
episodes every week. Fred, we're done for another another day. Thank you
so much, it's a pleasure on you and I look forward to talking to
you next time. Indeed, Professor Fred Watson, astronomer at large part of
the team here at Space Nuts. And thanks to all those people back in
the studio a number one named Hugh for helping out as always, And from
me Andrew Dunkley, thanks for your company on this edition of Space Nuts.
We'll catch again on the next episode. Until then, bye bye. You'll
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