#414: Stellar Collisions & Invisible Invitations: Unveiling the Universe's Secrets

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Hi there, thanks for joining us
on this a Q and A episode of

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Space Nuts. Andrew Dunkley here,
good to have your company. On this

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episode, questions from James, Lloyd, Rennie, and Ron. James is

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asking about planet nine. Lloyd is
asking about certain colliding objects in space.

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We talk about black holes knocking each
other off, and neutron stars and black

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holes, but what about stars and
stars or stars and stripes running into each

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other. I don't know. We'll
find out electromagnetism and how visible are we

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to other civilizations. That's a really
good question. We'll answer all of those

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and furnish you with a couple of
comments from the audience as well. On

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this episode of Space Nuts. Fifteen
said in Channel ten nine ignition quench Space

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Nuts NY four three two Space Nurse
as An actually bought it. Bill's good.

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Let's get all the answers from his
good self, Professor Fred. What's

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an astronomer at LA? Hello?
Fred? Hello, Andrew. Can't guarantee

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to have all the answers, but
well that's good. Now we're going to

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start with a couple of comments.
These came in in the last week or

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so. The first one is directed
at you, Hi, Andrew and Fred.

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Thanks for the shout out. Fred. We're Kate and Jeremy, the

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couple from the Central Coast who met
you on the Canadian train. We ended

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up in Gander on the island of
Newfoundland in Canada for the eclipse. We

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had clouds coming and going through the
initial stages, and then right before totality,

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clouds came over and we never saw
the sun again. Oh no,

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I still saw the surrounding effects.
But now to see if we can get

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to Spain in twenty twenty six.
Great to meet you and love listening to

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the podcast Kate and Jeremy and they
can come to Dubo in twenty twenty eight

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and catch it here. We should
have should have clease, guys, but

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you never know, do you.
But you had the opposite. You had

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clouds and then they disappeared right at
the last second for so that's right.

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And look, it was lovely to
meet Kate and Jeremy. We were all

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in a very party mood at the
time and I think they just joined it

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very briefly. But it was lovely
to see them and just a quick plug.

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That was our Canadian tour that Kate
and Jeremy's accepted on the Canadian train

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and we are going to do another
one for the Spanish Eclipse twenty twenty six,

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so there'll be a tour there,
so keep it touched, Kate and

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Jeremy. You never know. Yeah, fantastic with us. I think we're

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going to Gibraltar actually, which too. That place rocks. Okay, that

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was horrible and it was very quick
though, Yeah, it was very quick.

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I should work in radio. Now
I've got a comment directed to me.

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Just what to agree with Andrew.
I'm trying to read The Three Body

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Problem. It's a book that's now
been made into a TV series which I

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was intrigued by so much I had
to get the book. Now. The

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book was written by a Chinese author
and it had to be converted into English,

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and in doing so it sort of
became a bit convoluted. I suppose

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it was a bit It's a bit
of a tough read. And Ralph's messaged

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me to say, I agree with
Andrew. I'm trying to read Three Body

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Problem, but I'm about to give
up on it. No fun, Ralph.

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I have a solution for you.
I've reached a chapter which is very

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highly technical and it's sort of explanatory
notes about what they're trying to do at

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the research center that is the subject
of the story. I have taught my

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iPad to read to me. Apparently
you can change some settings in an iPad

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where it will read the book or
read what's on the screen to you.

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So I'm getting through those chapters by
having it read it to me, so

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I don't have to try and tangle
with it myself. It works pretty well,

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So maybe you want to look into
that. If you've got an iPad.

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I'm sure you can do it with
Android devices as well. Don't well,

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I think you can do it with
a kindle. They all come with

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spoken voice capability, I think.
But that's how I got around it,

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Ralph, don't give up. The
story is actually really good. The only

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problem I find is because all the
characters have Chinese names, I keep forgetting

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who's who, which is a bit
of a sad indictment on me culturally speaking.

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But I keep having the thing,
now, who's that which one?

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Because when you separate names like Fred
Watson and Andrew Dunkley and all, that's

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easy for us from a Western hemisphere, but the Eastern names I tend to

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I lose track of who's doing what
anyway, that's just that's my suggestion to

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you, Ralph, get the book
to read it to you rather than you

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struggling through it. Of course,
if you've got a paper copy, nothing

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I can do for you, bless
somebody else to read it to you.

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Maybe maybe now, Fred, they're
all text questions today because I had a

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computer meltdown, not just in recording
these episodes today, but last weekend when

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I was getting prepared, and so
I lost all my audio questions, which

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I'm going to regather. So we're
going text all away today. Planet nine.

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Should such a thing be discovered,
does it have a name that's just

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waiting for the body to be discovered, or would the individual who makes the

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discovery be allowed to name their discovery
following whatever naming guidelines exist. Thanks for

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putting a smile on my face.
Fellow's name and then that comes from James.

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Now a couple of things. It's
about planet nine. You actually spoke

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to someone on your recent tour who
has a thought about the planet. But

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well we might get to that in
a minute. The name, let's say

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they find it. Yeah, there's
the Astronomical International Astrotomical Union is charged with

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the responsibility of naming it. But
does did the does discoverer get us say

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in it? I'm sure they would. So the convention with planets is they're

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named after principally Roman gods, because
that's how it all started, you know,

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with Mars, Mars, Mercury,
Venus, and that was continued when

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planets started being discovered, of which
the first one was yeah, the one

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that's upside down Neptune. Yeah,
that's the other one. Sorry. Yeah,

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So until seventeen eighty one, when
William Herschel discovered the object that became

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known as Uranus, no planet had
ever been discovered because they were just known

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before that. That's where you yeah, okay, that's what through me.

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I was thinking, well, surely
it was one of the inner planets that

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was found first, but no,
they've just always been in our awareness and

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yes, that's right from you know
truly edentry times, as soon as people

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started looking at the sky and you
know, first nations people here in Australia

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would have known about them as well, but they gradually got associated with Roman

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names Mars, the god of war
and this other thing, and so that

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would continue with the discovery of another
planet. If it was classified as a

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planet. Now we have a glitch
in that, because Pluto was classified as

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a planet when it was discovered in
nineteen thirty. It was named, as

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you and I have spoken about before, by an eleven year old, a

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girl in Oxford in England, whose
name was Venicia Bernie. She basically suggested

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the name Pluto to her grandfather,
who was a mate of Herbert Hall Turner,

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who was the professor of astronomy in
Oxford, and he telegraphed it to

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the discoverers of the Loyal Observatory in
Arizona, and Pluto was agreed. But

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it was perfect because it was the
Roman god of the underworld, and so

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that's a great name. Venicia was
interested not just in astronomy, but also

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in mythology, Greek and Roman mythology, so it would have to follow that

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guideline. Unlike the objects that are
discovered, like and these are important in

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this story because these are the one
that suggest that planet nine might be there.

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The transit Neptunian objects objects in the
outer regions of the Solar System,

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which now include Pluto. They are
traditionally named now and again it's a convention

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imposed by the International astronomical union.
But again it probably has, you know,

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the guidance of the people who made
the discovery. They're named after deities

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in the First Nations culture of wherever
they were discovered, So that, for

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example, is why and it's not
a Kuiper Belt object, it's an interstellar

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object. But it's why Umua has
a Hawaiian name because it was discovered on

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the island of Maui with the pan
star's two telescope and Hawaiian word meaning first

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messenger from Afar. And so you
know, when you look at the list

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of names of particularly the trans Neptunian
objects, I'm thinking of Senna and thinking

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of Mahe mahe. I'm sorry,
it's Maki Maki. These are names that

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come from the culture of whatever tradition
it was in which they were discovered.

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But planets are given Greek or Greek
or Roman names of underworld. Oh sorry,

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got of deities basically their deities.
Yeah, well, I you know,

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something sparked in my brain when you
started talking about the discovery and naming

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of Uranus, and I was right
because I just looked it up. Herschel

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didn't name it Uranus. He named
it Georgie of Sidis, which is named

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after King George the Third. Now
we to call it George. Yeah,

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that's right, but they weren't.
You weren't allowed to keep that it was.

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Actually, it's really interesting. There
were there were three names. So

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he discovered it on the thirteenth of
March seventeen eighty one Urinus Day, internationally

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Urinas Day, and so over the
next twenty years there were basically different names

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given to this object. He was, as you said, he wanted to

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call it Georgimsidus, which means the
Georgian star, named after the King George

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the Third, who already was showing
signs of being a bit loopy, and

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that's why that was not a popular
name. On the certainly incontinental Europe.

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There was a body of opinion that
wanted to call it Herschel, after the

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discoverer, and that would be the
case if it was a comet. By

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modern convention, we'd call a comet
after the discoverer. But people didn't like

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that either, And it was actually
Johannes Border, who was a very well

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known astronomer in Germany, who suggested
the name Uranus is the I think the

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parent of Saturn in mythology, so
it kind of you know, it works

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quite well. Of course he would
have called it Urganness because he was of

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it. Than that's yeah, quite
an innocent name compared with what we call

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it. Indeed, so the answer
to the question is that the discoverer may

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have a say in it, but
the International Astronomical Union will basically rub a

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stamp it and it will probably take
the name of some kind of Roman Goddish

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person deity, King Queens. That's
my explanation. All right, thank you

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for the question, James Hope,
that helped. This is space Nuts Andrew

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Dunkley here with Professor Fred Watson.
Okay, we take a space nuts.

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Next question, very interesting the episode
about the neutron star collisions. You've spoken

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many times about black hole collisions and
neutron star collisions. But do just normal

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everyday stars like our sun ever collide
and what do they create? Thanks to

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the show Lloyd from Cans that's in
North Queensland on the east coast of Australia

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for those who've never heard of Cans
and it's not spelt c Ans now see

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A I. R. S.
Kenes. Now, well the answer would

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be yes, I mean just about
anything and everything could collide with something of

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its own making or something else,
couldn't it. Yes, that's absolutely right,

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And you know the collisions are.
It's not usually something smashing directly into

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something else. It's usually usually a
dance. It's a dunce, that's right.

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Yes, very spectacular one where things
basically circulate around one another. So

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if you yes, So if you
brought two stars together, say about you

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know, one to two solar masses
each, and then merge, then you're

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going to create something of order four
solar masses, supposing there were two solar

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masses each, which is more than
the limit imposed by the gravitational physics.

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I'm just trying to run this through
in my head because it's something thought before,

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which is terrible, isn't it.
So you might get super over explosion.

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Two big ones merged, they couldn't
hold. That's right. You've got

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something that's that's unstable, so you
might get a super and over explosion.

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I mean we see many instances.
In fact, probably half the stars in

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our galaxy are in pairs which are
orbiting around one another. We call them

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binary systems, and some of them
are very close. Some of them are

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close closely enough to stort the you
know, to distort the physical body of

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the star. There's something if you
get it's something called the rocial limit.

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If you get within the rocial limit, then you're going to distort the body

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of the star and you probably pull
one of these objects to pieces. So

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there will be tidal forces. That's
the trick that tidal forces which actually tend

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to destroy the envelope of these stars. Anyway, really interesting thinking. I

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mean, we do know that planets
can be goggled up by their stars,

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because we can see the evidence for
that. We see planet type chemicals in

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the atmosphere of some stars. And
so it's not that big a leap of

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the imagination that if you've got a
binary system where they're very close and ones

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inside the rocial limit of the other, then you'll get a combination of the

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two and it might be something relatively
gentle, or it could be super over

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I mean if it was gentle.
By that, I mean what would happen

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something like a plan industry and nebula, which is what will happen to us

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some it will shed its half to
layers and make a beautiful shape nebula.

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For anybody else who has to be
looking at it from the outside. So

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yeah, a really interesting speculation.
I think the answer is yes, two

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small stars could combine to make one
slightly larger star. Is that realistic?

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Yep? Ye, two large stars
just they just go Yeah, all right,

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very good. Thanks for the question. Lloyd was Lloyd? I should

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really format my list of questions better
because I keep losing the names. But

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Lloyd and Hope all those wells from
kings Yeah up in Queensland. Probably a

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Cowboys follower. This is Space Nuts
Andrew Dunkley with Professor Fred Watson spacebuts okay.

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The next question, Fred, is
about electromagnetism. Can you explain it

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as far as how it forms,
how it behaves, how common it is

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on other planets? Do galaxies as
a whole have electromagnetism and what happens to

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a planet that doesn't have it?
Love the show. That's from Rennie Traub,

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who used to send in audio questions
but has taken to the mighty pen

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or keyboard these days. Thanks for
the question. Really nice to hear from

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you. Yeah, we talked about
electromagneism magnetism. I think it was last

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week, wasn't It was very recent? Yeah, we it's the stock in

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trade of astrophysics, so we talk
about it a lot. So yeah,

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so you know, we we can
think about electromagnism in two ways. We

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can think of it as waves traveling
through space, which is what gives us

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the phenomenon of electromagnetic radiation like radio
waves, gamma rays, X rays,

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infrared all of them are infrared radio. Sorry, all of them are electromagnetic

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radiation, which are a different wavelengths
or different frequencies, which is the same

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thing but turned upside down frequency being
how how quickly they wobble wavelengthies O along

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the waves are so. But the
other way to think of it as is

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and to some extent that you know, Ready's question is easier to answer this

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in this scenario. We can also
think of it as photons because photons are

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the particles that carry electromagnetic radiation.
They're subatomic particles. We know they exist.

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We were talking last week about whether
the human eye is sensitive enough to

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detect single photons. We have the
conclusion that we've seen research recently that said,

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yes, it is possible for the
human eye to detect single photons.

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But yeah, so they're subatomic particles
and they interact with other subatomic particles,

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the particles of matter. And so
that's a great way of understanding how electromagnetic

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radiation is formed, because if you
have you know to put it in the

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old fashion nuclear scenario. Got electrons
orbiting their parent atom centers. Those electrons

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are in orbits. This is an
old fashioned way of looking at it,

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because it's a lot woolier than that
under quantum theory. But this is the

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really meant quantum theory. Those orbits
can be at higher or lower levels.

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And so if a photon hits an
atom, it boosts an electron up to

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oh maybe maybe put it a different
way, if another particle hits an atom,

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it can boost an electron up to
a higher energy level, a higher

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orbit. When it falls back,
it admits a photon that emits the electromagnetic

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radiation. And so that's how that's
one mechanism by which they are four.

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How does it behave? Well,
it travels in straight lines normally in a

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gravitational field, it might bend because
we know that space bends light as the

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space is distorted. How common is
it on other planets? Well, other

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planets are probably bathed in the electromagnetic
radiation from their parents stars. So are

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we as are we? That's right, we see it all around us.

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I'm watching it at the moment.
A few clouds in the way, but

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there's electromagnetic radiation coming from the Sun. Do galaxies as a whole have electromagnetism,

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Yes, they do. We now
have the wherewithal with sensitive detectors.

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In fact, I know one of
the astronomers who's built one of these sensitive

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detectors sensitive to one part in a
million. Andrew. It's extraordinary. He

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works at the University of himself Wales. You speak calling good mind at the

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end Australian observa treature, I mean
Bailey. So he builds what are called

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polarimeters, and a polarimitter is something
that takes light but can sense how it's

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polarized. And most of us are
familiar with polarized light, with the polarizing

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sunglasses and things of that sort.
His polarimeter is, as I said,

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it's kind of like a pair of
polarizing sunglasses. Stif it parts in a

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million, which is quite incredible.
And what that looks at is the way,

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for example, the way light interacts
with dust particles in a distant galaxy,

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for example, and those dust grains
are often aligned by magnetism. So

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if you've got a galaxy that's got
a magnetic field, it will actually show

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up a polar emitter will show up
the magnetic field around it by the way

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way that the light from it is
interacting with dust grains surrounding the the you

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know, the galaxy itself. So
we we've mapped the magnetism of galaxies really

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quite accurately. By we, I
mean the astronomical community. What happens to

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a planet that doesn't have it.
Well, our planet's magnetic because it's got

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an iron core, and we think
that Mars might well have an iron core,

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but it's kind of static. It's
just not hot and swishy like ours

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is. So Mars doesn't have a
magnetic field, so you don't have the

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protection from radiation from the Sun because
you don't have a you know, a

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magnetic field that actually deflects that radiation. So that they're very quick and glib

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answers to that list of questions you
sent, really and I hope they help

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because electromagnetism is everywhere. It's one
of the fundamental forces of the universe,

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and we probably couldn't do without it, certainly not here on Earth, because

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it would be well douarded by radiation
from the cell that would not be doing

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us any at all. No,
not really, Probably impossible for life to

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develop in an environment like that,
I would imagine, maybe, so yes,

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yeah, yeah, all right,
Thanks Rennie. And our final question

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today comes from Ron. I like
this one. I didn't like any of

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the others. No, of course
I did. If scientists in a distant

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solar system were searching for exoplanets using
the same technology that we are using,

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and if they were to observe our
planet, would they be able to tell

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with any degree of certainty that there
was life here? Or conversely, if

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we were to observe an exoplanet that's
exactly like Earth, teeming with carbon based

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life, and perhaps with an advanced
civilization modifying their atmosphere, could we tell

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that there was life there? Thanks
Ron. We've had variations of questions like

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this, but I always like revisiting
it because let's say somebody out the squidions

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of miles away put points a telescope
at us, you know, the John

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Webster space telescope, let's call it. Would they be able to tell that

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there is life here. The answer
is yes, yeah, I thought it

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would be yeah, and with and
that's because of the you know, the

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signature of living organisms in the atmosphere, and in the case of Earth,

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that we call these biomarkers. So
the biomarker would be oxygen, which is

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sort of out of balance with carbon
dioxide, and I think methane comes into

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the equation as well. How to
balance with methane, So that the only

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way that you could get this mixture
in the atmosphere is by the fact that

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we've got life pro this is going
on. If you had purely chemical reactions

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taking place, then you wouldn't get
these you know, these mismatches of some

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of the chemicals that we have in
the atmosphere. Not only do we think

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that's the case, we know it's
the case because it's been tested and this

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is an experiment that's been done many
times. You know, the phenomenon that

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we call earth shine Andrew, what
you see when you've got a crescent,

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really thin crescent moon, you can
actually see the rest of the moon dimly

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illuminated. Yes, yes, yes, yes, not so long ago.

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Yeah, you would probably see every
month because if you're looking at the right

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time. Yes, that's right.
It was Slenado who da Vinci who sust

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out what was going on there,
that what you're seeing is the light from

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the Sun hitting Earth and then being
reflected back to the Moon's surface and then

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reflect it back to us. Yes, so what you're seeing is second ancel

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lies, but it's passed through Theth's
atmosphere. And so if you with a

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spectroscope, one of these devices that
lets you see the barcode that's imprinted on

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light by these different chemicals. If
with a spectroscope you look at earth shine,

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you can see the signature of Earth's
atmosphere on it, and sure enough

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you would be able to detect that
there is life there, because that signature

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is revealed by earthshine tells you exactly
what we've just been talking about. Are

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these chemicals imbalance, in imbalance with
one another? In balanced? Moreover,

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as Ron suggests, if you've got
an advanced civilization modifying their atmosphere, which

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we've certainly done, could we tell
that there was life there? You could

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probably tell that there was technology there. One of the signatures which are sometimes

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to techno markers to look for in
the atmosphere of a planet is something like

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the CFCs, the chlorofluoro carbons,
which are created by industrial processes and do

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end up in the atmosphere. We
try to get rid of them, what

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they call it. One of the
other things I think you and I talked

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about once about detectability was the capacity. I think we've developed technology that would

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be able to detect radar signals on
another world. Was that something we talked

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about. Yes, that's right.
Well, indeed that's true because, for

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example, the square kilometer array radio
astronomy colleagues tell me would be sensitive to

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airport radar a distance of fifty light
years. Wow. You know, assuming

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that the airports we're using the sense
of of radar as we use here on

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Earth, and that's likely that they
might and nearly worlded develop the same way

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as we have. So the is
a resounding yes to that question. And

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it's one of the principal tools that
sorry astrobiologists are using to explore the details

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of exo planets. And indeed,
the gems Web telescope has actually I think

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probably half a dozen cases, maybe
even more, managed to sense the chemical

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elements in some of the exoplanets that
transit across the face of their parent star

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because some of the light that's coming
you know, that's that's coming past the

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planet, that's transiting across its parents
style in other words, that's between the

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parents style and ourselves. Some of
that line is going through its atmosphere,

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and so you can pick up what
the what these chemicals are, and there's

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various different chemicals that have been detected. Carbon dioxide's world water is another.

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You know, they are detectable.
It's a technology that's still in its infancy

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because our technology is limited. But
once the ELT has come along the extremely

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large telescopes, which the probably the
first one will be the European one,

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the ELT itself, the European Extremely
Large Telescope. Once that comes on stream,

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then we're likely to see more of
this kind of discovery chemical elements in

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the atmospheres of other star planet which
may eventually lead to the detection of an

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unambiguous biomarker which says, yes,
there's life somewhere else. Wouldn't that be

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amazing? I think it will just
as an after postcript there. The unambiguity

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is the difficult bit because often you
can find just purely chemical processes that might

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create the same thing. So These
imbalances are what people look for rather than

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just saying, oh there's oxygen,
there, there must be life. It's

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00:29:52.279 --> 00:29:57.839
got to be in a state of, you know, imbalance with other chemicals,

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which tells you that it's basically been
constantly creating. Something else is going

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00:30:03.240 --> 00:30:10.039
on. Somebody pushed the button,
all right. Of course, Just as

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a side note, the famous Stephen
Hawking has always said that we shouldn't reveal

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our presence in any way or form. He's not He was never confident that

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alien species would be kind to us. And I throw back to the three

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body problem, which is exactly what
that story is about an advanced civilization that

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contacts Earth and decides they're going to
come here because their planet sucks. And

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so the basis of the story is
they're interrupting our scientific development so that we

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don't jump ahead of them in the
four hundred years it's going to take for

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them to arrive. Really interesting story, really interesting story. That's why I'm

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persisting with it. I want to
know what happens. It's a trilogy,

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00:30:55.160 --> 00:30:59.799
it's a three book story. So
yeah, thank you, Ron, that's

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00:31:00.039 --> 00:31:03.480
it's a great question. Always a
good discussion point that one, And thanks

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00:31:03.519 --> 00:31:07.119
for every to everyone who sent questions
in, and of course don't forget to

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00:31:07.160 --> 00:31:10.680
send us your questions via our website
Space Nuts podcast dot com, space nuts

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00:31:10.720 --> 00:31:14.839
dot io. You can click on
the AMA tab up the top where you

353
00:31:14.880 --> 00:31:17.799
can send us text and audio questions, or the right hand side of the

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00:31:18.119 --> 00:31:21.720
homepage send us your questions. It's
audio only. As long as you've got

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00:31:21.720 --> 00:31:25.599
a device with a microphone, you're
all set. And don't forget to tell

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00:31:25.680 --> 00:31:29.799
us who you are and where you're
from. But we'll take both country and

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00:31:29.839 --> 00:31:37.799
Western questions. Text or audio not
a problem. Thanks Freda both. Thanks

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00:31:37.799 --> 00:31:42.279
fred as always great pleasure. Andrew, good to talk. Thanks to all

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00:31:42.279 --> 00:31:48.880
our listeners who have sent stuff in. It's always it's always inspiring and stimulating

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00:31:48.000 --> 00:31:52.559
to look at those questions. It
is indeed, fred Wat's an astronomer at

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00:31:52.680 --> 00:31:56.240
large. And Hugh in the studio, thanks for not asking us anything because

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00:31:56.279 --> 00:31:59.920
we don't know anything that you want
to know. And from me Andrew Dunkley,

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00:32:00.079 --> 00:32:01.799
thanks for your company again. We'll
catch you on the next episode of

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00:32:01.880 --> 00:32:07.880
Space Nuts. Bye bye. Thanks. You'll be listening to the Space Nuts

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00:32:07.880 --> 00:32:15.200
podcast available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player.

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00:32:15.359 --> 00:32:20.200
You can also stream on demand at
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00:32:20.279 --> 00:32:24.400
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