#421: Zebrafish & Cosmic Cold Spots: Swimming Through Space Mysteries

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Hi there, Thanks for joining us. This is Space Nuts where we talk

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astronomy and space science and sometimes recipes
and wallpaper design. Coming up on this

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episode, we're going to be talking
about zebra fish in space. Yep,

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they're up there, they're orbiting,
they're making crucial decisions, and we're going

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to find out why. We're also
going to look at the cold spot in

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space. It's part of the cosmic
microwave background radiation. But why is it

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there and what's it doing? That
is the sixty four thousand dollars question.

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And we'll talk about a few other
things as well. Coming up on this

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episode of Space Nuts fifteen second guidances
in Channal ten nine ignition sequence Space Nuts

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side or three two one Space Nuts
as when I report it Mel Goods And

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once again we're joined by Professor Fred
Watson, Astronomer at Large. Hello,

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Hello Andrew, How are you this
morning? How are you today? I'm

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cold, I'm cold. The weather's
really starting to chill down in my part

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of the world, which is not
my favorite time of the year. But

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it's not even winter yet, but
we've just hit a bit of a cold

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patch. We must be in the
middle of the cosmic microwave microwave background radiation

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because it's it's something kelvin here at
the moment. I think you hit one

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degree last night, didn't you.
I saw it's on the something like that.

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Yeah. Yeah, it's a lot
of people think that the West is

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just a hot dust pan, but
in winter it is definitely not. That.

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We get some very cold nights here. But you know, people in

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North America are probably going, oh, oh, yeah, you don't know

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what cold is. No, I
don't. I don't want to find out.

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That's all good and well, Fred, Before we get into your topics,

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I just wanted to bring something up
because we've talked about this before,

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and there's been an announcement made this
week that the thirty two hundred megapixel Legacy

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Survey of Space and Time camera that
was being built for the Verra sa Uben

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Telescope has been delivered. I finished
making it in April and it's been flown

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by seven four to seven cargo plane
to its location and it's now been delivered

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to the telescope. So they're really
getting to the pointy end of this project.

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What intrigues me about this is that
it's the biggest digital camera that's ever

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been produced, thirty two hundred megapixels, and it is super duper sensitive,

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and it will be able to take
a very wide field view. I think

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its observing power is seven times that
of the width of a full moon,

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which is amazing. So a four
months half a degree across, So what

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that's telling you is three and a
half degrees field of view, which is

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extraordinary for a telescope that size.
It's an eight point four meter telescope which

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is going to survey the whole sky
I think every five nights or three nights

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or something ridiculous like that, looking
for things that change. It's transient astronomy,

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as it's called. And yeah,
I think I read the term time

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lapse. They're going to do a
ten year time lapse of the southern sky.

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Yeah, that's right. What you
could learn from that might be just

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amazing because we just see the sky
in real time and it's so easy to

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miss things, I would imagine.
Yeah, so principally what they'll be looking

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at is things that move, and
that means it's going to net thousands and

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thousands of asteroids, possibly the more
distant ones it'll probably discover, you know,

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coyper melt objects may even find planet
nine. Actually, it's probably one

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of the best potential tools for finding
planet nine, if Planet nine exists.

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But also things that change in brightness, exploding stars, anything that kind of

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goes bump in the night, it'll
pick up because of that cadence of you

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know, observing the Hull sky every
few nights. It's a remarkable machine.

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I was looking at a picture.
Another announcement that you might have missed that

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came from it about three weeks ago
was that they've just put the coating on

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the main mirror. The main mirror, as I said, eight point four

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me in diameter, but it's a
very unusual mirror because it's dished like all

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telescope mirrors are. But there's a
section in the middle which is sort of

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probably more than half the diameter of
the mirror, which has a different curvature,

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so it's like a double dish.
Is really quite extraordinary to look at.

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If anybody feels like googling that,
look for surface coating of ver a

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c rubin telescope mirror or something like
that, and you'll see a marvelous picture

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of this strange double dish mirror.
And it's like that because the light from

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the stars hits the outer part of
the mirror, is reflected back then to

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a second mirror, and then hits
the main mirror again but in a different

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part, so the different curvature focuses
it in a different way. It's a

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very intriguing design of instrument, quite
different from the Northern Yeah, I knew

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you'd know all about it, because
I know you're just sew into telescopes.

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You've written a book about telescopes and
there they all came about you did,

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yes, And I just when I
spotted that story, I thought I'll just

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have to bring that up with for
it because you'll probably know the guff on

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it. But yeah, well,
with the camera now being delivered, they're

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getting really close to commissioning this,
this telescope. My only thought is like,

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it's going to be a ground based
telescope, but I'm guessing that this

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is going to be such an altitude
that atmosphere is not going to be as

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big a factor as it is in
other parts of It's a good site,

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that's right. It's in It's not
that far from Lace Arena in Chile.

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I've seen it actually from across the
other side of the Valley. Haven't visited

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the site, but I've seen it
and it shares that the dog. It

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shares that to sorry everybody. It
shares the site with the Germany South Telescope

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as well, which is another eight
meter telescope, but one that doesn't have

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that same field of view. So
yes, an extraordinary instruments have been been

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a long time in gestation, has
that telescope. We've been talking about it

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for many, many years, but
it's now very near to fruition and Australian

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astronomers have got a bit of a
tour in the door because we've got to

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deal with the observatory that allows us
to analyze the data and look at some

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of the stuff that's coming off it. So there might be Australian covery is

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made from that telescope as well.
One we can only hope so, and

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we will certainly be keeping an eye
on this and we'll talk about it when

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it gets up and running, whenever
that will be in astronomical terms, could

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be another twenty five years now,
it won't be that long, but twenty

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five million years sometimes maybe maybe From
the world's biggest camera to some of the

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world's smallest astronauts we're talking zebra fish
in space or aquaauts. Maybe they are,

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but these are zebra fish that are
on a Chinese mission. What's this

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all about, Fred, And how
did they make the helmets so small?

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It's about research. This is research
taking place on Tiangong, a space station,

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the Chinese space station. Tiangong,
of course, means Heavenly Palace,

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is a lovely name for what is
quite an able and certainly pretty efficient and

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effective piece of kit. It's about
a third the size of the International Space

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Station, so no when he was
big, but more modern in many ways.

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But they've got five hundred people in
there. I won't touch that one

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either. I think the standard crew
is three. I think that is correct.

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But of course there are experiments going
on on that space craft, just

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as there are on the International Space
Station, and one of them is to

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look at the effects of space on
fish, and in particularly zebra fish.

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Four of them, I'm sure they've
all got names, which are apparently doing

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really well. And they except they
don't know which way up to swim,

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as as you can't kind of expect
because you know the fielding the gravity,

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so that they're swimming upside down.
Things of that sort but anothers this is

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being take is being done. One
thing I didn't know is that they zebra

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fish apparently have genetic similarity to humans. I'm gobsmacked by yes. I mean,

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that doesn't surprise me that we're,
you know, only a couple of

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degrees away from a mountain gorilla.
But do you have a an anatomical similarity

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to the zebra fishes? Yeah,
I don't know that's quite anatomical, but

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it is certainly when you look at
the gene you know, the genetic makeup

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there there are in common. And
that's that's that's why they've chosen zebra fish,

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because it's a it's a model for
you know, perhaps seeing what the

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effects of space are on the zebra
fish that might correlate with some of the

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things that we know happened to humans
and maybe lead to treatments and things of

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that sort that we could use here
on Earth. So yes, very very

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interesting. They're calling them, I'm
just going to say they're calling them a

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quster a questronauts, because I can't
say it because they were a classic I

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guess, go for it. Yeah, I used to keep zebra fish when

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I had fish in my house.
I used to love keeping fish. I

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had several aquariums over the years.
Interest and zebra fish were great. They

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were a schooling fish, so if
you got enough of them, it just

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looked really good in the fish tank
with all these fish sort of swimming around

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seemingly aimlessly, but they all clustered
together. I cleaned the tank out once

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and I was just about to dump
the rubbish and I saw something moving in

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the bottom of the bucket and I
picked I actually captured it with a straw.

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I put the straw over it,
and then somehow managed to create a

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suction effects by squeezing the straw and
caught this thing and put it in the

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jar. Didn't know what it was, but it was. It was about

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the size of an eyelash. Oh
wow. And it grew into strawberry ze

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fish yep, yep. So it
makes me wonder how many I sucked down

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the toilet. But anyway, but
yeah, he grew into a he or

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she grew into a reasonable size until
another fish went, oh, I mean

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lunch. I'm pretty sure that's what
happened to him, because he disappeared.

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Yeah, but it was pretty exciting. But they are prolific breeders and that's

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one of the things they're going to
be looking at, is the effect of

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zero gravity on their eggs and everything
else. Pretty it's really interesting stuff,

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it is. But we've had so
many different creatures in space, spiders,

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and they've had ants. They've done
ant colonies in space, because we've had

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dogs in space and a few other
things. This is not the first fish

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in space. I didn't think that
goes back to nineteen seventy three. In

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fact, when Skylab hard experiments on
board which used fish, I would call

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them gudgeons, but I think they've
got different names in different parts of the

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world. D skippers, Yeah,
that's right, and they Yeah, so

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that was quite successful as well.
I think there's been other experiments. I

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think actually on the Apollo Soyots missions
there were fish as well. So it's

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I mean, you kind of wonder
whether they ever end up with chips on

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a plate or something like that,
but probably not. I was going to

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say that the first fish in space
was a beautiful salmon steak, but maybe

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I don't know if that's I don't
know if that's true. You mentioned gadgets.

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There's a specific gadget from our part
of the world that's en dangered,

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and I remember they were doing a
lot of work to try and restore its

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numbers in the Murray Darling base and
it was the purple spotted gud I think

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quite striking. Actually, when you
get up close to them, they've got

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these bright purple spots on them.
They're amazing fit. It's a it's a

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strange fish because it lives in and
out of the water, and it sort

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of it's one of those things that
sort of is sort of halfway between a

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sea creature and a land creature,
or a quatic creature and a land creature

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in the evolutionary scale. It's quite
quite amazing. So it doesn't surprise me

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they've had those in space. But
zebra fish, Yeah, that kind of

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came out and left the field.
But it sounds like their DNA makeup is

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a good reason to have them there
because we can learn a lot about what

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happens to them and thus maybe what
happens to us. I don't know.

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It's all part of a process,
isn't it for it? Indeed, that's

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right. Yeah, So we'll follow
that progress with interest. If there's any

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news about the zebra fish down the
train, it will come to you.

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Via space Notes. Oh and yeah, one thing that I also want to

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that I read about that story is
that they're trying to make these aquariums in

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space self sustaining. Yes, that's
right. Yeah, I think that's another

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experiment they want to see if they
can just sort of be in that environment

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and you don't have to do anything
with them, they'll look after themselves long

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term, which is another thing we'll
have to do as human beings if we're

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going to do long term space.
Although I didn't know that they've come to

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replace the food box on the on
the aquarium tak. Yeah. The only

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problem with this theory is that humans
can't hold their breath live long. So

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yeah, well that's right. I
mean you've touched on something that I just

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want to write about about. You've
really got to meet your anything that's going

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to involve long time, long term
visits to space to be self sustaining.

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All right. If you would like
to chase up that story about zebra fish,

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you can check out the Space daily
dot com website. This is space

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Nuts Andrew Dunkley here with Professor Frett
Watson. Okay, we checked all space

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nuts. Our next story, Fred
is a bit of a mystery. There's

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a cold spot in space and it's
got something to do with cosmic microwave microwave

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background radiation. And the reason I
say is a mystery is because they're not

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sure why it exists. Is that
where we're going with this, Yes,

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that's it in a nutshell, Andrew, So let's just revisit the cosmic microwave

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background radiation, that microwave hiss that
is all over the sky, it's over

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the entire sky, discovered by Panzeas
and Wilson Bucking the nineteen sixties and because

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they realized it was realized that what
we were seeing was a big bang,

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the flash of the Big bang,
that a look back time of thirteen point

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eight billion years. As we now
know, it's been a very important asset.

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And the thing about the cosmic microwave
background radiation, and this was predicted

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back in the early days when it
was just discovered as a kind of hiss

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in microwave telescopes. It's got temperature
variations in it, it's got slight changes

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in intensity as you look at it. So there's a sort of pattern there.

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And that also was predicted because without
that pattern of hot, warm,

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and cold spots we wouldn't exist,
the galaxies wouldn't have formed, there would

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not be structured in the universe,
and so that was a big discovery made.

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It was Jeffrey Burbage who suggested that
I might be get fingering the wrong

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astronomer, but it was certainly a
discovery made back in the time before we'd

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even got the wherewithal to measure that
that unevenness. The technical term for the

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unevenness of the cosmic microwave background radiation
is an isotropy. When something is isotropic,

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it is the same in all directions. When it's an isotropic, it's

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not, and that's what the cosmic
microwave background radiation is. So measurements of

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the anisotropy of the cosmic microwave background
radiation have been carried out by three major

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space missions. Kobe back in the
day nineteen nineties Cosmic Background Explorer that produced

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the first maps, and then we
realized that we could learn much much more

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if we had a finer resolution,
you know, rather than looking just at

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big blobs on the sky, could
you break them down into finer detail.

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So w MAP was launched around about
the turn of the century. I think

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if I remember rightly, w map
was the Wilkinson Microwave anisotropy probe, and

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then finally the Plank spacecraft p L
N p L A n c K,

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which was sent into orbit by the
Europeans, and that's given us the finest

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detail of finest detailed maps of the
cosmic microwave background radiation. All of that

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has pointed though two cold spots,
and in particular one cold spot that's bigger

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than the rest and actually colder than
the So it's quite extraordinary how small the

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variations in temperature are. They're you
know, in the region of ten to

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the minus five of a degree,
and so the basically the you know,

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you're you're looking at very very fine
details. It's you know, one part

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per million is really the kind of
level at which there is there is variation.

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And I should say that the average
temperature of that cosmic microwave background radiation

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is to I think it's two point
seven degrees kelvin roughly roughly three degrees kelvin,

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so minus two hundred and seventy degrees
celsius, very near absolute zero.

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So that is the backstory. What
we're talking about now though, is and

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this was discovered probably quite early on
in the history of our mapping of the

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cosmic microwave background radiation, nearly thirty
years ago. It's a spot that is

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bigger and colder than the average.
And so there's a few statistics that given

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by a very nice article about this
on space dot com, which our listeners

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might want to have a look at. If you think about the average cold

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spot on the cosmic microwave background radiation, it's about eighteen microkelvin's colder than average.

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A microkelvin is a millionth of a
degree calvin, which is effectively the

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same as a degree celsius in that
in that scale, So eighteen micro degrees

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colder. But this one is kind
of getting on for ten times that it's

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one hundred and forty Wait a minute, no, it's much more. It's

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much much more. I've misread that
because it's millie Calvin's one hundred and forty

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million calvit's colder than average. Yeah, so that's you know, nearly ten

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thousand times colder than the cold spots, the average cold spot. And it's

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also, as I said, it's
big, it's five degrees. We've just

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had a conversation about the field of
view of the of the V. C.

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Rubin telescope, which is smaller than
that. It's but it's a big

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field of view. It's three and
a half degrees, but five degrees is

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a colossal size on the sky.
So it's called and it's big. And

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that's very very interesting in you know, what is telling us you kind of

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expect to occasionally there'll be outliers of
you know, any distribution of things based

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on their size or the temperature or
whatever. You're going to have outliers which

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will be much more distinct from the
general levels. However, the chances of

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this being random are apparently less than
one percent, and maybe maybe even lower.

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And so there is thought as to
the fact that there's a reason for

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this. And excuse me, there
is a kind of explanation which is a

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bit complicated. I might read,
Actually, if space dot Com will forgive

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me, I will credit this to
them and read the article. Who's the

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author. It's Paul Suitor, who's
very very able writer on this kind of

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science. Let me just quote from
Paul's article. So he says, the

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favored exploration explanation for this strange cold
spot is that it's due to a giant

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cosmic void sitting between us and the
court and the cosmic microwave background radiation in

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that direction. Cosmic voids a big
patches of almost nothing, and we know

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they exist. I'm just an aside
from me. We see that kind of

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structure in the wider universe, what
we call the cosmic web is a network

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honeycomb of galaxies with not much in
the spaces between them, a kind of

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honeycomb space. And so that is
perhaps one theory. And what then imprints

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that a signal from that void on
to the cosmic microwave background radiation. As

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pointed out by Paul in his article, they influence the cosmic microwave background light.

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And that's because those voids are evolving. It's changing because the universe is

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a movable feast. The universe has
motion. Everything's moving in the universe,

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and so these voids are changing.
So I'm qutting Paul here. There's a

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very really good paragraph that explains this
very nicely. When light from the CNB

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first enters avoid it gains a little
energy as it transitions from a high density

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to a low density environment. In
a perfectly static universe, the light would

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lose an equivalent amount of energy when
it exited the other side. But because

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the voids are changing, when the
light first enters the void might be relatively

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small and shallow, and by the
time it leaves the void is big and

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deep. This leads to an overall
loss of energy the energy of the cosmic

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microwave background like crossing the void,
a process known as the integrated saxe Wolf

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effect of saxe wolfa is probably how
you should pronounce it, but we call

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it saxe wolf so check that out
online. The integrated sax Wolf effect is

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this loss of energy in an evolving
system. So, uh, there's there's

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one final mystery here. Sorry,
this is a long, complicated story,

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that's exactly. But we we don't
see avoid there because you know, we've

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got these galaxy surveys which I've been
involved with on the Anglo Australian Telescope and

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other and the UK Schmidt Telescope.
These are surveys that show us where the

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galaxy galaxies are distributed and give you
a map of in three dimensions of what

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those the structure of the universe is
like as as marked out by galaxies.

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And yes there are voids there.
This onny Come effect I was talking about

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so the direction of this cold spot
doesn't have an obvious void some and so

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you know, some researchers are saying, well, yes, our surveys are

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not complete, and that's certainly true. In completeness is one of the big

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banes of any studies that are based
on these galaxy surveys. But there there

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are, you know, this research. Some researchers have said, well,

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00:25:38.480 --> 00:25:41.880
we think we've seen a void or
a super void as it might be called.

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So, yes, like brought hes
void. Yes, that's right.

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Yeah, So so that this is
one of the mysteries that we're going to

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have to leave as a mystery,
I think, because nobody really knows what's

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00:26:00.079 --> 00:26:06.000
happening, and maybe this is what
we're what we're Yeah, what we're saying

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here is that cold spots in the
cosmic microwave background radiation are not unusual,

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but this is a bigger and much
colder spot and it doesn't appear to be

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associated with a void like all the
others, all most of it. That's

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correct, Yes, that's right.
So there's something spooky about it, but

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we don't know what it is.
It's that's bigger and weirder than you could

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imagine. And that's how they describe
it in the article bigger, weirdly,

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bigger, and weirdly cold. It's
right, which is scientific speech. It

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is, Well, that's when it's
weirdly. You know, you're really on

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the edge of knowledge that Yeah,
I suppose. Obviously the goal is to

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solve this, So I wonder what
we learn if we do solve it.

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There'd be something to learn, sure
they would, Yeah, that's right,

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they would. Indeed. It just
challenge, though, the notion that the

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universe is the same in all directions, which is a kind of fundamental tenet

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of cosmology. I mean, we
know there are galaxies and classes of galaxies

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and things like that in various different
directions, but when you average it over

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the whole universe, effectively, it's
the same in all directions. That's the

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isotropic that I was talking about.
That's what we we assume is the case.

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And so most cosmological theories of the
origin of the universe are based on

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that idea. And if that's wrong, then yeah, I've got to look

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00:27:32.000 --> 00:27:36.119
at it. Yeah, I've got
a rudimentary idea in my head which is

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00:27:36.160 --> 00:27:38.160
probably way wrong. But when I
was a kid, I used to go

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00:27:38.200 --> 00:27:42.759
and swim in the reservoir up behind
our house, and you'd swim through warm

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00:27:42.799 --> 00:27:47.839
patches and then you'd hear a cold
patch. It's that what the universe is

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00:27:48.000 --> 00:27:51.519
like. Yeah, maybe I do
remember that when I used to swim back

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00:27:51.559 --> 00:27:55.720
in the day as well, and
it would be all to do with just

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that, just the thermodynamics of what
was going on in the pool where the

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00:27:57.920 --> 00:28:02.880
one bit was in the shade of
trees and or you know what was deeper

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and the water rotating through cycles of
But that's true. You're very notice it,

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even probably only a degree or so
you'd notice. You think, oh

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gosh, that's a cool bit there. Yeah, yeah, yeah, Well

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we used to notice it because it
would be beautiful and warm and then you

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just swim. It's like swimming through
some kind of membrane and suddenly it's freezing

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cold. It is very strange,
very strange, all right. As Fred

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said, if you'd like to find
out more about that that strange cold spot

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00:28:37.079 --> 00:28:42.480
in the cosmic microwave background radiation,
it's space dot com and yeah, great

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00:28:42.480 --> 00:28:49.119
website and brilliantly written articles they publish
as well. Fred. That's brought us

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00:28:49.200 --> 00:28:52.920
to the end. I just remind
people If you're a YouTube follower, don't

333
00:28:52.920 --> 00:28:56.920
forget to subscribe below, and don't
forget about our website if you'd like to

334
00:28:57.039 --> 00:29:04.880
visit us and check out what we've
gotten offer there Space Nuts podcast dot com

335
00:29:06.119 --> 00:29:10.680
com or space Nuts dot io.
You can subscribe to the Astronomy Daily newsletter.

336
00:29:11.359 --> 00:29:15.680
Don't forget about our Astronomy Daily podcast
as well with Steve my brother one

337
00:29:15.720 --> 00:29:22.400
of the hosts, and plenty more
on our website Space Nuts podcast dot com.

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00:29:22.440 --> 00:29:26.519
Thanks Fred, will catch you again
real soon, hope. So I'm

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00:29:26.839 --> 00:29:29.599
looking forward to the next time.
There's so much going on in the world

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00:29:29.640 --> 00:29:34.079
of space there is. Indeed,
you never stop learning or wondering or wondering

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00:29:34.160 --> 00:29:40.440
what you can learn. Thanks Fred, Let's see you so, Fred Watson,

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00:29:40.680 --> 00:29:45.160
Astronomer at Large. And thanks to
here in the studio who's having breakfast

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00:29:45.200 --> 00:29:48.319
at the moment and can't talk,
and from me Andrew Dunpy, thanks for

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00:29:48.359 --> 00:29:52.759
your company. Catch you on the
very next episode of Space Nuts. Bye

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00:29:52.759 --> 00:30:00.000
bye. You'll be listening to the
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00:30:00.759 --> 00:30:04.880
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347
00:30:04.920 --> 00:30:11.119
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00:30:11.200 --> 00:30:12.880
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