· Explore the mind-bending mysteries of black holes and event horizons.
· Discover fascinating specializations within the fields of physics and astronomy.
· Uncover the constant evolution and breakthroughs in the astronomy field.
· Delve into the intriguing world of privatization of satellite launches.
"How do you tell the difference between something that is very, very dense but not infinite, and something that is infinite?" - Fred Watson
Exploring Specializations in Physics and Astronomy
We delve into various specializations in physics and astronomy like solar physics, space physics, and astro seismology. These fields are ever-evolving, and researchers often move between specializations. The discussion underscores the diverse and dynamic nature of these sciences, emphasizing that broad-based knowledge and collaboration are indispensable for progress.
The resources mentioned in this episode are:
· Visit our website to listen to more episodes of Space Nuts. https://spacenuts.io
· Check out our social media pages for updates and behind-the-scenes content.
· Subscribe to our podcast on your preferred podcast platform to never miss an episode. · Join our mailing list to receive exclusive content and updates.
· Explore our merchandise store to get your own Space Nuts shirt and show your support. · Submit your own questions for a chance to have them answered on a future episode.
· Follow Professor Fred Watson on social media for more astronomy insights.
· Learn more about black holes and their properties by reading scientific publications and books on the topic.
· Consider studying astronomy or physics to specialize in a specific field of research. · Support organizations and initiatives that promote scientific research and education, such as the Australian Academy of Science or the International Astronomical Union.
Become a supporter of this podcast: https://www.spreaker.com/podcast/space-nuts-astronomy-insights-cosmic-discoveries--2631155/support.
00:00:00
Hello again. Thanks for joining us. This is Space Nuts. My name
00:00:02
is Andrew Dunkley and yes, it is and just check the name on my
00:00:06
shirt. So good to have your company on another edition of
00:00:10
Space Nuts episode 380. And you know what that means? It's the
00:00:14
one after 379. It also means that we are doing 100% audience
00:00:20
questions and we might even answer one.
00:00:22
And we're going to be looking at things like black holes. Ah but
00:00:28
there's other stuff. We've got a question about different fields
00:00:30
in science. So that'll be a fun discussion. The LF bot has come
00:00:36
up. There's a question also questions about time and I
00:00:40
really like the sound of this one unborn universes. We'll be
00:00:44
discussing all of that very, very soon. In fact, right now on
00:00:48
Space Nuts.
00:00:53
10 9 ignition sequence Space Nuts. 5432 space as good.
00:01:06
And joining me to cover all of that and much, much more is
00:01:09
Professor Fred. What's an astronomer at large? Hello,
00:01:12
Fred.
00:01:13
Hello, Andrew. How are you this fine day?
00:01:16
Ish day avoiding storms. It's been pretty, wild and wooly
00:01:21
around here. And, I noticed on the radar this morning it's been
00:01:24
pretty wild and wooly all around the coast too.
00:01:27
So I drove up from Canberra to Sydney yesterday after that. Oh,
00:01:30
that would have been fun and went through the heaviest rain
00:01:34
I've ever seen on a drive. Never seen it. Anything like that. I
00:01:38
could probably see about 3 m in front of the car. It was
00:01:42
unbelievable. And most cars were pulled off the road with the
00:01:45
hazard lights flashing dozens and dozens of cars off the road.
00:01:49
I got caught in a hail storm coming home from Singleton To
00:01:52
Maitland on the New England highway many, many years ago.
00:01:55
And, I had to pull over. I couldn't see a foot in front of
00:01:59
the car, but then when I hit Maitland, I thought, oh, my
00:02:01
gosh, that it had cyclonic conditions and it was an
00:02:05
absolute mess. Yeah.
00:02:08
And you know what, those, those storms are getting much more
00:02:10
common now, which is unfortunate. I think, I think
00:02:14
the funniest story I've heard so far because there's always a
00:02:17
funny story when it comes to natural disasters is, there was
00:02:20
a, there's a, a monument to a whale or something on, in one of
00:02:25
the south coast towns and it fell off its foundation and
00:02:28
floated down the street.
00:02:34
I like that.
00:02:36
Yeah, it was anyway, certainly yesterday I I'm glad that I
00:02:40
wasn't staying in that area because I think they've had
00:02:43
serious flooding on the news this morning. So, yes, we are
00:02:48
all experiencing the consequences of climate change.
00:02:52
Looks that way in the new app, whatever it's called Epoch that
00:02:57
we've been in. I can't remember. Let's get some questions.
00:03:09
Yeah.
00:03:11
Sort it out. I can't either. I CEO d, I know that. Yeah, the
00:03:16
apothesil and guess what the topic is? Ok.
00:03:20
This is Bill Bogan from Ann Arbor Michigan. And I have a
00:03:24
question about black holes. Of course, like do they actually
00:03:28
have to be black? I was playing with the equation for escape
00:03:31
velocity and a square root of two GM over R and said, OK.
00:03:35
Well, what if you set that to C and instead of bass you use
00:03:39
density and it all comes out to be R times the square root of
00:03:43
density equals 1 times 10 to the 13.
00:03:47
Ok. So I thought, well, what's the density of a neutron star?
00:03:51
That's like 3.7 times 10 to the 17 to 5.9 times 10 to the 17,
00:03:56
you plug that in and you get a radius of 16.5 kilometers. So in
00:04:02
other words, if you had a neutron star with a radius of
00:04:04
16.5 kilometers, it would be a black hole but would not be a
00:04:08
singularity.
00:04:10
Does this make any sense? And of course, if you had something
00:04:13
like a cork star, which is being theoretically considered, then
00:04:18
you get density of 10 to the 20th and a radius of 1.3
00:04:22
kilometers, which I have no idea if that's even theoretically
00:04:25
what a cork star could be. So, just wondering, can you have a
00:04:28
effectively a black hole that is not a singularity? Thanks.
00:04:32
Ok, thank you, Bill.
00:04:35
What do you think, Fred?
00:04:37
I think the answer is yes. You can be which look, I'm not a
00:04:45
black hole specialist as you know. But certainly thinking
00:04:50
about some of the reports I've read from colleagues who are
00:04:54
black hole specialists that yes, you could have a singularity.
00:04:58
Sorry, you could have a black hole which does not have
00:05:01
infinite density. So it isn't a singularity.
00:05:05
And but it's still, it still has a high enough density that you
00:05:13
have an event horizon. And you know, the point of no return
00:05:19
for, for light light waves. Neutron stars do have some of
00:05:25
the properties of black holes in that they, you know, the, the,
00:05:28
the the density is so high that they are certainly curving the
00:05:33
space around them.
00:05:34
And so you're gonna get some peculiar optical phenomena
00:05:37
because it's acting like a gravitational lens, quark stars.
00:05:42
Likewise, if they exist, we don't know whether they exist or
00:05:46
not. But once again, you, you would have space time curvature
00:05:52
associated with that. So, I think, yeah, I think Phil's
00:05:55
right though, I think you can have black holes that aren't
00:05:58
singularities.
00:05:59
Wow, that's but we haven't seen anything as such.
00:06:03
I mean, well, we don't know that 's the problem because you can't
00:06:07
probe beyond the event horizon. All you can see is something
00:06:09
that's got very high density. Now, the formal definition of a
00:06:13
black hole is a point with infinite density. And you know,
00:06:19
if you've got something that's very, very dense, indeed.
00:06:24
Well, well, yes, I can see the spacetime curving around your
00:06:27
head there. No, that's right. It 's how do you, how do you tell
00:06:31
the difference between something that is very, very dense but not
00:06:35
infinite and something that is infinite? One's a singularity,
00:06:39
one isn't.
00:06:40
But yet they both generate an event to horizon and have the
00:06:43
same properties effectively. You, you've probably got an
00:06:46
accretion disc and all the rest of it. So, yeah, interesting
00:06:49
stuff. Which if I knew more about black holes, probably be
00:06:53
able to answer more Coly.
00:06:55
I think we were all wanting to know more about black holes.
00:06:58
Otherwise we wouldn't get so many questions on what I, what I
00:07:00
struggle with is how can you have something infinite in a
00:07:06
world or a universe that has limitations?
00:07:10
Yes, that's right. That's why it 's a singularity because it
00:07:14
doesn't fit the normal, you know, prescription for the
00:07:17
world. And the, and the universe, you know, normal space
00:07:21
time, space time is sort of twisted up. It's, it's basically
00:07:25
infinite density. Yeah.
00:07:26
All right. Thank you, Bill. Hopefully that helped and well
00:07:30
done on the mathematics. Yeah. Yep. I'm so jealous. We've got a
00:07:34
question from Rennie. Rennie often sends us audio questions
00:07:37
but he's, he sent us a text this time which I've got to find. Cos
00:07:41
it's not where I thought it was here. It is.
00:07:43
It fascinates me that there are so many specialty fields in
00:07:48
physics and astronomy. Can you briefly go over fields of,
00:07:52
specialty research and study for physics and astronomy? As, for
00:07:56
examples, there might be scientists who only study the
00:07:59
sun and its behavior.
00:08:01
Thank you for all the information packed into each
00:08:03
episode with a touch of humor. We need this desperately. Thanks
00:08:07
again, Renee Trout. Thank you ready. Lovely to hear from you.
00:08:11
Usually, as an audio, question, but, you sent us an email for a
00:08:16
change, which was nice. Yeah, lots of fields aside. So I
00:08:19
imagine with specialties, Fred.
00:08:21
Absolutely. And, that, you know, it, it is absolutely true that,
00:08:26
astronomers do specialize what tends to happen is that they,
00:08:31
they do a, you know, they do a degree in physics or astronomy.
00:08:34
They'll be in a university that has a speciality that who's, who
00:08:41
's, teaching staff who are also researchers, actually, that they
00:08:48
all concentrate on one particular area. And those,
00:08:53
those particular areas are, are pretty well defined but, but
00:08:57
they also are a bit blurry now because we, we're seeing, we are
00:09:01
seeing a lot of interchange between them.
00:09:03
And what I was gonna say was then typically what happens is
00:09:06
that the person stay, if they stay in that university, they do
00:09:09
a doctorate in whatever topic it is that that department
00:09:13
specializes in and they spend the rest of their career doing
00:09:16
that. Now, I think that is less true.
00:09:19
Now people do tend to bounce around a bit more now than they
00:09:23
did. But just to kind of, you know, go through some of the
00:09:28
things. Yes, some astronomers do study just the sun. We usually
00:09:34
call them solar physicists. The sun's environment, we usually
00:09:38
call space physics.
00:09:40
And because that's, you know, the, the area, you know, we
00:09:44
often talk about space weather, which is the physical properties
00:09:47
of the interplanetary medium and the, you know, the, the, the,
00:09:52
the, the earth's location within that.
00:09:55
And then you, you get to like, you know, the stellar physics is
00:10:02
the evolution of stars, the the mechanism and processes that
00:10:06
lead to the origin of stars, their evolution throughout their
00:10:09
lifetimes, star death. Often people concentrate on the end
00:10:13
products of stars, whether they're supernovae or, you know,
00:10:17
neutron stars.
00:10:18
All, all, all of the things that we talk a lot about are the end
00:10:22
products of stellar evolution. That's a speciality in its own,
00:10:26
right. And then you've got people who look further beyond
00:10:31
and study the galaxy, our galaxy, the structure and
00:10:37
history of our galaxy.
00:10:38
And that's an area that I've been involved with. It's often
00:10:42
called galactic archaeology. My involvement was more on o on the
00:10:48
observational aspects of that, how we collect data on very
00:10:52
large numbers of stars that led us to a kind of population
00:10:55
census type activities.
00:10:58
So my trade in a sense was what was called survey astronomy
00:11:03
surveying large numbers of objects, whether they're stars
00:11:06
or Galaxies. And I did both that, but so that people can
00:11:10
then specialize study those individual objects with a bigger
00:11:13
telescope, for example, look at the details of them.
00:11:16
So survey astronomy also. So it, it lets you I identify really
00:11:22
interesting and unusual objects, but it also gives you the these
00:11:25
population census statistics that extends not just to our own
00:11:31
galaxy but also to other Galaxies in our neighborhood.
00:11:35
Some specialize just in the local group of Galaxies. That's
00:11:40
how milky way Andromeda, the, the magellanic clouds, the
00:11:44
triangular galaxy and a few others. So there's, there's
00:11:48
these, you know, different specialities even in what might
00:11:52
be called extragalactic astronomy, ga astronomy beyond
00:11:55
our galaxy.
00:11:56
And that extends to the study of Galaxies in other environments
00:12:01
in clusters. And eventually you looking at the big picture stuff
00:12:04
you're doing. The science of cosmology, which is all about
00:12:08
the origin and evolution of the universe. And I might mention
00:12:11
just one more.
00:12:14
You know, well, maybe not one more. There's several here's a
00:12:18
branch that you might not have heard of Asos seismology. It's
00:12:21
about the vibrations of stars. There's a very strong field of
00:12:24
astro, a very strong field of practitioners in astro
00:12:29
seismology here in Sydney at Sydney University.
00:12:32
Another one is Astrobiology, mixing biology and things like
00:12:38
atmospheric science and all the things that we know about living
00:12:41
organisms, putting them in a, in a context beyond earth. The
00:12:47
origin of life elsewhere, all of that stuff. Astro chemistry
00:12:50
feeds into that.
00:12:52
That's sort of a fairly complete list of all the different
00:12:56
disciplines within astronomy. But you see that there are many,
00:13:00
many specialities and some people never stray outside. One
00:13:03
of those, you know, one of those specialist areas, is.
00:13:06
Is it possible that because of various specialties that
00:13:11
sometimes they might be working on something similar, one makes
00:13:17
a discovery that the other one should know about, but they'll
00:13:20
never ever cross paths. Could that happen?
00:13:22
It's, it's less happens less now. I mean, that that's why you
00:13:26
publish your results so that the, the, the learned journals
00:13:30
and there are many of those, some, some of which specialize
00:13:33
in particular topics. But in those journals, the it means
00:13:37
that, you know, people with the similar interests will, will
00:13:40
read them and see what your research is all about.
00:13:43
So when I was a young astronomer back in the seventies and
00:13:46
eighties, we, we, we kind of lived by the journals every,
00:13:51
every month or whenever these things came out, you'd scan
00:13:54
through to see what papers were there that were related to
00:13:57
research that you were doing.
00:13:58
Often, you'd know people who were working in the same field
00:14:03
as you and you'd send them what was called a preprint. These
00:14:06
days, that's all online. There's a thing called archive back back
00:14:10
in the day, it was actual physical paper, it was physical
00:14:14
paper, it was a preprint of what your paper was gonna say so that
00:14:18
you knew that in advance of it being published.
00:14:22
Yeah. So, so that, that side of it is different. But of course,
00:14:25
with, you know, the, the way communications have changed,
00:14:29
even things like social media are now used by astronomers to,
00:14:32
to, to compare notes, to talk to one another. And so it is much
00:14:37
less partitioned than it used to be.
00:14:39
People are a lot more fluid in what they know about the, the
00:14:43
universe which is often very important. So some people
00:14:47
working in one field might have, you know, for example, pe people
00:14:51
working in galactic science, the origin and evolution of our
00:14:56
galaxy want to know about stellar evolution, the way stars
00:14:59
evolve and maybe about planetary physics and things of that sort.
00:15:03
Alright, thank you, Rennie. Lovely to hear from you. Even if
00:15:06
it was in writing, he usually sends us audio questions. Our
00:15:08
next question comes from Mark.
00:15:11
Hello, Doctor Andrew. Luck here from somewhat sunny San Jose
00:15:16
California. Medium time listener. First time ask the
00:15:21
micro, the cosmic microwave background is the flash of light
00:15:24
from when the early universe went transparent because
00:15:28
formerly free electrons were finally able to combine with
00:15:32
four free protons.
00:15:33
My question is this, why were there roughly the same number of
00:15:37
free electrons and protons if there weren't, we would be awash
00:15:41
in a sea of remaining unmatched electrons of prop. But I've
00:15:44
never heard any mention of this. So the numbers must have been
00:15:49
relatively equal. How or why love your show. Keep it up.
00:15:53
Thanks.
00:15:55
Good one.
00:15:56
Do you know the way to San Jose?
00:16:03
Exactly. Sorry, Mark. You probably get that every time you
00:16:06
tell people where you're from a certain generation. That's a
00:16:11
really good question. And so the protons and electrons themselves
00:16:18
were formed in the Big Bang. And so the, the, you know, products,
00:16:28
the basically the process that took pure energy from the Big
00:16:32
Bang and turned it into particles.
00:16:36
Obviously has e essentially has parameters that will dictate how
00:16:44
many of each particle are formed. And i it, it, it's,
00:16:50
yeah, it's a really interesting, really interesting question and
00:16:53
I mean, the, the match will not be perfect. And in fact, we know
00:17:00
that that about half of the matter that we expect, is it
00:17:04
half, I think it's about half of the matter we expect from the
00:17:08
Big Bang that's not been detected.
00:17:10
Until recently when fast radio bursts show us that there is a
00:17:16
soup of electrons actually existing between the Galaxies.
00:17:21
So there you have some evidence that the balance, there is an
00:17:25
imbalance because we've got a surfeit of electrons actually
00:17:28
lurking between between Galaxies. That's what gives us
00:17:33
the dispersion effect in the signal of the fast radio burst.
00:17:36
So the, the match is not perfect.
00:17:40
It, and it, and it may not even be nearly perfect. You know, if
00:17:43
we're talking about a factor of two. So you've got lots of
00:17:46
electrons left over which is possibly what's happened.
00:17:50
Then you're going to get you, you, you gonna get the, the the
00:17:55
atoms being formed and the universe becoming transparent,
00:17:58
but you'll still have the surface of electrons, which I
00:18:01
think is the situation we have. So yeah, great question though.
00:18:06
Thank you for asking it.
00:18:08
Thank you, Mark. Always good to hear from you. Oh, well, no, I
00:18:12
think he's a first time questioner. So thanks for thanks
00:18:15
for biting the bullet and getting involved. This is Space
00:18:18
Nuts. Andrew Dunley with Professor Fred Watson.
00:18:22
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Well, we might as well get stuck straight into the next one,
00:19:30
Fred. This comes from Mike. I like this question.
00:19:34
Hi. Professor Watson and Andrew. I'm a new listener to your
00:19:39
podcast. Mike from Manchester in England. I think it's brilliant
00:19:45
podcast. I love listening to all your theories about space on the
00:19:48
questions you get in. I do have a question. It's about a recent
00:19:52
discovery by the Imperial College London. Professor
00:19:57
Ricardo Saza.
00:19:59
I think you, you say his name has discovered that they have
00:20:04
done a double slit experiment, not in a traditional way but
00:20:08
using time instead of particles and, and waves using light. And
00:20:15
they have found that depending on your reference point and your
00:20:20
viewpoint on this experiment, you can actually see time in the
00:20:24
future or in the past. Now, I'm wondering if this affects the
00:20:29
way that we have been looking at the the universe.
00:20:34
And and, and using obviously the, the time sorry, the
00:20:40
frequency shift from the red spectrum to see the distance of
00:20:46
stars and how old they are. Because this experiment actually
00:20:52
changes the frequency of, of the light, it shifts it. So I'm
00:20:56
wondering if gravitational lensing has in effect created
00:21:03
this event of what they have found at Imperial College
00:21:08
London.
00:21:08
And we have actually been looking at the universe and
00:21:12
recording it in, in incorrectly, in some cases as the light that
00:21:16
we're recording has actually got to us quicker than we originally
00:21:20
thought or actually slower than we originally thought, meaning
00:21:22
that we possibly have got the the age of the universe all
00:21:29
wrong.
00:21:32
I'd love to an answer to the question. I think it's quite
00:21:35
Interesting. So, re Herb, thank you.
00:21:38
Thank you, Mike. Wow, that's, that's pretty deep. We have had
00:21:41
the question come up officially scientifically that some believe
00:21:47
that the age of the universe is off.
00:21:50
So what he's asking is through this double slit experiment
00:21:54
using light, are we, in fact seeing I'll use the terminology
00:21:58
a time slip which could be forwards or backwards.
00:22:03
Interesting. Yes, I'm, I'm actually just looking at the I
00:22:05
hadn't heard of this work, Mike. So thank you for thank you for
00:22:11
alerting us to it. I'm looking at the Imperial College Press
00:22:15
release, which was published back in April this year.
00:22:19
Imperial physicists have recreated the famous double slit
00:22:23
experiment which showed that light behaving as particles and
00:22:26
waves, but in time rather than in space. And so what they're
00:22:32
doing is and looking at materials that can change their
00:22:41
properties, optical properties very, very rapidly at sort of
00:22:46
femtosecond timescales.
00:22:49
I can't remember what the femtosecond is. It's very small.
00:22:52
And then you you, I'd need to really read the article to, to
00:22:58
be across exactly what's happening. But it's, it clearly,
00:23:07
yes, that, that, that, so these, that there, there is exactly as
00:23:11
Mike said, a change in frequency involved.
00:23:14
So some, yeah, some colors are canceled out in a, in, in white
00:23:23
light. And some are enhanced I, I really need to sit down and
00:23:28
read this article to understand exactly what's being talked
00:23:31
about here because I can't really comment on the, the
00:23:37
effect it has on our understanding of light coming
00:23:40
from distant objects.
00:23:41
My guess is the problem we're talking about such an
00:23:44
extraordinary circumstance of this, this optical property
00:23:51
changing over time that you're talking about very, very special
00:23:55
circumstances that that really have no impact on our
00:23:59
understanding of, you know, what you might call cosmological red
00:24:04
shift, which is the red shifting of light.
00:24:07
But look, I I'm gonna read it. So maybe we can put that on the
00:24:11
list to come back to Andrew because it is a very interesting
00:24:14
homework list. Very interesting piece of work. One of the
00:24:19
co-author of the paper is a very well known name, Professor Sir
00:24:22
John Pendry, a very well known physicist.
00:24:26
He, his comment is the double time slit experiment, double
00:24:30
time slit experiment opens the door to a whole new spectroscopy
00:24:34
capable of resolving the temporal structure of a light
00:24:37
pulse on the scale of one period of the radiation. So it's, it's
00:24:42
really about how light changes in, in nature.
00:24:48
In general. But yeah, let me, let me let me come back to this
00:24:54
because I think it's worth pursuing. It's a really
00:24:56
interesting, really interesting piece of work.
00:24:59
Ok. Will do. Thanks, Mike. We'll get back to you shortly. Next
00:25:03
question comes from Justin, who says, hi, Fred and Andrew. I
00:25:07
wanted to ask a question about the recent LF bot luminous fast
00:25:12
blue optical transient reports. It seems this is being reported
00:25:16
as a brighter and more energetic explosion than a supernova. Ah,
00:25:20
but I have to wonder that reporting of an highly rather
00:25:28
than.
00:25:30
No, nobody knows what they are.
00:25:32
Yeah. Yeah. Well, that's, yeah. Some sources are reporting FLF
00:25:36
bots as a flash that reports repeats on regular or irregular
00:25:42
intervals. And that just reinforces my opinion that it
00:25:45
may be naturally occurring laser much like the mass we already
00:25:51
that know already occur or to Fred's thoughts. Thank you,
00:25:55
Justin.
00:25:56
Yeah. Really interesting. I mean, you know, micro masers are
00:26:01
microwave lasers effectively.
00:26:05
And they are well known in space. They're in the radio, you
00:26:09
know, radio regime, the well studied, I don't believe that
00:26:14
there is an optical equivalent in acting in nature.
00:26:21
Because it's not something that I've ever come across. And I,
00:26:26
and so I think these transients is a, an interesting thought
00:26:30
though.
00:26:32
You know, the, the possibility of, of there being optical
00:26:37
optical lasers that that occur in space.
00:26:43
If you look on Wikipedia as you always should do and don't
00:26:48
forget to contribute to Wikipedia either because it's it
00:26:51
needs money.
00:26:53
The precise definition of what constitutes a faster blue
00:26:57
optical transient is currently contentious in the literature
00:27:01
rather largely defined by the observational properties rather
00:27:05
than the underlying mechanisms or objects.
00:27:07
And you know, the comment here, even within the class growing
00:27:12
samples are beginning to reveal significant variation in
00:27:15
properties where the objects are studied in greater detail,
00:27:18
potentially indicative of different progenitor channels or
00:27:21
explosion mechanisms. In other words, nobody really knows what
00:27:24
they are. The idea of them being optical lasers is a, is an
00:27:28
interesting one.
00:27:30
It, I suspect one of the things that puts against that is that I
00:27:35
think these things are broadband. I think there's you
00:27:40
know that, that they're not a single wavelength that is being
00:27:44
emitted. Whereas generally in, in anything that's stimulating
00:27:51
emission, which is what the laser process involves. You get,
00:27:54
you essentially get monochromatic light.
00:27:57
It's very interesting. A number of you know, when you look down
00:28:01
the list of fast, fast blue optical transients, there, there
00:28:05
's a whole mixture of them. They, they date back to 2018,
00:28:10
various observatories have observed them. And I think yes,
00:28:14
one has been one of the recent ones is is the biggest and that
00:28:21
's the the object known as the cow.
00:28:25
I'm not quite sure why it's known as a cow, but it is and it
00:28:29
's, it's probably relatively nearby, but its peak luminosity
00:28:34
exceeds that of the super luminous supernovae. So we're
00:28:38
talking about really mysterious objects here about which well,
00:28:43
certainly my knowledge is relatively limited.
00:28:47
It could be po possibly a s you know, black hole related
00:28:55
something a bit like a quasar. But emitting basically short,
00:29:02
short period ie transient amounts of, of, of emission w
00:29:09
with perhaps radio emission as well as the visible light and X
00:29:13
ray emission.
00:29:13
But coming from different parts of whatever it is, we're talking
00:29:16
about something, some, some dense perhaps you know, almost a
00:29:21
black hole inside a, a dense medium that's, that's having all
00:29:25
kinds of basically pulsations that they, maybe they, maybe r
00:29:31
relatives of gamma ray bursts which are gamma rays that are
00:29:35
focused in a particular direction.
00:29:38
All the mystery continues, Justin. But yeah, there's all
00:29:42
sorts of ideas but no one really knows. Thanks for your question.
00:29:46
Next one comes from Nigel. This one should be quick and easy,
00:29:49
Fred.
00:29:50
Hello, space dots around the world. Hi, Fred and Andrew. This
00:29:54
is Nigel from Brisbane, Australia. I have a question
00:29:57
about launching satellites into space more exactly. I have a, a
00:30:01
question about launching privately owned non-government
00:30:04
satellites into space in recent years. There's companies like
00:30:08
spacex and Rocket Lab in New Zealand who launch privately
00:30:13
owned satellites into space.
00:30:15
But before they are around, I wanted to know who was doing it.
00:30:18
We've been launching privately owned satellites into space for
00:30:21
over 4050 plus years now. So, can you tell me who was
00:30:26
launching them into space? Was it all NASA or was it some other
00:30:30
company? Terrific? Love the show. Keep up the good work by.
00:30:35
Thanks Nigel. Yeah, that's a good point. III, I think NASA
00:30:39
was certainly doing it. I think Ross Cosmos was getting involved
00:30:44
because they needed money. I think ESA was doing it for a
00:30:47
while there and they might still be.
00:30:51
Well, So, yeah, I mean, most private satellites certainly
00:30:56
over the last 40 years have been communication satellites. So
00:31:00
we're talking about things like geostationary satellites which
00:31:02
are in those orbits that make them very suitable for
00:31:06
communications.
00:31:07
They are, I think almost exclusively privately owned by
00:31:11
companies like, well, Telstra here in in, in Australia. Other
00:31:17
other communications companies that, that's the, the main one.
00:31:22
Then as time's gone on, you've got universities which launch
00:31:27
effectively private satellites for research purposes.
00:31:31
Somebody pays the Bill on these. So they're not always being paid
00:31:35
for by NASA or ESA or Ros Cosmos or Jaxa, the other major space
00:31:40
agencies. But I think your comment really is about the
00:31:44
launch vehicles perhaps Andrew that that you know, that launch
00:31:49
vehicles themselves were often funded by these space agencies.
00:31:52
But even there launch agencies now are, are private concerns.
00:31:58
Ul A is one, the United Launch agency, spacex is another blue
00:32:02
origin is another. So it is yeah, it's it's the space is
00:32:08
privatized in a very, very big way. And in some senses, the,
00:32:12
you know, the government agencies are now the smaller
00:32:14
players except for the defense agencies which of course, are
00:32:18
major players about which we know virtually nothing.
00:32:21
Exactly. Exactly. With their mysterious shuttle that's up
00:32:25
there for years at a time, all that kind of things. But I
00:32:28
suppose it's an expanding and on and developing a market, isn't
00:32:33
it? I think Australia is looking at private satellite launching
00:32:36
in the distant, not too distant future.
00:32:39
So it's, yeah, but yeah, yeah, but I suppose the, the
00:32:43
government agencies before privatization came along were
00:32:47
probably the ones. But, it's, yeah, it's, it's a change, ever
00:32:52
changing market would be probably the, the answer Nick.
00:32:56
But, thanks for your question, we're going to, take a breath
00:32:59
and then we'll try and, whip in a few more questions before Fred
00:33:03
has to go. He's on a very tight timeline today.
00:33:10
Space Notes. Ok, Fred. We've got a question now from Rusty. I
00:33:14
absolutely love this one. Good name for it.
00:33:16
And Andrew, it's Rusty and enjoy book. Thank you so much for
00:33:20
answering my question about the, from one point of view trillions
00:33:25
of years old, infant universe that we're living in now,
00:33:33
pinhead size for all those trillions of years and then
00:33:36
suddenly bursting into life. So there's got to be more, doesn't
00:33:41
there?
00:33:41
Ah, so what's the possibility of one or more of these things
00:33:47
existing embedded in our own universe? They'd only be
00:33:51
detectable by the gravity, of course. So, the one that comes
00:33:56
to mind for a close exam, a relatively close example is the
00:34:00
greater tractor, but there could be more of, of those things
00:34:04
further out. So, yeah, what's the possibility of that?
00:34:08
Cheers guys. Thanks Rusty. I I've never thought about this as
00:34:13
a possibility for it.
00:34:16
So conventional wisdom doesn't allow that to happen.
00:34:26
No, he's not. You can't have something that's trillions of
00:34:28
years old in something that you know, billions only existed for
00:34:32
13.8 billions. Yeah, he did mention trillions of years.
00:34:36
Yeah. So, but the greatest tractor is pretty well
00:34:40
understood now. Because we with infrared telescopes, we can
00:34:44
actually see some of the Galaxies that that are causing
00:34:48
that attraction.
00:34:49
Remember the greatest tractor is a region of space which kind of
00:34:52
lines up with the milky way, which is why we can't see it
00:34:55
with normal optical telescopes, but it's where lots of gravity
00:34:58
seem, lots of Galaxies seem to be heading. Hence the name the
00:35:02
greater tractor.
00:35:05
John Deere or a Messi Ferguson, a great tractor.
00:35:09
Ok. Yes, I'm with you there. Yeah, I think international
00:35:14
harvester to be, to be precise. Yeah. Anyway, yeah. So, I think,
00:35:20
I think that's a nice thought, but I'm not gonna buy that one.
00:35:24
That's what you Rusty.
00:35:26
Nice to Rusty. Alright. We've got a question from Nick. The
00:35:29
psyche mission is testing the Deep Space Optical
00:35:33
communications system. Kindly explain what that is and how it
00:35:36
works. Thanks love the show. In spite of the bad dad jokes. Ah
00:35:39
Nick.
00:35:41
The indeed it is it's it is actually a test bed for for
00:35:51
optical communications. And in fact, there you know, if you go
00:35:57
to their web page, which I've just done the psyche mission Jet
00:36:00
Propulsion Laboratory web page. Psyche is going to an asteroid
00:36:04
called psyche which I studied actually when I was doing my
00:36:07
master's degree asteroid number 16 psyche.
00:36:10
It's it's got an interesting orbit but just reading directly
00:36:15
from the psyche website, we have one of the sections is Deep
00:36:20
Space Optical communication and it says the psyche mission will
00:36:23
test a sophisticated new laser communication technology that
00:36:27
encodes data in photons at near infrared wavelengths rather than
00:36:31
radio waves to communicate between the probe in deep space
00:36:35
and earth. Using light.
00:36:36
Instead of radio allows the spacecraft to communicate more
00:36:39
data in a given amount of time and the DS OC team, Deep Space
00:36:43
Optical communication team is based at the Jet Propulsion
00:36:46
Laboratory. So they've got receivers there that are picking
00:36:49
up infrared radiation coming from the psyche spacecraft and
00:36:53
with much higher bandwidth than what we would have for radio
00:36:57
waves.
00:36:58
Fascinating. I think I read the other day that there was some
00:37:02
kind of signal that came back to earth and they don't know where
00:37:05
it came from. And I think it was, described as a laser. I
00:37:11
don't know if that's what it was but they, they don't know its
00:37:13
origin.
00:37:14
And, it seemed to come from the, the portion of the universe that
00:37:18
's, you know, got nothing in it. So whether or not it's been
00:37:24
moved by something else and, and intercepted by earth. I don't
00:37:27
know. But, it, it was a, yeah, that, that, that's another
00:37:31
mystery. We have not solved threat.
00:37:34
Yeah. And II, I need to check that one out as well to find out
00:37:38
what it is. It's of interest.
00:37:39
I should have said it to you. I usually do when I see something
00:37:42
like that. Let's, can we squeeze in one more?
00:37:46
I'm already in the other meeting Andrew, with my camera turned
00:37:52
on. I'm just about to turn it off. So, they, they're not
00:37:56
seeing me. Yeah, I, look, we've got a minute or two because I
00:38:00
can see, on the screen that they're making. So, let's keep
00:38:04
going.
00:38:05
Ok. This last question comes from Robert.
00:38:08
Hi, I'm Noah from Mackay.
00:38:11
I just have a question about whether there is any stars in
00:38:14
the night sky today that were there 5060 or 100 years ago, you
00:38:22
know, has, is there any stars in the sky that the light has
00:38:27
finally reached earth and we can see them now and we couldn't so
00:38:31
long ago. But yeah, I absolutely love the podcast. I listen to
00:38:36
every episode. So keep doing what you are doing because I'm
00:38:38
loving it. Cheers. Hope you have a good day.
00:38:41
Thanks. Now, I think I called you Robert, my apologies. But
00:38:44
hello to Mackay. I used to live there many, many years ago.
00:38:47
Yeah. That's a good one. I, you know, I only knew stars in the
00:38:50
last couple of 100 years. I suppose this is something that
00:38:53
would, would be obvious to some. But you know, down here in
00:38:57
ordinary world we don't. Yeah, we don't really think about
00:39:00
that.
00:39:02
You, you probably over time scales of tens of thousands of
00:39:07
years, you'd see the evidence of new stars probably maybe
00:39:11
hundreds of thousands of years. Because star formation is a
00:39:14
process that takes a little while. And you know, they don't
00:39:19
just pop into existence all of a sudden, some stars do brighten.
00:39:24
So Noah's right. In the sense that, you know, for, for
00:39:29
example, the first nations people in Australia, we think
00:39:35
some of them and, and elsewhere, we think some of them have seen
00:39:37
stars that for a while were for a long time, were below the
00:39:42
limit of naked eye visibility.
00:39:44
But then that brightened up to the extent that they actually
00:39:47
became visible. And in fact, you know, some stars we think have
00:39:52
brightened up to be, to become very bright indeed, and then
00:39:55
faded away again. So that's an intrinsic property of a star
00:39:59
that's who's, who's, you know, basically whose environment is
00:40:04
changing often, it can be something that's blanketed by
00:40:07
dust.
00:40:08
So, that's, yeah, that's one of the ones I'm thinking of. That's
00:40:12
right. So, yeah, so, so the stars come and go in that
00:40:15
regard. But if you had a telescope, you'd still be able
00:40:18
to see it, you know, even when it was at its faintest type.
00:40:23
So, but nothing that's just kind of switched on out of the blue
00:40:27
like that.
00:40:28
So, great question, the sky probably hasn't changed much.
00:40:33
Exactly right.
00:40:36
And the other one is if you get a Nova which is a star that has
00:40:41
an outburst, a bright outburst, it may have been below
00:40:44
visibility beforehand and suddenly gets bright and of
00:40:47
course, supernovae do that as well. You have a very dim star
00:40:51
that suddenly becomes extremely bright. So, all of those events
00:40:56
that that are related to this and I see Andrew, my meeting has
00:41:00
now started all I have to go and join it, cut.
00:41:05
It very fine this week. Thank you.
00:41:08
You do the.
00:41:09
Thank you, Fred. And we'll let you get to your meeting. It's
00:41:12
been great as always Fred Watts, an astronomer at large. And
00:41:16
don't forget if you have questions for us, send them in
00:41:18
via our website. We'd love to hear from you whether they're
00:41:21
text or audio questions, have a look around while you're there.
00:41:23
Christmas is coming up. So don't forget to visit the shop and if
00:41:26
you're interested in becoming a patron, Yeah, just go to Space
00:41:31
Nuts, podcast.com or Space Nuts Dot IO. That's just about it.
00:41:36
Thanks again to Fred, thanks to everyone who contributed to the
00:41:40
380th episode of Space Nuts.
00:41:43
And thanks to Hugh in the studio for pushing all the buttons and
00:41:46
ringing all the bells and for pinching, Fred's dog's bottom so
00:41:51
that it made a lot of noise during the show this week. And
00:41:54
from me, Andrew Dunkley, thanks for your company. Look forward
00:41:57
to seeing you next time on Space Nuts.
00:42:00
Bye bye to the Nuts podcast available at Apple Podcasts,
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00:42:13
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00:42:17
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00:42:20
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00:42:22
Does this make any sense? And of course, if you have something
00:42:25
like a cork star, which is theoretically considered.
00:42:31
I'm gonna have to stop and I've got to go and attend to that.
00:42:34
Hang on a sec.
00:42:37
Yeah.
00:42:38
Hello? Fine, thank you.
00:42:43
That was the doorbell.
00:42:46
Ok.
00:42:48
That's so cool, straight face.
00:42:58
So sorry about your doorbell. Love your doorbell. Yeah. Yeah,
00:43:02
I knew, I knew as soon as he started what someone was there.
00:43:05
Yeah, it's actually the, it's a cleaner.