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Space-Time Dragging, Martian Rovers & Stellar Discoveries · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Andrew Dunkley: 15 seconds. Guidance is internal.
0:03
10, 9. Ignition
0:06
sequence start.
0:07
Professor Fred Watson: Space nuts I.
0:09
Andrew Dunkley: 4, 3, 2,
0:12
1. Space nuts. Astronauts
0:15
reported meals Good. Hello once again
0:18
and thank you for joining us on this edition
0:20
of the Space Nuts podcast.
0:23
And my name's Andrew Dudley, your host. And
0:25
with Me for episode 193 is
0:28
Astronomer in Charge from Professor Fred
0:31
Watson. Hello, Fred.
0:33
Professor Fred Watson: Hello, Andrew. I did used to be the
0:35
Astronomer in charge. That was my.
0:37
Andrew Dunkley: I thought I said Astronomer at Large.
0:39
Professor Fred Watson: Well, it's quite all right.
0:40
Andrew Dunkley: No, it's Freudian slip.
0:42
Professor Fred Watson: It's very. And of course, um, uh,
0:44
that's why I became the Astronomer at Large.
0:46
Because you only had to change four letters
0:48
on the office door to make it unknown to you.
0:51
Yes, yes.
0:52
Andrew Dunkley: Um, the organ. And that sort of harps on
0:55
something we talked about a while ago where
0:57
your organization has changed names about two
0:59
or three times, but didn't change the
1:02
lettering. So didn't change the logo.
1:04
Professor Fred Watson: Exactly. Same logo since
1:06
1991.
1:09
Andrew Dunkley: I think that's amazing. Uh, very
1:12
good.
1:12
Now, um, Fred, have you got enough toilet
1:14
paper at your place? Is my big question.
1:17
Professor Fred Watson: Well, it's very kind of you to ask. Um,
1:20
we haven't yet started tearing pages out the
1:23
Astrophysical Journal to use in the bathroom.
1:26
Andrew Dunkley: Did you hear about the Northern Territory
1:27
News? Uh, the newspaper in Darwin?
1:32
They published an edition last week with
1:34
several blank pages for people.
1:40
This whole thing is just insanity at the
1:42
highest level. There's so many people
1:45
panicking over nothing. It's.
1:49
Professor Fred Watson: You might want to explain the toilet paper
1:50
issue, though.
1:51
Andrew Dunkley: I think most people are aware, but if you're
1:53
not aware, I don't know where you've been.
1:55
But, uh, there's been a panic buy up of
1:57
toilet paper in Australia and all the
2:00
supermarket shelves are empty. Every
2:02
supermarket where I live has got no toilet
2:04
paper because people have been panic buying
2:07
because the prime minister said stock up
2:09
because you might have to be isolated for a
2:11
couple of weeks because of the coronavirus.
2:13
And everyone's freaking out about it. Well,
2:15
not everyone. I mean, we don't care. But a
2:17
lot of people are freaking out about it. But,
2:19
uh, I'm going to bring some astronomy
2:22
into this, Fred.
2:23
Professor Fred Watson: Oh, good. I wondered where it was going.
2:25
Andrew Dunkley: I think this is the 2020 version
2:28
of a caveman seeing an eclipse and thinking
2:31
the world's going to end. Oh, probably that's
2:34
what this is.
2:35
Professor Fred Watson: Yeah.
2:36
Andrew Dunkley: So I think people need to take a long, hard
2:38
look at themselves and give themselves an
2:40
uppercut, to use an Australian term, and just
2:43
get on with it. This is
2:46
ridiculous. Totally ridiculous.
2:49
Professor Fred Watson: The good news is that um,
2:52
those particular people will, you know,
2:54
they'll never need to go and buy another
2:56
toilet roll again.
2:57
Andrew Dunkley: Not for eternity. They'll
3:00
get like, they'll get buried with the stuff.
3:02
Professor Fred Watson: Yeah, that's right.
3:03
Andrew Dunkley: I'm suggesting that if they're going to, you
3:05
know, panic, buy toilet paper, get some baked
3:07
beans and some long life milk so that when
3:09
you eat it it'll taste a bit better.
3:13
M Now let's get down to business.
3:15
Today on Space Nuts we're going to uh, look
3:18
at something that scientists have discovered
3:20
for the first time and that is that space
3:22
time is dragging. Not everywhere, but they've
3:24
found that it is dragging in one particular
3:26
place, which sounds unusual. And what does
3:29
dragging actually mean? Uh, we're also going
3:32
to look at a couple of clever, uh, students,
3:35
um, uh, in terms of a name for the
3:38
next Martian rover. This follows on from
3:40
Sojourner, which I think is a great name.
3:42
Spirit, Opportunity, Curiosity. So what are
3:45
they calling the next one? We will tell you.
3:47
And a 17 year old intern at
3:50
NASA Day 3 on the job has
3:53
found a planet six times, uh, or nearly seven
3:55
times larger than Earth. I mean,
3:58
how lucky is that? Uh, those are some of the
4:01
things we'll look at today on Space Nuts with
4:03
Fred Watson.
4:04
Let's uh, start off Fred, with um, the
4:07
fact that space time is dragging. What is it
4:10
dragging and why?
4:13
Professor Fred Watson: Uh, it's a phenomenon
4:16
to do with the theory of general
4:19
relativity, or rather the general theory of
4:21
relativity, which of course was produced by
4:23
Albert Einstein in 1915. Uh, not
4:26
long after that, I think about three years
4:28
later. Well, uh, let me just step back a
4:31
minute. That theory of course says that
4:34
as soon as you put matter into space time
4:37
and space time's really just space, but with
4:40
a fancy name as, uh, soon as you put matter
4:43
into it, because of course time's part of it
4:44
as well. Uh, as soon as you put matter into
4:47
space time it is distorted and that
4:49
distortion is what we feel as gravity. Uh,
4:52
and that in itself is pretty hard to
4:55
get your head around. Space time bends
4:57
because matters there. But it was about,
5:00
uh, I think three years later
5:03
that two Austrian
5:05
scientists, uh, by the name of
5:08
Josef Lenzer unt Hans Turing,
5:12
um, they worked out that
5:15
uh, you would get a phenomenon,
5:17
um, if you have a
5:20
massive object rotating, you get a
5:22
phenomenon which is almost a swirling of
5:25
the space time around the object. It's called
5:28
frame dragging. Um, and
5:31
so as the Earth does it, as the Earth
5:33
turns, it's not only distorting the
5:36
space that's holding us on with the Force
5:39
of gravity, but to a much less,
5:42
a much lesser degree, it's also
5:45
dragging the surrounding space time with
5:48
it. Now I know you're
5:51
looking baffled, Andrew.
5:52
Andrew Dunkley: It's just a lack of sleep because I'm worried
5:54
about where I'm going to get a roll of toilet
5:56
paper.
5:58
Professor Fred Watson: Well, just watch out. Don't drag your space
6:01
time with it when you find it.
6:03
Um, we usually Anglicize,
6:06
uh, uh, Josef and Hans
6:09
names to the lens theory
6:12
precession or lens theorying effect.
6:14
Andrew Dunkley: Okay.
6:15
Professor Fred Watson: Um, that's um, how most people speak of
6:18
it, even though they wouldn't have called
6:19
themselves that. Uh, so, uh,
6:22
okay, it has been tested, this
6:25
theory. It was um, as I said, I think it
6:27
was 1918 when it was uh, when
6:30
it was produced. Um, but
6:34
uh, the first test of it was
6:36
done in the early 2000s.
6:39
A spacecraft called Gravity Probe B
6:42
was launched into orbit around the Earth
6:45
by NASA in collaboration, I think with
6:47
Stanford University, um,
6:50
which carried on board very, very sensitive
6:53
gyroscopes. And by using
6:56
those, uh, the
6:59
uh, physicists running the experiment could
7:01
detect the frame dragging of the Earth
7:04
itself. So it's all about subtle
7:07
motions in the satellite
7:10
and that tells you that yes, you have proved,
7:13
because there's nothing else that would give
7:15
rise to those subtle motions, you've proved
7:17
that frame dragging is true, uh,
7:21
but it's only been detected around the Earth.
7:24
So now cut to the chase, uh, because
7:27
uh, for the first time, uh, it has
7:29
now been detected in an astronomical object.
7:33
Uh, and this is a really nice story because
7:36
it pulls together uh, the
7:39
fundamental physics of frame dragging with
7:42
some of the big adventures that here
7:44
in Australia we are taking part in, uh,
7:47
particularly in terms of radio astronomy. The
7:50
story goes back 20 years actually, Andrew,
7:53
uh, to the Parkes Radio
7:55
Observatory, uh, in New South
7:58
Wales, the very same state that we are both
8:01
in at the moment.
8:03
Andrew Dunkley: One hour drive from that telescope.
8:05
Professor Fred Watson: Yeah, yeah, that's right. You are indeed.
8:06
Exactly. It's just down the road for you. Ah,
8:09
very, very well known telescope, uh, the Big
8:11
Dish it's usually called.
8:12
Andrew Dunkley: And very distracting when you're driving
8:15
along the highway because you just want to
8:16
look at it.
8:17
Professor Fred Watson: You can't stop looking at it. I know
8:20
I don't have that problem because usually
8:22
when I go down there, that's where I'm going.
8:24
So I just watch it getting bigger as you get
8:27
nearer to it. Um, 20 years ago,
8:30
uh, the Parkes radio telescope
8:33
discovered uh, a white
8:35
dwarf pulsar binary system.
8:38
Um, I'll tell you its name and then we can
8:41
get that out of the way. It is, actually.
8:43
I've got to magnify the screen so I can read
8:45
it.
8:48
Now, Fred, you're showing your PSR, uh,
8:51
J1141 minus 6545.
8:54
There you are. Uh, put that in your diary.
8:57
That's good already. As have
9:00
I. Uh, it is a white dwarf pulsar, uh, binary
9:03
system. What does that mean? It means you've
9:04
got a white dwarf star, which is, um, an
9:07
object the size of the Earth, but with the
9:09
mass of a star in it. Uh, made of electrons
9:12
all crushed together. Uh, or the electrons
9:14
are the only thing that hold that. Hold the
9:17
thing that start the thing from collapsing.
9:19
So, um, that is a massive object. Uh,
9:22
around it is this pulsar, which is another
9:24
massive object, uh, a neutron star. Uh,
9:27
the two are in mutual orbits and
9:31
the, uh. So the
9:33
telescope discovered that
9:36
phenomenon, the binary system. So the
9:39
pulsar itself is beaming out radiation from
9:41
its poles. Pulsars, as you know, because you
9:43
and I have spoken about this before, uh,
9:45
effectively are extremely accurate clocks.
9:49
They basically blip out
9:51
radio radiation as they rotate.
9:54
That's what the Parkes dish detected.
9:57
And, um, the precision with which
10:00
they do that is better than atomic clocks.
10:02
They are so regular. Um, Just
10:05
as one smaller piece of information in this.
10:08
The pulsar itself orbits the white
10:11
dwarf every 4.8 hours.
10:14
So it's, you know, it's a. It's
10:17
whizzing round. That's right. Um,
10:20
now what has happened over the last 20 years
10:23
is that astronomers have been able to use
10:26
this timing phenomenon,
10:29
the regular timing of the pulsar,
10:31
to measure the pulsar's
10:34
position in respect to the white
10:37
dwarf. Uh, because
10:40
essentially time. Accurate time means
10:42
accurate distance in terms of, uh, measuring
10:45
where the pulsar is. And it's that
10:48
measured over 20 years that has
10:51
demonstrated that this frame dragging
10:53
phenomenon is taking place out there,
10:56
uh, at PSR, whatever it was. Uh,
10:59
J1141 minus 6545.
11:02
Um, so what the
11:05
scientists. And there's a group of scientists
11:07
from, uh, many different institutions,
11:09
including, uh, institutions in Germany, the
11:13
Square Kilometer Array Organization. That
11:15
is, uh, the headquarters of this great
11:18
new telescope that we're planning, the Square
11:20
Kilometer Array in Western Australia and in
11:23
South Africa. Uh, the headquarters are in
11:26
Manchester, uh, or near Manchester at the
11:28
Jodrell Bank Radio Observatory. One of the
11:31
scientists involved with this work, uh, comes
11:33
from that organization. Uh, so that
11:36
means, uh, he is relatively closely connected
11:39
with Australia because Australia is one of
11:41
the host nations. Uh, and
11:44
I should just mention that the Parkes dish,
11:46
uh, plus another telescope called the
11:48
Malonglo Observatory Synthesis Telescope
11:51
again here in Australia, uh, which has been
11:54
involved with this work. They are both
11:56
Pathfinder telescopes for the Square
11:58
Kilometer Array. So very important
12:00
in this large scale project that
12:03
is currently uh, under construction or,
12:06
uh, soon will be under construction, um,
12:09
that's getting in the plug for ska. But the
12:12
research itself, as I said, involves
12:14
scientists from Germany, Australia, New
12:16
Zealand and actually Denmark too. Um, and
12:19
what they've done is they've um, looked at
12:22
the way these pulsar signals have changed
12:25
over the 20 years and they find
12:28
a change in the pulsar's
12:30
orbit which amounts to
12:33
150 kilometers. Uh, and
12:36
we're now talking about something that's
12:38
10,000 light years away. Andrews Being
12:41
able to measure uh, a change in orbit of
12:44
150 kilometers, uh, at that distance is
12:47
an astonishing accomplishment. But it turns
12:49
out that that change is exactly what you
12:52
would expect from frame dragging by
12:55
the white dwarf itself. And that's the only
12:57
thing that can account for it. So it is the
12:59
first time that we've demonstrated this
13:02
swirling of space actually, uh, uh,
13:05
beyond the Earth's vicinity. And it's an
13:07
important, um, you know, a really important
13:09
result which is rightly being celebrated all
13:11
over the science media, um, astronomers,
13:14
detective, Distant space time dragging for
13:16
the first time.
13:17
Andrew Dunkley: So I guess the point of
13:20
this is the massive um, or the
13:23
mass of this event rather than, you know, we
13:26
talked about how Earth does it, but we're
13:28
talking about something on a much larger
13:30
scale.
13:31
Professor Fred Watson: That's right, yes. Uh, well, the white dwarf
13:33
itself, whilst it's probably not much bigger
13:35
than the Earth, uh, its mass is much larger.
13:38
Yeah, uh, and yeah, you're talking about,
13:40
um, you know, you are talking about something
13:42
happening on a larger scale. I
13:45
confess that um, I am not an
13:47
expert on the lens searing effect, uh, but
13:50
it is very interesting stuff. Uh, and when
13:53
you read up about it, it's quite inspiring
13:56
that, you know, all those years ago these
13:58
guys worked out that space time is being
14:00
dragged around by the Earth.
14:02
Andrew Dunkley: And if you like me and you don't want to read
14:04
anything about it, there's a fabulous
14:06
animation on the
14:08
skatelescope.org website where you
14:11
can see um, in about 1 minute
14:14
and 20 seconds what they've learned over 20
14:16
years. It shows you how uh, effect works.
14:19
It's very, very good.
14:21
Professor Fred Watson: Um, I might give a call out to the, the
14:23
person who put that uh, animation together,
14:25
Mark Myers, who's at Swinburne University,
14:28
uh, because I was in touch with him
14:29
yesterday. I'm using one of his, um, graphics
14:32
in a newsletter that I prepare and I asked
14:35
him if that was all right. He said he, uh,
14:38
was delighted to let us use it. And
14:41
I absolutely agree with you, Andrew. His
14:43
animation, uh, which is on that website, the
14:45
skatelescope.org website, is terrific.
14:48
Andrew Dunkley: Yes, indeed.
14:49
All right, you're listening to the Space
14:51
Nuts podcast. Andrew Dunkley here with Fred
14:54
Watson. Let's
14:57
take a break from the show and hear a word or
14:59
two from our sponsored Grammarly. Now, I have
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16:35
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16:36
And now back to Space Nuts.
16:39
Three, two, one.
16:42
Space Nuts. Now, Fred, uh, just,
16:45
uh, another shout out to our patrons who
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We, um, thank you again for doing that. If
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17:17
But uh, anybody who contributes does get the
17:20
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17:22
website. Uh, they also get the commercial
17:25
free edition of the podcast,
17:28
uh, ahead of time. So, um, something to
17:30
consider anyway, um, now, uh, by the
17:33
way, Fred, um, my uh, new book,
17:37
um, Shameless Plug coming up, uh, is now
17:40
available for pre order as an
17:43
ebook. So, um, have a look for that
17:46
on the Amazon website. So, um,
17:49
that's, that's pretty exciting. I very, very
17:52
pleased with how it's all turned out. Uh,
17:54
someone actually messaged me the other day
17:55
and said I've ordered it, better be good.
17:59
Professor Fred Watson: Uh, you've got to remind us of the title,
18:01
Andrew.
18:01
Andrew Dunkley: It's called, uh, the Turanian Enigma. The
18:04
Tyranny Enigma. I'm starting. First time I
18:07
wrote that down and read it out, my tongue
18:09
tripped over it and I thought, no, this is,
18:11
this is too hard. But I'm getting used to it
18:14
now.
18:15
Professor Fred Watson: Very good.
18:15
Andrew Dunkley: I've developed a couple of synapses in my
18:17
brain that have got my mouth around the
18:19
Turanian in. No, no, I tripped over it. But
18:21
um, yeah, have a look for it. Uh, the
18:24
official release date of the ebook and
18:28
the paperback will be April 15th.
18:31
And um, a few people have
18:34
asked if I could turn it into an audiobook as
18:36
well. So I'll look into that. It's just
18:39
so time consuming to create an audiobook.
18:42
Uh, not so much the reading and recording of,
18:45
but the editing. Oh my gosh, that's a
18:47
nightmare. Uh, having.
18:49
Professor Fred Watson: Well, you did that for, um, almost.
18:51
Andrew Dunkley: There's Mud, which was a World
18:54
War I story about my grandfather in the Great
18:56
War. But that, that started
18:59
as an audiobook. So that was. I sort
19:01
of flipped the egg on that. I did the
19:04
audiobook and then, uh, made the paperback.
19:07
But these last two I've done the other way
19:09
around or haven't done the other way around.
19:10
But um, I'll, I'll look into it. I'll just.
19:13
It's got to be feasible. And that,
19:16
that sort of becomes the question. But, um,
19:19
we'll see how the demand goes. But yeah, have
19:22
a look for it. Um, Huw tells me he's going to
19:24
put it on our um, bytes.com
19:27
spacenuts page. So you might be able to pre
19:29
order through there. I haven't checked.
19:32
Uh, now let's get down to a couple of things
19:34
involving students. Fred. These are, uh,
19:36
um, exciting stories. I particularly like
19:39
this one, which involves the naming of the
19:41
next Mars rover. Now we've uh, heard of
19:44
Sojourner and Spirit and Opportunity and
19:47
Curiosity, uh some of which
19:50
have gone above and beyond the call of duty.
19:53
Uh, but um, they aren't the last rovers.
19:56
They'll be future rovers. And uh, it looks
19:59
like some students have got involved in the
20:00
naming of the next one.
20:02
Professor Fred Watson: Well, that's right. It was uh, uh,
20:05
uh, you know, I think this is what NASA
20:08
does normally with its rovers. Uh, it puts
20:11
out a um, competition, uh,
20:14
to uh, actually to
20:17
school students, uh, and
20:20
says suggests names for our next
20:22
rover. And of course the next rover is
20:25
what's been called until now Mars 2020.
20:28
Um, it will be launched uh, July or August
20:31
this year. I think its landing date
20:33
on Mars is the 18th of February next
20:36
year. So, um, uh, just under a year
20:39
away until now, called Mars
20:42
2020. So during the closing
20:45
months of last year, NASA put out the
20:48
invitation to school
20:50
students, I think it was, uh, school students
20:53
of all ages from kindy to year 12.
20:57
Uh, and uh, invited
21:00
them to submit
21:03
suggestions
21:06
uh, for the um, name, uh, of the
21:08
rover. And they received
21:11
uh, 28,000
21:13
submissions.
21:14
Andrew Dunkley: I know, that's amazing.
21:16
Professor Fred Watson: It's not bad, is it? That was uh, back in
21:19
August, at the end of August last year when
21:21
they put the invitation out. Uh,
21:24
but fortunately, uh, it wasn't just one
21:26
person who had to read all 28,000 because
21:28
these were essays, uh, saying why it should
21:30
be a particular name. They had 4,700
21:33
volunteer judges. They were educators, uh,
21:35
professionals in the space field and space
21:38
enthusiasts. And they eventually got down
21:41
to 155 semi
21:44
finalists and then nine finalists. And I
21:46
think, I can't remember, but I think you and
21:48
I talked about this last year because
21:50
there was a list of uh, very elegant. They
21:53
were all great names actually for uh, a
21:56
rover.
21:56
Andrew Dunkley: Robert.
21:58
Professor Fred Watson: Uh, and then they put that out for public
22:00
voting and in fact it was worldwide and there
22:03
were many submissions came from Australia.
22:06
They received a total of
22:08
770,000 votes
22:12
to, to, you know, to chew through, to work
22:14
out what uh, the final name should be.
22:17
And eventually, uh, they
22:20
got one answer and it came.
22:23
Andrew Dunkley: Hang on, Drumroll, drumroll.
22:25
Professor Fred Watson: Uh, it came from uh,
22:29
a youngster by the name of Alex
22:32
Mather, uh, who's at a school. I've
22:35
forgotten. I think he's in Virginia. I can
22:37
check that in a minute. Uh, but he. And
22:40
here's the drum roll. He was the person who
22:42
suggested the name Perseverance,
22:45
which is nice of the new
22:48
spacecraft. Yeah, yeah.
22:50
Andrew Dunkley: That is a fabulous name for it because it
22:52
does actually tell a story
22:55
behind all the missions to Mars over the
22:57
years and all the work that's gone into it.
22:58
They just, you know, uh, all the successes
23:01
and the failures and the near misses. It
23:04
is Perseverance that's going.
23:07
Professor Fred Watson: That's right. I mean this spacecraft as well
23:10
could be uh, it could be the one that
23:12
discovers life on Mars because
23:15
that's what it's, you know, what the aim is.
23:18
Um, uh, unlike Curiosity, whose mission was
23:21
to discover whether Mars was ever habitable,
23:24
which it did within about the first fortnight
23:26
of its presence on the planet, um, uh,
23:29
Perseverance is looking for evidence of past
23:31
or present life, um, with many different
23:34
instruments that will, will do that. Uh,
23:37
and I suspect perseverance might be
23:40
the characteristic that it needs more than
23:42
anything else. It will probably be quite a
23:44
long mission. Uh, it's unlikely that, you
23:46
know, as soon as it drops down it's going to
23:48
find evidence of um, Martian
23:51
microbes. One would expect that it might have
23:53
to move around on the surface a bit, but it
23:55
will do that.
23:58
Andrew Dunkley: Only slightly pipped, uh, the number
24:00
two, which was Do I have to go to Mars?
24:05
Professor Fred Watson: Yeah, that's the one.
24:07
Andrew Dunkley: Yeah. Um, I'm fascinated by the fact
24:10
that uh, they got 28,000 submissions for the
24:12
name. It reminds me of an author, a
24:14
children's author in Sri Lanka last week who
24:16
got 20,000 submissions for the ending of her
24:19
latest book. And they came out
24:22
and they're going to publish it with
24:24
1,250 endings, which is,
24:27
which is a, um, Guinness World Record. And I,
24:30
I think those sorts of responses really show
24:32
where you stand in the world. So when I asked
24:34
for a title for my book, I got five.
24:36
Professor Fred Watson: Yeah, you did. I think that's pretty good.
24:40
More than, more than the number of people who
24:42
read my book. Um, um,
24:45
the bottom line here is congratulations to
24:47
young Alexander Mather. He
24:50
is uh, a year, sorry a grade
24:53
seven student. Now I, I'm, I'm guessing that
24:56
that means he's about 13, uh, or
24:58
thereabouts. Um, and
25:01
uh, he put in, put together a really
25:04
uh, remarkable, um, you know,
25:07
remarkable uh, um,
25:10
entry. Um, he said some
25:13
very, very, very uh,
25:15
nice comments about the, the competition. And
25:18
his, his uh, his, his um
25:21
entry to it, he says, um, this
25:24
is actually in the NASA press release. He
25:26
says this was a chance to help the agency
25:28
that put humans on the moon and we'll soon do
25:30
it again. This Mars rover will help pave the
25:32
way for human presence there. And I wanted to
25:35
Try and help in any way I could. Refusal of
25:38
the challenge was not an option.
25:40
Lovely. That is great stuff, isn't it?
25:43
Andrew Dunkley: Good on him. Okay, uh, so watch out for
25:46
perseverance, uh, which should hit
25:49
the Martian surface in little under a year.
25:52
Still, uh, on students doing great things.
25:55
Uh, this is a fabulous story about a 17 year
25:58
old who's doing an internship at NASA and
26:01
has found a planet on day
26:03
three.
26:04
Professor Fred Watson: Day three. That's right, it is.
26:07
It's great stuff. Um, so, uh, this
26:10
is a young man called, uh, Wolf, Cukier,
26:13
I hope I'm pronouncing his name correctly.
26:15
Uh, he scored a two month
26:17
internship with NASA. Uh, so during
26:20
last northern summer he was at the Goddard
26:22
Space Flight center in Greenbelt in Maryland.
26:25
And, um, what he was doing, uh, on
26:28
day three, I think he probably started off
26:30
doing this. He was trawling through data from
26:33
tess. Uh, so TESS is a
26:36
NASA spacecraft. It is currently operational,
26:39
doing a great job. The name is an acronym
26:42
for Transiting Exoplanet Survey Satellite.
26:45
So it's actually looking for the dimming
26:48
of the light of stars as planets
26:50
pass in front of them. And unlike Kepler,
26:53
which only looked at a small, uh,
26:56
area of the sky to do the same job,
27:00
Kepler, now effectively defunct tess, uh,
27:03
actually looks at the whole sky. Uh, so
27:07
the word survey in its name is very important
27:10
because it actually has a chance to look at
27:12
the entire sky. So he was looking
27:15
through the data. Actually there's a nice
27:17
quote again, um, from Wolf. He
27:20
says, I was looking through the data for
27:22
everything the volunteers had flagged as an
27:24
eclipsing binary. That means, uh,
27:27
two stars orbiting around their common center
27:29
of mass. One passes in front of the other as
27:32
seen from the Earth. And so you get what we
27:35
call an eclipse. So they're well known stars.
27:38
They've been well known for more than a
27:40
century. It was looking, uh, through
27:43
everything Volunteers had flagged as an
27:45
eclipsing binary. A system where two stars
27:47
circle around each other and from our view,
27:49
eclipse each other every orbit. About
27:52
three days into my internship, I saw a signal
27:55
from a system called TOI
27:57
1338. At first I thought it was a
28:00
stellar eclipse, but the timing was
28:03
wrong. It turned out to be a planet.
28:06
Uh, I noticed a dip or a transit from the TOI
28:08
1338 system. And that was the first signal of
28:11
the planet. First saw the initial dip and
28:13
thought, oh, that looked cool. But then when
28:16
I looked at the full data from the telescope
28:18
at that start, I and my mentor also
28:20
noticed three different dips in the system.
28:23
So great stuff and very well
28:25
spotted.
28:26
Andrew Dunkley: And it's a big one too.
28:28
Professor Fred Watson: Yeah, that's right.
28:29
Andrew Dunkley: Planets, I suppose.
28:32
Professor Fred Watson: Um, it's somewhere between the size of
28:34
Neptune and Saturn. Uh,
28:37
rather larger than Uranus, about seven
28:40
times larger than the Earth. It's in the
28:43
constellation of Pictor and it's about 1300
28:45
light years away.
28:46
Andrew Dunkley: Um, is it a gas giant or a rocky planet?
28:49
Professor Fred Watson: Probably. Probably a gas giant. Yeah.
28:53
The name, uh, uh, uh,
28:56
TOI 1338. TOI
28:59
is an acronym for TESS, Object of
29:02
Interest. Uh, and, uh, um,
29:04
it's one that's floating around a lot these
29:06
days with a number attached to it.
29:09
So of course, um, because of the convention,
29:12
uh, that planet that, uh, Wolf has
29:15
discovered is now called TOI1338B
29:18
because the B signifies it is the first
29:20
discovered planet around the star.
29:23
Andrew Dunkley: Excellent. All right.
29:24
Professor Fred Watson: Great stuff.
29:25
Andrew Dunkley: Yeah, good, good stuff with involving
29:27
students, um, doing wonderful things. You're
29:30
listening to Space Nuts with Andrew Dunkley
29:32
and Professor Fred Watson.
29:38
Space Nuts and a big hello to all our
29:41
social media followers that contribute, um,
29:44
via our Facebook page. If you're not
29:46
following us on Facebook, uh, maybe have a
29:48
look. If you're a Facebook user, of course,
29:50
uh, you can also join the Space Nuts podcast
29:53
group on Facebook. That's a chance for you to
29:55
talk to each other and help each other out
29:57
with astronomy questions. And it's going
29:59
gangbusters. People are really, uh, enjoying
30:02
finding each other and, um, the
30:05
similarity in interest is rather fascinating.
30:08
So I occasionally poke my head in there. But
30:10
it's actually for you, the Space Nuts podcast
30:13
group, so you might want to take advantage of
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that. And of course YouTube Music. Uh, the
30:17
numbers continue to grow, so if you'd like to
30:19
subscribe to the Space Nuts YouTube Music
30:22
channel, you can do that too.
30:25
Now, Fred, uh, we have a couple of questions.
30:28
I didn't, uh, preview these because I forgot,
30:30
but, uh, we, we are going to tackle a couple
30:32
of questions and then we're going to do, um,
30:34
a little bit of homework or go back to
30:35
something we talked about a couple of weeks
30:37
ago just to finish it off, which was the
30:39
Roche limit, which, which actually came about
30:41
as a result of a question.
30:43
But our first question today comes from
30:45
Andrew Mitchell. I think Andrew's been in
30:47
touch with us before. Dear Fred and Andrew,
30:49
all this recent talk about black holes has
30:51
been fascinating. And the last installment
30:54
got me thinking. According to Einstein's
30:56
equations, black holes are supposed to have,
30:58
uh, infinite, uh, supposed to be infinitely
31:01
small, infinitely dense singularities
31:04
at their center. If that's the case, then how
31:07
do uh, two actually merge into one black.
31:10
Shouldn't they just keep orbiting each other,
31:12
getting closer forever? Or is the fact that
31:15
black holes do merge actually evidence that
31:17
singularities have size? Perhaps a sphere
31:20
with a diameter of one Planck length?
31:23
Uh, your regular plugs and YouTube Music
31:25
channel have been paying off. I just became
31:28
subscriber number 993, so it would, you know,
31:30
we're a bit overdue getting your question
31:32
done, Andrew. Thanks for joining us on
31:33
YouTube Music though still loving the show.
31:35
Um, please keep up the mind blowing stories.
31:39
Thank you, Andrew. Um, black holes, gee, we
31:41
don't talk about them very often.
31:43
Um, but yeah, it's an interesting
31:46
question because we talk about how the, the
31:49
black hole itself is quite small when
31:52
you compare it to the event horizon or the,
31:54
or the, you know, what's going on around it.
31:57
Um, but yeah, two
32:00
merging black holes, do they actually merge?
32:02
And how is it. So.
32:07
Professor Fred Watson: It'S a really good question. Um,
32:10
it's,
32:12
you know, the
32:15
whole black hole thing is hard to get your
32:18
head around, whether you're a physicist or an
32:20
astronomer or somebody fighting
32:23
over toilet rolls in the ah, aisle.
32:25
Andrew Dunkley: Vesuva involves a black hole too, doesn't it?
32:28
Professor Fred Watson: I'm sure it does, yeah. They are very, very
32:31
hard, uh, objects to understand. Uh,
32:33
and Andrew's question
32:36
made, um, how do two black
32:39
holes merge into one?
32:42
Um, I don't think
32:46
there is any need for them
32:48
to keep orbiting around each other
32:51
if they are of infinitely small
32:54
size. I do get his point that if you've got
32:56
something that's infinitely small, uh, and
32:59
you put something else that's infinitely
33:01
small next to it, they're never going to,
33:03
they're never going to touch, uh, because
33:05
the dimensions are infinitely small. But in
33:08
fact, as Andrew says, they do merge.
33:11
We have evidence of that, uh, from the
33:14
gravitational wave observations that have
33:16
been made, um, over the past, uh, two or
33:19
three years. Um, and
33:22
uh, there is this phenomenon, um,
33:25
called the ring down, which is
33:28
the sort of aftermath of the merging. Now I
33:30
don't know enough about black hole physics to
33:33
understand specifically what the mechanism of
33:36
the ring down is, but I suspect that is where
33:39
the evidence comes that you actually
33:41
have now merged black holes. In fact,
33:45
we know the evidence is there, um, because
33:48
you wind up with a black hole whose mass
33:51
is actually usually slightly less than the
33:54
sum of the masses of the two black holes that
33:55
have merged. And um, the excess has gone into
33:58
creating the gravitational waves. It's mass
34:01
into energy. Uh, but um,
34:04
Andrew goes on to make an interesting point.
34:06
He says, or is the
34:09
fact that black holes do merge. Actually
34:11
evidence that singularities have a size,
34:14
perhaps a sphere with a diameter of one
34:16
Planck length. Now
34:19
introducing the Planck length is a
34:22
really, ah, neat way of sidestepping the idea
34:25
of an infinitesimally small object,
34:28
because the Planck length is defined
34:31
as being the smallest
34:34
distance. And it does have a
34:37
proper physical definition. In fact, it's
34:39
actually the distance that light travels in
34:41
one unit of Planck time. Uh, so that
34:44
raises the question, well, what's Planck
34:46
time? Um, let me just
34:49
summarize though, and this is coming directly
34:51
off Wikipedia. The Planck length can be
34:53
defined. Uh, sorry, uh, from. Yeah,
34:56
let me read it. The Planck length can be
34:58
defined from three fundamental physical
35:00
constants. The speed of light in a vacuum,
35:02
the Planck constant. That's something, um,
35:04
which physicists are very familiar with. And
35:06
the gravitational constant. It's the smallest
35:09
distance about which current
35:12
experimentally corroborated models of
35:15
physics can make meaningful statements.
35:19
So what it says is. And I'll go on. At such
35:22
small distances, the conventional laws of
35:24
macrophysics no longer apply, and even
35:27
relativistic physics requires special
35:29
treatment. The bottom line is that a Planck
35:32
length below that, all bets are off. We
35:35
really don't understand what is happening to
35:37
the physics. And maybe Andrew's point is well
35:39
made that, uh, a Planck length
35:43
black hole is actually what you
35:45
have at the center of, uh,
35:48
constituting a black hole system. Um, I need
35:51
to talk to my, uh, expert friends about
35:54
this because, um, at this level of
35:56
technicality, my knowledge is
35:59
not specialist, But I do know people
36:02
whose knowledge is far better than mine.
36:05
And next time I run into them, uh, I'm going
36:08
to ask them exactly about these questions and
36:10
hopefully feed back to space nuts and to
36:13
Andrew and his, um, fellow listeners.
36:15
Andrew Dunkley: Okay, so the question remains open, Andrew.
36:19
Professor Fred Watson: Yeah.
36:19
Andrew Dunkley: I think we'll give you a definite maybe.
36:22
Professor Fred Watson: Maybe it's the answer. Yes.
36:23
Andrew Dunkley: All right, thanks, Andrew. Thanks for the
36:25
question. Let's move on to a question from
36:27
Ulf Petersen in Sweden.
36:29
Yeah, uh, alf, I've got some news from you
36:31
which you may or may not be aware of, but,
36:33
uh, a young lady named Julia Engstrom,
36:36
A professional golfer from Sweden, Just
36:39
won the new south wales women's open,
36:42
which we hosted here in dubbo a couple of
36:44
weeks ago.
36:45
Professor Fred Watson: Great.
36:45
Andrew Dunkley: I. Because our course was closed to play for
36:48
members, um, uh, we got to go out there and
36:51
watch these young ladies go around. It was a
36:52
European tour event. Uh, she won
36:55
not only her share of the prize money, but a
36:57
two year exemption on the European tour.
36:59
She's 18 years old. And she
37:02
swings it like a champion. I mean, she was
37:04
hitting it 260 to 280 meters,
37:07
whaling it past me. And she's just a slip of
37:10
a kid, but, uh, remarkable player and
37:12
someone to watch out for in the future, if
37:14
you're a golfer. Julia Engstrom is her name.
37:16
So there you go, Ulf. A little bit of. I can
37:19
feel his pride swelling now.
37:21
Um, now he says hello, uh, Andrew and
37:24
Fred, uh, what a fantastic community you've
37:26
started. And it's a global one, too. I've
37:28
been a faithful listener of your pods now for
37:30
a year and enjoy them very much. Never
37:32
imagined Thursdays could be that exciting.
37:34
I'd usually say something derogatory, but I'm
37:36
feeling good today. Um, don't know if
37:39
this question might be of interest to the
37:41
show. Is there any chance that it's a black
37:44
hole question? By the way, Fred, is there any
37:45
chance that a black hole might not exist in
37:48
its, uh. Inside its event horizon? After all,
37:51
black holes are claimed to be singularities
37:53
that is infinitesimal in size.
37:56
In practical terms, nothing. Right. Uh, if
37:58
so, could an event horizon act as a sort
38:01
of a delayed postal service, never
38:04
informing anyone outside what has
38:06
happened? So, like Australia Post, really?
38:09
Um, no, they're great. Actually, uh, there's
38:11
another piece of news. Dubbo Post Office
38:14
here in town. Got Post Office of the Year.
38:18
Professor Fred Watson: Oh, uh, fabulous. That's great, Nick.
38:20
Andrew Dunkley: About a month ago. So we're doing it right
38:22
here, aren't we?
38:23
Professor Fred Watson: Uh, you're doing well in Dubbo.
38:24
Andrew Dunkley: Extra questions. Would physics allow matter
38:27
still to be pulled into the vent event, uh,
38:30
into the horizon, even if the black hole was
38:33
gone?
38:35
Professor Fred Watson: Great, uh, question, Ulf. And, um,
38:38
In. In a sense, the. The, um. He's right
38:41
about the event horizon acting as a delayed
38:44
postal service because,
38:47
um, it stops the transfer of information.
38:49
We do know that, uh, black holes can
38:52
evaporate courtesy of Hawking radiation.
38:55
But, um, basically. And that
38:58
involves the transfer of information. We know
39:00
that, but it's very, very slow. So
39:03
the event horizon does shield the black
39:06
hole from the outside world, if I can put it
39:08
that way. But, um, in terms of
39:11
whether the black hole itself exists,
39:14
it's kind of the other way around. The only
39:16
way the event horizon can exist is if there
39:19
is a black hole at the center. Uh,
39:22
in other words, this infinitesimally small
39:24
singularity, essentially
39:27
distorting space time to the extent that
39:29
you've got this shield around it, this black
39:31
hole. The black hole. Uh, sorry, the black
39:34
hole. Event horizon. The event horizon, in
39:37
some ways, Is an illusion, Andrew, because,
39:40
um, it's just the point of no return. It's
39:43
the thing that won't let light out. And it
39:45
certainly is black. We've seen that from the
39:47
event horizon image, uh, that was released
39:50
last year. But, uh, without the black
39:53
hole, the event horizon doesn't exist. So,
39:56
uh, there has to be this
39:59
singularity at the middle with all its
40:01
complicated, uh, infinitesimally small
40:04
planck length dimensions that we've just been
40:07
discussing. Um, yeah, great question though,
40:10
and thank you very much. And yes, Sweden
40:12
rocks. I was there not very long ago.
40:14
Andrew Dunkley: And as monty python says, nothing can come
40:16
from nothing. Can't be nothing.
40:20
Professor Fred Watson: Yes, yes.
40:20
Andrew Dunkley: Um, thanks, alf. Appreciate the question.
40:23
One more thing before we finish up, fred, and
40:26
this is, um, a little bit of, um, an add on
40:28
from a question about the roche limit. A
40:30
couple of weeks ago, we were trying to figure
40:32
out the roche limit between
40:35
the earth and the moon. And as you explained,
40:36
the roche limit is the point where gravity,
40:39
uh, will destroy one of the
40:42
objects involved, um, uh, in
40:45
the, uh, situation. So, um, you could
40:47
probably explain it better than I just did.
40:49
But, um, uh, basically we were trying
40:52
to figure out how close the moon could get to
40:54
the earth before it was obliterated. Yeah,
40:57
life on earth would probably be obliterated
40:59
too.
40:59
Professor Fred Watson: Well, that's right. It would be a tricky
41:01
situation for all of us. But it is. It's much
41:03
less than I thought it would be, Andrew.
41:06
Um, the roche limit for the moon is
41:08
9,492 kilometers.
41:11
And I think that's from the center of the
41:13
earth. So it's actually 3,004, uh,
41:16
114 kilometers above the surface. Imagine
41:19
the moon 3,000 kilometers above the surface.
41:21
Whoa.
41:22
Andrew Dunkley: Wouldn't it look amazing?
41:23
Professor Fred Watson: It would look pretty amazing. That's right.
41:25
Andrew Dunkley: Just for a few moments until we all died of
41:27
fire or die.
41:28
Professor Fred Watson: I guess that's right. Yeah.
41:31
Andrew Dunkley: But that's okay. We'd have plenty of toilet
41:32
paper.
41:33
Professor Fred Watson: Ah, ah, we would. We'd be all right. Yes.
41:35
Andrew Dunkley: So three, uh, so 9,000.
41:39
Professor Fred Watson: Yeah, 9,492 kilometers
41:42
from the center of the earth.
41:43
Andrew Dunkley: Close as it could get before it was destroyed
41:45
by our gravity. And we would go down with the
41:48
ship.
41:49
Professor Fred Watson: Absolutely. Yeah.
41:51
Andrew Dunkley: In a nutshell. All right, now we've got that
41:53
sorted out. Uh, thank you, Fred, so much.
41:55
It's always a pleasure.
41:57
Professor Fred Watson: It's always a pleasure talking to you too,
41:58
Andrew. And we'll speak again soon, I hope.
42:00
Andrew Dunkley: You will indeed. And thank you for, uh,
42:02
listening. Thank you for your contributions.
42:04
Keep them coming. We love to hear from you,
42:06
whether it's on social media or via our
42:08
website where you can send us emails. Uh, we
42:10
have a little contact form there, so you can
42:12
send us questions and, uh, to the
42:15
patrons. There'll be some bonus material
42:17
coming up real soon. Uh, other than that,
42:20
thank you and we'll see you again next time
42:22
on another edition of the Space Nuts
42:25
Podcast, Space Notes. You'll be this
42:28
to the SpaceNuts Podcast,
42:31
available in Apple Podcasts, Google
42:33
Podcasts, Spotify,
42:35
iHeartRadio, or your favorite podcast
42:38
player. You can also stream on demand@ah,
42:41
bytes.com.
42:42
Professor Fred Watson: This has been another quality podcast
42:44
production from Thights.com.