#396: Cosmic Riddles & Martian Quakes: Unpacking the Universe's Expansion & Insight's Seismic Secrets

WEBVTT

1
00:00:00.080 --> 00:00:03.640
Hello again, thanks for joining us. This is Space Nuts coming up.

2
00:00:03.680 --> 00:00:11.039
We're talking questions about the expansion of
space again, the Insight mission and gravitational

3
00:00:11.080 --> 00:00:16.120
waves. That's all coming up on
this edition of Space Nuts. Fifteen seconds

4
00:00:16.199 --> 00:00:27.920
guidance in channel ten nine ignition sign
Space Nuts NY four three two one Space

5
00:00:28.160 --> 00:00:33.759
Nuts as when I re bought it, Bills Goods and joining me as always,

6
00:00:33.840 --> 00:00:38.079
Professor Fred. What's on Astronomer at
Large High Fred, Hello Andrew,

7
00:00:38.320 --> 00:00:41.920
very good to see you again.
Now Fred, it is time to talk

8
00:00:42.159 --> 00:00:46.759
questions and answers from our audience.
We've got a few text questions to go

9
00:00:46.880 --> 00:00:52.399
through today and the first one comes
from Nate. Now, this this is

10
00:00:52.399 --> 00:00:57.399
a question we've had probably many times, but it's worth three visiting because you

11
00:00:57.439 --> 00:01:00.280
never know what we're going to learn. As we heard early on, things

12
00:01:00.320 --> 00:01:07.760
can change in the astronomical world at
the flick of a switch on the James

13
00:01:07.760 --> 00:01:14.159
Webspace telescope. So Nate asks,
thirteen point eight billion years ago, something

14
00:01:14.280 --> 00:01:18.879
happened. We know that whatever,
whether it was a big bang, the

15
00:01:18.920 --> 00:01:23.400
big bounce, or a big mac, we know there was an event in

16
00:01:23.439 --> 00:01:29.319
a seemingly centralized location. My question
is if space is expanding What is it

17
00:01:29.359 --> 00:01:34.640
expanding into or on? Even the
singularity? If that's even correct, should

18
00:01:34.959 --> 00:01:41.120
have been residing in something right.
Thanks for making my evenings great. Every

19
00:01:41.159 --> 00:01:44.879
podcast is listened to the moment it
is dropped, and I cherish each and

20
00:01:44.879 --> 00:01:49.000
every one. You two are fabulous
and have been a part of our lives

21
00:01:49.040 --> 00:01:53.519
since day one. Have a great
holiday. We're back and I can't wait

22
00:01:53.560 --> 00:01:57.560
to hear your answer. Yeah,
it's an old chestnut, this one.

23
00:01:57.840 --> 00:02:01.959
What are we expanding into? Or
although he goes, now, what could

24
00:02:02.000 --> 00:02:08.560
be expanding on? At an interesting
angle? Well, yes, yes it

25
00:02:08.639 --> 00:02:15.800
is. It's a nice additional way
of putting it. So I think the

26
00:02:15.919 --> 00:02:25.199
problem is that we apply our common
garden, everyday logic to problems of cosmology

27
00:02:27.159 --> 00:02:35.680
that don't necessarily work on those logical
principles like parallel lines never meeting and things

28
00:02:35.800 --> 00:02:42.319
like that, which is, actually
it is logic, but it's geometrical logic

29
00:02:42.400 --> 00:02:47.159
of an unusual kind. So the
observation that we can make, and I

30
00:02:47.199 --> 00:02:52.039
guess there's two or three of them, are that refer to relate to this.

31
00:02:52.159 --> 00:02:59.919
We can observe that the universe has
expanding because we've got this signature velocity

32
00:03:00.039 --> 00:03:05.280
distribution of galaxies, that the further
away galaxy you see, the faster it

33
00:03:05.400 --> 00:03:09.000
is moving away from you, and
that's exactly what you will get from space

34
00:03:09.080 --> 00:03:16.879
that is expanding. We also know
that as far as we can see,

35
00:03:16.919 --> 00:03:23.360
there isn't an edge to it.
We can see a horizon, and that

36
00:03:23.560 --> 00:03:30.000
the easiest one to envisage is the
cosmic microwave background radiation, where you're looking

37
00:03:30.520 --> 00:03:34.439
so far back in time when you
look out into space that you're seeing the

38
00:03:34.479 --> 00:03:38.400
flash of the Big Bang, which
is now stretched from light waves to radio

39
00:03:38.719 --> 00:03:46.439
waves microwaves by the expansion of the
universe. So the likelihood is that the

40
00:03:46.520 --> 00:03:52.000
universe just goes on beyond that.
And if we were and there's nothing to

41
00:03:52.039 --> 00:03:55.159
suggest that's not the case, if
we were somewhere else in the universe and

42
00:03:55.159 --> 00:04:00.919
looked out from our vantage point,
which is different from where we are at

43
00:04:00.919 --> 00:04:05.080
the moment on our galaxy, from
somebody else's galaxy somewhere else, we would

44
00:04:05.120 --> 00:04:10.000
see the same thing, which is
cosmic microwave background radiation and lots of galaxies

45
00:04:10.039 --> 00:04:16.759
all expanding away from us. So
the the question about what's it expanding into.

46
00:04:19.680 --> 00:04:27.639
We don't even know whether that's a
meaningful question, because it's actually compressing

47
00:04:27.680 --> 00:04:32.279
the thing into our own, you
know, perception of space and time.

48
00:04:33.160 --> 00:04:43.000
Whereas there are are possibilities, certainly
in terms of the geometry of the universe,

49
00:04:43.040 --> 00:04:46.399
there are possibilities that might say,
well, it doesn't have an edge,

50
00:04:46.839 --> 00:04:50.279
for example, if you you know, it's like that the idea of

51
00:04:50.720 --> 00:04:55.480
In fact, this is quite good
analogy. Actually, if you think of

52
00:04:56.439 --> 00:05:01.720
your excuse me, perception of the
universe reduced to two dimensions. Now,

53
00:05:01.759 --> 00:05:06.600
we normally think of two dimensions as
being on a piece of paper, a

54
00:05:06.600 --> 00:05:12.399
flat a flat surface, but it
could equally well be on a curved surface

55
00:05:12.439 --> 00:05:18.240
like a balloon. So if you
have your perception of space sitting on the

56
00:05:18.720 --> 00:05:27.079
surface of a balloon, it expands
as you blow up the balloon. And

57
00:05:27.199 --> 00:05:31.240
yes, in our that you know, that view that we've got, it

58
00:05:31.399 --> 00:05:36.000
is expanding into an additional dimension,
which is the third dimension of space.

59
00:05:36.519 --> 00:05:43.040
So maybe maybe it will turn out
that we will discover that there are hyper

60
00:05:43.079 --> 00:05:48.360
dimensional spaces within what we've been thinking
of as the universe. But maybe the

61
00:05:48.439 --> 00:05:53.120
universe is just something part of something
much smaller. So if you thought,

62
00:05:53.879 --> 00:05:56.879
sorry, I'm rambling a bit here, Andrew, but we've got a universe

63
00:05:56.959 --> 00:06:00.279
that's got three dimensions of space and
one of time. But if it was

64
00:06:00.319 --> 00:06:06.800
embedded in a fifth dimension or something
in the same way that the balloon is

65
00:06:06.800 --> 00:06:14.839
embedded in proper space, then it
maybe is expanding into something else. That's

66
00:06:14.879 --> 00:06:18.360
a complex way of describing something quite
simple, which is, we don't really

67
00:06:18.439 --> 00:06:25.480
know, but you know, we
think there are possibilities. There are geometrical

68
00:06:25.480 --> 00:06:29.199
possibilities that would allow that to happen, for the universe not to have an

69
00:06:29.279 --> 00:06:35.160
edge and be expanding, but to
be expanding perhaps in relation to something like

70
00:06:35.399 --> 00:06:41.519
an additional dimension. We haven't seen
any evidence of extra dimensions yet in any

71
00:06:41.759 --> 00:06:46.240
sense, but there are some various
due to people that do believe that that

72
00:06:46.360 --> 00:06:50.680
may be a possibility. Yeah,
and that there are multiple universes as well,

73
00:06:50.920 --> 00:06:54.279
yes, of course. And what's
the other one? I heard?

74
00:06:54.319 --> 00:06:59.839
That the universe is folding back on
itself. That's another one I heard.

75
00:07:00.639 --> 00:07:05.319
But like a pile of washing,
yes, yes, the universe is just

76
00:07:05.360 --> 00:07:13.560
a massive laundry. Yeah. Well
it is a rather dirty place, isn't

77
00:07:13.600 --> 00:07:16.240
it. I mean it's just full
of dust. It's absolutely dusty, dust

78
00:07:16.279 --> 00:07:20.560
and gas and humans. Yeah,
just the mess. Yeah, that's right,

79
00:07:20.639 --> 00:07:27.439
completely all right, thank you,
Nate. The answer is yes,

80
00:07:27.480 --> 00:07:31.399
it's expanding. It's expanding at an
accelerating rate. And what it's expanding into

81
00:07:31.639 --> 00:07:38.000
we do not know. Lee Stevenson
has sent us a question. Hi guys,

82
00:07:38.040 --> 00:07:42.079
I'm an avid listener since discovering your
show around six months ago. You

83
00:07:42.160 --> 00:07:46.800
are funny and educational at the same
time, which one of us. Okay,

84
00:07:47.399 --> 00:07:51.560
it's a great show. My question
is how can we learn so much

85
00:07:51.600 --> 00:07:57.839
about Mars interior from the Insight mission. I can't figure out how we got

86
00:07:57.879 --> 00:08:01.720
the knowledge we have from a single
point of reference down to the estimated location

87
00:08:01.959 --> 00:08:07.439
of meteor impact. This has been
puzzling me for quite a while, and

88
00:08:07.480 --> 00:08:09.680
I hope you can explain and educate
me. Best wishes. Lee, an

89
00:08:09.759 --> 00:08:16.639
Englishman in speeding yat was it's not
that big a hot from England to Sweden,

90
00:08:16.720 --> 00:08:22.199
so stopped showing off. Actually I
meant to. I meant to.

91
00:08:22.439 --> 00:08:26.360
I saw this question and meant to
check it out. Because of being ill

92
00:08:28.040 --> 00:08:30.959
for the plus a few days,
I haven't really had time. But there

93
00:08:31.040 --> 00:08:37.240
is some yeah, there there's some
very very clever work that's been done by

94
00:08:37.399 --> 00:08:43.240
the by the Insight team, and
I think it involves of course, it

95
00:08:43.480 --> 00:08:48.600
like all seismology. You know,
most seismology, you've got a volcano or

96
00:08:48.639 --> 00:08:56.720
something that that erupts, or there's
something hits the ground, and you pick

97
00:08:56.799 --> 00:09:01.679
up by a network of seismographs or
seismometers all over the planet. This is

98
00:09:01.759 --> 00:09:07.960
on the Earth, of course,
you pick up the echoes of that particular

99
00:09:09.399 --> 00:09:16.279
seismic event, whether it's a reflection
off the core mental boundary, or whether

100
00:09:16.320 --> 00:09:20.279
it's a refraction past the core.
These are all things that you can pick

101
00:09:20.360 --> 00:09:24.039
up. But it's fairly easy to
understand what's going on that you can explore

102
00:09:24.080 --> 00:09:28.399
the inside of the Earth by having
multiple sample points. By that, I

103
00:09:28.399 --> 00:09:33.279
mean, you know lots of seismographs
all over Well, on Mars, you

104
00:09:33.320 --> 00:09:39.080
don't. You don't have that.
You've got one little seismic one little lander

105
00:09:39.200 --> 00:09:43.799
in sight, which I think I'm
right in turning is now defunct. It's

106
00:09:43.440 --> 00:09:52.399
yes, switching often there last year. It's got one censer. So how

107
00:09:52.399 --> 00:10:00.720
do you know when you are listening
to the seismic signal of a meteorite hitting

108
00:10:00.960 --> 00:10:05.559
Mars thirteen thousand kilometers away or something
like that. But it's a very very

109
00:10:05.559 --> 00:10:09.480
good question now because I meant to
look this up I'm not going to give

110
00:10:09.480 --> 00:10:11.759
a definitive anti here, but we
might we might take that down as a

111
00:10:11.799 --> 00:10:18.039
bit of homework. And but I'm
guessing it may be to do with the

112
00:10:18.039 --> 00:10:24.519
fact that seismic waves don't just come
in one variety. There are if I

113
00:10:24.559 --> 00:10:28.919
remember these pea waves and S waves. PA waves, I think are pressure

114
00:10:28.960 --> 00:10:35.639
waves and S waves are sheer waves, which is two different ways that the

115
00:10:35.639 --> 00:10:43.080
you know, the medium that this
is being transmitted through vibrates and it actually

116
00:10:43.120 --> 00:10:46.840
it's akin to sheer wave will be
a bit like a light wave, which

117
00:10:46.919 --> 00:10:52.120
is a transverse wave, that's what
we call it in electromodetic radiation, whereas

118
00:10:52.159 --> 00:10:56.399
a pea wave will be like a
sound wave. Because sound is transmitted by

119
00:10:56.519 --> 00:11:01.120
pressure mibratish variations in a medium.
It's got to have medium to transmit it.

120
00:11:01.679 --> 00:11:07.039
And I suspect that you can do
things with those like the kind of

121
00:11:07.080 --> 00:11:11.519
things that we do with fast radio
bursts in astronomy, where you know that

122
00:11:11.639 --> 00:11:20.159
the slower, the longer wavelength signals
are going to come slower than the higher

123
00:11:20.159 --> 00:11:24.039
sorry shorter wavelength signals. You otherwise
that the higher frequency signals are going to

124
00:11:24.120 --> 00:11:30.120
arrive first, and that's what causes
that dispersion that lets you get the distance

125
00:11:30.200 --> 00:11:33.720
to something without actually knowing its red
shift. You get the dispersion because you

126
00:11:33.759 --> 00:11:39.039
know, does it transmits as it
transmits through what we think of as empty

127
00:11:39.039 --> 00:11:43.840
space, But it's actually a lot
of electrons being very excited, so you

128
00:11:43.879 --> 00:11:48.440
can pick up information by that.
So I'm guessing it's something like that.

129
00:11:48.000 --> 00:11:50.679
But I will look that up because
that's such a good question. And as

130
00:11:50.679 --> 00:11:54.480
I said, I saw it and
I thought, yes, do some research

131
00:11:54.519 --> 00:12:01.200
into that. It's very clever science
though, that they can detect an impact

132
00:12:01.320 --> 00:12:07.399
so far away and actually isolates its
location. That's the thing, exactly the

133
00:12:07.440 --> 00:12:13.879
point of the question. And Insight
did go there with the intent of studying

134
00:12:13.960 --> 00:12:18.399
the interior of Mars, so it
had equipment that was designed to pick up

135
00:12:18.440 --> 00:12:22.919
these kinds of activities. So that
would go halfway to answering Lee's question.

136
00:12:24.000 --> 00:12:26.000
But we'll put it in the homework
homework folder. And for the record,

137
00:12:26.120 --> 00:12:33.679
Insights mission ended in December twenty twenty
two, about fourteen months ago before Give

138
00:12:33.759 --> 00:12:37.399
or Take Yeah, Thanks Lindsay,
Thank you, Lee, and to our

139
00:12:37.440 --> 00:12:43.720
final question for this episode from Wayne. Greetings, gentlemen, longtime Patreon supporter

140
00:12:43.840 --> 00:12:46.200
thank you, Wayne, We appreciate
it. First time questioner, though,

141
00:12:46.279 --> 00:12:50.559
what kind of gravitation wave, if
any, is generated by a supernova?

142
00:12:50.960 --> 00:12:56.360
Would these be detectable by late ligo? Love all the horrible dad jokes.

143
00:12:56.639 --> 00:13:03.159
Keep up the great work. Let's
someone then that's one. I mean,

144
00:13:03.519 --> 00:13:07.639
we do so. They're actually hard
to find some of them. Some of

145
00:13:07.639 --> 00:13:13.200
them are so yeah. I mean
I've found thousands, but ninety nine point

146
00:13:13.240 --> 00:13:18.320
nine percent of them are not airworthy. We must have a different website.

147
00:13:18.399 --> 00:13:22.480
I don't mean they're rude, they're
just so so terrible. Oh yeah,

148
00:13:22.679 --> 00:13:31.759
so Paulin, Yeah, so yeah, super nova does it make a gravitational

149
00:13:31.799 --> 00:13:33.679
wave? And as I suppose the
question, if I can expand it on

150
00:13:33.759 --> 00:13:41.320
a bit, is our gravitation waves
different according to what causes them? Yeah?

151
00:13:41.320 --> 00:13:46.440
Well the answer to that is certainly
yes. And you know, the

152
00:13:46.440 --> 00:13:52.759
the things that we can measure with
ligo in terms of gravitational ways, it's

153
00:13:52.879 --> 00:14:01.759
the amplitude and frequency of the wave
and the rate at which it decay or

154
00:14:01.679 --> 00:14:09.919
increases. In the case of merging
neutron stars, what you get is this

155
00:14:09.399 --> 00:14:16.039
chirp where the signal, if you
transfer transfer it to audio, becomes up

156
00:14:16.960 --> 00:14:22.159
because the they're spinning around one another, and then when they actually merge the

157
00:14:22.480 --> 00:14:24.879
that's the chirp. That's when it
goes up like that. But I think,

158
00:14:26.759 --> 00:14:31.440
and once again I'm sort of dragging
out from the bottom of my memories

159
00:14:31.480 --> 00:14:37.759
of researching into this quite a quite
deeply a few years ago. But what

160
00:14:37.759 --> 00:14:43.759
what what causes? Excuse me?
I'll be better when I've started the new

161
00:14:43.879 --> 00:14:48.320
dose of antibioty, which might be
the chemistry. You must really tick you

162
00:14:48.440 --> 00:14:52.879
off. I tell you, I've
never been as ticked off as I was

163
00:14:52.879 --> 00:14:56.799
when I discovered what it was.
Yeah, that's right, Yeah, that

164
00:14:56.919 --> 00:15:01.720
whatever bit me. Yeah, I'll
refrain from showing you what it Oh,

165
00:15:01.799 --> 00:15:05.840
yeah, thank you because we are
on YouTube at the moment. Don't want

166
00:15:05.840 --> 00:15:11.559
to get banned. No, we
don't get banned for showing horrible stuff anyway.

167
00:15:11.279 --> 00:15:15.639
So just going back to it,
So, to generate a gravitational wave,

168
00:15:15.720 --> 00:15:20.799
you've got to have an accelerating mass, and that's why neutron styles in

169
00:15:20.879 --> 00:15:28.960
orbits around on another do generate strong
gravitational ways because you've got two objects which

170
00:15:28.960 --> 00:15:37.960
are spinning around each other, revolving
around each other, and that basically constitutes

171
00:15:37.000 --> 00:15:43.440
an accelerating mass now with a supernova, and in a sense we don't know

172
00:15:45.159 --> 00:15:52.960
that much about these details, but
supernova sort of generally speaking, are symmetrical.

173
00:15:52.799 --> 00:16:00.559
So you have an explosion and you
but you have stuff going out in

174
00:16:00.600 --> 00:16:07.200
all directions which kind of cancels itself
out, so you're not really generating a

175
00:16:07.360 --> 00:16:11.559
huge whatever in the background. I
can hear it. I know, I

176
00:16:11.559 --> 00:16:15.679
know there is. I'm trying to
ignore him actually, because he's he's just

177
00:16:15.720 --> 00:16:25.000
such a pain. Many Marney sent
me a cartoon this morning showing a little

178
00:16:25.000 --> 00:16:30.000
dog dressed in armor with a sword
in one hand of shield in the other,

179
00:16:30.080 --> 00:16:34.799
and it said, how small dogs
think of themselves when somebody rings the

180
00:16:34.840 --> 00:16:41.039
doorbell. That's exactly what he's likes, exactly what He's still only a puppy.

181
00:16:41.080 --> 00:16:44.840
He's only ten months old, so
you've got to give him some you

182
00:16:44.879 --> 00:16:48.879
know, understanding. Maybe one day
he won't do that anymore. Anyway,

183
00:16:48.399 --> 00:16:55.200
he is definitely an accelerating mass when
anybody comes to the door, and will

184
00:16:55.240 --> 00:17:02.480
probably generate his own gravitational word or
so. But just to carry it this

185
00:17:02.559 --> 00:17:10.599
a little bit further, I have
seen the question of whether a neutron star

186
00:17:11.200 --> 00:17:15.279
itself, which is often the end
product of a super and over explosion,

187
00:17:15.920 --> 00:17:22.359
Whether the neutron star that will be
left behind because it's rotating, whether that

188
00:17:22.400 --> 00:17:30.759
would generate a gravitational wave. But
it's because it's only rotating, it's not

189
00:17:30.559 --> 00:17:37.119
a mass being accelerated, you know, Linearly, it wouldn't unless it has

190
00:17:37.200 --> 00:17:40.759
mountains on it. And you and
I have spoken before about these millimeter high

191
00:17:40.759 --> 00:17:45.000
mountains. Yes, that neutron stars
might have. So if it's got a

192
00:17:45.000 --> 00:17:52.440
few melometer high mountains on it,
then it will generates generate a gravitational way.

193
00:17:52.480 --> 00:17:56.319
But to the best of my knowledge, nothing has yet been seen by

194
00:17:56.400 --> 00:18:03.000
Lego or the other detectors that actually
represents that. A great question from word.

195
00:18:03.880 --> 00:18:07.720
You might be interested to know Fred
that Wayne is actually watching us on

196
00:18:07.839 --> 00:18:14.599
YouTube right now, and apparently we've
got our YouTube listeners and viewers are pretty

197
00:18:14.599 --> 00:18:18.039
excited by the fact that Wayne's question
happened up happened to be served up right

198
00:18:18.079 --> 00:18:22.200
now, so that doesn't happen often. So that's really good. Thanks,

199
00:18:22.319 --> 00:18:26.119
Thanks for thanks for the question,
and thanks for watching. Wed. Sorry

200
00:18:26.119 --> 00:18:29.119
I've got a straight answer, but
I'll once again and have a look at

201
00:18:29.160 --> 00:18:30.359
the details, and so well,
it's just a look to all this stuff

202
00:18:30.960 --> 00:18:36.119
very good, all right, thank
you Wayne, and thanks for listening and

203
00:18:36.200 --> 00:18:38.920
good to have you along live.
And if you do have questions for us,

204
00:18:40.039 --> 00:18:44.920
remember you can send them through via
our website Space Nuts podcast dot com

205
00:18:45.039 --> 00:18:48.680
or space nuts dot io and click
on the AMA link to send us a

206
00:18:48.720 --> 00:18:51.880
text or audio question, or just
click on the purple thing on the right

207
00:18:51.920 --> 00:18:55.799
hand side of the homepage to send
us audio. As long as you've got

208
00:18:55.839 --> 00:19:00.240
a device with a microphone, you're
all set. And tell us who you

209
00:19:00.319 --> 00:19:03.440
are and where you're from. We
always like to know. And if you're

210
00:19:03.480 --> 00:19:06.960
watching this on YouTube, don't forget
I've got to do it again. Don't

211
00:19:07.039 --> 00:19:12.960
forget to press the subscribe button below. They all do it, are they?

212
00:19:14.039 --> 00:19:17.759
The people on YouTube? Don't forget
it to subscribe button below. So

213
00:19:17.839 --> 00:19:21.480
there we go. I've just done
it. And that brings us to the

214
00:19:21.559 --> 00:19:26.039
end of another program. Thank you
so much, Fred, pleasure, Andrew,

215
00:19:26.640 --> 00:19:29.720
good to talk again, and we'll
speak again to it we will,

216
00:19:29.759 --> 00:19:33.759
indeed, Professor Fred Watson, Astronomer
at Large getting over his tick bite.

217
00:19:33.960 --> 00:19:38.839
And to Hugh in the studio who
just gets ticked off all the time,

218
00:19:40.039 --> 00:19:41.920
and from me Andrew Untley, thanks
so much. For your company. Looking

219
00:19:41.960 --> 00:19:48.880
forward to joining you again on the
next episode of Space Nuts. Bye Byepacenuts.

220
00:19:48.160 --> 00:19:56.200
You'll be listening to the Nuts podcast
available at Apple Podcasts, Spotify,

221
00:19:56.519 --> 00:20:00.519
iHeartRadio, or your favorite podcast player. You can also stream on demand at

222
00:20:00.559 --> 00:20:07.720
bytes dot com. This has been
another quality podcast production from fights dot com.