Primordial Black Holes, Ancient Galaxies & The Ultimate Lagrange Point: #488 - Q&A Edition |...

WEBVTT
Kind: captions
Language: en

00:00:00.120 --> 00:00:02.230
hi there thanks for joining us on a Q&A


00:00:02.240 --> 00:00:05.590
Edition or even a Q&A edition of Space


00:00:05.600 --> 00:00:07.510
Nuts my name is Andrew Dunley your host


00:00:07.520 --> 00:00:09.430
great to have your company coming up


00:00:09.440 --> 00:00:11.350
this time we're going to be answering


00:00:11.360 --> 00:00:13.070
questions from our audience about


00:00:13.080 --> 00:00:15.509
primordial black holes this is a wh if


00:00:15.519 --> 00:00:17.750
question we love those uh someone else


00:00:17.760 --> 00:00:20.870
is asking about old galaxies uh we are


00:00:20.880 --> 00:00:24.429
looking for the ultimate lrange point


00:00:24.439 --> 00:00:26.669
and the accelerating universe which we


00:00:26.679 --> 00:00:28.990
debunked in the last episode but uh


00:00:29.000 --> 00:00:30.509
we're going to unbun


00:00:30.519 --> 00:00:34.630
on this episode of Space Nuts 15 seconds


00:00:34.640 --> 00:00:38.990
guidance is internal 10 9 ignition


00:00:39.000 --> 00:00:44.229
sequence start space Nets 5 4 3 2 1 2 3


00:00:44.239 --> 00:00:48.310
4 5 5 4 3 2 1 Space Nuts asut reported


00:00:48.320 --> 00:00:51.189
feels good and joining me again is


00:00:51.199 --> 00:00:52.750
Professor Fred Watson astronomer at


00:00:52.760 --> 00:00:54.910
large and Professor johy Horner


00:00:54.920 --> 00:00:57.389
professor of astrophysics gentlemen


00:00:57.399 --> 00:01:00.110
welcome thanks for joining us great


00:01:00.120 --> 00:01:01.950
pleasure Andrew good to be here good to


00:01:01.960 --> 00:01:04.990
have jonty on board as well which this


00:01:05.000 --> 00:01:07.270
this was your last show for a little


00:01:07.280 --> 00:01:11.310
while because you're jetting off to um


00:01:11.320 --> 00:01:14.190
somewhere to look uh well it's Sweden


00:01:14.200 --> 00:01:17.469
Norway Iceland and Greenland and this


00:01:17.479 --> 00:01:20.230
will be these tours are pretty regular


00:01:20.240 --> 00:01:23.109
occasions as you know from man's dark


00:01:23.119 --> 00:01:25.149
sky traveler company I do the sign she


00:01:25.159 --> 00:01:27.710
does all the real work uh but this will


00:01:27.720 --> 00:01:29.310
be our the first time we've including


00:01:29.320 --> 00:01:31.350
Greenland in one of these so we're


00:01:31.360 --> 00:01:33.789
hoping for very spectacular views of


00:01:33.799 --> 00:01:35.870
icebergs as well as spectacular views of


00:01:35.880 --> 00:01:38.149
the Northern Lights Fantastic get an


00:01:38.159 --> 00:01:41.030
American visa yet for Greenland


00:01:41.040 --> 00:01:44.389
no it's okay our Mary won't let it go I


00:01:44.399 --> 00:01:45.830
can tell


00:01:45.840 --> 00:01:49.469
you yeah well I'm Judy and I are


00:01:49.479 --> 00:01:51.590
visiting Greenland later this year so we


00:01:51.600 --> 00:01:55.429
won't know who's actually


00:01:55.439 --> 00:01:57.469
controlling we'll let you know what it's


00:01:57.479 --> 00:02:00.270
like yeah but I've got my us uh Visa


00:02:00.280 --> 00:02:04.029
exemption so I should be right


00:02:04.039 --> 00:02:07.510
I um shall we get straight into it why


00:02:07.520 --> 00:02:10.669
not all right uh our first question


00:02:10.679 --> 00:02:13.470
comes from somebody who's never sent a


00:02:13.480 --> 00:02:14.910
question in before except for the other


00:02:14.920 --> 00:02:18.190
25 times Rusty from Donny Donny Brook TR


00:02:18.200 --> 00:02:20.030
Andrew okay it's


00:02:20.040 --> 00:02:23.710
Rusty a question about black


00:02:23.720 --> 00:02:27.589
Hol if a primordial black hole


00:02:27.599 --> 00:02:30.190
comparable with the THS of the Earth


00:02:30.200 --> 00:02:33.550
were to enter the solar system at a high


00:02:33.560 --> 00:02:37.790
angle to the ecliptic and impact one of


00:02:37.800 --> 00:02:39.910
the rocky planets


00:02:39.920 --> 00:02:45.509
directly would it a pass through largely


00:02:45.519 --> 00:02:50.350
unnoticed B leave a huge hole through


00:02:50.360 --> 00:02:53.030
the center of the planet which would


00:02:53.040 --> 00:02:55.710
cause a lot of mayem or


00:02:55.720 --> 00:03:00.630
C explode the planet completely or D


00:03:00.640 --> 00:03:04.190
none of the above heavy handing


00:03:04.200 --> 00:03:08.350
Che um like I should tell you jonty that


00:03:08.360 --> 00:03:11.070
uh Rusty has a habit of throwing curve


00:03:11.080 --> 00:03:12.869
balls at us he's always trying to trick


00:03:12.879 --> 00:03:15.830
Fred so just bear that in mind when we


00:03:15.840 --> 00:03:18.070
we try and Tackle this one well so I've


00:03:18.080 --> 00:03:20.750
got a clarification request here because


00:03:20.760 --> 00:03:22.830
you get two very different answers


00:03:22.840 --> 00:03:25.149
depending on manuia here he says it's


00:03:25.159 --> 00:03:27.630
the size of the Earth but if it's the


00:03:27.640 --> 00:03:30.229
size of the Earth then it's 2,200 times


00:03:30.239 --> 00:03:33.229
the mass of the Sun a black hole that's


00:03:33.239 --> 00:03:35.470
the Earth if it's a black hole the mass


00:03:35.480 --> 00:03:38.270
of the Earth then it's 9 millimet across


00:03:38.280 --> 00:03:39.990
and so you get a very different outcome


00:03:40.000 --> 00:03:41.990
depending on which of those it is I mean


00:03:42.000 --> 00:03:43.309
either way you're going to change the


00:03:43.319 --> 00:03:45.789
orbits of the planets particularly the


00:03:45.799 --> 00:03:48.550
one that it encounters but if it's the


00:03:48.560 --> 00:03:50.789
size of the Earth and therefore 2200


00:03:50.799 --> 00:03:52.990
times the mass of the Sun the solar


00:03:53.000 --> 00:03:54.830
system will be utterly disrupted the


00:03:54.840 --> 00:03:57.110
planets will be ejected the thing it


00:03:57.120 --> 00:04:00.390
hits will just kind of um inside it and


00:04:00.400 --> 00:04:01.990
its mass will have gone up a tiny little


00:04:02.000 --> 00:04:04.949
amount if it's the mass of the Earth and


00:04:04.959 --> 00:04:07.830
left on 9 mm across we probably wouldn't


00:04:07.840 --> 00:04:09.869
see it coming we'd see the orbits


00:04:09.879 --> 00:04:12.830
changing it will probably punch a 9 mm


00:04:12.840 --> 00:04:14.429
sized hole through the Earth but there's


00:04:14.439 --> 00:04:16.110
not really any friction there to slow it


00:04:16.120 --> 00:04:18.030
down so I don't know that you get much


00:04:18.040 --> 00:04:20.110
in the way of recoil but you would get a


00:04:20.120 --> 00:04:21.789
gravitational perturbation change in the


00:04:21.799 --> 00:04:23.990
Earth's orbit that would be my take so


00:04:24.000 --> 00:04:25.870
if it came through the Earth our orbit


00:04:25.880 --> 00:04:28.189
would become more tilted Seasons would


00:04:28.199 --> 00:04:29.870
be more pronounced you'd also have a


00:04:29.880 --> 00:04:32.469
fairly dramatic change in where the


00:04:32.479 --> 00:04:34.070
planets are in the sky and all that


00:04:34.080 --> 00:04:37.469
stuff um if it was 2200 times the mass


00:04:37.479 --> 00:04:39.350
of the Sun this will be the last last


00:04:39.360 --> 00:04:44.390
podcast yeah I think um so yeah my take


00:04:44.400 --> 00:04:46.710
on it is pretty well what yours is jonty


00:04:46.720 --> 00:04:48.350
I just assumed it was the mass of the


00:04:48.360 --> 00:04:49.550
Earth we were talking about and I think


00:04:49.560 --> 00:04:52.469
it's the um radius of the Event Horizon


00:04:52.479 --> 00:04:55.710
that's 9 millimeters uh of of an earth


00:04:55.720 --> 00:04:58.590
sized an earth Mass black hole but


00:04:58.600 --> 00:05:01.310
something that size I mean you know you


00:05:01.320 --> 00:05:03.510
you said in in the intro to this Andrew


00:05:03.520 --> 00:05:06.270
that it was Rusty throwing a curved ball


00:05:06.280 --> 00:05:07.710
and that's what it's going to be it


00:05:07.720 --> 00:05:10.469
would be it probably wouldn't be a


00:05:10.479 --> 00:05:12.590
direct hit because those are quite rare


00:05:12.600 --> 00:05:15.270
it would but it would still be near


00:05:15.280 --> 00:05:18.309
enough to a direct hit that the uh orbit


00:05:18.319 --> 00:05:20.790
of the black hole would you know if it


00:05:20.800 --> 00:05:22.469
came close enough to the Earth the tidal


00:05:22.479 --> 00:05:25.150
effects on the Earth itself would be


00:05:25.160 --> 00:05:27.029
disastrous uh one side of the earth


00:05:27.039 --> 00:05:28.990
feeling much more of a pull than the


00:05:29.000 --> 00:05:31.430
other side so yeah effectively we would


00:05:31.440 --> 00:05:32.390
still be


00:05:32.400 --> 00:05:35.270
spaghettified uh and um maybe a bit


00:05:35.280 --> 00:05:36.950
slower than you would if you just fell


00:05:36.960 --> 00:05:39.230
into a black hole yourself but it would


00:05:39.240 --> 00:05:41.430
be a fairly disastrous scenario as well


00:05:41.440 --> 00:05:43.629
as you know per perturbing the orbits of


00:05:43.639 --> 00:05:46.270
the other planets it will be a mess so I


00:05:46.280 --> 00:05:48.749
think it's D isn't it none of the above


00:05:48.759 --> 00:05:51.870
is the correct answer for this the with


00:05:51.880 --> 00:05:53.189
it with the Earth and Moon though will


00:05:53.199 --> 00:05:55.270
be because of the way the Earth and Moon


00:05:55.280 --> 00:05:58.469
move if it came through you know if it's


00:05:58.479 --> 00:05:59.950
more than two or three times the Earth's


00:05:59.960 --> 00:06:01.590
radius away we're not going to be


00:06:01.600 --> 00:06:03.270
disrupted but we will have big tidal


00:06:03.280 --> 00:06:05.150
effects but the Earth and the moon will


00:06:05.160 --> 00:06:07.110
be pulled by different amounts in


00:06:07.120 --> 00:06:09.230
different directions and so it might be


00:06:09.240 --> 00:06:10.950
enough to dissociate the Earth and Moon


00:06:10.960 --> 00:06:12.469
and suddenly we'll have five planets not


00:06:12.479 --> 00:06:14.749
four in the inner solar system with the


00:06:14.759 --> 00:06:16.230
added impact that down the line of the


00:06:16.240 --> 00:06:17.589
Earth and the moon might Collide and


00:06:17.599 --> 00:06:19.670
that will be yet another bad


00:06:19.680 --> 00:06:23.629
day indeed on the flood Side Golf is be


00:06:23.639 --> 00:06:24.990
drilled because it would increase their


00:06:25.000 --> 00:06:30.870
chances of Hall in one significantly


00:06:30.880 --> 00:06:33.110
oh dear all right Rusty thanks for that


00:06:33.120 --> 00:06:35.550
one you're always um throwing one out


00:06:35.560 --> 00:06:38.070
there and uh that certainly did apply in


00:06:38.080 --> 00:06:40.510
this case uh our next question comes


00:06:40.520 --> 00:06:43.589
from Marcel uh science currently holds


00:06:43.599 --> 00:06:45.749
the belief that our universe is 13.8


00:06:45.759 --> 00:06:47.710
billion years old the James web Space


00:06:47.720 --> 00:06:50.230
Telescope keeps on finding older and


00:06:50.240 --> 00:06:52.950
older galaxies uh some of the oldest


00:06:52.960 --> 00:06:55.670
galaxies observed I beli to have formed


00:06:55.680 --> 00:06:58.430
over 300 million years after the big


00:06:58.440 --> 00:07:02.150
bang what if we find a Galaxy that is 14


00:07:02.160 --> 00:07:04.670
million years old how will we begin to


00:07:04.680 --> 00:07:07.710
adjust our theories to match reality


00:07:07.720 --> 00:07:09.629
which theories will be first to get


00:07:09.639 --> 00:07:11.350
thrown out the window versus which


00:07:11.360 --> 00:07:15.670
theories do we believe are absolutely


00:07:15.680 --> 00:07:18.469
correct um can I have a shot at


00:07:18.479 --> 00:07:22.110
this yeah the um it's not going to


00:07:22.120 --> 00:07:24.749
happen that we'll find a Galaxy older


00:07:24.759 --> 00:07:26.710
than the universe it actually in the


00:07:26.720 --> 00:07:28.950
early days of the of The Big Bang Theory


00:07:28.960 --> 00:07:30.909
that was one of of the problems uh that


00:07:30.919 --> 00:07:34.550
our measurements then uh s suggested


00:07:34.560 --> 00:07:36.909
that the the Big Bang occurred more


00:07:36.919 --> 00:07:39.390
recently than the ages of the planets


00:07:39.400 --> 00:07:41.029
and the stars that you know you have a


00:07:41.039 --> 00:07:42.749
universe that's younger than its


00:07:42.759 --> 00:07:44.749
contents and that's clearly not a


00:07:44.759 --> 00:07:46.629
possibility and it was only when we


00:07:46.639 --> 00:07:48.270
really worked out just how old the


00:07:48.280 --> 00:07:50.749
universe is and our current thinking is


00:07:50.759 --> 00:07:54.070
indeed 13.8 billion years uh that um


00:07:54.080 --> 00:07:56.110
that that was all rectified but the


00:07:56.120 --> 00:07:58.629
bottom line is that the the yard stick


00:07:58.639 --> 00:08:01.749
by which the age of galaxies is measured


00:08:01.759 --> 00:08:03.950
is basically as a fraction of the age of


00:08:03.960 --> 00:08:06.869
the universe so you're never G to find a


00:08:06.879 --> 00:08:08.589
Galaxy that's older older than the


00:08:08.599 --> 00:08:11.430
universe because you're you're sort of


00:08:11.440 --> 00:08:13.710
you know you're looking back certainly


00:08:13.720 --> 00:08:16.749
perhaps 90% 95% of the age of the


00:08:16.759 --> 00:08:18.830
universe for some of these uh some of


00:08:18.840 --> 00:08:21.430
these really um primitive galaxies that


00:08:21.440 --> 00:08:22.950
we're seeing but it's never going to be


00:08:22.960 --> 00:08:24.909
older than the universe because we can't


00:08:24.919 --> 00:08:27.149
we Define it as a as essentially a


00:08:27.159 --> 00:08:30.029
fraction of the of the universe's age so


00:08:30.039 --> 00:08:32.430
that won't happen what is more


00:08:32.440 --> 00:08:34.949
interesting is the suffy of this which


00:08:34.959 --> 00:08:38.110
is that we do see galaxies which are in


00:08:38.120 --> 00:08:40.389
seen as the universe was as it was when


00:08:40.399 --> 00:08:43.029
it was only perhaps two or 300 million


00:08:43.039 --> 00:08:45.350
years old which look more mature than we


00:08:45.360 --> 00:08:47.790
expected them to be we see black holes


00:08:47.800 --> 00:08:49.430
that are bigger than we expected them to


00:08:49.440 --> 00:08:50.910
be because we thought they'd take a lot


00:08:50.920 --> 00:08:53.470
longer uh to grow to their super massive


00:08:53.480 --> 00:08:56.190
size so those are the conundrums uh not


00:08:56.200 --> 00:08:57.550
that we're going to find a Galaxy that's


00:08:57.560 --> 00:09:00.110
older than the universe but trying to


00:09:00.120 --> 00:09:02.030
understand how how it is that some of


00:09:02.040 --> 00:09:04.190
these phenomena that we see spiral


00:09:04.200 --> 00:09:06.190
alarms for example uh occurred so


00:09:06.200 --> 00:09:07.790
quickly in the early history of the


00:09:07.800 --> 00:09:11.110
Universe I suppose his point was that uh


00:09:11.120 --> 00:09:12.870
you know if we find something that's so


00:09:12.880 --> 00:09:16.230
close to when the universe began how do


00:09:16.240 --> 00:09:18.110
you how do you equate for


00:09:18.120 --> 00:09:21.069
that well that's the bottom line is what


00:09:21.079 --> 00:09:22.509
what I was just saying you know it means


00:09:22.519 --> 00:09:25.310
we have to revise our theories of Galaxy


00:09:25.320 --> 00:09:27.310
Evolution not that we have to throw away


00:09:27.320 --> 00:09:29.030
the Big Bang which is what a lot of


00:09:29.040 --> 00:09:31.389
these questions are aiming at the Big


00:09:31.399 --> 00:09:33.790
Bang is absolutely secure we can still


00:09:33.800 --> 00:09:36.790
see it uh we we you know we know that it


00:09:36.800 --> 00:09:38.990
happened and yet we get people


00:09:39.000 --> 00:09:41.949
questioning us on it Fred semi-regularly


00:09:41.959 --> 00:09:43.790
uh there are quite a few people who


00:09:43.800 --> 00:09:46.550
don't believe in it well nether did uh


00:09:46.560 --> 00:09:49.030
my namesake Fred Hy he was a staunch


00:09:49.040 --> 00:09:50.750
believer in the study State Theory until


00:09:50.760 --> 00:09:53.630
he went to his grave yeah yeah what yous


00:09:53.640 --> 00:09:54.949
Johnny well there's interesting


00:09:54.959 --> 00:09:56.389
parallels the other thing that comes


00:09:56.399 --> 00:09:58.670
into this is uncertainty which is we


00:09:58.680 --> 00:10:00.590
never measure edge with perfect


00:10:00.600 --> 00:10:02.509
Precision there's always a bit of an


00:10:02.519 --> 00:10:04.150
error bar on it and I'm reminded of the


00:10:04.160 --> 00:10:05.990
story probably about a decade ago of


00:10:06.000 --> 00:10:08.150
that sty that people du the methusa


00:10:08.160 --> 00:10:13.350
start which is HD 140283 lovely barcode


00:10:13.360 --> 00:10:16.750
and that made news back in like 2013


00:10:16.760 --> 00:10:18.269
because people had measured its age it's


00:10:18.279 --> 00:10:20.269
an incredibly metal paw star it's one of


00:10:20.279 --> 00:10:21.910
the oldest stars in the galaxy for


00:10:21.920 --> 00:10:24.069
certain but they'd measured the Age


00:10:24.079 --> 00:10:25.910
based on all these observations of it


00:10:25.920 --> 00:10:27.750
and estimated an age of


00:10:27.760 --> 00:10:31.910
14.46 plus or minus is 0.8 billion years


00:10:31.920 --> 00:10:33.389
and that age is older than the edge of


00:10:33.399 --> 00:10:34.870
the universe so people were saying how


00:10:34.880 --> 00:10:36.470
can we have a star older than the edge


00:10:36.480 --> 00:10:38.910
of the universe and the subtlety here is


00:10:38.920 --> 00:10:40.710
in the uncertainty on the measurement


00:10:40.720 --> 00:10:43.829
because that plus or minus 0.8 billion


00:10:43.839 --> 00:10:48.030
years is saying that in 66% of cases


00:10:48.040 --> 00:10:50.509
this is one Sigma error so 66% of the


00:10:50.519 --> 00:10:52.910
time the age will fall in that age range


00:10:52.920 --> 00:10:55.030
and 33% of the time it'll fall outside


00:10:55.040 --> 00:10:58.350
that ede range so that age is compatible


00:10:58.360 --> 00:10:59.990
with the ede of the unit IE it's just


00:11:00.000 --> 00:11:02.470
telling you that the star is very old


00:11:02.480 --> 00:11:03.910
it's not saying the star is older than


00:11:03.920 --> 00:11:06.710
the edge of the universe necessarily and


00:11:06.720 --> 00:11:08.030
what's actually happen in the followup


00:11:08.040 --> 00:11:09.509
from that is a couple of more recent


00:11:09.519 --> 00:11:12.389
Studies have given it ages of 13.7 or 12


00:11:12.399 --> 00:11:15.350
billion years so as we've got more data


00:11:15.360 --> 00:11:16.790
the error bar has shrunk but it's


00:11:16.800 --> 00:11:18.870
noticeable that it's that age has moved


00:11:18.880 --> 00:11:21.470
by more than a single error bar which is


00:11:21.480 --> 00:11:23.269
not uncommon when the errors are quite


00:11:23.279 --> 00:11:25.750
large other than that it is like Fred


00:11:25.760 --> 00:11:27.629
says the problem is that even if you


00:11:27.639 --> 00:11:29.030
change the edge of the universe a little


00:11:29.040 --> 00:11:30.509
bit these galaxies will still have


00:11:30.519 --> 00:11:33.590
formed within the first 2% or 5% of its


00:11:33.600 --> 00:11:35.750
life you're just stretching the timeline


00:11:35.760 --> 00:11:37.990
or shrinking the timeline a little bit


00:11:38.000 --> 00:11:40.069
um it's like what we talked about in the


00:11:40.079 --> 00:11:40.949
other


00:11:40.959 --> 00:11:43.550
podcasts the way that theory and


00:11:43.560 --> 00:11:45.629
observation interact is that theory is


00:11:45.639 --> 00:11:47.150
the best possible explanation of what


00:11:47.160 --> 00:11:48.710
we've already seen and it predicts what


00:11:48.720 --> 00:11:50.350
we should see in the future with better


00:11:50.360 --> 00:11:52.110
instruments and when those better


00:11:52.120 --> 00:11:54.350
instruments Give us new measurements


00:11:54.360 --> 00:11:56.829
that allows us to refine or improve or


00:11:56.839 --> 00:11:58.550
disprove or kill the theory you know


00:11:58.560 --> 00:11:59.990
there's an argument you can never prove


00:12:00.000 --> 00:12:03.030
a theory but you can disprove it and the


00:12:03.040 --> 00:12:04.629
more you fail to disprove it the more


00:12:04.639 --> 00:12:07.069
confident we are that it's a good theory


00:12:07.079 --> 00:12:10.030
and in this case it's telling us not


00:12:10.040 --> 00:12:11.590
that the Big Bang Theory is wrong it's


00:12:11.600 --> 00:12:12.990
not telling us that the Universe wasn't


00:12:13.000 --> 00:12:14.430
form that way but instead it's telling


00:12:14.440 --> 00:12:16.430
us that our understanding of how stars


00:12:16.440 --> 00:12:19.670
and galaxies form in those early days is


00:12:19.680 --> 00:12:22.110
incomplete and that's exactly why people


00:12:22.120 --> 00:12:24.430
wanted these incredible telescopes go up


00:12:24.440 --> 00:12:25.590
there because that's the only way we can


00:12:25.600 --> 00:12:28.470
find it out and I suppose we have to


00:12:28.480 --> 00:12:30.110
keep making a adjusts for the fact that


00:12:30.120 --> 00:12:31.910
we've decided all this because of two


00:12:31.920 --> 00:12:34.350
kilos of mush inside


00:12:34.360 --> 00:12:37.150
out yes so what a little bit of gooey


00:12:37.160 --> 00:12:38.590
carbon can


00:12:38.600 --> 00:12:41.189
do it's the uh it's the 100 billion


00:12:41.199 --> 00:12:44.389
neurons in it the tricky bit


00:12:44.399 --> 00:12:46.990
yes uh thanks Marcel great question


00:12:47.000 --> 00:12:49.069
always a good discussion point that one


00:12:49.079 --> 00:12:51.110
this is Space Nuts with Andrew Dunley


00:12:51.120 --> 00:12:55.389
Professor Fred Watson and Professor johy


00:12:55.399 --> 00:12:58.550
hor okay we checked all four systems and


00:12:58.560 --> 00:13:01.350
With It Go face nuts and jonty we have


00:13:01.360 --> 00:13:04.670
Movement we have movement I see a dog


00:13:04.680 --> 00:13:07.030
with it who is coming over to say hello


00:13:07.040 --> 00:13:09.790
to you yeah what's his name that's Maya


00:13:09.800 --> 00:13:11.269
that's the sister we've got a brother


00:13:11.279 --> 00:13:12.910
and sister who are coming eight years


00:13:12.920 --> 00:13:14.430
old but she's the


00:13:14.440 --> 00:13:16.790
most um she's heading off to see if


00:13:16.800 --> 00:13:18.030
there's anything interesting happening


00:13:18.040 --> 00:13:20.750
elsewhere yes yeah nothing interesting


00:13:20.760 --> 00:13:22.870
happening here that's I


00:13:22.880 --> 00:13:25.629
was uh let's go to our next question


00:13:25.639 --> 00:13:27.389
this is an audio question from one of


00:13:27.399 --> 00:13:29.829
our regular contributors hello buddy


00:13:29.839 --> 00:13:32.189
hello space Nets buddy from Oregon again


00:13:32.199 --> 00:13:34.710
hey guys um would the center of a galaxy


00:13:34.720 --> 00:13:37.069
be like the ultimate like range point


00:13:37.079 --> 00:13:39.350
like for the Galaxy um you were saying


00:13:39.360 --> 00:13:41.670
if Earth had a tunnel in it that once


00:13:41.680 --> 00:13:42.710
you got in the middle you'd be


00:13:42.720 --> 00:13:44.790
weightless is that' be like a grange


00:13:44.800 --> 00:13:48.590
point0 um and uh if so wouldn't that


00:13:48.600 --> 00:13:50.949
make the black hole weightless to the


00:13:50.959 --> 00:13:54.509
Galaxy um and would that no point in the


00:13:54.519 --> 00:13:56.350
center from the little Grange Point


00:13:56.360 --> 00:13:59.829
create a u a gravitational well that


00:13:59.839 --> 00:14:01.550
look like your donut that you were


00:14:01.560 --> 00:14:02.870
talking about in the Galaxy where the


00:14:02.880 --> 00:14:05.030
priation all right thanks guys of the


00:14:05.040 --> 00:14:07.470
podcast keep up the good work got a bit


00:14:07.480 --> 00:14:09.110
glitchy there at the end buddy but uh


00:14:09.120 --> 00:14:10.509
that's the internet for you thanks for


00:14:10.519 --> 00:14:12.870
the question uh the ultimate lrange


00:14:12.880 --> 00:14:15.870
point would the center of the Galaxy be


00:14:15.880 --> 00:14:18.749
the ultimate lrange Point who wants to


00:14:18.759 --> 00:14:21.150
tackle that one first I can dive in


00:14:21.160 --> 00:14:24.910
briefly if you want um so the background


00:14:24.920 --> 00:14:27.629
here is that the lrange points are local


00:14:27.639 --> 00:14:30.829
areas of increased ability and it comes


00:14:30.839 --> 00:14:32.310
out of something called the restricted


00:14:32.320 --> 00:14:34.629
three body problem where you've got in


00:14:34.639 --> 00:14:36.030
the solar system which is where I do a


00:14:36.040 --> 00:14:38.590
lot of my work the sun and a planet and


00:14:38.600 --> 00:14:40.310
something else and that something else


00:14:40.320 --> 00:14:43.470
is pretty small and Tiny and you can


00:14:43.480 --> 00:14:45.629
play games so when I was a kid I was in


00:14:45.639 --> 00:14:47.590
Scouts and we used to go out in the


00:14:47.600 --> 00:14:50.069
countryside and we had contour maps


00:14:50.079 --> 00:14:51.590
which were maps of the local area that


00:14:51.600 --> 00:14:53.069
had these lines on and they told you how


00:14:53.079 --> 00:14:55.389
high or how low you were yeah and what


00:14:55.399 --> 00:14:56.949
those Contour are actually is telling


00:14:56.959 --> 00:14:58.590
you what your gravitational potential


00:14:58.600 --> 00:14:59.749
energy it's a measure of the


00:14:59.759 --> 00:15:01.030
gravitational


00:15:01.040 --> 00:15:03.030
potential you can do the same with the


00:15:03.040 --> 00:15:04.629
solar system you can make a map of the


00:15:04.639 --> 00:15:07.470
solar system that is like a contour map


00:15:07.480 --> 00:15:09.829
and when you do that you find the sun's


00:15:09.839 --> 00:15:11.189
a big well in the middle and the Earth's


00:15:11.199 --> 00:15:13.430
a small and M where the Earth is but


00:15:13.440 --> 00:15:15.670
there are five locations where you have


00:15:15.680 --> 00:15:18.509
local plateaus local flat bits and


00:15:18.519 --> 00:15:20.389
they're your LR points and they're more


00:15:20.399 --> 00:15:24.389
realistically LR areas and three of them


00:15:24.399 --> 00:15:26.790
are like Sables on a hillside so they're


00:15:26.800 --> 00:15:28.389
fairly stable but if you roll a little


00:15:28.399 --> 00:15:30.790
way you'll fall off and that's lrange 1


00:15:30.800 --> 00:15:32.230
2 and three and they're on the line


00:15:32.240 --> 00:15:34.790
between the Sun and the Earth one is on


00:15:34.800 --> 00:15:37.509
the far side of the sun one is between


00:15:37.519 --> 00:15:38.829
the Earth and the Sun and one is just on


00:15:38.839 --> 00:15:40.870
the far side of the Earth on that line


00:15:40.880 --> 00:15:42.550
the other two the Gran points four and


00:15:42.560 --> 00:15:44.990
five which are like these big plateaus


00:15:45.000 --> 00:15:46.670
that are 60 degrees ahead and behind the


00:15:46.680 --> 00:15:48.350
Earth in its orbit or behind Jupiter in


00:15:48.360 --> 00:15:49.509
its orbit that's where you get the


00:15:49.519 --> 00:15:53.110
Jupiter Trojans and so these are points


00:15:53.120 --> 00:15:54.670
where the Contours are flatter so you


00:15:54.680 --> 00:15:56.269
can sit there fairly stable before you


00:15:56.279 --> 00:15:57.910
roll off in any given


00:15:57.920 --> 00:16:00.110
Direction the middle of the Sun in that


00:16:00.120 --> 00:16:03.350
analogy isn't a lrange point if that's a


00:16:03.360 --> 00:16:05.590
slightly different concept so you are


00:16:05.600 --> 00:16:07.069
entirely right that if you're in the


00:16:07.079 --> 00:16:08.990
middle of an object you don't feel any


00:16:09.000 --> 00:16:11.389
gravitational pull from that object more


00:16:11.399 --> 00:16:13.230
strictly you feel the gravitational pull


00:16:13.240 --> 00:16:15.030
from every atom individually but they


00:16:15.040 --> 00:16:16.870
all cancel out so if you're in the


00:16:16.880 --> 00:16:18.470
middle of the Earth you're being pulled


00:16:18.480 --> 00:16:21.069
by people stood in America the same


00:16:21.079 --> 00:16:22.430
amount as you are by people stood in


00:16:22.440 --> 00:16:23.590
Australia but they're pulling in


00:16:23.600 --> 00:16:26.189
opposite direction so it all cancels out


00:16:26.199 --> 00:16:27.550
so if you were in the middle of the


00:16:27.560 --> 00:16:30.629
black hole um and ignoring all the other


00:16:30.639 --> 00:16:32.790
issues that would entail you wouldn't


00:16:32.800 --> 00:16:34.790
feel the gravitational pull of the black


00:16:34.800 --> 00:16:36.629
hole and if that was exactly at the


00:16:36.639 --> 00:16:39.230
center of the Galaxy all the matter in


00:16:39.240 --> 00:16:40.710
the Galaxy would cancel out but you'd


00:16:40.720 --> 00:16:43.069
still feel the pull from things locally


00:16:43.079 --> 00:16:44.269
so if you were in the middle of the


00:16:44.279 --> 00:16:46.309
Earth and you were massless from the


00:16:46.319 --> 00:16:47.949
point of view of the earth you'd still


00:16:47.959 --> 00:16:49.590
feel the pull from the Moon in One


00:16:49.600 --> 00:16:50.910
Direction and the sun in the other


00:16:50.920 --> 00:16:52.470
direction you'd still feel all those


00:16:52.480 --> 00:16:53.790
things so you would be still being


00:16:53.800 --> 00:16:56.670
pulled around and I dare say that you'd


00:16:56.680 --> 00:16:58.110
probably be pulled slightly off center


00:16:58.120 --> 00:17:00.030
if you could move around around and then


00:17:00.040 --> 00:17:01.189
youd start to feel the pull from the


00:17:01.199 --> 00:17:02.829
gravitation of the black hole pulling


00:17:02.839 --> 00:17:03.949
you back towards the middle and the


00:17:03.959 --> 00:17:06.270
further out you go the more pull you


00:17:06.280 --> 00:17:08.750
feel cuz you only feel the pull from the


00:17:08.760 --> 00:17:11.510
stuff that is interior to you everything


00:17:11.520 --> 00:17:12.870
and this used to make my head hurt when


00:17:12.880 --> 00:17:15.189
we did electromagnetism at Uni and


00:17:15.199 --> 00:17:17.069
trying to get your head around this


00:17:17.079 --> 00:17:18.630
everything more distant from the middle


00:17:18.640 --> 00:17:20.990
than you are cancels out with everything


00:17:21.000 --> 00:17:23.390
else everything nearer to the middle you


00:17:23.400 --> 00:17:25.710
feel added up as though it's pulling


00:17:25.720 --> 00:17:28.029
from the center so technically it


00:17:28.039 --> 00:17:29.549
wouldn't be able to Grant point because


00:17:29.559 --> 00:17:32.150
it's not one of those plateaus it's the


00:17:32.160 --> 00:17:34.830
bottom of a well instead but it would be


00:17:34.840 --> 00:17:36.590
a place where you would effectively be


00:17:36.600 --> 00:17:39.070
weightless massless well weightless


00:17:39.080 --> 00:17:40.830
rather than massless as a technical


00:17:40.840 --> 00:17:42.750
thing you still have mass but there'd be


00:17:42.760 --> 00:17:44.029
nothing pulling on you so you wouldn't


00:17:44.039 --> 00:17:46.390
have weight um but it wouldn't count as


00:17:46.400 --> 00:17:49.070
a LR point from my point of view until


00:17:49.080 --> 00:17:50.549
you turned into


00:17:50.559 --> 00:17:52.789
spaghetti you perceive would be the same


00:17:52.799 --> 00:17:54.029
thing and it will probably be a lot of


00:17:54.039 --> 00:17:56.950
pain as you become spaghettified yes as


00:17:56.960 --> 00:17:59.750
you go to get there to get there that's


00:17:59.760 --> 00:18:04.190
right so that absolutely jont um so I


00:18:04.200 --> 00:18:06.630
think that means the um the answer to


00:18:06.640 --> 00:18:11.029
the question is is just yes uh except we


00:18:11.039 --> 00:18:13.590
don't consider you know the center of


00:18:13.600 --> 00:18:16.549
things as being a LR point it's the LR


00:18:16.559 --> 00:18:19.310
points are quite specific or areas is a


00:18:19.320 --> 00:18:20.710
much better term for them because


00:18:20.720 --> 00:18:22.990
they're you know we think of them as a


00:18:23.000 --> 00:18:24.590
an individual point in space but they're


00:18:24.600 --> 00:18:27.029
not they're far from it that's why for


00:18:27.039 --> 00:18:30.750
example the L2 point in the earth's gr


00:18:30.760 --> 00:18:32.710
system it can be occupied by many


00:18:32.720 --> 00:18:35.430
spacecraft at once which it is yes and


00:18:35.440 --> 00:18:38.750
and it's not like Dead Steel the the the


00:18:38.760 --> 00:18:41.430
spacecraft have to adjust to the motion


00:18:41.440 --> 00:18:42.750
and that's CA they're starting to roll


00:18:42.760 --> 00:18:44.789
off the saddle so these Halo orbits that


00:18:44.799 --> 00:18:46.750
they move around are actually rolling


00:18:46.760 --> 00:18:48.470
around the saddle essentially along a


00:18:48.480 --> 00:18:50.710
line of constant height like one of


00:18:50.720 --> 00:18:53.350
those Contours on your contour map but


00:18:53.360 --> 00:18:55.029
it's very easy to roll off so that's why


00:18:55.039 --> 00:18:57.990
you burn fuel to stay on location


00:18:58.000 --> 00:19:00.070
because with the AL in particular if you


00:19:00.080 --> 00:19:01.510
fall off you'll eventually fall off


00:19:01.520 --> 00:19:02.750
properly CU you've been pulled by


00:19:02.760 --> 00:19:04.950
everything else yeah and land in a pile


00:19:04.960 --> 00:19:06.350
of dirt which is what happened when I


00:19:06.360 --> 00:19:07.909
rolled off the saddle once but it was


00:19:07.919 --> 00:19:10.310
like go there um I was not injured I


00:19:10.320 --> 00:19:13.190
wasn't not injured you're very lucky


00:19:13.200 --> 00:19:15.470
most people do get


00:19:15.480 --> 00:19:19.190
injured uh thank you buddy so um yeah as


00:19:19.200 --> 00:19:20.990
always I love the way buddy thinks he


00:19:21.000 --> 00:19:22.750
comes up with these Amazing Ideas I


00:19:22.760 --> 00:19:25.390
don't know where he uh his brain is


00:19:25.400 --> 00:19:27.710
obviously going at 10,000 mil hour all


00:19:27.720 --> 00:19:28.870
the time he comes up with some some


00:19:28.880 --> 00:19:31.029
interesting questions our last question


00:19:31.039 --> 00:19:33.630
today comes from Michael in Evanston


00:19:33.640 --> 00:19:36.190
Illinois gentlemen greetings uh


00:19:36.200 --> 00:19:38.710
regarding the expansion of the universe


00:19:38.720 --> 00:19:40.230
it is my understanding that an


00:19:40.240 --> 00:19:41.990
accelerating expansion means that


00:19:42.000 --> 00:19:43.789
everything in the universe is moving


00:19:43.799 --> 00:19:46.549
apart faster and faster this means that


00:19:46.559 --> 00:19:48.470
eventually nothing will be visible from


00:19:48.480 --> 00:19:50.950
anywhere else does this mean that the


00:19:50.960 --> 00:19:52.990
planets in our solar system are moving


00:19:53.000 --> 00:19:56.029
apart and that our moon is moving apart


00:19:56.039 --> 00:20:00.310
from Earth due to the universe's expans


00:20:00.320 --> 00:20:01.990
uh not withstanding what we talked about


00:20:02.000 --> 00:20:04.669
in the last episode regarding a new


00:20:04.679 --> 00:20:06.310
theory about the expansion of the


00:20:06.320 --> 00:20:09.029
universe and dark matter uh let's stick


00:20:09.039 --> 00:20:10.710
with the model that we all agree on at


00:20:10.720 --> 00:20:13.909
the moment and look he's right it is


00:20:13.919 --> 00:20:16.830
expanding everything's moving apart but


00:20:16.840 --> 00:20:18.590
there are other factors in play aren't


00:20:18.600 --> 00:20:21.390
they afid indeed it's gravity that


00:20:21.400 --> 00:20:23.430
dominates on the scale of the solar


00:20:23.440 --> 00:20:25.789
system uh we can't feel the expansion of


00:20:25.799 --> 00:20:27.990
the Universe on the scale of the solar


00:20:28.000 --> 00:20:30.070
system it's to small gravity is the


00:20:30.080 --> 00:20:32.390
overwhelmingly important Force it's only


00:20:32.400 --> 00:20:34.470
when you get out to you know you start


00:20:34.480 --> 00:20:36.310
looking at objects which are perhaps


00:20:36.320 --> 00:20:39.350
more than 10 20 million light years away


00:20:39.360 --> 00:20:42.070
before you start seeing that expansion


00:20:42.080 --> 00:20:44.830
never mind the accelerated expansion and


00:20:44.840 --> 00:20:46.830
even if the accelerated expansion does


00:20:46.840 --> 00:20:49.990
continue uh until we get the Big Rip


00:20:50.000 --> 00:20:51.909
which is what some people think might


00:20:51.919 --> 00:20:53.990
happen uh it's going to be a long time


00:20:54.000 --> 00:20:55.909
before the distance from the Earth to


00:20:55.919 --> 00:20:58.149
the Moon is affected by that particular


00:20:58.159 --> 00:20:59.549
geometry


00:20:59.559 --> 00:21:02.950
uh gravity is the force what I've never


00:21:02.960 --> 00:21:05.789
had clarified for me and there's all


00:21:05.799 --> 00:21:07.070
these kind of things is where that


00:21:07.080 --> 00:21:09.430
boundary comes so there is other the


00:21:09.440 --> 00:21:11.029
local scale of the scale of the Milky


00:21:11.039 --> 00:21:13.269
Way even gravity WIS so the Milky Way


00:21:13.279 --> 00:21:15.470
gets held together the local cluster


00:21:15.480 --> 00:21:17.630
should get held together as well but I


00:21:17.640 --> 00:21:19.310
don't know where the threshold is where


00:21:19.320 --> 00:21:20.870
it doesn't because the local cluster is


00:21:20.880 --> 00:21:22.269
part of a bigger cluster which is part


00:21:22.279 --> 00:21:25.190
of a super cluster and at some point you


00:21:25.200 --> 00:21:28.750
have this boundary where expansion wins


00:21:28.760 --> 00:21:30.990
but if it it has to be link to that


00:21:31.000 --> 00:21:33.269
cluster structure so it can't be halfway


00:21:33.279 --> 00:21:35.430
across the super cluster because


00:21:35.440 --> 00:21:36.430
something halfway across the


00:21:36.440 --> 00:21:38.029
supercluster is still attracted to its


00:21:38.039 --> 00:21:40.909
neighbors so it comes down to the voids


00:21:40.919 --> 00:21:43.190
and everything else and nobody's been


00:21:43.200 --> 00:21:46.029
able to give a definitive essentially


00:21:46.039 --> 00:21:48.510
Horizon where things will stay closer to


00:21:48.520 --> 00:21:50.470
us or where things will move away so I


00:21:50.480 --> 00:21:51.990
guess we just don't know that yet we've


00:21:52.000 --> 00:21:53.750
not we don't have a deep enough


00:21:53.760 --> 00:21:55.630
foundational enough knowledge of the


00:21:55.640 --> 00:21:56.870
structure of matter on that kind of


00:21:56.880 --> 00:21:59.590
Scale near us to know but I think the


00:21:59.600 --> 00:22:01.350
eventual Horizon is of that kind of


00:22:01.360 --> 00:22:03.190
scale of the Virgo cluster will still be


00:22:03.200 --> 00:22:05.190
just about there but the more distant


00:22:05.200 --> 00:22:07.269
structure what I don't know where that


00:22:07.279 --> 00:22:09.990
threshold is it's probably a very Wiggly


00:22:10.000 --> 00:22:11.750
one because it's going to follow the you


00:22:11.760 --> 00:22:14.909
know the inh aacy of what we see around


00:22:14.919 --> 00:22:18.110
us in in our local part of the Universe


00:22:18.120 --> 00:22:21.870
um it's uh yeah it's a it's a good point


00:22:21.880 --> 00:22:24.110
that you know we can't say well beyond


00:22:24.120 --> 00:22:26.310
you 50 million light years you're going


00:22:26.320 --> 00:22:28.750
to see the expansion dominating uh


00:22:28.760 --> 00:22:30.909
because it it will depend exactly on the


00:22:30.919 --> 00:22:34.230
on the presence I mean um it throws back


00:22:34.240 --> 00:22:37.070
to one of the Hot Topics 20 years ago


00:22:37.080 --> 00:22:39.390
which was the great ATT tractor uh the


00:22:39.400 --> 00:22:40.789
great ATT tractor being this thing


00:22:40.799 --> 00:22:43.070
hidden behind the Milky Way That We


00:22:43.080 --> 00:22:45.470
Believe now is a part of a of a super


00:22:45.480 --> 00:22:47.830
cluster of galaxies uh that seem to be


00:22:47.840 --> 00:22:49.310
pulling everything towards it but it's


00:22:49.320 --> 00:22:52.149
only in one particular direction uh so


00:22:52.159 --> 00:22:54.029
so you've got that kind of thing going


00:22:54.039 --> 00:22:56.750
on all around us uh and at different


00:22:56.760 --> 00:22:59.710
distances so you yes it would be a a


00:22:59.720 --> 00:23:01.190
wiggly you know thinking back to those


00:23:01.200 --> 00:23:02.549
Contours you were talking about a minute


00:23:02.559 --> 00:23:05.029
ago jonty it's a it's a contour but it's


00:23:05.039 --> 00:23:07.070
a very Wiggly one I


00:23:07.080 --> 00:23:10.149
think Heritage of this as well I I


00:23:10.159 --> 00:23:11.789
always love these things where we detect


00:23:11.799 --> 00:23:13.190
something indirectly because that's what


00:23:13.200 --> 00:23:14.830
we do with Exel planets now it's how


00:23:14.840 --> 00:23:16.990
Neptune was found yeah so we've got


00:23:17.000 --> 00:23:20.549
several hundred years of inferring that


00:23:20.559 --> 00:23:22.070
something exists when we can't see it


00:23:22.080 --> 00:23:23.510
because it's effect on something else


00:23:23.520 --> 00:23:25.190
and the great attractor is just another


00:23:25.200 --> 00:23:27.789
in a long list of we can't see it but we


00:23:27.799 --> 00:23:29.710
know it's there we see what it does to


00:23:29.720 --> 00:23:31.230
everything


00:23:31.240 --> 00:23:35.230
else I do yeah yeah the great you got


00:23:35.240 --> 00:23:37.269
You' Ena me to revive and a really old


00:23:37.279 --> 00:23:39.310
dad joke but the great attractor is the


00:23:39.320 --> 00:23:42.310
Massie Ferguson because my uncle used to


00:23:42.320 --> 00:23:45.110
work for that company but right off John


00:23:45.120 --> 00:23:47.950
de um and and as far as expansion's


00:23:47.960 --> 00:23:49.950
concerned expansion wins when you eat


00:23:49.960 --> 00:23:51.510
too many


00:23:51.520 --> 00:23:54.110
donuts it's speeding me too much


00:23:54.120 --> 00:23:55.950
information to work with well that's


00:23:55.960 --> 00:23:57.510
this is why I'm gradually resembling


00:23:57.520 --> 00:23:59.630
Patrick more more more because I growing


00:23:59.640 --> 00:24:01.110
vertically when I was 13 and I've just


00:24:01.120 --> 00:24:03.029
been spamming horizontally ever since


00:24:03.039 --> 00:24:05.669
yeah just don't don't um espouse his


00:24:05.679 --> 00:24:09.070
politics that's all JY oh no absolutely


00:24:09.080 --> 00:24:11.149
not I lean so far left I'm horizontal


00:24:11.159 --> 00:24:14.909
like


00:24:14.919 --> 00:24:20.950
many 3 2 one Space Nuts Andrew I was


00:24:20.960 --> 00:24:24.029
going to say you know this is a Q&A uh


00:24:24.039 --> 00:24:26.710
session uh can I throw in a question for


00:24:26.720 --> 00:24:29.830
J for it you you questions for because


00:24:29.840 --> 00:24:31.909
I'm not um I'm not going to be around


00:24:31.919 --> 00:24:34.750
for the next episode so I just want to


00:24:34.760 --> 00:24:37.110
know what jonty's take on planet N9 is


00:24:37.120 --> 00:24:40.029
oh yes um it it really interesting so


00:24:40.039 --> 00:24:41.870
the first paper I ever published back


00:24:41.880 --> 00:24:45.190
when I was doing my PhD was debunking


00:24:45.200 --> 00:24:47.590
one of the many variants of Planet X and


00:24:47.600 --> 00:24:49.909
this is a recurring theme that comes up


00:24:49.919 --> 00:24:51.950
about every 15 or 20 years when we get


00:24:51.960 --> 00:24:53.590
better data on things that are pushing


00:24:53.600 --> 00:24:54.830
the limits of our understanding of the


00:24:54.840 --> 00:24:57.909
solar system so in the early 1980s you


00:24:57.919 --> 00:25:00.190
had is which was Richard Muller's


00:25:00.200 --> 00:25:03.789
hypothesis of a brown dwarf or a red


00:25:03.799 --> 00:25:05.870
dwarf orbiting the Sun on a 26 million


00:25:05.880 --> 00:25:07.830
year Orbin that was giving us comets


00:25:07.840 --> 00:25:11.990
killing caat extinctions and that even


00:25:12.000 --> 00:25:13.710
though it sums down now at the time it


00:25:13.720 --> 00:25:16.149
was a reasonable possibility as an


00:25:16.159 --> 00:25:17.830
explanation of the data that made a


00:25:17.840 --> 00:25:19.630
prediction which was if it's there


00:25:19.640 --> 00:25:21.350
you'll see it and then we didn't see it


00:25:21.360 --> 00:25:23.789
we got good enough satellites to do it


00:25:23.799 --> 00:25:25.510
um so that died away and then back when


00:25:25.520 --> 00:25:29.789
I started my PhD in 2000 there was a


00:25:29.799 --> 00:25:32.029
regurgitation of the idea in this case


00:25:32.039 --> 00:25:34.590
being Planet X because Pluto at that


00:25:34.600 --> 00:25:36.750
point hadn't yet rightfully been demoted


00:25:36.760 --> 00:25:39.230
so people still counted it with a


00:25:39.240 --> 00:25:42.510
Grimace um but looking at the data of


00:25:42.520 --> 00:25:44.470
where comets come in towards the Sun


00:25:44.480 --> 00:25:46.710
from so not their per helium which is


00:25:46.720 --> 00:25:48.269
where their closest Sun but where on the


00:25:48.279 --> 00:25:50.269
sky their up helion would be their


00:25:50.279 --> 00:25:51.990
furthest from the Sun there were


00:25:52.000 --> 00:25:54.230
suggestions that there was a bit of an


00:25:54.240 --> 00:25:56.389
enhancement of comets coming from a


00:25:56.399 --> 00:25:57.789
great circle on the sky so one


00:25:57.799 --> 00:26:00.950
particular ring 360 gr around the sky


00:26:00.960 --> 00:26:03.269
had more comets than any other and there


00:26:03.279 --> 00:26:05.789
were two papers identifying this um The


00:26:05.799 --> 00:26:07.430
Twist was that both of them had great


00:26:07.440 --> 00:26:08.950
circles that were at right angles to


00:26:08.960 --> 00:26:12.070
each other and that didn't agree um so


00:26:12.080 --> 00:26:14.149
the first thing I did in my PhD was look


00:26:14.159 --> 00:26:16.029
at all this and say well hang on our


00:26:16.039 --> 00:26:17.950
discoveries of comets are biased by the


00:26:17.960 --> 00:26:19.430
fact that we see them when they're near


00:26:19.440 --> 00:26:21.750
the sun we see them at certain months we


00:26:21.760 --> 00:26:23.070
see them from the northern hemisphere is


00:26:23.080 --> 00:26:24.630
where that all these different biases he


00:26:24.640 --> 00:26:26.549
put them in and both great circles


00:26:26.559 --> 00:26:29.029
disappear so it was actually a result of


00:26:29.039 --> 00:26:31.149
our observational biases and so that one


00:26:31.159 --> 00:26:33.310
went away as we got more data and then


00:26:33.320 --> 00:26:35.470
what's happened over the last decade or


00:26:35.480 --> 00:26:38.669
so is that our ability to find small


00:26:38.679 --> 00:26:40.269
objects in the out Sol system has got


00:26:40.279 --> 00:26:42.230
better and better so we're starting to


00:26:42.240 --> 00:26:44.950
find things out beyond the kind of n


00:26:44.960 --> 00:26:47.029
nominal edge of the edge with ker belt


00:26:47.039 --> 00:26:50.070
Beyond about 50 Au and these are objects


00:26:50.080 --> 00:26:52.510
that are far enough aare that the


00:26:52.520 --> 00:26:55.110
influence of the planets isn't enough to


00:26:55.120 --> 00:26:59.269
modify their orbits in any real sense


00:26:59.279 --> 00:27:02.110
but there has been a set of detections


00:27:02.120 --> 00:27:04.669
of objects further out that a bit like


00:27:04.679 --> 00:27:06.669
that great circle appear to be more


00:27:06.679 --> 00:27:08.149
likely to be found in one part of the


00:27:08.159 --> 00:27:10.909
sky than anywhere else now one


00:27:10.919 --> 00:27:12.789
explanation for that is that there is


00:27:12.799 --> 00:27:14.230
something that we haven't seen that's


00:27:14.240 --> 00:27:16.149
further out that is stirring them up and


00:27:16.159 --> 00:27:18.710
has coralled them and that works really


00:27:18.720 --> 00:27:21.230
well to explain what we see another


00:27:21.240 --> 00:27:23.549
explanation is that this is an artifact


00:27:23.559 --> 00:27:25.190
of the observational bias because the


00:27:25.200 --> 00:27:26.990
survey is primarily done by the Canada


00:27:27.000 --> 00:27:29.070
France Hawaii telescope


00:27:29.080 --> 00:27:32.230
which sees Northern Hemisphere Sky by


00:27:32.240 --> 00:27:34.950
preference to Southern hemisphere has a


00:27:34.960 --> 00:27:36.909
varying cycle of cloudiness through the


00:27:36.919 --> 00:27:38.269
year it's harder to find these things


00:27:38.279 --> 00:27:40.389
where the Milky Way is so there are some


00:27:40.399 --> 00:27:41.750
people arguing that this will turn out


00:27:41.760 --> 00:27:44.350
to be an observational bias you've also


00:27:44.360 --> 00:27:48.029
got a few different versions of Planet X


00:27:48.039 --> 00:27:50.149
being proposed so the most famous one is


00:27:50.159 --> 00:27:51.509
the one that gets talked about a lot


00:27:51.519 --> 00:27:53.990
which is Ban and people like that


00:27:54.000 --> 00:27:56.070
talking about a fairly massive Planet X


00:27:56.080 --> 00:27:57.269
but a really good friend of mine who


00:27:57.279 --> 00:27:59.870
actually visited me unq a couple of


00:27:59.880 --> 00:28:02.950
months ago Patrick Saia Leafa from Japan


00:28:02.960 --> 00:28:04.750
there's been quietly running simulations


00:28:04.760 --> 00:28:08.630
looking at an earth Mass object which


00:28:08.640 --> 00:28:10.549
would work from the point of view of our


00:28:10.559 --> 00:28:11.549
understanding of the formation of the


00:28:11.559 --> 00:28:12.870
giant planets you would have formed a


00:28:12.880 --> 00:28:14.430
lot of objects that size that were then


00:28:14.440 --> 00:28:17.029
ejected that weren't Incorporated some


00:28:17.039 --> 00:28:18.830
of which will have been ejected but not


00:28:18.840 --> 00:28:21.190
fully ejected so you could have Earth


00:28:21.200 --> 00:28:23.509
sized objects in the alt Cloud quite


00:28:23.519 --> 00:28:25.549
reasonably and he's been looking at the


00:28:25.559 --> 00:28:27.190
distributions of all these things Beyond


00:28:27.200 --> 00:28:29.590
Neptune if you had something the mass of


00:28:29.600 --> 00:28:32.470
the Earth two or three or 400 Au away


00:28:32.480 --> 00:28:34.029
that we couldn't conly detect but we'll


00:28:34.039 --> 00:28:35.750
be able to find in the next five or 10


00:28:35.760 --> 00:28:39.310
years and that does a really good job of


00:28:39.320 --> 00:28:41.029
explaining the groups of objects we


00:28:41.039 --> 00:28:43.549
can't currently explain doesn't mean


00:28:43.559 --> 00:28:45.750
it's right what it's doing is saying


00:28:45.760 --> 00:28:47.389
here is something we can't explain


00:28:47.399 --> 00:28:49.110
observationally here's a couple of


00:28:49.120 --> 00:28:51.149
different teams proposing hypotheses


00:28:51.159 --> 00:28:53.029
that do were really good job of fitting


00:28:53.039 --> 00:28:55.230
the data and explaining what we


00:28:55.240 --> 00:28:57.549
otherwise can't do and they then make a


00:28:57.559 --> 00:28:59.470
prediction in both cases which is as


00:28:59.480 --> 00:29:01.590
Vera Rubin comes online this incredible


00:29:01.600 --> 00:29:03.870
new Observatory there going to increase


00:29:03.880 --> 00:29:05.110
the number of objects We Know by a


00:29:05.120 --> 00:29:07.110
factor of 10 to 100 times in the solar


00:29:07.120 --> 00:29:09.190
system we'll certainly have a lot more


00:29:09.200 --> 00:29:12.509
data and if these theories are correct


00:29:12.519 --> 00:29:15.029
these data will support them if not


00:29:15.039 --> 00:29:17.230
they'll shoot them down now I think


00:29:17.240 --> 00:29:20.310
given the past history of Nemesis and


00:29:20.320 --> 00:29:23.190
Planet X people are understandably very


00:29:23.200 --> 00:29:25.190
skeptical but it's very good science


00:29:25.200 --> 00:29:28.110
been done by really reputable scientists


00:29:28.120 --> 00:29:29.710
who are not saying this is definitely


00:29:29.720 --> 00:29:31.350
there they're saying here's something we


00:29:31.360 --> 00:29:33.950
cannot explain here is one way of


00:29:33.960 --> 00:29:36.669
explaining it that works really well and


00:29:36.679 --> 00:29:38.389
fits with the observational contraints


00:29:38.399 --> 00:29:40.830
we currently have it the truth could be


00:29:40.840 --> 00:29:42.430
out there you know it's kind of xal


00:29:42.440 --> 00:29:45.190
thing but we won't know until we get


00:29:45.200 --> 00:29:47.230
more data when that data comes in this


00:29:47.240 --> 00:29:49.149
is what we should look for and that's


00:29:49.159 --> 00:29:51.669
really important because if you do some


00:29:51.679 --> 00:29:53.350
modeling and and some solar system


00:29:53.360 --> 00:29:54.750
groups have done this in the past with


00:29:54.760 --> 00:29:57.430
very famous models that explain very


00:29:57.440 --> 00:29:59.669
well what we currently see but nothing


00:29:59.679 --> 00:30:02.029
else they don't make predictions of what


00:30:02.039 --> 00:30:04.110
we don't currently see then that to me


00:30:04.120 --> 00:30:05.750
stamp collecting it's not actually


00:30:05.760 --> 00:30:07.710
science because there's an infinite


00:30:07.720 --> 00:30:09.149
number of ways of explaining what we


00:30:09.159 --> 00:30:11.269
currently see and what both these models


00:30:11.279 --> 00:30:12.470
are doing really well is they're


00:30:12.480 --> 00:30:13.750
explaining what we currently see but


00:30:13.760 --> 00:30:15.870
also predicting what we will find in the


00:30:15.880 --> 00:30:18.190
future if their model is correct and if


00:30:18.200 --> 00:30:20.350
their model is not correct so they're


00:30:20.360 --> 00:30:22.990
testable hypotheses and that's really


00:30:23.000 --> 00:30:25.110
important because that sh how we do our


00:30:25.120 --> 00:30:27.230
future science what we look for so I


00:30:27.240 --> 00:30:30.029
find it really exciting I'm you know


00:30:30.039 --> 00:30:32.750
really Keen to see what happens with the


00:30:32.760 --> 00:30:34.750
very situations on planet 9 over the


00:30:34.760 --> 00:30:37.110
coming decades and it if it dies down


00:30:37.120 --> 00:30:39.509
I'm sure that in 20 30 years when we get


00:30:39.519 --> 00:30:41.269
the next generation of next generation


00:30:41.279 --> 00:30:43.230
of next generation of telescopes the


00:30:43.240 --> 00:30:45.509
idea might come up again because we're


00:30:45.519 --> 00:30:47.509
looking at this ever growing Circle of


00:30:47.519 --> 00:30:48.830
Knowledge around the soul system but


00:30:48.840 --> 00:30:51.950
it's not that big yet so the the five


00:30:51.960 --> 00:30:53.149
minutes You' to spend on that could have


00:30:53.159 --> 00:30:56.470
been answered with a maybe with a maybe


00:30:56.480 --> 00:30:59.190
but I think it's it's important to


00:30:59.200 --> 00:31:00.669
clarify that this is good science


00:31:00.679 --> 00:31:02.149
because it does sometimes get passed off


00:31:02.159 --> 00:31:04.310
as a bit of a joke because it's a past


00:31:04.320 --> 00:31:06.950
history of things falling flat and those


00:31:06.960 --> 00:31:08.870
things that fell flat were also very


00:31:08.880 --> 00:31:11.029
good science it's just this is the way


00:31:11.039 --> 00:31:14.629
science gets done and it runs counter to


00:31:14.639 --> 00:31:15.950
the opinion that a lot of people get


00:31:15.960 --> 00:31:17.310
when they come out of school because of


00:31:17.320 --> 00:31:19.470
the challenges of the curriculum that


00:31:19.480 --> 00:31:21.070
science is fapped and is science sealed


00:31:21.080 --> 00:31:22.190
and delivered and it's one of the


00:31:22.200 --> 00:31:24.789
problems we've seen with accepting that


00:31:24.799 --> 00:31:26.669
cigarettes cause cancer accepting that


00:31:26.679 --> 00:31:28.629
climate change is an issue


00:31:28.639 --> 00:31:31.509
is that people get taught that science


00:31:31.519 --> 00:31:33.110
is signed and sealed and delivered and


00:31:33.120 --> 00:31:35.350
then when things change like Pluto is


00:31:35.360 --> 00:31:37.549
demoted that feels like a betrayal it


00:31:37.559 --> 00:31:39.990
feels like you've been lied to that


00:31:40.000 --> 00:31:43.590
somehow things nefarious are going on


00:31:43.600 --> 00:31:46.750
and it makes it much harder then to get


00:31:46.760 --> 00:31:49.149
changes in our understanding through and


00:31:49.159 --> 00:31:50.470
so it's really important to stress that


00:31:50.480 --> 00:31:51.950
this is how science works and this is


00:31:51.960 --> 00:31:54.789
really good science no fair point great


00:31:54.799 --> 00:31:58.230
Point very good very good um jents


00:31:58.240 --> 00:31:59.190
that's where we're going to have to


00:31:59.200 --> 00:32:02.110
finish up uh thank you so very much


00:32:02.120 --> 00:32:04.310
Professor Fred Watson and and enjoy your


00:32:04.320 --> 00:32:07.029
travels and we will catch up with you uh


00:32:07.039 --> 00:32:09.230
round like February botle look of it


00:32:09.240 --> 00:32:11.190
rounds like it y thank you Andrew thank


00:32:11.200 --> 00:32:13.629
you jont T and I look forward to um


00:32:13.639 --> 00:32:16.830
listening to Space Nuts podcast without


00:32:16.840 --> 00:32:17.990
being on


00:32:18.000 --> 00:32:20.509
it that would be rare yeah that's just


00:32:20.519 --> 00:32:24.470
plenty of thought okay yes please do and


00:32:24.480 --> 00:32:26.710
uh Professor Johny Horner thank you for


00:32:26.720 --> 00:32:29.310
being a part of uh space Q&A today as


00:32:29.320 --> 00:32:31.669
well we'll catch you on the next episode


00:32:31.679 --> 00:32:33.669
it's a pleasure thank you for having me


00:32:33.679 --> 00:32:35.549
and thanks to H in the studio who


00:32:35.559 --> 00:32:37.029
couldn't really do much because he was


00:32:37.039 --> 00:32:39.549
caught in the ultimate lrange point and


00:32:39.559 --> 00:32:41.549
from me Andrew Dunley oh don't forget to


00:32:41.559 --> 00:32:43.190
send us your questions via our website


00:32:43.200 --> 00:32:46.310
Space Nuts podcast.com SPAC nuts.i get


00:32:46.320 --> 00:32:47.990
your questions in we'll get to them as


00:32:48.000 --> 00:32:50.549
soon as we possibly can uh so from me


00:32:50.559 --> 00:32:52.070
Andrew Dunley thanks to your company see


00:32:52.080 --> 00:32:53.950
you again on the next episode of Space


00:32:53.960 --> 00:32:56.909
Nuts bye-bye Space Nuts you'll be


00:32:56.919 --> 00:32:59.750
listening to the space face nuts


00:32:59.760 --> 00:33:02.830
podcast available at Apple podcasts


00:33:02.840 --> 00:33:05.789
Spotify ihart radio or your favorite


00:33:05.799 --> 00:33:08.070
podcast player you can also stream on


00:33:08.080 --> 00:33:10.789
demand at bites.com this has been


00:33:10.799 --> 00:33:13.190
another quality podcast production from


00:33:13.200 --> 00:33:16.039
bites.com