Snowball Earth, Dinosaur Asteroids & the Hubble Tension Unravelled | Space Nuts: Astronomy...

WEBVTT
Kind: captions
Language: en

00:00:00.240 --> 00:00:02.389
Space Nuts is taking a bit of a break at


00:00:02.399 --> 00:00:04.630
the moment. Uh Fred and I will be back


00:00:04.640 --> 00:00:06.630
uh in the not too distant future with


00:00:06.640 --> 00:00:08.710
fresh episodes. In the meantime, enjoy


00:00:08.720 --> 00:00:11.589
some of uh the key episodes that we have


00:00:11.599 --> 00:00:14.390
presented over the years, major events


00:00:14.400 --> 00:00:17.830
in astronomy and space science and we'll


00:00:17.840 --> 00:00:19.670
see you real soon.


00:00:19.680 --> 00:00:20.870
>> Space Nuts.


00:00:20.880 --> 00:00:22.630
>> Hi there. Thanks for joining us on


00:00:22.640 --> 00:00:24.790
another episode of Space Nuts. Andrew


00:00:24.800 --> 00:00:26.550
Dunley here and it's good to have your


00:00:26.560 --> 00:00:29.029
company. Coming up on this episode,


00:00:29.039 --> 00:00:31.589
we're going to be looking at Snowball


00:00:31.599 --> 00:00:33.910
Earth. There was a time where it was


00:00:33.920 --> 00:00:37.510
just a frozen sphere of nothingness for


00:00:37.520 --> 00:00:39.910
well, billions of years. Uh, now they


00:00:39.920 --> 00:00:41.910
have a new theory about that and it's no


00:00:41.920 --> 00:00:43.910
Irish joke.


00:00:43.920 --> 00:00:46.310
There's a clue in there. Uh, the


00:00:46.320 --> 00:00:48.869
dinosaur asteroids origin has been


00:00:48.879 --> 00:00:50.790
revealed. Yep. The thing that started


00:00:50.800 --> 00:00:52.389
the


00:00:52.399 --> 00:00:54.229
getting rid of them all across the


00:00:54.239 --> 00:00:57.189
planet. We know where it came from. and


00:00:57.199 --> 00:00:59.430
uh the so-called crisis in cosmology


00:00:59.440 --> 00:01:01.430
might not be a crisis at all. We're


00:01:01.440 --> 00:01:03.670
talking about the Hubble tension. We'll


00:01:03.680 --> 00:01:05.910
talk about all of that on this episode


00:01:05.920 --> 00:01:07.750
of Space Nuts.


00:01:07.760 --> 00:01:12.630
>> 15 seconds. Guidance is internal. 10 9


00:01:12.640 --> 00:01:14.310
Ignition sequence start.


00:01:14.320 --> 00:01:15.270
>> Space Nuts.


00:01:15.280 --> 00:01:20.230
>> 5 4 3 2 1 2 3 4 5 5 4 3 2 1


00:01:20.240 --> 00:01:21.350
>> Space Nuts.


00:01:21.360 --> 00:01:24.550
>> Astronauts report. It feels good. And to


00:01:24.560 --> 00:01:27.510
help us uh unravel all of that, decipher


00:01:27.520 --> 00:01:30.469
it, and uh use his code book to figure a


00:01:30.479 --> 00:01:32.230
few more things out is Professor Fred


00:01:32.240 --> 00:01:34.069
Watson, an astronomer at large. Hello,


00:01:34.079 --> 00:01:34.789
Fred.


00:01:34.799 --> 00:01:36.950
>> Hello, Andrew. Keep up the good work


00:01:36.960 --> 00:01:40.069
there. It's going very well.


00:01:40.079 --> 00:01:42.789
>> Uh good to see you. Now I I just I


00:01:42.799 --> 00:01:44.390
thought I'd sort of start out of left


00:01:44.400 --> 00:01:48.789
field because um I I spotted a story uh


00:01:48.799 --> 00:01:52.149
only today actually uh which doveetales


00:01:52.159 --> 00:01:53.670
with something we talked about some time


00:01:53.680 --> 00:01:55.910
ago and and that was the work that's


00:01:55.920 --> 00:01:59.109
being done to perfect uh engine


00:01:59.119 --> 00:02:02.550
technology to achieve greater speeds


00:02:02.560 --> 00:02:05.510
>> uh for interstellar travel in years to


00:02:05.520 --> 00:02:07.030
come or maybe not interstellar but


00:02:07.040 --> 00:02:09.830
interplanetary perhaps. And we know NASA


00:02:09.840 --> 00:02:12.229
is is working on this kind of technology


00:02:12.239 --> 00:02:16.470
to to create uh really


00:02:16.480 --> 00:02:19.110
fast and high performance engines.


00:02:19.120 --> 00:02:20.550
They're working with I think it's


00:02:20.560 --> 00:02:23.190
General Electric to achieve that. Uh


00:02:23.200 --> 00:02:25.270
they may have been gazumped. Fred, have


00:02:25.280 --> 00:02:29.350
you heard about this? Uh no.


00:02:29.360 --> 00:02:32.470
Uh the Chinese the Chinese claim to have


00:02:32.480 --> 00:02:36.309
developed a a new engine that can


00:02:36.319 --> 00:02:39.910
achieve a speed of 12,000


00:02:39.920 --> 00:02:44.949
mph or 19,700 km an hour and uh the


00:02:44.959 --> 00:02:47.270
aircraft can reach an altitude of 30


00:02:47.280 --> 00:02:49.589
kilome. Now you compare that to the


00:02:49.599 --> 00:02:55.430
Concord uh it's uh Mac 16 versus Mac 2


00:02:55.440 --> 00:02:58.309
uh which is an extraordinary claim. Now,


00:02:58.319 --> 00:02:59.910
apparently they've released a paper


00:02:59.920 --> 00:03:02.229
which has been peer reviewed from what I


00:03:02.239 --> 00:03:05.110
understand. Um, and it's not April the


00:03:05.120 --> 00:03:08.070
1st. I'm confident of that. So, they


00:03:08.080 --> 00:03:10.550
reckon that they've they've made this


00:03:10.560 --> 00:03:15.110
leap in technology to develop a Max 16


00:03:15.120 --> 00:03:17.910
engine. And just think of this, Fred,


00:03:17.920 --> 00:03:20.470
you'd be able to fly from Sydney to New


00:03:20.480 --> 00:03:23.350
York in 50 minutes.


00:03:23.360 --> 00:03:24.949
>> Yes, that's what


00:03:24.959 --> 00:03:28.869
>> 50 minutes. Uh, That's extraordinary if


00:03:28.879 --> 00:03:31.110
it if it's real. And I I don't see why


00:03:31.120 --> 00:03:32.869
it wouldn't be, but you never know with


00:03:32.879 --> 00:03:35.750
these things. But um apparently uh


00:03:35.760 --> 00:03:37.110
according to the paper, the engine


00:03:37.120 --> 00:03:38.630
operates in two modes. There's a


00:03:38.640 --> 00:03:40.869
continuous rotating detonation engine,


00:03:40.879 --> 00:03:42.550
which is a scary thing in itself by the


00:03:42.560 --> 00:03:43.910
sound of it, which will get it to mark


00:03:43.920 --> 00:03:47.509
7. And uh you know, the air and the fuel


00:03:47.519 --> 00:03:49.830
create a rotating shock wave with


00:03:49.840 --> 00:03:52.229
continuous thrust. and then a straight


00:03:52.239 --> 00:03:55.190
line oblique detonation engine which


00:03:55.200 --> 00:03:58.229
fires above Mark 7 and pushes it all the


00:03:58.239 --> 00:04:02.630
way to Mark 16. Um, it sounds amazing.


00:04:02.640 --> 00:04:06.470
Sounds amazing. Uh, how far short they


00:04:06.480 --> 00:04:08.630
are of getting this into production, I


00:04:08.640 --> 00:04:10.710
don't know, but um, it certainly sounds


00:04:10.720 --> 00:04:12.789
like it's in development. That would be


00:04:12.799 --> 00:04:15.429
amazing to to be able to achieve those


00:04:15.439 --> 00:04:17.509
kinds of speeds. Uh, it would


00:04:17.519 --> 00:04:20.469
revolutionize travel around the world.


00:04:20.479 --> 00:04:23.430
But it's been done already


00:04:23.440 --> 00:04:24.790
by


00:04:24.800 --> 00:04:26.870
>> Yeah. The British have been working on


00:04:26.880 --> 00:04:31.350
this for decades now with their air.


00:04:31.360 --> 00:04:34.469
It's an air breathing um it's a hybrid


00:04:34.479 --> 00:04:37.990
engine that breathes air at at at low


00:04:38.000 --> 00:04:40.150
altitudes and turns into a rocket motor


00:04:40.160 --> 00:04:41.189
when you get above the Earth's


00:04:41.199 --> 00:04:41.990
atmosphere.


00:04:42.000 --> 00:04:44.150
>> Yeah, I think I did hear about that. I


00:04:44.160 --> 00:04:45.350
didn't know it got to those sorts of


00:04:45.360 --> 00:04:45.990
speeds.


00:04:46.000 --> 00:04:47.749
>> Yeah. Well, it can it's capable of


00:04:47.759 --> 00:04:49.510
entering orbit. So, it can get up to,


00:04:49.520 --> 00:04:52.390
you know, 26,000 kilometers an hour, but


00:04:52.400 --> 00:04:54.070
but but it's then acting as a rocket


00:04:54.080 --> 00:04:56.629
motor. So, it's um the project was


00:04:56.639 --> 00:05:00.150
called well hotel was the style of thing


00:05:00.160 --> 00:05:03.110
horizontal takeoff and landing. Um, so


00:05:03.120 --> 00:05:05.270
it's flies like a plane, takes off like


00:05:05.280 --> 00:05:07.830
a plane with the air burning jet


00:05:07.840 --> 00:05:11.110
engines, just gradually accelerates, uh,


00:05:11.120 --> 00:05:15.510
clicks over into being a, um, a rocket


00:05:15.520 --> 00:05:17.670
motor, uh, when the atmosphere gets too


00:05:17.680 --> 00:05:20.469
rarified and then sends you up to orbit.


00:05:20.479 --> 00:05:22.629
Uh, but the, as I remember right, I


00:05:22.639 --> 00:05:24.310
think it's called the Saber, the engine,


00:05:24.320 --> 00:05:26.950
if I remember right, it's Saber. But the


00:05:26.960 --> 00:05:31.110
big problem was, um, keeping the air


00:05:31.120 --> 00:05:32.310
cool.


00:05:32.320 --> 00:05:34.629
And there was some the main breakthrough


00:05:34.639 --> 00:05:37.110
was apparently a heat exchanger that


00:05:37.120 --> 00:05:39.670
could bring the temperature of the air


00:05:39.680 --> 00:05:43.990
uh down from 700° C or something to


00:05:44.000 --> 00:05:45.990
liquid nitrogen temperatures in


00:05:46.000 --> 00:05:47.590
something like a thousandth of a second


00:05:47.600 --> 00:05:49.350
as it passes through the engine.


00:05:49.360 --> 00:05:51.510
>> Um and and that was a big breakthrough.


00:05:51.520 --> 00:05:53.270
Now we've I think we've spoken about it


00:05:53.280 --> 00:05:54.950
before a long long time ago because


00:05:54.960 --> 00:05:56.710
there hasn't really been much news. It


00:05:56.720 --> 00:05:58.150
was being supported by the British


00:05:58.160 --> 00:05:59.590
government. I don't know whether that


00:05:59.600 --> 00:06:03.110
support has has now dwindled um because


00:06:03.120 --> 00:06:05.110
it would be you know the idea about this


00:06:05.120 --> 00:06:07.029
was economics. It was to be able to have


00:06:07.039 --> 00:06:08.790
the same spa spacecraft that will take


00:06:08.800 --> 00:06:10.710
you up there and bring you back and was


00:06:10.720 --> 00:06:13.270
completely reusable and to some extent I


00:06:13.280 --> 00:06:16.710
think um uh Elon Musk SpaceX and their


00:06:16.720 --> 00:06:18.550
Falcon 9 have kind of cornered the


00:06:18.560 --> 00:06:20.469
market on the because they've they've


00:06:20.479 --> 00:06:22.790
now got reusable spacecraft which are


00:06:22.800 --> 00:06:25.029
routinely being used every day uh


00:06:25.039 --> 00:06:27.670
almost. So maybe there's no space for


00:06:27.680 --> 00:06:29.909
it, but yeah, extraordinary technology


00:06:29.919 --> 00:06:32.150
and and I'm sure the Chinese technology


00:06:32.160 --> 00:06:34.390
is is above board what you've just been


00:06:34.400 --> 00:06:34.950
describing.


00:06:34.960 --> 00:06:36.710
>> Yeah, it's from the Beijing Power


00:06:36.720 --> 00:06:38.309
Machinery Institute and they've


00:06:38.319 --> 00:06:40.390
published their paper in the Chinese


00:06:40.400 --> 00:06:42.950
Journal of Propulsion Technology. I can


00:06:42.960 --> 00:06:44.390
I can see a problem with it though.


00:06:44.400 --> 00:06:46.790
Let's say they do create an airliner


00:06:46.800 --> 00:06:49.029
that can do that trip in 50 minutes from


00:06:49.039 --> 00:06:51.189
New York to Sydney, for example. You'd


00:06:51.199 --> 00:06:52.870
leave at 7:00 in the morning in New


00:06:52.880 --> 00:06:55.270
York. You'd arrive at 11:00 p.m. 50


00:06:55.280 --> 00:06:59.430
minutes later in Sydney. So you'd get up


00:06:59.440 --> 00:07:01.430
and get on the plane and then get to


00:07:01.440 --> 00:07:02.870
Sydney and then have to go to bed wide


00:07:02.880 --> 00:07:03.270
awake.


00:07:03.280 --> 00:07:05.270
>> Yes,


00:07:05.280 --> 00:07:08.309
>> that's right. That's the issue is it


00:07:08.319 --> 00:07:10.950
would make jet lag all the more worse.


00:07:10.960 --> 00:07:13.189
>> Yeah. You know, I think I'd put up with


00:07:13.199 --> 00:07:15.510
that rather than have all those


00:07:15.520 --> 00:07:16.950
>> 20 hours.


00:07:16.960 --> 00:07:19.350
>> Yeah. 20our flight. Yeah. I've got one


00:07:19.360 --> 00:07:21.110
of those coming up very soon actually.


00:07:21.120 --> 00:07:22.950
>> You do? That's right. Yeah. Yeah.


00:07:22.960 --> 00:07:24.790
>> Yeah. It'll be Yeah. It's a watch this


00:07:24.800 --> 00:07:26.309
space story, but I just find it


00:07:26.319 --> 00:07:28.390
fascinating these these kinds of um


00:07:28.400 --> 00:07:30.469
leaps in technology.


00:07:30.479 --> 00:07:32.950
>> Let's move on. Uh a new theory about


00:07:32.960 --> 00:07:35.990
snowball earth. Fred, I said there's um


00:07:36.000 --> 00:07:37.670
there's no Irish joke attached to this,


00:07:37.680 --> 00:07:41.350
and there's a good reason I said that,


00:07:41.360 --> 00:07:42.950
>> which I'm probably going to sidestep


00:07:42.960 --> 00:07:45.589
completely. Uh it's about rocks in


00:07:45.599 --> 00:07:47.990
Scotland and in Australia.


00:07:48.000 --> 00:07:49.430
>> I thought it was I thought they said


00:07:49.440 --> 00:07:50.950
there was some of these rocks in Ireland


00:07:50.960 --> 00:07:52.629
as well. Yeah, I think I think there are


00:07:52.639 --> 00:07:55.430
I think that's right. I think that's the


00:07:55.440 --> 00:07:58.390
loose connection I made with it.


00:07:58.400 --> 00:08:02.230
>> Um it it also includes rocks in Namibia


00:08:02.240 --> 00:08:05.589
uh and North America uh as well as uh


00:08:05.599 --> 00:08:07.510
Scotland. Uh you're probably right,


00:08:07.520 --> 00:08:10.150
Ireland in Ireland because um it's the


00:08:10.160 --> 00:08:11.909
west of Scotland where these where these


00:08:11.919 --> 00:08:13.909
rocks are that have recently been


00:08:13.919 --> 00:08:17.110
analyzed. Uh and the I mean it's an


00:08:17.120 --> 00:08:18.469
interesting story. I've often wondered


00:08:18.479 --> 00:08:20.070
about Snowball Earth. never really


00:08:20.080 --> 00:08:23.189
looked at at the details of it. So, it's


00:08:23.199 --> 00:08:27.430
a period of about 60 million years ago.


00:08:27.440 --> 00:08:30.869
Oh, sorry, 60 million years long, but it


00:08:30.879 --> 00:08:33.110
was a long time ago. It began 700


00:08:33.120 --> 00:08:36.070
million years ago. Uh, in fact, probably


00:08:36.080 --> 00:08:39.029
more like 720 million years ago and


00:08:39.039 --> 00:08:41.750
lasted until about 635 million years


00:08:41.760 --> 00:08:44.550
ago. And it's called the Cryogenian


00:08:44.560 --> 00:08:46.790
Cryogenian geological period. And


00:08:46.800 --> 00:08:48.630
anything with cryo in the front of it


00:08:48.640 --> 00:08:50.470
means it's frozen solid.


00:08:50.480 --> 00:08:51.190
>> Yeah.


00:08:51.200 --> 00:08:54.630
>> And so um and so I thought well how do


00:08:54.640 --> 00:08:58.710
we know this? And the way we know it


00:08:58.720 --> 00:09:01.990
and the way we know that glacial ice


00:09:02.000 --> 00:09:05.430
covered the whole planet is because you


00:09:05.440 --> 00:09:08.710
can see in the geology the effects of


00:09:08.720 --> 00:09:10.230
glaciation


00:09:10.240 --> 00:09:13.269
uh everywhere. It's not just, you know,


00:09:13.279 --> 00:09:15.829
I I grew up in a country where 10,000


00:09:15.839 --> 00:09:17.269
years ago, the whole of the northern


00:09:17.279 --> 00:09:20.310
part of Britain was under ice. And so my


00:09:20.320 --> 00:09:22.550
all my school lessons were about glacial


00:09:22.560 --> 00:09:25.829
features uh in the north of England. And


00:09:25.839 --> 00:09:29.030
so so you could tell from rocks uh


00:09:29.040 --> 00:09:31.990
whether something has been glaciated.


00:09:32.000 --> 00:09:34.310
And that's how we know everywhere there


00:09:34.320 --> 00:09:37.269
is this layer of rock uh corresponding


00:09:37.279 --> 00:09:40.470
to looking back you know six 6 700


00:09:40.480 --> 00:09:42.630
million years where you see the evidence


00:09:42.640 --> 00:09:45.030
of glaciation. Um and so the


00:09:45.040 --> 00:09:48.470
interpretation of that is that you uh


00:09:48.480 --> 00:09:51.750
you had an ice age that was the put it


00:09:51.760 --> 00:09:54.310
the the grandfather of all ice ages. Uh


00:09:54.320 --> 00:09:58.070
the whole planet was frozen. Uh and so


00:09:58.080 --> 00:10:00.550
the the new research concerns uh


00:10:00.560 --> 00:10:03.269
evidence from rocks in Scotland. Uh and


00:10:03.279 --> 00:10:08.150
what's remarkable is that uh the sort of


00:10:08.160 --> 00:10:10.870
glacia the glacial evidence there shows


00:10:10.880 --> 00:10:13.590
up really clearly. Uh for some reason


00:10:13.600 --> 00:10:16.069
that has been preserved very well uh


00:10:16.079 --> 00:10:17.990
there, you know, underneath the


00:10:18.000 --> 00:10:20.150
sediments that were dropped on top of on


00:10:20.160 --> 00:10:24.550
top of it um later on. But um the bottom


00:10:24.560 --> 00:10:28.870
line about the uh the reason why we got


00:10:28.880 --> 00:10:32.630
this ice age is a is a question um I'm


00:10:32.640 --> 00:10:35.110
not sure that the article I sent you it


00:10:35.120 --> 00:10:37.670
goes into detail about it. Uh but the


00:10:37.680 --> 00:10:41.430
thinking is that we were seeing a period


00:10:41.440 --> 00:10:45.110
when um or before this period uh we were


00:10:45.120 --> 00:10:51.350
seeing a time when uh volcanic rocks


00:10:51.360 --> 00:10:54.389
were being were being uh eroded. They


00:10:54.399 --> 00:10:56.630
were being weathered very rapidly. And


00:10:56.640 --> 00:10:58.310
apparently these were particularly in


00:10:58.320 --> 00:11:01.190
Canada uh these volcanic rocks. I'm


00:11:01.200 --> 00:11:03.990
looking back now perhaps 720 million


00:11:04.000 --> 00:11:08.310
years. um they were eroded by weathering


00:11:08.320 --> 00:11:11.269
and that process sucks carbon dioxide


00:11:11.279 --> 00:11:14.949
out of the atmosphere. Uh and so um what


00:11:14.959 --> 00:11:18.470
you're seeing is a situation where the


00:11:18.480 --> 00:11:22.069
atmospheric carbon dioxide is lower uh


00:11:22.079 --> 00:11:25.430
than normal and in fact uh it is


00:11:25.440 --> 00:11:28.470
probably was probably about half uh what


00:11:28.480 --> 00:11:31.190
today's level is. today's levels in the


00:11:31.200 --> 00:11:33.190
region of 400 parts per million of


00:11:33.200 --> 00:11:35.110
carbon dioxide in the atmosphere. And


00:11:35.120 --> 00:11:37.269
that's enough to blanket our planet and


00:11:37.279 --> 00:11:39.509
keep the temperature stable. Uh unless


00:11:39.519 --> 00:11:41.030
you put more in in which case the


00:11:41.040 --> 00:11:43.509
temperature goes up as you know. Uh but


00:11:43.519 --> 00:11:46.870
uh if you drop too far down uh then you


00:11:46.880 --> 00:11:50.069
get an ice ball. Um they estimate the


00:11:50.079 --> 00:11:54.069
atmospheric carbon dioxide levels uh


00:11:54.079 --> 00:11:56.389
back in the cryogenic period or


00:11:56.399 --> 00:11:59.910
cryogenonian period. uh they estimate


00:11:59.920 --> 00:12:02.230
they were below 200 parts per million.


00:12:02.240 --> 00:12:04.069
And what that does is lets the heat just


00:12:04.079 --> 00:12:07.190
radiate out into the uh into space and


00:12:07.200 --> 00:12:09.190
you lose heat. The earth's surface


00:12:09.200 --> 00:12:12.069
becomes very cold. Uh and uh and


00:12:12.079 --> 00:12:13.670
basically you get the snowball earth.


00:12:13.680 --> 00:12:15.350
You get an earth that is covered with


00:12:15.360 --> 00:12:18.710
ice. Um the it's the same sort of thing


00:12:18.720 --> 00:12:20.389
that we think happened on Mars. Mars is


00:12:20.399 --> 00:12:22.230
very low carbon dioxide content and


00:12:22.240 --> 00:12:24.629
that's why we think it got cold and dry


00:12:24.639 --> 00:12:26.389
rather than warm and white as it once


00:12:26.399 --> 00:12:27.990
was. M


00:12:28.000 --> 00:12:29.750
>> the other there's a lot of moving parts


00:12:29.760 --> 00:12:32.230
to this story but uh one of the things I


00:12:32.240 --> 00:12:37.030
found most interesting was if this mega


00:12:37.040 --> 00:12:40.069
freeze hadn't happened life as we know


00:12:40.079 --> 00:12:42.389
it may not have developed


00:12:42.399 --> 00:12:44.470
>> because up until this time it was just


00:12:44.480 --> 00:12:47.829
microbial just that was it.


00:12:47.839 --> 00:12:50.790
>> That's that's correct. Um so uh and the


00:12:50.800 --> 00:12:52.069
thinking yes it was it was


00:12:52.079 --> 00:12:54.310
single-sellled organisms until that time


00:12:54.320 --> 00:12:56.710
and they they were around for you know


00:12:56.720 --> 00:12:59.670
three billion years or so um that


00:12:59.680 --> 00:13:01.430
nothing happened except these single


00:13:01.440 --> 00:13:03.750
cellled organisms uh principally


00:13:03.760 --> 00:13:05.910
cyanobacteria they just did their thing


00:13:05.920 --> 00:13:08.150
and got on with life but didn't evolve


00:13:08.160 --> 00:13:12.949
in any way. Uh but the end this this end


00:13:12.959 --> 00:13:17.269
of the glacial period was such a sort of


00:13:17.279 --> 00:13:20.230
rapid climate change by the standards of


00:13:20.240 --> 00:13:23.190
the of the time by geological standards


00:13:23.200 --> 00:13:25.590
that the thinking is that you've got to


00:13:25.600 --> 00:13:30.949
uh almost an arms race uh to adapt um to


00:13:30.959 --> 00:13:34.790
to to this new situation where the


00:13:34.800 --> 00:13:36.389
microbes are not permanently in deep


00:13:36.399 --> 00:13:39.350
freeze. you've got a warming climate and


00:13:39.360 --> 00:13:41.590
the and the evolution of the microbes


00:13:41.600 --> 00:13:44.230
kicks in at a much higher level than it


00:13:44.240 --> 00:13:47.430
was before and that is where uh we think


00:13:47.440 --> 00:13:49.590
that the multi-elled organism started to


00:13:49.600 --> 00:13:52.310
be formed and that's what are the


00:13:52.320 --> 00:13:54.150
ancestors of all the animals that we see


00:13:54.160 --> 00:13:56.710
today. Yeah. So basically those who


00:13:56.720 --> 00:14:00.310
survived the thor or adapted to it uh


00:14:00.320 --> 00:14:02.550
created life as we know it. Yeah. just


00:14:02.560 --> 00:14:06.790
this extraordinary um sort of factor to


00:14:06.800 --> 00:14:09.990
come out of it. The other thing I and I


00:14:10.000 --> 00:14:11.990
correct me if I'm wrong, but these rocks


00:14:12.000 --> 00:14:13.910
we were talking about in Ireland and


00:14:13.920 --> 00:14:15.910
Scotland and Australia and everywhere


00:14:15.920 --> 00:14:19.110
else uh the reason that these are so


00:14:19.120 --> 00:14:21.750
different is I believe these were rocks


00:14:21.760 --> 00:14:24.870
that actually stuck out of the ice. Is


00:14:24.880 --> 00:14:27.509
that correct?


00:14:27.519 --> 00:14:29.430
>> During that period,


00:14:29.440 --> 00:14:32.150
>> they may have done or or at least been


00:14:32.160 --> 00:14:34.949
subject to less glacial activity. So,


00:14:34.959 --> 00:14:37.430
yes, they they they may have, you know,


00:14:37.440 --> 00:14:39.269
had only a thin layer of ice over them


00:14:39.279 --> 00:14:41.990
rather than be under kilometers of ice.


00:14:42.000 --> 00:14:44.949
Um, so I think you're right there. And


00:14:44.959 --> 00:14:47.590
and and just to to confirm, you're quite


00:14:47.600 --> 00:14:48.949
right that some of these rocks are in


00:14:48.959 --> 00:14:51.350
Ireland as well. Uh I hadn't spotted


00:14:51.360 --> 00:14:53.269
that, Andrew, in my reading of the


00:14:53.279 --> 00:14:58.150
paper. Uh but yes, so you've got um uh


00:14:58.160 --> 00:15:01.189
particularly you've got uh these rocks


00:15:01.199 --> 00:15:03.990
on some of the Scottish islands. These


00:15:04.000 --> 00:15:06.790
are small islands called the Gavllas. Uh


00:15:06.800 --> 00:15:09.350
and it's um basically in the west of


00:15:09.360 --> 00:15:13.350
Scotland. Uh it's under the Portas


00:15:13.360 --> 00:15:15.670
formation. This is a geological area.


00:15:15.680 --> 00:15:17.670
Potas very well known to Scots people


00:15:17.680 --> 00:15:19.189
because it's a name of a well-known pipe


00:15:19.199 --> 00:15:22.870
tune. Um so let me quote from one of the


00:15:22.880 --> 00:15:25.189
authors of this work um and he's he's


00:15:25.199 --> 00:15:30.870
actually a PhD uh candidate at the UN uh


00:15:30.880 --> 00:15:33.350
University College London. The layers of


00:15:33.360 --> 00:15:35.750
rocks exposed on the Garvellis are


00:15:35.760 --> 00:15:37.829
globally unique. Underneath the rocks


00:15:37.839 --> 00:15:40.550
laid down during the unimaginable cold


00:15:40.560 --> 00:15:43.509
of the glaciation are 70 m of older


00:15:43.519 --> 00:15:45.829
carbonate rocks formed in tropical


00:15:45.839 --> 00:15:48.790
waters. These layers record a tropical


00:15:48.800 --> 00:15:50.470
marine environment with flourishing


00:15:50.480 --> 00:15:52.470
cyanobacterial life that gradually


00:15:52.480 --> 00:15:54.550
became cooler, marking the end of a


00:15:54.560 --> 00:15:56.710
billion years or so of a temperate


00:15:56.720 --> 00:15:59.509
climate on Earth. Um, most areas of the


00:15:59.519 --> 00:16:01.030
world are missing this remarkable


00:16:01.040 --> 00:16:04.150
transition because the ancient glacias


00:16:04.160 --> 00:16:06.310
scraped and eroded the way the rocks


00:16:06.320 --> 00:16:08.790
underneath. But in Scotland, by some


00:16:08.800 --> 00:16:10.550
miracle, the transition can be seen. And


00:16:10.560 --> 00:16:12.389
I think that's underlining what you


00:16:12.399 --> 00:16:13.509
said. They were either sticking up


00:16:13.519 --> 00:16:14.870
through the ice or they weren't


00:16:14.880 --> 00:16:17.990
particularly deeply covered by ice. So,


00:16:18.000 --> 00:16:20.790
it's minerals and uh radiometric dating


00:16:20.800 --> 00:16:23.670
of the minerals that have allowed this


00:16:23.680 --> 00:16:26.150
discovery to to to be made.


00:16:26.160 --> 00:16:28.470
>> Yeah. It's incredible, isn't it? All the


00:16:28.480 --> 00:16:30.069
answers are right there in front of us


00:16:30.079 --> 00:16:31.910
in the dirt sometimes.


00:16:31.920 --> 00:16:33.269
>> Simple as that.


00:16:33.279 --> 00:16:36.230
>> That's how we it's we know so much about


00:16:36.240 --> 00:16:38.790
the history of not just our planet, but


00:16:38.800 --> 00:16:40.790
the you know, the other planets of the


00:16:40.800 --> 00:16:42.470
solar system. just learned from looking


00:16:42.480 --> 00:16:44.230
at the rocks. That's right.


00:16:44.240 --> 00:16:46.790
>> Yeah. Fantastic. Uh if you'd like to


00:16:46.800 --> 00:16:49.189
read the article or chase up that story,


00:16:49.199 --> 00:16:52.870
it's uh on the cosmosine.com


00:16:52.880 --> 00:16:55.110
website. This is Space Nuts. Andrew


00:16:55.120 --> 00:16:58.870
Dunley here with Professor Brad Watson.


00:16:58.880 --> 00:17:00.389
Let's take a break from the show to tell


00:17:00.399 --> 00:17:04.150
you about our sponsor, Anti-gravity A1.


00:17:04.160 --> 00:17:05.990
Have you ever wished you could actually


00:17:06.000 --> 00:17:08.470
feel what it's like to fly? not just


00:17:08.480 --> 00:17:10.150
control a drone from the ground, but


00:17:10.160 --> 00:17:12.949
truly experience the air around you.


00:17:12.959 --> 00:17:15.669
Well, that future has just arrived.


00:17:15.679 --> 00:17:18.470
Introducing the Anti-gravity A1, the


00:17:18.480 --> 00:17:22.390
world's first all-in-one 8K 360 drone,


00:17:22.400 --> 00:17:25.590
and it's officially available now. Uh,


00:17:25.600 --> 00:17:27.350
this isn't just another drone. It's an


00:17:27.360 --> 00:17:30.390
entirely new category. The camera is


00:17:30.400 --> 00:17:34.870
unreal. Anti-gravity A1 captures 8K full


00:17:34.880 --> 00:17:37.990
360 degree video on every flight. No


00:17:38.000 --> 00:17:40.710
missed shots, no worrying about gimbals


00:17:40.720 --> 00:17:44.230
or lining up angles. Just fly first,


00:17:44.240 --> 00:17:46.950
frame later. You can create cinematic


00:17:46.960 --> 00:17:50.630
pans, add special effects, or achieve


00:17:50.640 --> 00:17:52.870
perfectly stabilized action footage


00:17:52.880 --> 00:17:55.990
thanks to the flow state stabilization.


00:17:56.000 --> 00:17:59.029
And the whole drone weighs in at just


00:17:59.039 --> 00:18:02.950
249 g. That means travel ready,


00:18:02.960 --> 00:18:05.270
regulation friendly, and it fits in the


00:18:05.280 --> 00:18:08.150
palm of your hand. The anti-gravity A1


00:18:08.160 --> 00:18:10.230
is now available in three bundles at the


00:18:10.240 --> 00:18:12.470
anti-gravity store, Best Buy, and


00:18:12.480 --> 00:18:15.110
authorized retailers worldwide. So, if


00:18:15.120 --> 00:18:17.270
you ever wanted to rethink what a drone


00:18:17.280 --> 00:18:20.390
can be or what flight can feel like,


00:18:20.400 --> 00:18:23.110
check out the anti-gravity A1. Just


00:18:23.120 --> 00:18:26.390
visit anti-gravity.te. tech. That's


00:18:26.400 --> 00:18:28.470
anti-gravity.te


00:18:28.480 --> 00:18:31.669
for the anti-gravity A1. This is a new


00:18:31.679 --> 00:18:34.230
revolution in drone and drone


00:18:34.240 --> 00:18:37.590
photography. That's anti-gravity.te


00:18:37.600 --> 00:18:39.830
or you can tap on the link in the show


00:18:39.840 --> 00:18:41.590
notes.


00:18:41.600 --> 00:18:43.029
>> You're clear also.


00:18:43.039 --> 00:18:44.150
>> Space nuts.


00:18:44.160 --> 00:18:47.029
>> Uh speaking of dirt, Fred, uh we've got


00:18:47.039 --> 00:18:49.110
we've got the dirt on the dinosaur


00:18:49.120 --> 00:18:52.870
asteroid. We uh uh we now know thanks to


00:18:52.880 --> 00:18:55.510
a new study where it came from. This is


00:18:55.520 --> 00:18:57.029
fascinating, too.


00:18:57.039 --> 00:18:59.750
>> It it is. That's right. Uh and you know,


00:18:59.760 --> 00:19:01.830
it's not that long ago that people were


00:19:01.840 --> 00:19:04.070
really still speculating about where the


00:19:04.080 --> 00:19:07.350
remnants of this asteroid was. Uh we're


00:19:07.360 --> 00:19:09.909
now pretty certain that it's in the


00:19:09.919 --> 00:19:12.310
Chicelog Basin


00:19:12.320 --> 00:19:15.350
in the Gulf of Mexico. that that is the


00:19:15.360 --> 00:19:18.150
uh the site which uh actually was the


00:19:18.160 --> 00:19:20.950
impact site of this asteroid. So what


00:19:20.960 --> 00:19:23.270
you can do is you can look at the the


00:19:23.280 --> 00:19:26.549
rocks um that you find in that region.


00:19:26.559 --> 00:19:28.150
Once again, we're looking down at the


00:19:28.160 --> 00:19:32.230
dirt and um but basically look to see


00:19:32.240 --> 00:19:35.350
whether we know of anything like it out


00:19:35.360 --> 00:19:40.870
there in the solar system. Um and the


00:19:40.880 --> 00:19:45.190
bottom line is that yes we do find that


00:19:45.200 --> 00:19:47.990
uh in in particular and this is work


00:19:48.000 --> 00:19:49.669
being done at the University of Cologne


00:19:49.679 --> 00:19:54.789
in Germany um the uh the element


00:19:54.799 --> 00:19:56.549
ruthenium


00:19:56.559 --> 00:20:00.470
um is basically a chemical marker if I


00:20:00.480 --> 00:20:04.230
can put it that way that is found in the


00:20:04.240 --> 00:20:07.590
debris around the chicks impactor And


00:20:07.600 --> 00:20:09.750
apparently in other sediments around the


00:20:09.760 --> 00:20:11.430
world because the debris from that


00:20:11.440 --> 00:20:13.590
explosion spread all around the world.


00:20:13.600 --> 00:20:16.870
It was so, you know, such a uh such a a


00:20:16.880 --> 00:20:20.230
major uh piece of uh piece of of


00:20:20.240 --> 00:20:22.710
explosive material. It it was only


00:20:22.720 --> 00:20:24.710
explosive because it hit the ground at a


00:20:24.720 --> 00:20:27.270
very high speed, probably 30 or 40


00:20:27.280 --> 00:20:30.310
kilometers/s. Um but the the fingerprint


00:20:30.320 --> 00:20:32.549
of ruthenium has been found in that


00:20:32.559 --> 00:20:36.149
debris. And it turns out that that


00:20:36.159 --> 00:20:40.950
coincides with rocks in the the main


00:20:40.960 --> 00:20:43.430
asteroid belt. That's the region between


00:20:43.440 --> 00:20:47.510
Mars and Jupiter, but at the outer edge


00:20:47.520 --> 00:20:50.390
uh outer edge of the main asteroid belt.


00:20:50.400 --> 00:20:52.710
Not sort of not the kind of place you'd


00:20:52.720 --> 00:20:55.029
expect. You would think if the if that


00:20:55.039 --> 00:20:57.430
rock had come from uh the asteroid belt,


00:20:57.440 --> 00:20:58.549
you'd think it would be the near the


00:20:58.559 --> 00:21:01.110
inner edge, but the chemical um


00:21:01.120 --> 00:21:03.270
specifics tell you that it's actually at


00:21:03.280 --> 00:21:07.830
the outer edge. Uh and um that is really


00:21:07.840 --> 00:21:11.029
very very interesting deduction. Uh who


00:21:11.039 --> 00:21:12.470
would have thought that we we would be


00:21:12.480 --> 00:21:14.310
able to pinpoint where that asteroid


00:21:14.320 --> 00:21:17.270
came from uh 66 million years after the


00:21:17.280 --> 00:21:19.270
event. Uh and um


00:21:19.280 --> 00:21:21.430
>> maybe the asteroid I


00:21:21.440 --> 00:21:22.950
>> Yeah, I guess they worked it out on the


00:21:22.960 --> 00:21:25.110
chemical composition elements rather


00:21:25.120 --> 00:21:27.029
than backtracking.


00:21:27.039 --> 00:21:29.590
>> Yes, that's right. Um it's it we don't


00:21:29.600 --> 00:21:31.350
have enough information to backtrack. We


00:21:31.360 --> 00:21:33.510
don't know what angle it came in at or


00:21:33.520 --> 00:21:35.909
you know what its orbit was before it


00:21:35.919 --> 00:21:37.909
collided with Earth. So it's it's all


00:21:37.919 --> 00:21:40.070
about chemistry is this and um and in


00:21:40.080 --> 00:21:43.110
particular some quite uh quite


00:21:43.120 --> 00:21:44.789
sophisticated well I suppose you call it


00:21:44.799 --> 00:21:47.029
chemical physics because they're using


00:21:47.039 --> 00:21:51.029
radiation techniques uh basically to to


00:21:51.039 --> 00:21:54.630
to look for these levels of runium uh in


00:21:54.640 --> 00:21:57.590
in the basically in the debris from the


00:21:57.600 --> 00:22:01.590
uh from the um uh asteroid uh crater and


00:22:01.600 --> 00:22:06.789
and surroundings. uh and um basically uh


00:22:06.799 --> 00:22:09.669
you know looking at uh how it compares


00:22:09.679 --> 00:22:13.590
with other um asteroid impacts and


00:22:13.600 --> 00:22:16.789
carbonatous meteorites which also come


00:22:16.799 --> 00:22:18.789
from that region of the of the solar


00:22:18.799 --> 00:22:20.390
system.


00:22:20.400 --> 00:22:23.750
>> So what might have caused a rock from


00:22:23.760 --> 00:22:25.990
that particular part of the solar system


00:22:26.000 --> 00:22:28.549
to you know turn its attention to us?


00:22:28.559 --> 00:22:30.789
Did Saturn get upset and chuck a rock at


00:22:30.799 --> 00:22:33.669
us or something? is


00:22:33.679 --> 00:22:37.830
um it's probably uh it's it's probably


00:22:37.840 --> 00:22:42.950
um a a just a gravitational disturbance,


00:22:42.960 --> 00:22:47.110
you know, something that disturbed the


00:22:47.120 --> 00:22:49.830
uh orbit of this asteroid in its


00:22:49.840 --> 00:22:52.470
comfortable zone of the asteroid belt.


00:22:52.480 --> 00:22:53.990
Maybe an interaction with another


00:22:54.000 --> 00:22:56.470
asteroid because when objects come


00:22:56.480 --> 00:22:58.390
together, they needn't necessarily


00:22:58.400 --> 00:23:01.029
collide. But if they can interact with


00:23:01.039 --> 00:23:02.630
each other gravitationally so that one


00:23:02.640 --> 00:23:05.029
of them gets thrown out of of of its


00:23:05.039 --> 00:23:07.350
orbits and you know it's possible that


00:23:07.360 --> 00:23:09.909
that would have been the case. U it's


00:23:09.919 --> 00:23:11.350
kind of like being in a crowd at a


00:23:11.360 --> 00:23:14.070
Chinese supermarket. Really? That's


00:23:14.080 --> 00:23:15.750
>> that's what it's like.


00:23:15.760 --> 00:23:16.710
>> Yes. Yes.


00:23:16.720 --> 00:23:18.789
>> You didn't want to go that way but you


00:23:18.799 --> 00:23:20.310
you ended up going


00:23:20.320 --> 00:23:21.750
>> you have to you have to go that way.


00:23:21.760 --> 00:23:23.510
Yeah. Just because everything's so


00:23:23.520 --> 00:23:25.830
crowded. It's it's it's a bit like that.


00:23:25.840 --> 00:23:30.230
The um um the thing is that that event


00:23:30.240 --> 00:23:31.750
whatever tipped it out of its


00:23:31.760 --> 00:23:34.149
comfortable orbit that might have


00:23:34.159 --> 00:23:36.630
happened a long time before the 66


00:23:36.640 --> 00:23:41.110
million year date a ago uh that we for


00:23:41.120 --> 00:23:43.190
the uh for the impact for the extinction


00:23:43.200 --> 00:23:45.270
of the dinosaurs. So it might have been


00:23:45.280 --> 00:23:47.430
in a in an orbit that intersected the


00:23:47.440 --> 00:23:49.990
earth's orbit for a long long time uh


00:23:50.000 --> 00:23:52.470
before the crunch finally came when it


00:23:52.480 --> 00:23:53.830
tried to be in the same place at the


00:23:53.840 --> 00:23:56.710
same time as the earth. Uh so yes, so so


00:23:56.720 --> 00:23:58.710
we there's details for this story that


00:23:58.720 --> 00:24:02.070
we still have a long way to finding out.


00:24:02.080 --> 00:24:04.950
Um but it may well have been, as I said,


00:24:04.960 --> 00:24:07.110
it's either a collision with another uh


00:24:07.120 --> 00:24:11.190
asteroid or maybe even something like


00:24:11.200 --> 00:24:13.510
the gravitational pull of gas giants.


00:24:13.520 --> 00:24:17.830
Maybe Jupiter uh perturbed that object's


00:24:17.840 --> 00:24:19.750
orbit in such a way that it interacted


00:24:19.760 --> 00:24:21.750
with another asteroid and got got thrown


00:24:21.760 --> 00:24:24.149
out of uh thrown out of the asteroid


00:24:24.159 --> 00:24:26.310
belt. We probably will never know that.


00:24:26.320 --> 00:24:27.909
Uh it's interesting enough, I think, to


00:24:27.919 --> 00:24:30.470
to discover whereabouts it came from.


00:24:30.480 --> 00:24:32.710
>> Yes. The other thing that uh came out of


00:24:32.720 --> 00:24:36.070
this is that it all but writes off that


00:24:36.080 --> 00:24:38.070
this was a comet impact.


00:24:38.080 --> 00:24:38.470
>> Yes.


00:24:38.480 --> 00:24:41.510
>> Um but not absolutely.


00:24:41.520 --> 00:24:43.669
>> Yeah, that's right. There's still uh


00:24:43.679 --> 00:24:45.750
there's still a possibility, but you


00:24:45.760 --> 00:24:47.990
know, comets are a different beast from


00:24:48.000 --> 00:24:51.350
from asteroids. They contain lots of ice


00:24:51.360 --> 00:24:53.269
uh as well as the rock. And that means


00:24:53.279 --> 00:24:57.590
that the chemistry of the the residual


00:24:57.600 --> 00:24:59.269
material from the impact would have


00:24:59.279 --> 00:25:02.549
different properties. Uh so I think um


00:25:02.559 --> 00:25:05.750
it's uh you know you can never say never


00:25:05.760 --> 00:25:09.029
but the the the body of opinion seems to


00:25:09.039 --> 00:25:10.549
be that it was actually an asteroid


00:25:10.559 --> 00:25:11.909
rather than a comet.


00:25:11.919 --> 00:25:12.630
>> Yeah.


00:25:12.640 --> 00:25:14.789
>> I do have just one more question about


00:25:14.799 --> 00:25:16.310
this story and this is the most


00:25:16.320 --> 00:25:19.110
important one for it. most important.


00:25:19.120 --> 00:25:22.230
You mentioned the element recinium.


00:25:22.240 --> 00:25:22.549
>> Yes.


00:25:22.559 --> 00:25:24.789
>> So, was the person who discovered that


00:25:24.799 --> 00:25:28.390
named Ruth?


00:25:28.400 --> 00:25:30.149
>> Um, that's a good question. I'd have to


00:25:30.159 --> 00:25:31.830
take that one on notice, but my guess is


00:25:31.840 --> 00:25:35.669
that that's where the name came from or


00:25:35.679 --> 00:25:38.230
maybe maybe it was somebody who was


00:25:38.240 --> 00:25:39.909
ruthless.


00:25:39.919 --> 00:25:41.830
>> And they thought, "Yeah, I'll call it


00:25:41.840 --> 00:25:43.830
Runthenian because I'm ruthless." Who


00:25:43.840 --> 00:25:44.390
knows that?


00:25:44.400 --> 00:25:46.310
>> Yeah. Yeah, that's that's a thought,


00:25:46.320 --> 00:25:49.430
too. Uh that story if you would like to


00:25:49.440 --> 00:25:53.990
read it is available at space.com.


00:25:54.000 --> 00:25:55.909
>> This is Space Nuts. Andrew Dunley here


00:25:55.919 --> 00:26:01.430
with Professor Fred Watson


00:26:01.440 --> 00:26:02.630
and I feel


00:26:02.640 --> 00:26:03.830
>> space nuts.


00:26:03.840 --> 00:26:07.029
>> Uh now Fred to the so-called crisis in


00:26:07.039 --> 00:26:09.669
cosmology. We're talking about uh the


00:26:09.679 --> 00:26:12.310
the Hubble tension. Now we've we've done


00:26:12.320 --> 00:26:14.710
this story a few times over the years.


00:26:14.720 --> 00:26:18.549
This this is where the basically the


00:26:18.559 --> 00:26:21.110
expansion speed of the universe um


00:26:21.120 --> 00:26:23.990
depending on how how you calculate


00:26:24.000 --> 00:26:25.909
uh that number comes up with two


00:26:25.919 --> 00:26:27.830
different answers and they have never


00:26:27.840 --> 00:26:30.950
been able to figure out why. But now


00:26:30.960 --> 00:26:32.310
they're starting to think well there's


00:26:32.320 --> 00:26:36.549
no crisis at all. Everything's right. Um


00:26:36.559 --> 00:26:39.110
yes. So


00:26:39.120 --> 00:26:43.110
um the let me just explain how the this


00:26:43.120 --> 00:26:45.190
this tension the Hubble tension comes


00:26:45.200 --> 00:26:45.990
about.


00:26:46.000 --> 00:26:46.230
>> Yeah.


00:26:46.240 --> 00:26:48.310
>> Uh because there are there are two ways


00:26:48.320 --> 00:26:52.950
of of measuring uh the expansion of the


00:26:52.960 --> 00:26:57.510
universe. Uh one uses standard candles


00:26:57.520 --> 00:27:00.149
and the other uses a standard ruler.


00:27:00.159 --> 00:27:02.630
>> Um put it that way. So the standard


00:27:02.640 --> 00:27:05.430
candle's taking that first. Um if you


00:27:05.440 --> 00:27:07.510
know how bright your candle is, then you


00:27:07.520 --> 00:27:09.110
can work out how far away it is from


00:27:09.120 --> 00:27:12.070
you. Uh because you you you know you


00:27:12.080 --> 00:27:13.510
know it's real brightness, it's


00:27:13.520 --> 00:27:15.750
intrinsic brightness, then you can work


00:27:15.760 --> 00:27:19.830
out what is going on uh in terms of


00:27:19.840 --> 00:27:21.830
because we know the way light gets


00:27:21.840 --> 00:27:23.990
fainter. We know the rule by which light


00:27:24.000 --> 00:27:25.909
gets fainter as you move to greater and


00:27:25.919 --> 00:27:27.430
greater distances. It's what called the


00:27:27.440 --> 00:27:30.149
inverse square law. Um it it goes as the


00:27:30.159 --> 00:27:31.909
square of the distance or one over the


00:27:31.919 --> 00:27:34.390
square of the distance. So uh standard


00:27:34.400 --> 00:27:39.990
candles are usually stars in galaxies.


00:27:40.000 --> 00:27:43.430
Uh and in fact this is what uh let us


00:27:43.440 --> 00:27:45.990
detect the expansion of the universe in


00:27:46.000 --> 00:27:48.390
the first place because u in the early


00:27:48.400 --> 00:27:52.070
years of the last century around 1900 um


00:27:52.080 --> 00:27:54.870
a group of astronomers uh in the United


00:27:54.880 --> 00:27:57.190
States measured the intrinsic brightness


00:27:57.200 --> 00:27:59.110
of a particular kind of variable star.


00:27:59.120 --> 00:28:01.510
one whose brightness varies uh but it


00:28:01.520 --> 00:28:04.070
varies in a in a periodic way. And it


00:28:04.080 --> 00:28:05.590
turns out that there's a relationship


00:28:05.600 --> 00:28:08.470
between how frequently it varies and


00:28:08.480 --> 00:28:10.230
what the intrinsic brightness is. And


00:28:10.240 --> 00:28:11.750
you usually take it at peak brightness


00:28:11.760 --> 00:28:13.430
or minimum brightness, whichever it


00:28:13.440 --> 00:28:14.950
doesn't doesn't really matter as long as


00:28:14.960 --> 00:28:17.190
you know what it is. And so that's the


00:28:17.200 --> 00:28:20.310
timehonored way of working out how far


00:28:20.320 --> 00:28:23.190
away galaxies are. uh to look for these


00:28:23.200 --> 00:28:27.190
variable stars and then basically uh


00:28:27.200 --> 00:28:30.149
look at um uh you know how bright they


00:28:30.159 --> 00:28:32.230
look to us and from that work out the


00:28:32.240 --> 00:28:35.350
distance. Uh and that lets you produce a


00:28:35.360 --> 00:28:36.870
value for what we call the Hubble


00:28:36.880 --> 00:28:40.549
constant which is the number that


00:28:40.559 --> 00:28:42.149
basically tells you how fast the


00:28:42.159 --> 00:28:45.590
universe is expanding. Uh the Hubble


00:28:45.600 --> 00:28:48.310
constant is in units of kilometers/s per


00:28:48.320 --> 00:28:50.710
mega par. But we don't really need to


00:28:50.720 --> 00:28:52.070
worry about that because at the moment


00:28:52.080 --> 00:28:54.149
all we're interested in is the number.


00:28:54.159 --> 00:28:58.470
And so until now uh the best estimates


00:28:58.480 --> 00:29:00.389
uh from the standard candles in other


00:29:00.399 --> 00:29:03.510
words the sephiid variables have come


00:29:03.520 --> 00:29:07.590
out at uh about 74 kilometers/s mega


00:29:07.600 --> 00:29:10.710
parc. But then the standard ruler method


00:29:10.720 --> 00:29:13.029
is uh looking back at the flash of the


00:29:13.039 --> 00:29:14.789
big bang, the cosmic microwave


00:29:14.799 --> 00:29:17.350
background radiation which we see uh as


00:29:17.360 --> 00:29:20.230
it was about 13 billion years ago. And


00:29:20.240 --> 00:29:22.710
there are features in that variation


00:29:22.720 --> 00:29:26.149
which uh have separations that we know


00:29:26.159 --> 00:29:29.590
would be characteristic of a certain the


00:29:29.600 --> 00:29:31.269
particular time and and what we're


00:29:31.279 --> 00:29:33.110
talking about here when I say features I


00:29:33.120 --> 00:29:35.350
mean peaks and troughs in the


00:29:35.360 --> 00:29:37.110
temperature of the big bang. effectively


00:29:37.120 --> 00:29:39.830
what you're looking at. Um and from that


00:29:39.840 --> 00:29:41.990
you can also deduce the Hubble constant


00:29:42.000 --> 00:29:44.950
the expansion rate as it is today. Uh


00:29:44.960 --> 00:29:48.470
but the answer you get from that is 67.5


00:29:48.480 --> 00:29:50.950
kilometers/s per mega par.


00:29:50.960 --> 00:29:51.190
>> Yeah.


00:29:51.200 --> 00:29:53.909
>> Uh which is round about 6 and a half


00:29:53.919 --> 00:29:56.310
kilometers/s per mega par different from


00:29:56.320 --> 00:29:58.549
the other one. And that is now we're in


00:29:58.559 --> 00:30:01.269
such a precise era that now now has


00:30:01.279 --> 00:30:04.549
people worried. Um so what's happened?


00:30:04.559 --> 00:30:07.909
Well, the same team who've done a huge


00:30:07.919 --> 00:30:10.070
amount of this work in the past led by


00:30:10.080 --> 00:30:13.029
um Dr. Wendy Free Freriedman, one of the


00:30:13.039 --> 00:30:15.750
big names in this kind of science in the


00:30:15.760 --> 00:30:18.710
United States. Uh Wendy and her team


00:30:18.720 --> 00:30:23.029
have used our new toy, the web, the


00:30:23.039 --> 00:30:25.669
James Web Space Telescope. Uh


00:30:25.679 --> 00:30:27.510
>> we always knew it would it would solve


00:30:27.520 --> 00:30:28.870
this problem.


00:30:28.880 --> 00:30:30.630
>> We knew it would certainly help. It


00:30:30.640 --> 00:30:32.149
would either make it worse or it would


00:30:32.159 --> 00:30:33.990
solve it. And yeah, you're right. to cut


00:30:34.000 --> 00:30:35.830
to the chase, it's probably solved it


00:30:35.840 --> 00:30:39.750
because it's now looking as though the


00:30:39.760 --> 00:30:43.029
method um is more like that, you know,


00:30:43.039 --> 00:30:44.149
the method where you measure the


00:30:44.159 --> 00:30:46.070
brightness of these variable stars is


00:30:46.080 --> 00:30:47.510
giving an answer more like 70


00:30:47.520 --> 00:30:50.470
kilometers/s per mega parc which is much


00:30:50.480 --> 00:30:52.789
closer to that 67.5 that you get from


00:30:52.799 --> 00:30:54.149
the cosmic microwave background


00:30:54.159 --> 00:30:56.630
radiation. And it turns out that when


00:30:56.640 --> 00:30:59.269
you think about the the error uh


00:30:59.279 --> 00:31:01.510
potential error of both of them, then it


00:31:01.520 --> 00:31:04.389
overlaps. So in that regard, you've got


00:31:04.399 --> 00:31:05.909
something that falls within the error


00:31:05.919 --> 00:31:08.389
bounds of both of these methods. And so


00:31:08.399 --> 00:31:10.149
maybe we are seeing the right answer at


00:31:10.159 --> 00:31:10.630
last.


00:31:10.640 --> 00:31:12.789
>> So it it basically brings it back to an


00:31:12.799 --> 00:31:14.389
average.


00:31:14.399 --> 00:31:16.549
>> That's right. Methods. Yeah.


00:31:16.559 --> 00:31:19.190
>> Yes. Yeah. You know when I started my


00:31:19.200 --> 00:31:23.029
career, Andrew, um there were two camps


00:31:23.039 --> 00:31:25.990
uh and basically they were using similar


00:31:26.000 --> 00:31:29.430
methods. uh one said that the uh Hubble


00:31:29.440 --> 00:31:31.669
constant was 50 kilometers/s per mega


00:31:31.679 --> 00:31:33.590
per second. The other said it was 100


00:31:33.600 --> 00:31:35.830
kilometers/s per mega per second. They


00:31:35.840 --> 00:31:37.830
were both right.


00:31:37.840 --> 00:31:39.590
They thought they were both right and it


00:31:39.600 --> 00:31:41.350
turned out that the the answer the real


00:31:41.360 --> 00:31:44.389
answer was the average of the 70 or 75


00:31:44.399 --> 00:31:45.909
for that.


00:31:45.919 --> 00:31:48.549
>> There you go. Um pretty simple solution


00:31:48.559 --> 00:31:50.230
at the end of the day, but a lot of hard


00:31:50.240 --> 00:31:53.269
work went into went in finding it and we


00:31:53.279 --> 00:31:55.029
yeah we hope that's that resolves the


00:31:55.039 --> 00:31:56.389
Hubble tension. It would be great.


00:31:56.399 --> 00:31:57.190
Hopefully


00:31:57.200 --> 00:31:59.430
>> cosmic crash disappeared. Yeah.


00:31:59.440 --> 00:32:01.029
>> Yeah. I I wouldn't be surprised though


00:32:01.039 --> 00:32:03.110
in months to come somebody comes up with


00:32:03.120 --> 00:32:05.350
a debunking theory.


00:32:05.360 --> 00:32:07.029
>> Uh well, there you go.


00:32:07.039 --> 00:32:09.909
>> It could happen. It could happen. But um


00:32:09.919 --> 00:32:12.070
at this point in time, looks like it


00:32:12.080 --> 00:32:14.389
might have been resolved. This has been


00:32:14.399 --> 00:32:16.470
frustrating for a long time, but u may


00:32:16.480 --> 00:32:18.789
may be as simple as Oh, hang on a sec.


00:32:18.799 --> 00:32:20.950
>> You're both right, and here's why.


00:32:20.960 --> 00:32:21.830
>> Yeah. Yeah.


00:32:21.840 --> 00:32:23.830
>> Yeah. Um that's stories on


00:32:23.840 --> 00:32:25.590
scitecdaily.com.


00:32:25.600 --> 00:32:27.669
Um question without notice, Fred, that's


00:32:27.679 --> 00:32:29.110
come through from one of our live


00:32:29.120 --> 00:32:32.630
viewers. Uh Wayne, hi Wayne. Um this


00:32:32.640 --> 00:32:35.830
harks back to the snowball earth story


00:32:35.840 --> 00:32:38.789
we did. Uh Wayne asks, "I wonder how


00:32:38.799 --> 00:32:40.870
much bigger the diameter of a frozen


00:32:40.880 --> 00:32:43.269
earth would be to the current earth. Do


00:32:43.279 --> 00:32:45.590
we have any idea what that might have


00:32:45.600 --> 00:32:45.990
been?"


00:32:46.000 --> 00:32:48.070
>> Yeah, I it probably wasn't that much


00:32:48.080 --> 00:32:52.070
different. Um it um you know I mean at


00:32:52.080 --> 00:32:54.549
the moment a lot of that water's still


00:32:54.559 --> 00:32:56.630
there but it's wet.


00:32:56.640 --> 00:32:59.269
Uh and you know this is now it's it's


00:32:59.279 --> 00:33:02.149
turned into ice. So um it's not going to


00:33:02.159 --> 00:33:05.350
be it's certainly not going to be k um


00:33:05.360 --> 00:33:08.230
tens of kilometers different um it might


00:33:08.240 --> 00:33:10.950
be a few kilometers different um on


00:33:10.960 --> 00:33:12.230
average and I'm talking about the


00:33:12.240 --> 00:33:14.389
average uh but but I don't think it


00:33:14.399 --> 00:33:15.509
would uh you know it wouldn't have


00:33:15.519 --> 00:33:17.190
turned into a gas giant or anything like


00:33:17.200 --> 00:33:18.950
that. It's an interesting question


00:33:18.960 --> 00:33:20.549
though because we think it's because of


00:33:20.559 --> 00:33:22.950
frozen water out in the depths of the


00:33:22.960 --> 00:33:26.230
solar system adding to the mass of the


00:33:26.240 --> 00:33:28.310
gas giants as they were being formed. We


00:33:28.320 --> 00:33:30.389
think that is one reason why they became


00:33:30.399 --> 00:33:32.549
so big because they had enough bands to


00:33:32.559 --> 00:33:36.149
hold onto a a gas envelope. Um and so


00:33:36.159 --> 00:33:39.190
it's a good question to to ask that what


00:33:39.200 --> 00:33:40.870
difference would the ice make? But it


00:33:40.880 --> 00:33:42.630
but this is really just a surface layer


00:33:42.640 --> 00:33:45.110
of ice rather than a solid block of ice


00:33:45.120 --> 00:33:47.110
which may be at the core of the of the


00:33:47.120 --> 00:33:48.710
gas giants.


00:33:48.720 --> 00:33:50.470
>> Indeed. All right. Thank you, Wayne.


00:33:50.480 --> 00:33:52.149
Nice to get questions without notice


00:33:52.159 --> 00:33:54.310
while we're going out live during our


00:33:54.320 --> 00:33:56.230
recording sessions. Good to hear from


00:33:56.240 --> 00:33:58.230
you. Uh Fred, we're just about done.


00:33:58.240 --> 00:33:59.669
Thank you very much.


00:33:59.679 --> 00:34:02.470
>> A pleasure, Andrew. Good to talk and uh


00:34:02.480 --> 00:34:04.149
some interesting topics and there'll be


00:34:04.159 --> 00:34:05.750
more next week.


00:34:05.760 --> 00:34:07.509
>> Indeed there will. Thanks, Fred.


00:34:07.519 --> 00:34:08.950
Professor Fred Watson, astronomer at


00:34:08.960 --> 00:34:11.109
large. Don't forget to check us out


00:34:11.119 --> 00:34:13.030
online, spacenutspodcast.com,


00:34:13.040 --> 00:34:14.710
spacenuts.io,


00:34:14.720 --> 00:34:16.470
where you can check out the shop, maybe


00:34:16.480 --> 00:34:18.629
become a supporter of the podcast if


00:34:18.639 --> 00:34:20.950
you're interested. Um, just have a bit


00:34:20.960 --> 00:34:23.030
of a flick around. And if you follow us


00:34:23.040 --> 00:34:24.550
on social media, don't forget to like


00:34:24.560 --> 00:34:26.710
us, follow us, add us to your favorites


00:34:26.720 --> 00:34:28.790
list, or click the subscribe button


00:34:28.800 --> 00:34:32.149
depending on which platform it is. Uh,


00:34:32.159 --> 00:34:34.629
and uh, thanks to Hugh in the studio as


00:34:34.639 --> 00:34:36.310
always. And from me, Andrew Dunley, we


00:34:36.320 --> 00:34:38.790
will see you again soon on the very next


00:34:38.800 --> 00:34:41.349
episode of Space Nuts. Bye-bye.


00:34:41.359 --> 00:34:42.389
>> Space Nuts.


00:34:42.399 --> 00:34:44.470
>> You'll be listening to the Space Nuts


00:34:44.480 --> 00:34:46.710
podcast


00:34:46.720 --> 00:34:49.669
>> available at Apple Podcasts, Spotify,


00:34:49.679 --> 00:34:52.310
iHeart Radio, or your favorite podcast


00:34:52.320 --> 00:34:54.470
player. You can also stream on demand


00:34:54.480 --> 00:34:56.149
ates.com.


00:34:56.159 --> 00:34:58.150
This has been another quality podcast


00:34:58.160 --> 00:35:02.119
production from byes.com.