00:00:00 --> 00:00:02 Stuart Gary: This is space time series 29, episode 80
00:00:02 --> 00:00:05 for broadcast on 6 July 2026.
00:00:06 --> 00:00:09 Coming up on Space Time, did ancient
00:00:09 --> 00:00:11 asteroid impacts prevent Earth's continents
00:00:11 --> 00:00:14 from forming? Could the ice giants Uranus and
00:00:14 --> 00:00:17 Neptune really be magma worlds? And the
00:00:17 --> 00:00:20 world's biggest atom smasher, uh, powers down
00:00:20 --> 00:00:23 all that and more coming up on, uh, Space
00:00:23 --> 00:00:26 Time. Welcome to
00:00:26 --> 00:00:28 Space Time with Stuart G.
00:00:44 --> 00:00:44 Jonathan Nally: Uh.
00:00:44 --> 00:00:47 Stuart Gary: A new study suggests that the barrage of
00:00:47 --> 00:00:48 asteroid impacts that slammed into the
00:00:48 --> 00:00:51 ancient Earth during the hadean aeon between
00:00:51 --> 00:00:53 4.6 and 4 billion years ago may have
00:00:53 --> 00:00:56 prevented the formation of the planet's first
00:00:56 --> 00:00:58 continents. The findings reported in the
00:00:58 --> 00:01:01 journal Nature, suggest that these collisions
00:01:01 --> 00:01:03 may have been the dominating force shaping
00:01:03 --> 00:01:03 the Earth.
00:01:03 --> 00:01:04 Jonathan Nally: Early Earth.
00:01:05 --> 00:01:07 Stuart Gary: The continuous reign of asteroid, comet and
00:01:07 --> 00:01:09 meteor impacts during this chaotic period
00:01:09 --> 00:01:12 delivered vast amounts of heat to the
00:01:12 --> 00:01:14 planet's interior, delaying the formation of
00:01:14 --> 00:01:17 stable continental crust. The study's
00:01:17 --> 00:01:19 lead author, Timms uh Johnson from Curtin
00:01:19 --> 00:01:21 University, says the Earth was hit far more
00:01:21 --> 00:01:24 frequently back then than today, with each
00:01:24 --> 00:01:26 impact injecting energy deep into the planet.
00:01:27 --> 00:01:29 Johnson says rather than a relatively stable
00:01:29 --> 00:01:32 early planet, the findings point to a much
00:01:32 --> 00:01:34 hotter, weaker, more unstable Earth. Uh, the
00:01:34 --> 00:01:37 new research challenges the idea that large
00:01:37 --> 00:01:40 impacts were brief events. Johnson
00:01:40 --> 00:01:41 says all you have to do is look at the Moon.
00:01:41 --> 00:01:44 It preserves evidence of violent times in the
00:01:44 --> 00:01:46 early solar system. And those impacts carried
00:01:46 --> 00:01:49 enormous amounts of energy and that energy
00:01:49 --> 00:01:51 had to go somewhere. He says the extra heat
00:01:51 --> 00:01:53 from impacts would have kept much of the
00:01:53 --> 00:01:56 early crust of the Earth weak and partly
00:01:56 --> 00:01:58 molten, making it difficult for rocks to
00:01:58 --> 00:02:01 survive. At the same time, those conditions
00:02:01 --> 00:02:03 would have helped produce more silica rich
00:02:03 --> 00:02:05 crust, which would go on to become the
00:02:05 --> 00:02:08 foundations of today's continents. The
00:02:08 --> 00:02:10 modelling shows the effects of impacts
00:02:10 --> 00:02:12 extended far beyond the moment of collision.
00:02:13 --> 00:02:15 See, on the early Earth, much of the energy
00:02:15 --> 00:02:17 would have been transferred into the planet's
00:02:17 --> 00:02:20 mantle as heat. And that would have caused
00:02:20 --> 00:02:22 the mantle beneath and around the impact site
00:02:22 --> 00:02:25 to rise and melt, producing huge volumes of
00:02:25 --> 00:02:27 magma. The study's results suggest that the
00:02:27 --> 00:02:30 early crust was thin and unstable for much of
00:02:30 --> 00:02:33 the Hadean. Impacts would have helped keep
00:02:33 --> 00:02:35 the crust hot, weak and mobile, while driving
00:02:35 --> 00:02:38 melting and recycling on the planetary scales
00:02:38 --> 00:02:40 for tens to hundreds of millions of years.
00:02:41 --> 00:02:43 The findings also help explain why almost no
00:02:43 --> 00:02:46 rock survived from the first 500 million
00:02:46 --> 00:02:48 years of Earth's history, and why the long
00:02:48 --> 00:02:50 lived continents appear to have formed only
00:02:50 --> 00:02:53 after the intensity of impacts started to
00:02:53 --> 00:02:56 decline. Johnson says it's apparent from the
00:02:56 --> 00:02:59 Moon that by around 3.9 billion years ago,
00:02:59 --> 00:03:01 the global effect of impact heating became
00:03:01 --> 00:03:04 much less Important, which is also around the
00:03:04 --> 00:03:06 same time as Earth began to preserve
00:03:06 --> 00:03:09 continental crust. And that all seems
00:03:09 --> 00:03:11 unlikely to have simply been a coincidence.
00:03:11 --> 00:03:14 Jonathan Nally: I've been thinking about the role of
00:03:14 --> 00:03:16 impacts on the Earth for uh, around about a
00:03:16 --> 00:03:19 decade or so now. And it really started when
00:03:19 --> 00:03:21 I started working on the Moon with a
00:03:21 --> 00:03:23 colleague and did a little bit of work
00:03:23 --> 00:03:25 calculating how the Moon would have
00:03:25 --> 00:03:27 crystallised from a month to what we see
00:03:27 --> 00:03:30 today. And of course we've spent an awful lot
00:03:30 --> 00:03:32 of time and effort and brain power thinking
00:03:32 --> 00:03:35 about the Moon and it's probably one of our
00:03:35 --> 00:03:37 finest achievements is to send people there
00:03:38 --> 00:03:39 to collect rocks. So we have some
00:03:39 --> 00:03:42 quantitative, lots of quantitative data from
00:03:42 --> 00:03:44 the Moon so we know how old the surface is,
00:03:44 --> 00:03:47 which is mainly older than 4 billion years.
00:03:47 --> 00:03:50 So Hadean and you just need to look at
00:03:50 --> 00:03:52 that surface and look at them and you can see
00:03:52 --> 00:03:55 what was going on at that time. It was impact
00:03:55 --> 00:03:58 everywhere. There's not 10 square metres of
00:03:58 --> 00:04:00 the Moon that hasn't been hit by an impact
00:04:00 --> 00:04:02 and most of it has been hit many times by
00:04:02 --> 00:04:05 impacts. So working out what was happening in
00:04:05 --> 00:04:08 the Hadean aeon on Earth is very
00:04:08 --> 00:04:11 difficult because Earth has very efficient
00:04:11 --> 00:04:13 engines, plate tectonic of recycling
00:04:13 --> 00:04:16 that surface. So we don't see this record
00:04:16 --> 00:04:18 that we see on the Moon, but you can't just
00:04:18 --> 00:04:21 wish it away. It did happen. And we need
00:04:21 --> 00:04:23 to think about what the effects of those
00:04:23 --> 00:04:26 hugely energetic events was on Earth, uh in
00:04:26 --> 00:04:28 terms of individual impacts, but also in
00:04:28 --> 00:04:31 terms of the accumulated energy. And
00:04:31 --> 00:04:33 that's really what this paper is, is
00:04:34 --> 00:04:36 accumulation of those thoughts over quite
00:04:36 --> 00:04:37 some time.
00:04:37 --> 00:04:40 Stuart Gary: So it's not just a case of the Earth, uh,
00:04:40 --> 00:04:42 starting off as a molten uh, sea following
00:04:42 --> 00:04:45 the Theia uh, proto Earth impact which formed
00:04:45 --> 00:04:47 the Moon and then slowly cooling. But there
00:04:47 --> 00:04:49 being lots of radioactive elements within the
00:04:49 --> 00:04:51 Earth that keeps it warm. But additional heat
00:04:51 --> 00:04:52 came from all these impacts.
00:04:52 --> 00:04:55 Jonathan Nally: Exactly. So people have been trying to
00:04:55 --> 00:04:58 understand the thermal evolution of Earth uh
00:04:58 --> 00:05:00 for a very long time. And as you said
00:05:00 --> 00:05:03 there's various sources of energy, there is
00:05:03 --> 00:05:05 radioactive decay. So very early on there
00:05:05 --> 00:05:08 would have been short lived isotopes like
00:05:08 --> 00:05:11 aluminium 26 which would have been a really
00:05:11 --> 00:05:14 big source in the early stages,
00:05:14 --> 00:05:16 in the first few tens of millions of years.
00:05:16 --> 00:05:18 And then you have the leftover energy of
00:05:18 --> 00:05:20 accretion of uh, actual coming together.
00:05:21 --> 00:05:23 And as uh, cooled down from its
00:05:23 --> 00:05:26 molten or semi molten form, we know the
00:05:26 --> 00:05:29 core would have formed. And as that core
00:05:29 --> 00:05:31 starts crystallising that provides some
00:05:31 --> 00:05:33 energy as well. But people have been trying
00:05:33 --> 00:05:36 to solve this equation really of the Heat
00:05:36 --> 00:05:38 energy of the Earth. Only thinking about
00:05:38 --> 00:05:41 these internal sources and
00:05:41 --> 00:05:44 you can't do it, but you can reconcile that
00:05:44 --> 00:05:46 energy budget if you think about the energy
00:05:46 --> 00:05:48 coming from outside, which is in the form of
00:05:48 --> 00:05:51 impacts of course. And we can see
00:05:51 --> 00:05:54 statistically at least the impact the Earth
00:05:54 --> 00:05:57 uh, would have endured if you just scale up
00:05:57 --> 00:05:59 what we've looked at from the Moon. So I
00:05:59 --> 00:06:01 think it's a pretty robust way of thinking
00:06:01 --> 00:06:01 about the earlier.
00:06:01 --> 00:06:04 Stuart Gary: And not only do the timescales match the Late
00:06:04 --> 00:06:07 Heavy Bombardment, when a lot of the craters
00:06:07 --> 00:06:09 we see on the Moon and other celestial bodies
00:06:09 --> 00:06:11 were formed, it also matches current
00:06:11 --> 00:06:14 thinking, current hypotheses regarding when
00:06:14 --> 00:06:16 the first continents began to form.
00:06:16 --> 00:06:17 Tim Mendham: That's exactly right.
00:06:17 --> 00:06:19 Jonathan Nally: So continental crust, these pale coloured
00:06:19 --> 00:06:22 granitic rocks that characterise all the land
00:06:22 --> 00:06:24 masses that sit above the water, the
00:06:24 --> 00:06:26 continents that we live on. We know the
00:06:26 --> 00:06:29 oldest continental rock that we have is
00:06:29 --> 00:06:31 about 4 billion years old. That's in the
00:06:31 --> 00:06:34 Acasta Gneiss Complex in Canada. But
00:06:35 --> 00:06:37 shortly after that large tracts of
00:06:37 --> 00:06:39 continent continental crust started appearing
00:06:39 --> 00:06:42 in what is now southwest Greenland and then
00:06:43 --> 00:06:45 in the Pilbara in native Australia of course
00:06:45 --> 00:06:48 and the Cap Val in southern Africa. So yes,
00:06:48 --> 00:06:50 we have almost no record for the first half a
00:06:50 --> 00:06:53 billion years of Earth history. And then the
00:06:53 --> 00:06:56 continents all start popping up together. And
00:06:56 --> 00:06:59 I think that is a very simple first
00:06:59 --> 00:07:02 order observation that requires some
00:07:02 --> 00:07:04 explanation. Now I'll challenge you slightly
00:07:04 --> 00:07:07 on the idea of the Late Heavy Bombardment. It
00:07:07 --> 00:07:10 has been a very popular idea that many of the
00:07:10 --> 00:07:13 ages that it's based on are uh, so called
00:07:13 --> 00:07:15 argon, Argon ages that we now know
00:07:15 --> 00:07:18 are quite easily reset by impacts.
00:07:19 --> 00:07:21 And if we look at the zircon record which is
00:07:21 --> 00:07:24 much more robust in terms of the older
00:07:24 --> 00:07:27 events, it seems more likely that we
00:07:27 --> 00:07:29 had an exponential decay of
00:07:29 --> 00:07:32 impacts from 4.5 to about
00:07:32 --> 00:07:35 3.8 or 3.5 and there
00:07:35 --> 00:07:37 might have been a spike in that impact
00:07:38 --> 00:07:41 flux around about 3.9 which
00:07:41 --> 00:07:43 as you know, as you call the Late Heavy
00:07:43 --> 00:07:45 Bombardment. But I think people, think many
00:07:45 --> 00:07:47 people would say that that was a ah, minor
00:07:47 --> 00:07:50 event on top of a overall exponential
00:07:50 --> 00:07:52 decline. But like many other things it's
00:07:52 --> 00:07:54 difficult to prove these things. It's so long
00:07:54 --> 00:07:55 ago and there's so little evidence.
00:07:55 --> 00:07:57 Stuart Gary: Well Jupiter didn't move to its current
00:07:57 --> 00:07:59 orbital position overnight. It took a while
00:07:59 --> 00:08:00 to get there.
00:08:00 --> 00:08:03 Jonathan Nally: Oh absolutely agreed. I'm a fan of
00:08:03 --> 00:08:05 the swapping over of, I can't remember what
00:08:05 --> 00:08:06 the name of that theory is.
00:08:07 --> 00:08:09 Stuart Gary: Uh, uh, starts with this model and then
00:08:09 --> 00:08:12 forgets to the uh, JTAC yes, yes, thank you.
00:08:12 --> 00:08:14 Jonathan Nally: So yes, I'm very happy that that happened. I
00:08:14 --> 00:08:17 just don't think. And that would have
00:08:17 --> 00:08:20 perturbed uh, droid belt. There would have
00:08:20 --> 00:08:22 been no doubt an increase in the flux of
00:08:22 --> 00:08:23 impacts, but I think it would have been a
00:08:23 --> 00:08:26 relatively minor uh, additional contribution
00:08:26 --> 00:08:29 on top of the overall pattern. But as I say,
00:08:29 --> 00:08:31 you know, who knows what the truth will turn
00:08:31 --> 00:08:32 out to be if we can find it.
00:08:32 --> 00:08:34 Stuart Gary: Tell us more about the Hadean period.
00:08:34 --> 00:08:37 Jonathan Nally: So that the Hadean period in our view and
00:08:37 --> 00:08:39 consistent with our result was a period where
00:08:39 --> 00:08:42 the Earth would have been very, very hot
00:08:42 --> 00:08:45 due to this impact heat. And that super
00:08:45 --> 00:08:47 hot mantle means that the crust
00:08:48 --> 00:08:50 would only have been able to get a few
00:08:50 --> 00:08:52 kilomet, perhaps five kilometres in
00:08:52 --> 00:08:54 thickness. Now other people, up until
00:08:55 --> 00:08:57 now people have usually considered the
00:08:57 --> 00:09:00 Hadean either as a planet not
00:09:00 --> 00:09:03 unlike our modern Earth, uh, so there was
00:09:03 --> 00:09:06 certainly water on the planet in Hadean, but
00:09:06 --> 00:09:08 some would consider that the Earth uh, cooled
00:09:08 --> 00:09:11 down very rapidly and was able to go into a
00:09:11 --> 00:09:14 plate tectonic mode of
00:09:14 --> 00:09:16 geodynamics if you like, not the same as, but
00:09:16 --> 00:09:19 similar to what we see today. And the other
00:09:19 --> 00:09:21 idea, end member idea anyway, is
00:09:21 --> 00:09:23 that the Earth was, because it was much
00:09:23 --> 00:09:26 hotter, these things called mantle plumes
00:09:26 --> 00:09:27 would have been much more common. So they're
00:09:27 --> 00:09:30 these like lava lamp things that raise from
00:09:30 --> 00:09:32 deep within the Earth sort of bubbles of heat
00:09:32 --> 00:09:34 that raise up to the surface and then they
00:09:34 --> 00:09:37 drive all the tectonics and magnetism at uh,
00:09:37 --> 00:09:39 the surface. But both those models, even
00:09:39 --> 00:09:41 though they're very different, they're both
00:09:41 --> 00:09:43 just thinking about the internal energy,
00:09:43 --> 00:09:45 whereas when you think about the impact
00:09:45 --> 00:09:48 energy, the Hadean looks very different. So
00:09:48 --> 00:09:51 we would have had a thin, very thin crust.
00:09:51 --> 00:09:52 There would have been more or less continuous
00:09:52 --> 00:09:55 basaltic magnetism. So dark coloured
00:09:55 --> 00:09:58 magnetism, volcanism we see at Illawaya,
00:09:58 --> 00:10:01 Hawaii, those sorts of places. And the
00:10:01 --> 00:10:04 ocean would have been very iron rich, so it
00:10:04 --> 00:10:06 probably would have been a murky greenish
00:10:06 --> 00:10:09 colour. And the atmosphere, no oxygen of
00:10:09 --> 00:10:11 course, and lots of carbon monoxide and
00:10:11 --> 00:10:13 dioxide. Um, so that probably would have been
00:10:13 --> 00:10:16 a dull sort of orangey brown hue.
00:10:16 --> 00:10:18 Of course there's no life around, so it would
00:10:18 --> 00:10:20 have. The Heidean would have looked very,
00:10:20 --> 00:10:23 very odd. Not at all like the modern planet
00:10:23 --> 00:10:23 in my view.
00:10:23 --> 00:10:25 Stuart Gary: Apart from the water issue, you're really
00:10:25 --> 00:10:27 sou. Like you're describing Venus today.
00:10:28 --> 00:10:31 Jonathan Nally: Exactly, yes. And I think once we get smart
00:10:31 --> 00:10:33 enough to do it and we're getting close now,
00:10:33 --> 00:10:36 I think we will find continents on Venus.
00:10:36 --> 00:10:39 They won't be quite the Same as on Earth, but
00:10:39 --> 00:10:41 we will definitely find some buoyant evolved
00:10:41 --> 00:10:43 crust in my opinion. But let's wait to see
00:10:43 --> 00:10:46 what the next few years or decades bring.
00:10:46 --> 00:10:48 Stuart Gary: That's Professor Timms Johnson from Curtin
00:10:48 --> 00:10:51 University. And this is space time
00:10:51 --> 00:10:54 still to come. Could the ice giants Uranus
00:10:54 --> 00:10:57 and Neptune actually be magma worlds? And
00:10:57 --> 00:10:59 the world's most powerful atom smasher, a
00:10:59 --> 00:11:01 large hadron collider, uh, has been shut
00:11:01 --> 00:11:04 down. All that and more still to come
00:11:04 --> 00:11:05 on space time.
00:11:11 --> 00:11:13 A new study suggests that the solar system's
00:11:13 --> 00:11:16 two ice giants, Uranus and Neptune, might
00:11:16 --> 00:11:19 actually be magma worlds. The findings,
00:11:19 --> 00:11:21 reported on the pre press physics website
00:11:21 --> 00:11:24 arXiv.org and submitted for publication in
00:11:24 --> 00:11:25 the Astrophysical Journal are, uh, based on
00:11:25 --> 00:11:28 new computer simulations by astronomers at
00:11:28 --> 00:11:30 the University of California, Los Angeles.
00:11:31 --> 00:11:33 Uranus and Neptune are uh, two of the most
00:11:33 --> 00:11:35 mysterious worlds in the solar system because
00:11:35 --> 00:11:37 only one spacecraft has ever visited them.
00:11:37 --> 00:11:40 That's NASA's Voyager 2 swooping by
00:11:40 --> 00:11:43 Uranus in 1986 and Neptune in
00:11:43 --> 00:11:46 1989. Their classification
00:11:46 --> 00:11:49 as ice giants is based on the hypothesis that
00:11:49 --> 00:11:51 their gaseous hydrogen helium atmospheres
00:11:51 --> 00:11:54 cover a vast layered icy mantle composed
00:11:54 --> 00:11:57 of water, ammonia and methane surrounding a
00:11:57 --> 00:12:00 small rocky core. Problem is,
00:12:00 --> 00:12:02 studies of both ice giants, magnetic fields
00:12:02 --> 00:12:05 and heat distribution have puzzled scientists
00:12:05 --> 00:12:07 because they don't fit in comfortably with
00:12:07 --> 00:12:09 that hypothesis. So to work out what's
00:12:09 --> 00:12:12 actually going on, the authors used a series
00:12:12 --> 00:12:14 of computer models to simulate the likely
00:12:14 --> 00:12:17 internal compositions and process inside
00:12:17 --> 00:12:20 both Uranus and Neptune. The new simulation
00:12:20 --> 00:12:22 suggests that the interiors of Uranus and
00:12:22 --> 00:12:24 Neptune are uh, composed of a magma ocean as
00:12:24 --> 00:12:26 opposed to an icy composition. The
00:12:26 --> 00:12:29 planetary layers this new study proposes
00:12:29 --> 00:12:31 includes the hydrogen helium atmosphere,
00:12:31 --> 00:12:33 which then transports heat to the upper
00:12:33 --> 00:12:35 atmosphere and radiates that into space.
00:12:35 --> 00:12:38 Below this is a boundary layer composed of
00:12:38 --> 00:12:41 hydrogen, helium, magnesium, silicon monoxide
00:12:41 --> 00:12:44 and oxygen. And at the base is a
00:12:44 --> 00:12:47 magma ocean composed of silicate, iron and
00:12:47 --> 00:12:50 hydrogen. The authors admit that
00:12:50 --> 00:12:52 while this is just one of a number of models
00:12:52 --> 00:12:54 that successfully reproduced the observations
00:12:54 --> 00:12:57 featured on Uranus and Neptune, it does have
00:12:57 --> 00:12:59 several features in its favour, including the
00:12:59 --> 00:13:02 connection with other gas planets. They say
00:13:02 --> 00:13:04 it's not clear why gas giants and sub
00:13:04 --> 00:13:06 neptunes should be fundamentally different
00:13:06 --> 00:13:08 simply because of their distance from their
00:13:08 --> 00:13:11 host star. The new findings could
00:13:11 --> 00:13:13 act as analogues for so called sub Neptune
00:13:13 --> 00:13:16 exoplanets, I.e. planets orbiting other stars
00:13:16 --> 00:13:19 which have radii, uh, between 1 and 4.5 times
00:13:19 --> 00:13:21 that of the Earth. And that's important
00:13:21 --> 00:13:23 because sub Neptune planets are the most
00:13:23 --> 00:13:26 common type of exoplanet in our galaxy. Yet
00:13:26 --> 00:13:28 There are no similar planets in our solar
00:13:28 --> 00:13:31 system and so their formation and evolution
00:13:31 --> 00:13:34 remains a mystery. This is space
00:13:34 --> 00:13:37 time. Still to come. The world's biggest
00:13:37 --> 00:13:39 atom smasher powers down. And later in the
00:13:39 --> 00:13:42 Science report, a new study shows that
00:13:42 --> 00:13:44 artificial nighttime lighting has now made
00:13:44 --> 00:13:47 planet Earth some 16% brighter at
00:13:47 --> 00:13:49 nights. All that and more still to come
00:13:50 --> 00:13:51 on, uh, space time.
00:14:00 --> 00:14:00 Tim Mendham: Foreign.
00:14:08 --> 00:14:11 Stuart Gary: Smasher has been shut down for a four year
00:14:11 --> 00:14:13 major refit. It's the third major
00:14:13 --> 00:14:15 scheduled shutdown for the Large Hadron
00:14:15 --> 00:14:17 Collider, the giant particle accelerator
00:14:17 --> 00:14:20 beneath the Franco Swiss border near Geneva.
00:14:20 --> 00:14:23 The facility, which is operated by cern, the
00:14:23 --> 00:14:25 European Organisation for Nuclear Research,
00:14:25 --> 00:14:28 accelerates packets of subatomic particles at
00:14:28 --> 00:14:31 speeds of up to 99% the
00:14:31 --> 00:14:34 speed in two 27 kilometres long
00:14:34 --> 00:14:36 circular pipes guided by cryogenically
00:14:36 --> 00:14:39 cooled superconducting magnets. The beams
00:14:39 --> 00:14:41 can then be crossed at four particle
00:14:41 --> 00:14:44 detectors, atlas, alice, CMS
00:14:45 --> 00:14:47 and lhcb. Each of these
00:14:47 --> 00:14:50 detectors are located in a giant cathedral
00:14:50 --> 00:14:53 sized cavern. There the particle packets
00:14:53 --> 00:14:55 can collide, producing pressures and
00:14:55 --> 00:14:57 temperatures similar to those generated in
00:14:57 --> 00:15:00 the moments after the Big Bang 13.8 billion
00:15:00 --> 00:15:03 years ago. The debris produced by those
00:15:03 --> 00:15:05 collisions provide new windows into the
00:15:05 --> 00:15:07 fundamental laws of nature behind the
00:15:07 --> 00:15:09 standard model of particle physics, the
00:15:09 --> 00:15:11 foundation stone of science's understanding
00:15:11 --> 00:15:14 of the universe. It was the Large Hadron
00:15:14 --> 00:15:16 Collider, which in 2012 enabled scientists to
00:15:16 --> 00:15:19 discover the Higgs boson, a force particle
00:15:19 --> 00:15:21 which gives mass to all the other particles
00:15:21 --> 00:15:23 through its all pervasive Higgs field. In the
00:15:23 --> 00:15:25 years that followed, the Large Hadron
00:15:25 --> 00:15:28 Collider enabled hundreds of major advances,
00:15:28 --> 00:15:30 including the discovery of more than 85
00:15:30 --> 00:15:32 hadron hadrons, which are composite subatomic
00:15:32 --> 00:15:34 particles made up of quarks held together by
00:15:34 --> 00:15:37 the strong nuclear force. It also set
00:15:37 --> 00:15:39 exclusion limits on the discovery of new
00:15:39 --> 00:15:41 particles, undertook searches into the
00:15:41 --> 00:15:44 imbalance between matter and antimatter,
00:15:44 --> 00:15:47 explored the nature of the quark gluon plasma
00:15:47 --> 00:15:48 which existed at the start of the universe,
00:15:49 --> 00:15:51 and searched for signs of that mysterious
00:15:51 --> 00:15:53 substance called dark matter.
00:15:54 --> 00:15:57 This so called high luminosity upgrade will
00:15:57 --> 00:15:59 increase the collider's luminosity by a
00:15:59 --> 00:16:00 factor of up to 10 beyond its original
00:16:00 --> 00:16:02 design, improving its ability ability to
00:16:02 --> 00:16:05 generate high quality data. See in particle
00:16:05 --> 00:16:08 physics, luminosity measures the rate of
00:16:08 --> 00:16:11 particle collisions over time. So higher
00:16:11 --> 00:16:13 luminosity increases opportunities to detect
00:16:13 --> 00:16:15 rare phenomena, providing clues to new
00:16:15 --> 00:16:18 physics beyond the standard model. Currently,
00:16:18 --> 00:16:20 the collider's detectors record around 60
00:16:20 --> 00:16:23 proton proton interactions during each
00:16:23 --> 00:16:25 collision. The upgrade will increase that to
00:16:25 --> 00:16:28 between 140 and 200. It
00:16:28 --> 00:16:31 will also allow the generation of up to 380
00:16:31 --> 00:16:33 million Higgs bosons, a substantial increase
00:16:33 --> 00:16:36 in the roughly 55 million that have been
00:16:36 --> 00:16:38 produced since the collider first began
00:16:38 --> 00:16:40 operations. A key objective of the
00:16:40 --> 00:16:43 upgrade will involve detecting rare events
00:16:43 --> 00:16:45 where two Higgs bosons are created
00:16:45 --> 00:16:47 simultaneously. That would allow deeper
00:16:47 --> 00:16:49 insights into the behaviour of the Higgs
00:16:49 --> 00:16:51 field and offer a new glimpse into the
00:16:51 --> 00:16:53 conditions of the early universe following
00:16:53 --> 00:16:56 the Big Bang. The shutdown won't
00:16:56 --> 00:16:58 be a small event. It will involve thousands
00:16:58 --> 00:17:00 of scientists, engineers and technicians
00:17:00 --> 00:17:03 replacing major detector components,
00:17:03 --> 00:17:05 including the injectors, installing new
00:17:05 --> 00:17:08 timing systems and upgrading over 1.2
00:17:08 --> 00:17:10 kilometres of superconducting magnets.
00:17:10 --> 00:17:13 Technicians will also use this opportunity to
00:17:13 --> 00:17:15 carry out essential renovation projects
00:17:15 --> 00:17:17 across the entire accelerator complex and
00:17:17 --> 00:17:19 experimental facilities. From the
00:17:19 --> 00:17:21 consolidation of the new super proton
00:17:21 --> 00:17:23 synchrotron north area area, the dismantling
00:17:23 --> 00:17:26 of the CERN neutrinos de Gran Sasso target
00:17:26 --> 00:17:28 area, and the transformation of the
00:17:28 --> 00:17:30 experimental cavern north three into a high
00:17:30 --> 00:17:33 intensity fixed target facility. It's all
00:17:33 --> 00:17:36 going to be very exciting and potentially
00:17:36 --> 00:17:38 completely change our, uh, understanding of
00:17:38 --> 00:17:41 the universe. This is space, time.
00:17:57 --> 00:17:58 And time. Now to take a brief look at some of
00:17:58 --> 00:18:00 the other storeys making news in Science this
00:18:00 --> 00:18:02 week with a Science report.
00:18:02 --> 00:18:05 A new study has found that for each extra
00:18:05 --> 00:18:07 hour of prolonged uninterrupted sedentary
00:18:07 --> 00:18:09 behaviour in a person's day, there's an
00:18:09 --> 00:18:12 additional 9% higher risk of death by
00:18:12 --> 00:18:14 cancer. Uh, the findings reported in the
00:18:14 --> 00:18:16 journal Plosmedicine are, uh, based on an
00:18:16 --> 00:18:19 analysis of Data from over 90 UK
00:18:19 --> 00:18:21 Biobuts bank participants who wore activity
00:18:21 --> 00:18:23 monitors for a week and were then followed up
00:18:23 --> 00:18:26 for around 12 years. Prolonged sedentary
00:18:26 --> 00:18:28 behaviour, described as 30 minutes or more,
00:18:28 --> 00:18:31 during which at least 90% of the time spent
00:18:31 --> 00:18:33 sedentary was linked to a higher risk of
00:18:33 --> 00:18:35 cancer incidence and death. Obesity related
00:18:35 --> 00:18:38 cancers and type 2 diabetes related cancers.
00:18:39 --> 00:18:41 Interrupted sedentary behaviour which lasts
00:18:41 --> 00:18:43 less than 30 minutes or was broken up with
00:18:43 --> 00:18:46 more than 10% non sedentary time, showed the
00:18:46 --> 00:18:48 opposite pattern with lower risks of cancer
00:18:48 --> 00:18:50 across all outcomes.
00:18:51 --> 00:18:54 A review looking at billions of doses of
00:18:54 --> 00:18:56 MRNA vaccines has found that the current
00:18:56 --> 00:18:59 vaccinations are both safe and highly
00:18:59 --> 00:19:02 effective. When first introduced, it was
00:19:02 --> 00:19:04 concerned that MRNA vaccines could cause
00:19:04 --> 00:19:07 alterations to people's genetic codes.
00:19:07 --> 00:19:09 The new research by scientists from the
00:19:09 --> 00:19:11 University of British Columbia found the
00:19:11 --> 00:19:13 vaccines protected against COVID 19,
00:19:13 --> 00:19:15 including severe Covid in a range of
00:19:15 --> 00:19:18 populations including children, pregnant
00:19:18 --> 00:19:20 women and the immunocompromised. They also
00:19:20 --> 00:19:23 found that serious side effects were rare and
00:19:23 --> 00:19:25 were substantially outweighed by protection
00:19:25 --> 00:19:27 against severe disease, hospitalisation and
00:19:27 --> 00:19:30 death. The authors also highlighted the
00:19:30 --> 00:19:32 potential of MRNA vaccines to treat and
00:19:32 --> 00:19:35 prevent other conditions such as cancer, RSV
00:19:35 --> 00:19:38 and the flu. A new
00:19:38 --> 00:19:41 study using satellite data has found that
00:19:41 --> 00:19:43 artificial nighttime lighting has made planet
00:19:43 --> 00:19:46 Earth 16 times brighter. Uh, what it used to
00:19:46 --> 00:19:48 be. The findings, based on data from
00:19:48 --> 00:19:51 2014 to 2022, are reported in the
00:19:51 --> 00:19:54 journal Nature and include more than 1.1
00:19:54 --> 00:19:57 million individual satellite images. The
00:19:57 --> 00:19:59 authors say the growth in artificial light
00:19:59 --> 00:20:02 has outpaced population growth. They also
00:20:02 --> 00:20:04 found changes in brightness were volatile,
00:20:04 --> 00:20:06 with both brightening and dimming, indicating
00:20:06 --> 00:20:07 periods of construction and demolition,
00:20:08 --> 00:20:10 energy instability such as grid failures in
00:20:10 --> 00:20:12 Venezuela, fossil fuel production and
00:20:12 --> 00:20:15 societal disruption such as conflicts in the
00:20:15 --> 00:20:18 Middle East. A new study has
00:20:18 --> 00:20:19 found that sending an electric current
00:20:19 --> 00:20:22 through black coffee provides a quick and
00:20:22 --> 00:20:23 simple way of measuring its strength and
00:20:23 --> 00:20:26 roast. The findings, reported in the journal
00:20:26 --> 00:20:28 Nature Communications, claims the test
00:20:28 --> 00:20:30 involves applying voltage to coffee and
00:20:30 --> 00:20:32 measuring the current passed through it as it
00:20:32 --> 00:20:34 responds to the electric field, which allows
00:20:34 --> 00:20:36 differences in strength and roast to be
00:20:36 --> 00:20:39 calculated. It seems the strength of coffee
00:20:39 --> 00:20:41 increases or becomes darker the less
00:20:41 --> 00:20:44 electrical charge is generated. The authors
00:20:44 --> 00:20:46 say this weakening of the current is due to
00:20:46 --> 00:20:49 coffee molecules such as caffeine sticking to
00:20:49 --> 00:20:52 the electrodes. Existing methods of testing
00:20:52 --> 00:20:54 coffee often involve tasting panels and
00:20:54 --> 00:20:56 indirect measurements, which can be both
00:20:56 --> 00:20:59 costly and unreliable or slow expensive lab
00:20:59 --> 00:21:01 tests that look for individual molecules.
00:21:03 --> 00:21:05 Lying dishonest politicians and corrupt
00:21:05 --> 00:21:08 biassed journalism have become commonplace in
00:21:08 --> 00:21:10 today's world. The rise of
00:21:10 --> 00:21:13 misinformation and disinformation has led to
00:21:13 --> 00:21:15 what is now a, uh, dystopian post truth era.
00:21:16 --> 00:21:18 And for people like you and me who just want
00:21:18 --> 00:21:20 the truth, who want to hear the fact without
00:21:20 --> 00:21:23 any bias, it's a struggle to easily identify
00:21:23 --> 00:21:26 what's verifiable fact and why it is simply
00:21:26 --> 00:21:28 fabricated. Instead of helping fix this
00:21:28 --> 00:21:30 growing problem, our growing reliance on
00:21:30 --> 00:21:32 artificial intelligence is actually making
00:21:32 --> 00:21:35 the situation worse. As the sceptics
00:21:35 --> 00:21:37 Timms Mendham explains, When it comes to
00:21:37 --> 00:21:39 artificial intelligence, like everything else
00:21:39 --> 00:21:41 on the Internet, it really is a case of
00:21:41 --> 00:21:43 garbage in, garbage out.
00:21:43 --> 00:21:46 Tim Mendham: Yes, this era is regarded as a lot of fake
00:21:46 --> 00:21:48 facts, sort of areas or debatable truths and
00:21:48 --> 00:21:50 that sort of stuff. Post truth era almost.
00:21:50 --> 00:21:52 And that, uh, people are finding it difficult
00:21:52 --> 00:21:54 to identify what's real and what's not,
00:21:54 --> 00:21:56 particularly in medicine areas. Actually
00:21:57 --> 00:21:59 every DP will tell you about people who come
00:21:59 --> 00:22:02 in with a picture of a, uh, TikTok video or
00:22:02 --> 00:22:04 a Facebook post, or this sort of thing. This
00:22:04 --> 00:22:06 disease doesn't exist. Or here's a better
00:22:06 --> 00:22:08 cure for me, et cetera. What can you do for
00:22:08 --> 00:22:10 me? And it's a little like it's going to take
00:22:10 --> 00:22:13 a while to diffuse misinform, if you
00:22:13 --> 00:22:15 like people. But the truth is you can't just,
00:22:15 --> 00:22:17 you can say that's not true. The trouble is
00:22:17 --> 00:22:18 people often won't believe that. They don't
00:22:18 --> 00:22:19 react well to that sort of thing. So you've
00:22:19 --> 00:22:21 got to think of ways of doing it. AI in
00:22:21 --> 00:22:24 particular, it can be amplifying facts, it
00:22:24 --> 00:22:25 can find facts for you, it can find
00:22:25 --> 00:22:27 information for you, or could also
00:22:27 --> 00:22:29 misinterpret facts in its own right. It's not
00:22:29 --> 00:22:31 purposely lying but it just, it's just the
00:22:31 --> 00:22:34 algorithms in there. Yeah, it doesn't know.
00:22:34 --> 00:22:35 That's the whole problem. And the interesting
00:22:35 --> 00:22:37 thing is it is becoming more and more
00:22:37 --> 00:22:39 prevalent. I mean there are storeys of best
00:22:39 --> 00:22:41 selling novels which are totally written by
00:22:41 --> 00:22:43 AI. There's one that came out fairly
00:22:43 --> 00:22:45 recently, a romance novel, I think it was in
00:22:45 --> 00:22:46 the UK and people said, hang on a second,
00:22:46 --> 00:22:47 that looks a bit dodgy. And the author
00:22:47 --> 00:22:49 admitted that actually a lot of it was
00:22:49 --> 00:22:51 written by AI. There's a recent case of a
00:22:51 --> 00:22:53 Australian government inquiry into
00:22:53 --> 00:22:56 misinformation in medicine areas, false
00:22:56 --> 00:22:58 claims and things. And some of the
00:22:58 --> 00:23:00 submissions were written by AI. So I mean,
00:23:01 --> 00:23:03 it's very prevalent. What can you do about
00:23:03 --> 00:23:06 it? Very hard. Obviously,
00:23:06 --> 00:23:07 from a medical point of view, they suggest
00:23:07 --> 00:23:09 that listing is probably better than being
00:23:09 --> 00:23:11 dogmatic. People might react better to that.
00:23:11 --> 00:23:13 You can try and name misinformation without
00:23:13 --> 00:23:15 ridicule and um, if you ridicule your
00:23:15 --> 00:23:16 patient, you're not going to, they're going
00:23:16 --> 00:23:18 to find another doctor. It's got to be
00:23:18 --> 00:23:20 transparent. The thing is though, discussing
00:23:20 --> 00:23:23 with a patient within normal practise can be
00:23:23 --> 00:23:25 difficult because it takes time. So there's a
00:23:25 --> 00:23:27 lot of issues with misinformation generally.
00:23:27 --> 00:23:30 AI is part of that, not necessarily the
00:23:30 --> 00:23:32 evil thing. It's the victim as much as
00:23:32 --> 00:23:33 anything else of the information it gathers.
00:23:33 --> 00:23:35 It's only as good as the info it picks up and
00:23:35 --> 00:23:37 therefore that's in the algorithm. There are
00:23:37 --> 00:23:39 nefarious uses of misinformation, obviously,
00:23:39 --> 00:23:41 people selling stuff that may not work and
00:23:41 --> 00:23:44 that's classic for influencers and TikToks
00:23:44 --> 00:23:45 and that sort of thing. It's a key problem
00:23:45 --> 00:23:47 and very much a problem that doctors are
00:23:47 --> 00:23:49 facing increasingly. There are cases these
00:23:49 --> 00:23:51 days of people going for medical diagnosis
00:23:51 --> 00:23:54 with an AI and preferring that it seems to be
00:23:54 --> 00:23:56 more compassionate by the terms it uses. It's
00:23:56 --> 00:23:58 never judgmental and it's actually written
00:23:58 --> 00:24:00 that way, not to be judgmental on purpose,
00:24:00 --> 00:24:02 but then you come to the situation where you
00:24:02 --> 00:24:03 can actually pull it up on a fact that's
00:24:03 --> 00:24:04 quoting and say that's not correct. And they
00:24:04 --> 00:24:07 say, yes, you are right and you think it
00:24:07 --> 00:24:09 backtracks very quickly on, uh, false
00:24:09 --> 00:24:10 information that it's sort of confronted
00:24:10 --> 00:24:10 with.
00:24:10 --> 00:24:12 Stuart Gary: That's the sceptics. Timms Mendham and this
00:24:12 --> 00:24:13 is Space Time.
00:24:29 --> 00:24:32 And that's the show for now. Space Time is
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