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In this episode of SpaceTime, we tackle some of the universe's most pressing mysteries, including new insights into the Hubble constant, the surprising geology of Venus, and the building blocks of stellar formation.
Resolving the Hubble Constant Debate
New data from the James Webb Space Telescope may have finally reconciled the long-standing discrepancy in the measurement of the Hubble constant, the rate at which the universe expands. For years, scientists have grappled with differing values derived from cosmic microwave background radiation and supernova observations. Lead author Wendy Friedman discusses how recent findings suggest that the standard model of cosmology holds up, with the Hubble constant now estimated at 70.4 kilometres per second per megaparsec, aligning more closely with earlier measurements. This breakthrough could reshape our understanding of the universe’s expansion and evolution.
Venus's Thin Crust
New research indicates that Venus's crust is unexpectedly thin, challenging previous assumptions about the planet's geology. A study published in Nature Communications reveals that Venus lacks the tectonic activity seen on Earth, resulting in a crust that is about 40 to 65 kilometres thick. This research proposes a model of crust metamorphism that could explain how volcanic activity persists on Venus, despite the absence of plate tectonics. Upcoming missions, including NASA's Davinci and Veritas, aim to gather more data that could confirm these findings and enhance our understanding of Venus's geological processes.
Building Blocks of Stellar Formation
A recent study highlights that the formation of stars is influenced not only by the amount of gas in a galaxy but also by its distribution. Observations from the WALLABY survey, conducted using the Australian Square Kilometre Array Pathfinder Telescope, reveal that star formation is concentrated in areas with higher gas density. Lead author Seona Lee explains how this research sheds light on the intricate processes that govern star formation, suggesting that gas location is critical for the birth of new stars across various galaxy types.
www.spacetimewithstuartgary.com
✍️ Episode References
Astrophysical Journal
https://iopscience.iop.org/journal/0004-637X
Nature Communications
https://www.nature.com/naturecommunications/
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00:00 This is Space Time Series 28, Episode 66 for broadcast on 2 June 2025
01:00 Resolving the Hubble constant debate
12:15 Venus's surprisingly thin crust
22:30 Building blocks of stellar formation
30:00 Science report: New links between autism and Parkinson's disease
00:00:00 --> 00:00:02 Stuart Gary: This is space Time Series 28, episode
00:00:02 --> 00:00:05 66, for broadcast on the 2nd of June,
00:00:05 --> 00:00:08 2025. Coming up on Space.
00:00:08 --> 00:00:11 Finally, a possible resolution to ongoing debate
00:00:11 --> 00:00:14 over the Hubble constant. New data suggest
00:00:14 --> 00:00:17 that Venus's crust is surprisingly thin
00:00:17 --> 00:00:20 and targeting the building blocks of stellar
00:00:20 --> 00:00:22 formation. All that and more coming up
00:00:23 --> 00:00:24 on, Space Time.
00:00:25 --> 00:00:28 Voice Over Guy: Welcome to Space Time with Stuart.
00:00:44 --> 00:00:47 Stuart Gary: New data from the Webb Space Telescope may finally
00:00:47 --> 00:00:50 have found a solution to the long standing debate over the
00:00:50 --> 00:00:53 universe's rate of expansion, a, figure known as the
00:00:53 --> 00:00:55 Hubble constant. For the past decade,
00:00:55 --> 00:00:58 scientists have been trying to get to the bottom of what seemed to be a
00:00:58 --> 00:01:01 major inconsistency in the universe. The
00:01:01 --> 00:01:04 universe has been expanding out ever since the big
00:01:04 --> 00:01:07 bang, 13.82 billion years ago.
00:01:07 --> 00:01:10 And that rate of expansion, that is how fast the universe
00:01:10 --> 00:01:13 is moving, is known as the Hubble constant. The
00:01:13 --> 00:01:16 problem is that figure is different depending on how you
00:01:16 --> 00:01:19 measure it, whether you're looking at it through cosmic history
00:01:19 --> 00:01:22 or back from the present day. It was always
00:01:22 --> 00:01:25 thought that as measurements got better and more accurate, the
00:01:25 --> 00:01:28 differences between the two figures would gradually narrow
00:01:28 --> 00:01:31 down. But in reality, the opposite seems
00:01:31 --> 00:01:33 to have happened. The more precise the data got, the bigger the
00:01:33 --> 00:01:36 gap grew. And it's become a major problem
00:01:36 --> 00:01:39 in science's understanding of the universe and its evolution.
00:01:39 --> 00:01:42 With more than a thousand papers published so far, all trying to
00:01:42 --> 00:01:45 find a solution. But now new
00:01:45 --> 00:01:47 observations using data from the James Webb Space
00:01:47 --> 00:01:50 Telescope may well finally have solved the problem.
00:01:50 --> 00:01:53 The study's lead author, Wendy Friedman from the University of
00:01:53 --> 00:01:56 Chicago, says the new evidence from Webb suggests that
00:01:56 --> 00:01:59 the standard model of the universe is holding up
00:01:59 --> 00:02:02 now. It doesn't mean we won't find things in the future that are
00:02:02 --> 00:02:05 inconsistent with the model. But for the moment at least, Hubble
00:02:05 --> 00:02:07 constant doesn't seem to be a problem after all.
00:02:08 --> 00:02:11 Okay, so what are we actually talking about here? Well, there
00:02:11 --> 00:02:14 are currently two major approaches to calculating how
00:02:14 --> 00:02:17 fast our universe is expanding. The first
00:02:17 --> 00:02:20 measures the cosmic microwave background radiation.
00:02:20 --> 00:02:22 That's the leftover heat from the Big Bang itself.
00:02:23 --> 00:02:26 That radiation, now cooled down to 2.7
00:02:26 --> 00:02:28 degrees above absolute zero, can still be found
00:02:28 --> 00:02:31 today as the white noise you hear between stations
00:02:31 --> 00:02:34 on old analogue radio and TVs.
00:02:34 --> 00:02:37 And it tells astronomers what the conditions were like
00:02:37 --> 00:02:40 380 years after the Big Bang, when the
00:02:40 --> 00:02:43 universe cooled down enough for protons and electrons to
00:02:43 --> 00:02:45 come together and form the first atoms.
00:02:46 --> 00:02:49 The second approach is quite different. It measures
00:02:49 --> 00:02:52 the universe's current rate of expansion using standard
00:02:52 --> 00:02:54 candles such as type 1A supernovae, which can act
00:02:54 --> 00:02:57 as cosmic distance markers because of the
00:02:57 --> 00:03:00 conditions that cause them to go supernova. These stars always
00:03:00 --> 00:03:03 explode with the same level of luminosity, regardless of
00:03:03 --> 00:03:06 distance. So like a row of streetlights on
00:03:06 --> 00:03:09 a road, you can tell how far away they are by their apparent
00:03:09 --> 00:03:11 brightness using the inverse square law.
00:03:11 --> 00:03:14 So if we know the maximum brightness of these supernovae,
00:03:14 --> 00:03:17 measuring their apparent luminosities allows us to
00:03:17 --> 00:03:20 calculate their distance. And the further away something
00:03:20 --> 00:03:23 is from us, the faster it's moving. So additional
00:03:23 --> 00:03:25 observations tell us how fast the galaxy in which the
00:03:25 --> 00:03:28 supernova occurred is moving away from us.
00:03:28 --> 00:03:31 Friedmann has also pioneered two other methods that use what we know
00:03:31 --> 00:03:34 about two types of old stars, Red
00:03:34 --> 00:03:37 giants and carbon stars. However, there are
00:03:37 --> 00:03:39 many corrections that must be applied to these measurements before
00:03:39 --> 00:03:42 a final distance can be declared. For example,
00:03:42 --> 00:03:45 scientists first need to account for cosmic dust that
00:03:45 --> 00:03:48 permeates the universe and it dims the light between us
00:03:48 --> 00:03:51 and these distant stars in the host galaxies.
00:03:51 --> 00:03:54 And astronomers also need to check and correct for luminosity
00:03:54 --> 00:03:56 differences that can arise over cosmic time.
00:03:57 --> 00:04:00 Finally, subtle measurement uncertainties in the instrumentation
00:04:00 --> 00:04:03 used to make these measurements also need to be identified
00:04:03 --> 00:04:05 and corrected for. But with technological
00:04:05 --> 00:04:08 advances, such as the launch of the much more powerful Webb
00:04:08 --> 00:04:11 space telescope in 2021, scientists have now
00:04:11 --> 00:04:14 been able to increasingly refine these measurements.
00:04:14 --> 00:04:17 M. Friedman says astronomers have now more than
00:04:17 --> 00:04:19 doubled the sample of galaxies being used to calibrate
00:04:19 --> 00:04:22 supernovae. The statistical improvements from
00:04:22 --> 00:04:25 this is significant and considerably strengthens the result.
00:04:26 --> 00:04:28 And this is where we get to the nitty gritty. According to
00:04:28 --> 00:04:31 Friedman's latest calculations, reported in the
00:04:31 --> 00:04:34 Astrophysical Journal, and which incorporates data from both the
00:04:34 --> 00:04:37 Hubble and Webb space telescopes, we can now give the Hubble
00:04:37 --> 00:04:40 constant a value of 70.4 kilometres per
00:04:40 --> 00:04:43 second per megaparsec, plus or minus 3%.
00:04:44 --> 00:04:46 And that brings the value into statistical
00:04:46 --> 00:04:49 agreement with recent measurements from the cosmic microwave
00:04:49 --> 00:04:51 background radiation, which places the constant at
00:04:51 --> 00:04:53 67.4 kilometres per second per
00:04:53 --> 00:04:56 megaparsec. The thing you got to remember is that Webb
00:04:56 --> 00:04:59 has four times the resolution of Hubble and that allows it to
00:04:59 --> 00:05:02 identify individual stars previously detected in
00:05:02 --> 00:05:05 blurry groups. It's also about 10 times
00:05:05 --> 00:05:08 as sensitive as Hubble, which provides higher precision and
00:05:08 --> 00:05:10 the ability to find even fainter objects of interest.
00:05:11 --> 00:05:14 Friedman says astrophysicists have been trying to come up with
00:05:14 --> 00:05:17 a theory that would have explained different rates of expansion
00:05:17 --> 00:05:19 as the universe ages. And scientists, ah, are still trying
00:05:19 --> 00:05:22 to find cracks in the standard model that describes the universe,
00:05:22 --> 00:05:25 which could provide new clues about the nature of Two big
00:05:25 --> 00:05:28 outstanding myster of the cosmos, namely
00:05:28 --> 00:05:31 dark matter and dark energy. But at least for
00:05:31 --> 00:05:33 now, the Hubble constant increasingly seems not to be
00:05:33 --> 00:05:36 the place to look. This is space time.
00:05:37 --> 00:05:40 Still to come. New data suggest that Venus's crust
00:05:40 --> 00:05:43 is surprisingly thin and locating the building blocks
00:05:43 --> 00:05:46 of stellar formation. All that and more still to come
00:05:46 --> 00:05:47 on Spacet
00:05:58 --> 00:05:58 Foreign
00:06:04 --> 00:06:07 suggests that the crust of the planet Venus is unusually
00:06:07 --> 00:06:10 thin. And this new model of the Venusian crust has come up
00:06:10 --> 00:06:12 with some surprises about the planet's geology.
00:06:13 --> 00:06:15 Scientists always expected that the outermost layer of Venus's
00:06:15 --> 00:06:18 crust would grow thicker and thicker over time, given its
00:06:18 --> 00:06:21 apparent lack of forces that would drive the crust back into
00:06:21 --> 00:06:24 the planet's interior. But the paper published
00:06:24 --> 00:06:27 in the journal Nature Communications, proposes a crust
00:06:27 --> 00:06:30 metamorphism process based on rock density and melting
00:06:30 --> 00:06:33 melting cycles. Now, the Earth's crust is made
00:06:33 --> 00:06:36 up of massive slabs that slowly move, forming
00:06:36 --> 00:06:38 folds and faults in a process known as plate
00:06:38 --> 00:06:41 tectonics. Material rises from deep within
00:06:41 --> 00:06:44 the mantle through convection until it reaches the surface.
00:06:44 --> 00:06:47 It then spreads out across the surface in these massive
00:06:47 --> 00:06:49 plates. And when two plates collide, the
00:06:49 --> 00:06:52 lighter plate slides on top of the denser one,
00:06:52 --> 00:06:55 forcing the denser one downwards back into the mantle.
00:06:55 --> 00:06:58 And this process, known as subduction, helps control the
00:06:58 --> 00:07:01 thickness of Earth's crust. The rocks making up the
00:07:01 --> 00:07:04 bottom plate, the heavier plate, also experience changes
00:07:04 --> 00:07:07 caused by increasing pressure and temperature as the plate
00:07:07 --> 00:07:09 continues to sink deeper and deeper back into the
00:07:09 --> 00:07:11 mantle. These changes are known as
00:07:11 --> 00:07:14 metamorphism and it's also one of the causes of
00:07:14 --> 00:07:17 volcanic activity. in contrast,
00:07:17 --> 00:07:20 Venus is a crust that's all in one piece. There's
00:07:20 --> 00:07:22 simply no evidence of subduction caused by plate tectonics
00:07:22 --> 00:07:25 as we see on Earth. Modelling determined that
00:07:25 --> 00:07:28 Venus crust is about 40 kilometres thick on
00:07:28 --> 00:07:31 average and, at very most, 65 kilometres thick.
00:07:31 --> 00:07:34 Now, by comparison, Earth's continental crust, that's the lighter
00:07:34 --> 00:07:37 crust, is between 25 and 70 kilometres thick
00:07:37 --> 00:07:40 and mostly composed of less dense, more felt like rocks such as
00:07:40 --> 00:07:43 granite. However, in some places, such as the
00:07:43 --> 00:07:46 Tibetan Plateau, the Altiplano and the eastern
00:07:46 --> 00:07:48 Baltic Shield, the continental crust can be up to 80
00:07:48 --> 00:07:51 kilometres thick. On the other hand, Earth's oceanic
00:07:51 --> 00:07:54 crust is just five to 10 kilometres thick, composed
00:07:54 --> 00:07:57 primarily of denser, heavier mafric rocks such as
00:07:57 --> 00:08:00 basalt, diabase and grabo. one of the study's
00:08:00 --> 00:08:03 authors, Justin Filberto from NASA's Johnson Space Centre in
00:08:03 --> 00:08:05 Houston, Texas, says Venus crust appears to be
00:08:05 --> 00:08:08 surprisingly thin given conditions on the planet.
00:08:08 --> 00:08:11 It turns out that according to this model, as the crust
00:08:11 --> 00:08:14 grows thicker, the bottom of the crust becomes so dense that it
00:08:14 --> 00:08:17 either breaks off and becomes part of the mantle or gets hot
00:08:17 --> 00:08:20 enough to melt. So while Venus doesn't have
00:08:20 --> 00:08:23 any moving plates, its crust does experience a form of
00:08:23 --> 00:08:26 metamorphism. Now, if this new model is correct, the
00:08:26 --> 00:08:29 findings would be an important step towards understanding geological
00:08:29 --> 00:08:31 processes and the evolution of the planet itself.
00:08:32 --> 00:08:35 Fulberta says this breaking off and melting can
00:08:35 --> 00:08:37 put water and elements back into the planet's interior,
00:08:37 --> 00:08:40 thereby helping drive volcanic activity.
00:08:40 --> 00:08:43 He says it gives scientists a new model for how
00:08:43 --> 00:08:46 material returns to the interior of Venus and another way
00:08:46 --> 00:08:48 to make lava, and spur volcanic eruptions.
00:08:49 --> 00:08:51 In a sense, it's sort of resetting the playing field
00:08:51 --> 00:08:54 for how the geology, crust and atmosphere on Venus
00:08:54 --> 00:08:57 all work together. Of course, the next step is to gather direct
00:08:57 --> 00:09:00 data about Venus crust in order to test and refine these
00:09:00 --> 00:09:03 models. And there are several upcoming missions about to
00:09:03 --> 00:09:06 do just that. These include NASA's Davinci
00:09:06 --> 00:09:09 and Veritas spacecraft and the European Space Agency's
00:09:09 --> 00:09:12 Envision mission. And combined, they'll aim to study the
00:09:12 --> 00:09:15 planet's surface and atmosphere in far greater detail than
00:09:15 --> 00:09:18 ever before. These efforts could help confirm
00:09:18 --> 00:09:20 whether processes like metamorphism and recycling
00:09:20 --> 00:09:23 are actively reshaping Venus crust today.
00:09:24 --> 00:09:26 And that could reveal how such activity may be tied to
00:09:26 --> 00:09:28 volcanic and atmospheric evolution.
00:09:29 --> 00:09:32 Filberto says scientists don't actually know how much
00:09:32 --> 00:09:35 volcanism is happening on Venus now. They assume
00:09:35 --> 00:09:37 it's a lot. In fact, a lot of scientists believe Venus is
00:09:37 --> 00:09:40 probably the most volcanic planet in the solar system. Only
00:09:40 --> 00:09:43 the Jovian volcanic moon IO is more active.
00:09:43 --> 00:09:46 But to know for sure, scientists need more data.
00:09:46 --> 00:09:49 And that's where these missions come in. This is
00:09:49 --> 00:09:52 space time. Still to come, locating
00:09:52 --> 00:09:55 the building blocks of stellar formation, and later in the
00:09:55 --> 00:09:58 Science report, confirmation of a new type of
00:09:58 --> 00:10:01 plesiosaur. All that and more still to come
00:10:01 --> 00:10:02 on, space time.
00:10:18 --> 00:10:20 A new study has shown how stellar formation isn't just
00:10:20 --> 00:10:23 based on how much gas there is in a galaxy, but also where that
00:10:23 --> 00:10:26 gas is located. Astronomers made the new
00:10:26 --> 00:10:29 observations by studying gas distribution in thousands
00:10:29 --> 00:10:31 of galaxies as part of the Wallaby Survey.
00:10:32 --> 00:10:34 Wallaby is being undertaken by ascap, the
00:10:34 --> 00:10:37 Australian Square Kilometre Array Pathfinder
00:10:37 --> 00:10:40 Telescope, located at the Murchison Radio Astronomy
00:10:40 --> 00:10:42 Observatory in Outback, Western Australia.
00:10:42 --> 00:10:45 The study's lead author, Siona Lee, from the University of
00:10:45 --> 00:10:48 Western Australia node of the International Centre for Radio
00:10:48 --> 00:10:51 Astronomy Research, says the findings give new insights into
00:10:51 --> 00:10:53 how stars are born from clouds of gas.
00:10:54 --> 00:10:56 She says while earlier surveys could only map gas
00:10:56 --> 00:10:59 distribution, in a few Hundred galaxies. The Wallaby survey
00:10:59 --> 00:11:02 successfully mapped atomic hydrogen gas in a significantly
00:11:02 --> 00:11:05 larger sample. Atomic hydrogen refers to an
00:11:05 --> 00:11:08 isolated hydrogen atom consisting of a single proton
00:11:08 --> 00:11:11 nucleus orbited by a single electron. now typically,
00:11:11 --> 00:11:14 hydrogen exists in molecular form as diatomic
00:11:14 --> 00:11:17 molecules comprising two atoms. But under the
00:11:17 --> 00:11:19 right conditions, such as high temperatures or during
00:11:19 --> 00:11:22 some chemical reactions, these molecules can be split up into
00:11:22 --> 00:11:25 individual atoms, resulting in atomic hydrogen.
00:11:26 --> 00:11:28 The new findings reported in the publications of the
00:11:28 --> 00:11:31 Astronomical Society of Australia show that having more gas in
00:11:31 --> 00:11:34 a galaxy doesn't automatically mean it's going to be creating
00:11:34 --> 00:11:37 more stars. Instead, galaxies that are
00:11:37 --> 00:11:40 forming stars usually have higher concentrations of gas
00:11:40 --> 00:11:43 in areas where stars reside. Lee says
00:11:43 --> 00:11:46 she was excited to see a correlation between star formation
00:11:46 --> 00:11:48 and exactly where the hydrogen gas is located.
00:11:48 --> 00:11:51 The higher resolution observations available through ASCAP's
00:11:51 --> 00:11:54 36 parabolic disharray allowed Li and colleagues
00:11:54 --> 00:11:57 to measure the location and density of atomic hydrogen for an,
00:11:57 --> 00:12:00 unprecedented number of galaxies. Understanding
00:12:00 --> 00:12:03 how stars form requires astronomers to measure the atomic
00:12:03 --> 00:12:06 gas in the areas where stars are actually forming, rather than simply
00:12:06 --> 00:12:09 considering the total gas content of the galaxy, which also
00:12:09 --> 00:12:12 includes the unused gas in outer regions of the galaxy.
00:12:12 --> 00:12:15 The research showed that being able to conduct more detailed radio
00:12:15 --> 00:12:18 observations is key to helping scientists understand
00:12:18 --> 00:12:21 how galaxies grow and change over time. The
00:12:21 --> 00:12:23 authors looked at radio waves and visible light from nearby
00:12:23 --> 00:12:26 galaxies to determine the amount of gas in the parts of the
00:12:26 --> 00:12:29 galaxy where the stars are being born. And this was
00:12:29 --> 00:12:32 important for figuring out just how much gas is really
00:12:32 --> 00:12:34 supporting the creation of new stars.
00:12:34 --> 00:12:37 Katarina Miljkovic : Wallaby Survey is an ongoing whole
00:12:37 --> 00:12:40 sky survey which observes atomic
00:12:40 --> 00:12:42 hydrogen gas of like over
00:12:43 --> 00:12:45 200 galaxies eventually
00:12:45 --> 00:12:48 in all southern hemisphere.
00:12:48 --> 00:12:50 Stuart Gary: And you're using the ASCAP Australian Square
00:12:50 --> 00:12:52 Kilometre Ray Pathfinder telescopes.
00:12:52 --> 00:12:55 Katarina Miljkovic : Yeah, its advantage is a large field of view
00:12:55 --> 00:12:58 so it can observe large field of sky
00:12:58 --> 00:13:01 in a short time. So Wallaby
00:13:01 --> 00:13:04 takes an advantage of it, so it
00:13:04 --> 00:13:06 observes whole sky in quite a short
00:13:07 --> 00:13:09 time with a, relatively good resolution.
00:13:09 --> 00:13:12 Stuart Gary: And this resolution has allowed you to look at the
00:13:12 --> 00:13:15 gas inside different galaxies and study these
00:13:15 --> 00:13:18 nebulae closely and look at how that leads to
00:13:18 --> 00:13:20 star formation. What have you found?
00:13:20 --> 00:13:23 Katarina Miljkovic : So we analysed the distribution of atomic
00:13:23 --> 00:13:25 hydrogen gas for one, thousand galaxies used
00:13:25 --> 00:13:28 from Wallaby survey. And we compared
00:13:28 --> 00:13:31 atomic hydrogen gas and the star forming
00:13:31 --> 00:13:34 region and atomic hydrogen gas in the
00:13:34 --> 00:13:37 outer part, which is star forming quiet
00:13:37 --> 00:13:39 region, and then found that gas
00:13:40 --> 00:13:43 in the star forming region is more related
00:13:43 --> 00:13:45 to star formation in galaxies.
00:13:45 --> 00:13:47 Stuart Gary: Now you talked about atomic hydrogen and when
00:13:47 --> 00:13:50 atomic hydrogen gets with friends with other
00:13:50 --> 00:13:53 atomic hydrogen atoms, then they over time
00:13:53 --> 00:13:56 they can cool down. When they cool down, they slow
00:13:56 --> 00:13:58 down and when they slow down they can bunch up
00:13:59 --> 00:14:01 and eventually form a point of
00:14:01 --> 00:14:04 intense gravity which causes the surrounding
00:14:04 --> 00:14:06 gas to collapse. Is that what's going on?
00:14:07 --> 00:14:09 Katarina Miljkovic : So basically there is atomic hydrogen
00:14:09 --> 00:14:12 and then when it becomes cooled down and
00:14:12 --> 00:14:15 it can come when there is a gravity, it
00:14:15 --> 00:14:18 can combine and then it becomes more
00:14:18 --> 00:14:21 complex molecule like hydrogen molecule.
00:14:21 --> 00:14:24 Atomic hydrogen gas is normally broadly
00:14:24 --> 00:14:27 spread the gal in the galaxy. So and
00:14:27 --> 00:14:30 inside there is a star near
00:14:30 --> 00:14:33 the centre there is a star forming region like
00:14:33 --> 00:14:35 concentrated that we observe as a
00:14:35 --> 00:14:38 galaxy disc. And then in the outer part
00:14:38 --> 00:14:41 atomic hydrogen gas is broadly
00:14:41 --> 00:14:44 distributed and the atomic hydrogen gas
00:14:44 --> 00:14:46 outside the optically thin stellar
00:14:46 --> 00:14:49 disc, then it's too stable
00:14:49 --> 00:14:52 to decollate and to form
00:14:52 --> 00:14:55 stars. So what I focused on
00:14:55 --> 00:14:58 is atomic hydrogen gas in the region
00:14:58 --> 00:15:01 on the top of the lattice. So that's what I studied
00:15:01 --> 00:15:01 is what.
00:15:01 --> 00:15:04 Stuart Gary: You'Re saying that you found atomic hydrogen
00:15:04 --> 00:15:07 everywhere, all over a galaxy. But there are some
00:15:07 --> 00:15:09 areas where it's more concentrated and stellar
00:15:09 --> 00:15:11 formations only happening in those areas.
00:15:11 --> 00:15:14 Katarina Miljkovic : Yeah. So star formation is concentrated
00:15:14 --> 00:15:17 near the centre of the galaxy. So I
00:15:17 --> 00:15:20 focused on that part and
00:15:20 --> 00:15:23 then found the gas density there
00:15:23 --> 00:15:26 is essential for that galaxy to
00:15:26 --> 00:15:26 form stars.
00:15:26 --> 00:15:29 Stuart Gary: And is this true of all galaxies or only
00:15:29 --> 00:15:32 spiral galaxies or what was the distribution like?
00:15:32 --> 00:15:35 Katarina Miljkovic : So what ah, I'm targeting is whole kinds of
00:15:35 --> 00:15:37 galaxies and that's what is important. It's not
00:15:37 --> 00:15:40 only certain type of galaxies but any
00:15:40 --> 00:15:43 type of galaxies to form stars they need
00:15:43 --> 00:15:46 gas and that gas have to be in the right
00:15:46 --> 00:15:47 place to form a star.
00:15:47 --> 00:15:50 Stuart Gary: Did you find atomic hydrogen in sufficient quantities and
00:15:50 --> 00:15:53 densities to make stars in elliptical galaxies as
00:15:53 --> 00:15:55 well or are they just old, dead and red?
00:15:56 --> 00:15:59 Katarina Miljkovic : Good question. So as you said
00:15:59 --> 00:16:02 elliptical galaxies that have, they have less
00:16:02 --> 00:16:05 star formation but of course there is a star
00:16:05 --> 00:16:08 formation and they have less
00:16:08 --> 00:16:10 gas so it's hard to detect but
00:16:10 --> 00:16:13 if we can observe it. So
00:16:13 --> 00:16:16 right now using Oscar telescope
00:16:16 --> 00:16:19 Hullaby is observing like many number
00:16:19 --> 00:16:21 of galaxies to study the evolution of
00:16:21 --> 00:16:24 galaxy evolution of the universe. But in the near
00:16:24 --> 00:16:27 future there is going to be SKA telescope
00:16:27 --> 00:16:30 which will even detect more faint and more
00:16:30 --> 00:16:33 distant galaxies and it will
00:16:33 --> 00:16:36 with much higher resolution. So these are
00:16:36 --> 00:16:39 going to be very helpful to unveil
00:16:39 --> 00:16:42 questions about galaxy evol the near
00:16:42 --> 00:16:42 future.
00:16:42 --> 00:16:45 Stuart Gary: That's Yona Lee from the University of Western Australia
00:16:45 --> 00:16:48 node of the International Centre for Radio Astronomy Research.
00:16:49 --> 00:16:51 And this is space, time
00:17:06 --> 00:17:07 and time out of.
00:17:07 --> 00:17:10 Take a brief look at some of the other stories making news in science this
00:17:10 --> 00:17:12 week. With the Science report,
00:17:13 --> 00:17:16 Swedish and American scientists have found a link between
00:17:16 --> 00:17:18 autism spectrum disorder and a future risk of
00:17:18 --> 00:17:21 developing Parkinson's disease. A report in
00:17:21 --> 00:17:24 the Journal of the American Medical association looked at data
00:17:24 --> 00:17:27 from over 2.2 million people, finding that
00:17:27 --> 00:17:30 Parkinson's occurred in just 0.02%
00:17:30 --> 00:17:33 of people who didn't have autism, but it occurred in
00:17:33 --> 00:17:35 0.5% of people who did have the condition.
00:17:36 --> 00:17:39 Now, while this kind of research can't prove that being on the spectrum
00:17:39 --> 00:17:42 will directly affect your chances developing Parkinson's, the
00:17:42 --> 00:17:45 authors say there might be a potential shared base
00:17:45 --> 00:17:48 between neurodevelopmental disorders and Parkinson's
00:17:48 --> 00:17:51 disease. A new study
00:17:51 --> 00:17:53 claims that amber deposits found in ancient deep sea
00:17:53 --> 00:17:56 mud samples in Japan may be one of the oldest known
00:17:56 --> 00:17:59 records of a tsunami. The findings, published
00:17:59 --> 00:18:02 in the journal Scientific Reports, shows that large
00:18:02 --> 00:18:05 fossilised tree resin deposits discovered in a quarry on
00:18:05 --> 00:18:08 Hokkaido island in northern Japan were swept out from
00:18:08 --> 00:18:10 a forest to what was then an ocean by, one or more
00:18:10 --> 00:18:13 tsunami between 116 and 114
00:18:13 --> 00:18:16 million years ago. Looking closely at the amber,
00:18:16 --> 00:18:19 the team found that some of it wasn't fully hardened at the
00:18:19 --> 00:18:22 time it was caught up in the tsunami. And that suggests that
00:18:22 --> 00:18:25 huge amounts of amber were being rapidly carried out from land
00:18:25 --> 00:18:27 to the ocean by the backwash from one or more
00:18:27 --> 00:18:30 tsunami events. The thing is, traces of
00:18:30 --> 00:18:33 ancient tsunamis are hard to find. So
00:18:33 --> 00:18:36 amber formed on land and then transported out into the sea
00:18:36 --> 00:18:38 could provide a new way of identifying them.
00:18:40 --> 00:18:43 A small group of 85 million year old fossils,
00:18:43 --> 00:18:46 including the official fossil emblem of British Columbia,
00:18:46 --> 00:18:48 have now been scientifically described as a new type of
00:18:48 --> 00:18:51 plesiosaur. A report in the Journal of
00:18:51 --> 00:18:54 Systematic Palaeontology claims the fossils, which were
00:18:54 --> 00:18:57 first discovered on Vancouver island back in 1988,
00:18:57 --> 00:18:59 likely all came from one type of elasmosaur
00:18:59 --> 00:19:02 plesiosaur, which has now been named Truscosaurus
00:19:02 --> 00:19:05 sandrae. The new classification includes the
00:19:05 --> 00:19:08 description of 36 well preserved clavicle vertebrae,
00:19:08 --> 00:19:10 indicating at least 50 neck bones.
00:19:10 --> 00:19:13 Truscosaur lived during the age of the dinosaurs
00:19:13 --> 00:19:16 in the Cretaceous period. Palaeontologists say the
00:19:16 --> 00:19:19 long necked marine reptile reached lengths of 12 metres
00:19:19 --> 00:19:22 and featured sharp and heavy teeth, along with an
00:19:22 --> 00:19:25 odd mix of primitive and newer traits. And
00:19:25 --> 00:19:27 unlike other elasmosaur plesiosaurs, its unique
00:19:27 --> 00:19:30 suite of adaptations enabled it to hunt prey from above.
00:19:32 --> 00:19:35 It's in the back of most bathroom medicine cabinets, right next
00:19:35 --> 00:19:38 to the calamine lotion and behind that old packet of band
00:19:38 --> 00:19:41 aids. We're talking about that Famous blue jar
00:19:41 --> 00:19:43 of Vicks VapoRub. It's been with us for over
00:19:43 --> 00:19:46 a century now as an ointment to rub on the body to
00:19:46 --> 00:19:49 relieve coughs, congestion and minor arthritic pains.
00:19:49 --> 00:19:52 But Tim Mendham from Strange Sceptics says people are now
00:19:52 --> 00:19:54 claiming you should be rubbing it on your feet.
00:19:54 --> 00:19:57 Tim Mendham: Vicks vapour rub. We probably all had a whack of Vicks
00:19:57 --> 00:20:00 vapour rub on our chest at some stage, but, yeah, stick it on your desk.
00:20:00 --> 00:20:03 When you're a kid, you have a breathing problem and you know the fumes
00:20:03 --> 00:20:06 get up your nose, et cetera. it's camphor, it's
00:20:06 --> 00:20:09 eucalyptus oil, it's menthol and it's something called
00:20:09 --> 00:20:12 petrolatum and it's an international product. All those things come
00:20:12 --> 00:20:15 from different places, including eucalyptus oil from Australia. And
00:20:15 --> 00:20:18 this was the formulation made you smelly. Stick it on your chest
00:20:18 --> 00:20:21 and do your pyjamas back up, et cetera, and you'll breathe it in
00:20:21 --> 00:20:23 all night and you'll have a clear nose and you'll be able to breathe
00:20:23 --> 00:20:26 easily. Yeah. This is extended into other areas. Now it's
00:20:26 --> 00:20:29 suggesting that you put it on your feet. And this is sort of like a
00:20:29 --> 00:20:32 version of reflexology. You massage the foot and that will
00:20:32 --> 00:20:35 affect other parts of your body. Stick vapour rub on your feet
00:20:35 --> 00:20:37 and it will help you breathe better and sleep better.
00:20:37 --> 00:20:40 Stuart Gary: there was this story going around a while ago. I don't know if
00:20:40 --> 00:20:43 it's true because I've never tried it, but if you rub garlic on
00:20:43 --> 00:20:45 your feet, you'll wind up getting garlic breath.
00:20:45 --> 00:20:48 Tim Mendham: Well, depends on how much you lick your feet, I suppose. Yeah,
00:20:48 --> 00:20:51 but I mean. Yeah, It's been told to me that vapour rub on your
00:20:51 --> 00:20:54 toenails and things can actually help fungus clear up. Fungus?
00:20:54 --> 00:20:55 Stuart Gary: Oh. Probably kill anything there.
00:20:55 --> 00:20:58 Tim Mendham: Yeah, I know, I know, but I mean, I don't know if it's true, but the thing is about
00:20:58 --> 00:21:01 your breathe and it makes you having a good sleep. How does it work out? Why
00:21:01 --> 00:21:04 not just stick it on your chest? Why not on your feet? And then
00:21:04 --> 00:21:07 you put your socks on on top of. So it's making your socks rather smelly and
00:21:07 --> 00:21:09 oily. But it's not going to get into your bloodstream. Right. It doesn't get into
00:21:09 --> 00:21:12 your bloodstream on your chest. It's something you breathe. But, I
00:21:12 --> 00:21:15 mean, why the feet? It's a strange thing, but I'm sure there's
00:21:15 --> 00:21:18 actually every other part of the body you can rub vapour of. It
00:21:18 --> 00:21:21 hasn't actually been suggested that it actually can have problems
00:21:21 --> 00:21:23 associated with it. Yeah, skin irritation, headaches,
00:21:23 --> 00:21:26 dizziness, confusion and hallucinations if you
00:21:26 --> 00:21:29 use cancer, inappropriately. So it's not a
00:21:29 --> 00:21:32 totally benign product, but, you know, sits there in your
00:21:32 --> 00:21:35 medicine cabinet for 35 years. But, you know, hey, there's a lot of things in the
00:21:35 --> 00:21:37 back of your medicine cabinet you probably shouldn't need using.
00:21:37 --> 00:21:39 Stuart Gary: That's Tim Mendham from Australian Sceptics.
00:21:55 --> 00:21:58 And that's the show for now. Space Time
00:21:58 --> 00:22:01 is available every Monday, Wednesday and Friday through
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00:22:08 --> 00:22:11 bitesz.com, soundcloud, YouTube,
00:22:11 --> 00:22:14 your favourite podcast download provider, and from
00:22:14 --> 00:22:16 spacetimewithstuartgary.com
00:22:17 --> 00:22:19 spacetime's also broadcast through the National Science
00:22:19 --> 00:22:22 foundation on Science Zone Radio and on both
00:22:22 --> 00:22:25 iHeartradio and TuneIn radio. And
00:22:25 --> 00:22:28 you can help to support our show by visiting the Space Time
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00:22:48 --> 00:22:48 details.
00:22:49 --> 00:22:51 Tim Mendham: you've been listening to Space Time with Stuart Gary.
00:22:52 --> 00:22:54 This has been another quality podcast production from
00:22:54 --> 00:22:56 bitesz.com
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