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Stuart Gary: This is space time series 26 episode 80 for
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broadcast on the fifth of July 2023. Coming up on space time, a
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new never before seen way to annihilate star Australia's new
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Deep Space Laser Communications Network and the unusual origin
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of the Jim its meteor shower. All that and more coming up on
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space time.
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Generic: Welcome to space time with Stuart Garry.
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Stuart Gary: Astronomers have discovered a new way for stars
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to die. Most stars in the universe die in predictable ways
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depending on their mass, relatively low mass stars like
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our sun, for example, will eventually lose their outer
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layers in old age, exposing their white hot stellar core,
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which we call a white dwarf and they'll slowly fade over time as
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the white dwarf cools.
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But stars more than say eight times the mass of our sun burn
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brighter and end up dying sooner.
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And usually in cataclysmic ways such as a core collapsed
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supernova explosion, resulting in the creation of ultra dense
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objects like neutron stars and stellar mass black holes stars
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can also die if they consume too much mass from a companion star
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in a binary system, eventually exploding in a thermonuclear
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supernovae or they can be ripped apart by a black hole in a tidal
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disruption event.
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Now, a report in the journal nature shows new research
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pointing to a long hypothesized but never before seen fifth
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option. While searching for the origins of a long duration gamma
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ray burst astronomers using the Gemini South telescope in Chile,
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uncovered evidence of a demolition derby like collision
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of stars or stellar remnants in the chaotic and densely packed
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region near an ancient galaxy supermassive black hole.
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The study's lead author Andrew Levin from Rabou University in
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the Netherlands says these new results show that stars can meet
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their dears in some of the densest regions in the universe
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where they can quite literally be driven to collide.
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Levin says this is exciting both for understanding how stars die
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and for answering other questions such as what
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unexpected sources could create gravitational waves that we
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detect here on Earth.
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Ancient Galaxies are long past their star forming prime and so
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would have few if any remaining giant stars, the principal
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source of long duration gamma ray bursts, their galactic cores
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however, are teeming with stars in a collection of ultra dense
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stellar remnants such as white dwarves, neutron stars and
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stellar mass black holes.
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Now, astronomers have long suspected that in this turbulent
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beehive of activity surrounding a supermassive black hole, it
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would only be a matter of time for two stellar objects to
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collide with each other producing a long duration gamma
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ray burst.
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The trouble is evidence of this type of merger has been elusive,
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but maybe all that's changed. Now, the first hint that such an
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event had occurred was seen on the 19th of October 2019 when
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NASA's Swift Space telescope detected a bright flash of gamma
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rays that lasted for more than a minute.
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Now, any gamma ray burst lasting for more than two seconds is
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considered long. And these bursts typically come from the
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supernova death of stars at least 10 times the mass of our
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sun. But not always. The authors then use the Gemini South
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telescope to undertake some long term observations of the gamma
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ray bursts fading afterglow to learn more about its origins.
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Now, these observations allow the team to pinpoint the exact
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location of the gamma ray burst to a region less than 100 light
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years from the nucleus of an ancient galaxy, placing it very
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near that galaxy's supermassive black hole.
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And when they studied the area in more detail, Leven and
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colleagues found no evidence of a corresponding supernova which
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would have left its imprint in the light studied by a Gemini
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South Levin says follow up observations suggested that
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rather than being a massive star collapsing, the burst was most
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likely caused by the merger of two compact objects.
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He says by pinpointing its location to the center of a
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previously identified ancient galaxy, they've had their first
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tantalizing evidence of a new pathway for stars to meet their
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demise.
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Now, in normal galactic environments, the production of
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long duration gamma ray bursts from colliding stellar remnants
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such as neutron stars or stellar mass black holes is thought to
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be vanishingly rare. The course of ancient Galaxies however, are
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anything but normal and there may be a million or more stars.
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All crammed into a region.
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Just a few layers across such extreme population densities may
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be great enough for the occasional stellar collisions to
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occur, especially under the titanic gravitational influence
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of a supermassive black hole which would perturb the motions
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of stars, setting them Carey in random directions.
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Eventually, these wayward stars would intersect and merge,
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triggering a titanic explosion which could be observed over
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vast cosmic distances. Now, it's likely that similar events are
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occurring all the time in crowded regions right across the
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universe, but they've gone unnoticed until now.
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Now, a possible reason for their obscurity could be that galactic
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centers are brimming with dust and gas and they could hide the
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initial flash of the gamma ray burst and the resulting
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afterglow. So this particular long duration gamma ray burst,
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which by the way has been cataloged as GRB 1910 19.
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A may be a rare exception allowing astronomers to detect
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the burst and study its after effects. This is space time
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still to come Australia, developing a new Deep Space
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Laser Communications Network and the unusual origins of the
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geminid meteor shower, all that and more still to come on space
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time.
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Last week, on space time, we looked at the massive upgrade
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now under way at NASA's Deep Space Communications Network and
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its primary base stations at Goldstone, California Madrid
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Spain and at Tid Bin Villa on the outskirts of Canberra.
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Now, as we mentioned last week, part of that upgrade involves
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experimenting with new high speed laser optical
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communication systems, both between spacecraft and between
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space and the ground. An Australian project is now
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underway to develop an operational optical laser
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communications network specifically designed to talk to
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spacecraft both in orbit and also deep space.
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It's called terra net and it's at least 1000 times faster than
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the radio communications systems currently used to communicate in
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space. Associate Professor Sascha Schediwy from the
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University Of Western Australia.
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No, at the International Center For Radio Astronomy Research
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says the project will be one of the first commercial optical
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communications networks in Australia to be capable of
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providing day to day support for space missions. The network's
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main commercial application will be transferring data to and from
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satellites orbiting the planet.
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One of the strongest drivers for increased data rates is the rise
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of advanced Earth observation and imaging satellites carrying
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hyper spectral cameras. These satellites take high resolution
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images of the Earth's surface used for National Defense and
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disaster management in the process, generating huge amounts
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of data.
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In fact, currently, the data on some of these satellites needs
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to be compressed or thrown away because the capacity is simply
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not there to down link at all. Shed. Schediwy says by expanding
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to optical communications with a ground station network capable
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of supporting them terran net will be able to use them to
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their full capacity.
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The project which has been partly funded by the Australian
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Space Agency will also explore high speed communications in
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deep space including the moon and will be capable of providing
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the communications needed for NASA's atom lunar missions.
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The initial network will be made up of two fixed ground stations,
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one at the University Of Western Australia and the other at Mingo
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with a third mobile station initially deployed at New Norcia
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and it should be operational by 2026 shed. Schediwy says NASA
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and other space agencies need communication stations worldwide
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in order to maintain continuous contact with missions as the
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Earth rotates.
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Associate Professor Sascha Sch.: The terrine project is about
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taking some of the cutting edge technologies that were developed
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here at the International Center For Radio Astronomy Research
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located at the University Of Western Australia and
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translating those technologies into the world's first optical
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communications ground station network.
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This network will allow us to download critical data from
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satellites in space to Earth faster than has ever been done
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before. It allows us to also create commercialization
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opportunities for our industry partners. Goon Heli Australia,
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Tallis, Australia and our other partners around the world,
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including the German Space Agency, the French Space Agency
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and the European Space Agency.
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So with this project, we're going to be able to validate the
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commercial opportunities for this ground station and then
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have it be a revenue stream for income into the state going
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forward. One of the key challenges facing the world at
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the moment is with the explosion of satellites, er the number of
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satellites in orbit and the increasing capability, we don't
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have enough bandwidth to get all that information down on the
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ground.
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One of the things that Terrene will allow us to do is move on
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to a new technology, optical communications technologies and
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this will allow us to download information from space thousands
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of times faster than it is currently possible.
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Stuart Gary: That's Associate Professor Sasa Shed we from the
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University Of Western Australia node of the International Center
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For Radio Astronomy Research.
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And this space time still to come the unusual origin of the
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geminid meteor shower and later in the science report, a new
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study shows that just like the modern day white pointer Karang
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Cacao, the ancient giant shark Megalodon was also warm blooded
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all that and more still to come on space time.
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Every December, the geminid meteor shower lights up the
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night skies of planet Earth. But mysteries surrounding the origin
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of this meteor stream have long fascinated scientists because
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while most meteor showers are created when a comet emits a
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tail of dust and ice, the geminid actually stem from an
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asteroid, a chunk of rock that normally doesn't produce a tail.
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Till recently, the geminid had only ever been studied from
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Earth. But now scientists have used observations from NASA's
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Parker Solar probe mission to study the sun to deduce that the
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geminid may have been created by a violent catastrophic event
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such as a high speed collision with another body or some
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gaseous explosion.
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The findings reported in the planetary science journal
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narrowed down hypotheses about the asteroid's composition in
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history which may explain its unconventional behavior. One of
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the study's authors, Jamie Sale from Princeton University says
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asteroids are sort of like little time capsules dating back
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to the formation of the solar system.
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They were formed when it was formed and understanding their
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composition gives scientists another feature of the puzzle of
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the solar system's history. Unlike most known meteor showers
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that come from comets which are made up of ice and dust, the
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geminid stream seems to originate from an asteroid.
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A huge chunk of rock and metal cataloged as 3200 ft on the
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study's co-author wolf cougar also from Princeton says most
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meteoroid storms are formed by way of cometary debris trails.
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So it's unusual that this one is formed from an asteroid.
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Additionally, the streams actually orbiting slightly
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outside its pa and body when it's closest to the sun.
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When a comet travels close to the sun, it gets hotter, that
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heat causes ice on the surface and inside the comet to release
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lots of gas. Some of which drags bits of dust and ice with it and
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that forms a halo around the comet nucleus and also creates
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spectacular cometary tails. This material continues to troll
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behind the comet as it stays within the sun's gravitational
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pole.
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And over time, this repeated process fills the orbit of the
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parent body with material to form a meteoroid stream. But
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because asteroids like 3200 Faton are made of rock and
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metal, they're not typically affected by the sun's heat. In
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the same way, comets are that leaves scientists wondering
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exactly what's causing the formation of 3200 photos meteor
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stream across the night sky.
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Now, in the past, astronomers have seen bits of 1200 ft on
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flake off the parent body under the blistering head of the sun
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around closest approach. It's also been suggested a 1200 ft on
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which appears to be on a cometary orbit. Not that of a
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typical asteroid may be a dead comet one that's lost all its
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ice leaving behind only a rocky core which resembles an
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asteroid.
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But this is where the New Parker Solar probe data comes in. It
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shows that while some of the 30 to photons activities are
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related to temperature, the creation of the geminid stream
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itself was likely caused by something catastrophic to learn
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more.
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The authors used the New Parker Solar probe data to model three
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possible formation scenarios. And they then compare these
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models to existing models created from Earth based
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observatories. These different models reflect the chain of
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events which would transpire according to the laws of physics
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based on different scenarios.
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And the authors found that a violent collision with another
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object or alternatively a gaseous explosion rather than
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just being baked by the sun on a close approach was most
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consistent with the Parker Solar probe data and probably best
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explains the genes we see now this space time and time to take
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another brief look at some of the other stories making news in
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science.
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This week with the science report, archaeologists have
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discovered the oldest known caving gravings made by
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Neanderthals ever found in France.
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The findings reported in the journal plans are thought to be
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over 57 years old based on the shape spacing and
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arrangement of these engravings. Scientists think they're
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deliberate organized and intentional finger fluting
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created by human hands. Further dating of the cave found that it
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would have become closed off by infilling sediment around 57
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years ago.
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Long before Homo sapiens were established in the region. This
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combined with the stone tools found in the cave strongly
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suggest the engravings are work of Neanderthals and suggested
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their behavior and culture may have been similarly complex and
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diverse as those of Homo sapiens.
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A new study has found that as men age, some of their cells
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lose the very thing that makes them biological males, they're Y
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chromosomes and it turns out this loss hampers the body's
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ability to fight cancer.
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The study reported in the journal nature found the loss of
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the Y chromosome helps cancer cells evade the body's immune
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system. This apparently common impact in the aging process in
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men results in aggressive bladder cancer but somehow also
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renders the disease more vulnerable and responsive to a
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standard treatment called immune checkpoint inhibitors.
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Now, based on their research, scientists developing a test for
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the loss of the Y chromosome in tumors. With the goal of helping
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clinicians tailor immune checkpoint inhibitor treatments
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for male patients with bladder cancer.
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A new study shows that one of the largest carnivores ever to
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live on the face of the Earth, the gigantic shark, Megalodon
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was warm blooded. The findings reported in the journal, the
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proceedings of the National Academy Of Sciences confirms
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that Megalodon s body temperature was much higher than
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previously thought.
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Megalodon, which lived in the oceans between 23 million and
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3.6 million years ago, could reach lengths of over 20 m or 60
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ft and was the apex predator of the ocean during its reign.
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Previous studies had suggested that Megalodon was likely warm
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blooded or more precisely regionally endo thermic, just
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like some modern day sharks, including Karine Karri, the
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great white or white pointer.
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We've previously reported average body temperatures
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ranging from 22 to 26.6 degrees Celsius, which could be between
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10 and 21 degrees Celsius higher than ambient ocean temperatures.
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However, the new study instead suggests that Megalodon had an
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overall average body temperature of 27 degrees Celsius. And while
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previous studies were based on pure inference, the new research
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provides the first empirical evidence of warm bloodedness in
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the extinct shark. See, the research team used a novel
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geochemical technique.
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It involved both clumped isotope, thermometry and
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phosphate oxygen isotope thermometry in order to test the
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Megalodon endothermic hypothesis. The new study found
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that Megalodon had a body temperature significantly higher
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than sharks considered cold blooded or ecto. The mic
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consistent with the fossil shark having a degree of internal heat
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production as modern warm blooded animals.
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Do hackers find a new way to get around voice authentication
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security systems and using artificial intelligence to
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determine which songs are likely to be hits and which are misses
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with the details. We're joined by technology editor Alex
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Zaharov-Reutt from Tech Visar live.
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Alex Zaharov-Reutt: Well, computer scientists at Canada's
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University Of Waterloo have discovered a method of attack
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and can successfully bypass voice authentication security
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systems and they're claiming up to a 99 per cent success rate
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after only six tries.
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Now, obviously, this is bad news for the voice authentication
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systems used by banks and government departments call
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centers, etc, where they let you log into services by voice and
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normally you enroll your voice print by repeating a certain
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phrase in your own voice.
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The system then extracts your unique vocal signature or voice
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print and you can log in and when you repeat a different
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phrases in the future, they will compare those two. But obviously
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hackers figured out they could use deep fakes to generate
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convincing copies of your voice.
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And so that obviously led to people making voice
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authentication systems to come up with defenses, spoofing
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counter measures. But the University Of Waterloo
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researchers have identified markers in deep fake audio that
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betray that it is being computer generated.
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And they wrote a program that removes these markers, making it
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indistinguishable from authentic audio. So they tested it against
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Amazon connects voice authentication system. Now,
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that's a bit more advanced. They only had a 10% success rate in
00:19:58
14 2nd attack. This rate rose to over 40% in less than 30
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seconds.
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But with some of the less sophisticated voice
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authentication systems, they targeted, they achieved a 99%
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success rate after six attempts. And they're saying that the only
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way to create a secure system is to think like an attacker. If
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you don't, you're just wanting to be attacked.
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And they say that by demonstrating the insecurity of
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voice authentication, we hope that companies relying on voice
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authentication as their only authentication factor will
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consider deploying additional or stronger authentication
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measures.
00:20:27
And this is what's very important to use the Google or
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Microsoft or some sort of other authentication app and not rely
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upon the SMS messages that come through. Because if somebody
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steals a thing out of your phone or convinces a phone company to
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transfer your SIM over to an E SIM in one of their phones.
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And you have all of your banking and other systems set up to
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receive an SMS message. They'll get those messages you won't.
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And a lot of people have been caught in that way. So
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definitely use as many factors of authentication as you can and
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voice is sadly not invulnerable.
00:20:55
Stuart Gary: And the other big story this week has been AI has
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now moved into the music industry in a different way to
00:21:00
what one might expect by looking at your heartbeat and being to
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work out what you're into.
00:21:05
Alex Zaharov-Reutt: Yeah, look, this was because the US
00:21:07
Entertainment magazine variety revealed last year that there
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are over 100 songs released every single day to all the
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major streaming services like Spotify, Apple Music and others.
00:21:17
And the problem is that whether it's using human intuition,
00:21:21
aided by existing algorithms to analyze the song's lyrics and
00:21:24
other metadata to predict hits, they're only getting about a 50
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per cent success rate, which is sort of one in two.
00:21:29
So Paul Jz, a professor at Claremont Graduate University
00:21:34
and the senior author of this study was telling Z magazine
00:21:38
that they use neurological data and AI techniques to see how our
00:21:41
brains respond to music. And Zach stated that my lab
00:21:44
previously identified what appears to be the brain's
00:21:47
valuation system for social and emotional experiences, which is
00:21:51
called immersion.
00:21:52
And in talks to the streaming service, he says they told me
00:21:54
that they struggled to suggest new music for subscribers due to
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the high volume of new music, 1000 songs every day is a lot. I
00:22:00
mean, sadly most of it's crap, all the hits from the last
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century.
00:22:05
But you know, so he says that he thought that measuring this
00:22:08
neurologic immersion could help solve the problems. And so he
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had 33 participants from the university campus and from the
00:22:15
community and they fitted them with non invasive neurop
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physiological recording devices using commercially available off
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the shelf devices such as cardiac sensors on smart
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watches.
00:22:26
And then they fed this data into their immersion Neuroscience
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platform, which uses this data including a person's heart rate
00:22:32
to infer neural states from the activity of cranial nerves.
00:22:37
And so basically, by using these brain signals, they looked at 24
00:22:41
recently released songs from a streaming service and they
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looked at three months of data to see whether the song was a
00:22:45
hit or not based on the number of plays. And this set of songs
00:22:49
included both hits and flops.
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And at least 700 listens on a particular service could tell
00:22:55
that from their results. When people were listening, they
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could tell 97 per cent of the time whether the song was a hit
00:23:00
or a flop and the strength of the system lies in the fact,
00:23:02
these signals can be measured with something as simple as a
00:23:05
smart watch or fitness armband.
00:23:06
Whereas brain activity is typically recorded using
00:23:09
cumbersome lab equipment. So whether this means we're going
00:23:12
to hear a sea of sort of same, same songs that AI says is a hit
00:23:16
or not. I don't know that's.
00:23:18
Stuart Gary: Alex Sahara Roy from Tech Advice dot life.
00:23:37
And that's the show for now. SpaceTime is available every
00:23:40
Monday, Wednesday and Friday through Apple podcasts, itunes,
00:23:44
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