SpaceTime Series 27 Episode 140
*Revisiting the Milky Way's Black Hole Image
A new study questions the accuracy of the first-ever image of Sagittarius A, the supermassive black hole at the centre of the Milky Way. Researchers suggest the image may not accurately represent its appearance, proposing a more elongated accretion disc instead of the ring-like structure previously released by the Event Horizon Telescope.
*Methane in Titan's Crust
Data from NASA's Cassini spacecraft indicates that Saturn's moon Titan may have a methane-rich crust up to 10 kilometres thick. This insulating layer could explain Titan's shallow impact craters and its methane-rich atmosphere, providing insights into its unique geological and atmospheric dynamics.
*Updates on Earth's Ozone Hole
NASA reports that the annual ozone hole over Antarctica was smaller this year, ranking as the seventh smallest since recovery efforts began. The ozone layer is on track to fully recover by 2066, thanks to international agreements curbing ozone-depleting chemicals.
The Science Report
Antarctic ice core samples suggest Earth has already surpassed a 1.5°C global temperature rise due to human-induced climate change. A study links outdoor lighting at night to increased Alzheimer's risk for those under 65. LED lights on surfboards could reduce shark attacks by mimicking natural camouflage. Nord's latest survey reveals continued use of weak passwords, with "123456" and "password" among the most common.
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00:00 New study suggests first ever picture of Milky Way's black hole might not be accurate
00:47 New study claims first ever images of Sagittarius A may be inaccurate
03:57 New study suggests Saturn's moon Titan may have an insulating methane crust
09:12 Scientists say Antarctic ozone layer could fully recover by 2066
20:04 New study suggests Earth has already passed 1.5 degrees Celsius warming attributable to climate change
21:24 A new study claims exposure to outdoor lighting at night increases Alzheimer's risk
25:29 Space Time with Stuart Gary is available on numerous podcast platforms
Episode link: https://play.headliner.app/episode/24171840?utm_source=youtube
00:00:00 --> 00:00:03 this is spacetime series 27 episode 140
00:00:03 --> 00:00:06 for broadcast on the 20th of November
00:00:06 --> 00:00:09 2024 coming up on space time a new study
00:00:09 --> 00:00:11 suggest the first ever picture of the
00:00:11 --> 00:00:13 Milky Ways black hole might not be
00:00:13 --> 00:00:16 accurate claims that methane might be
00:00:16 --> 00:00:18 infused in the crust of the saturnian
00:00:18 --> 00:00:22 Moon Titan and NASA's latest update on
00:00:22 --> 00:00:24 Earth's ozone hole all that and more
00:00:24 --> 00:00:27 coming up on
00:00:27 --> 00:00:30 SpaceTime welcome to SpaceTime with
00:00:30 --> 00:00:40 Stuart
00:00:40 --> 00:00:46 [Music]
00:00:46 --> 00:00:49 Gary a new study claims that those
00:00:49 --> 00:00:51 historic first ever images of
00:00:51 --> 00:00:53 Sagittarius A star that's the super
00:00:53 --> 00:00:55 massive black hole at the center of our
00:00:55 --> 00:00:57 Milky Way galaxy might not be a true
00:00:57 --> 00:01:00 reflection of its actual appearance the
00:01:00 --> 00:01:02 astronomers behind the new analysis say
00:01:02 --> 00:01:04 that their study points the Sagittarius
00:01:04 --> 00:01:07 A star having a more elongated accretion
00:01:07 --> 00:01:09 disc as opposed to the ring like donut
00:01:09 --> 00:01:12 image released back in 2022 by The Event
00:01:12 --> 00:01:15 Horizon telescope collaboration located
00:01:15 --> 00:01:18 some 27 light years away Sagittarius
00:01:18 --> 00:01:21 A star has some 4.3 million times the
00:01:21 --> 00:01:24 mass of the Sun and it's the central
00:01:24 --> 00:01:26 Pivot Point around which our entire
00:01:26 --> 00:01:29 Milky Way galaxy revolves the event
00:01:29 --> 00:01:32 Horizon telescope collaboration's image
00:01:32 --> 00:01:34 shows a central dark region where the
00:01:34 --> 00:01:37 black hole resides circled By the Light
00:01:37 --> 00:01:38 coming from superhe headed gas being
00:01:38 --> 00:01:42 accreted by immense gravitational forces
00:01:42 --> 00:01:43 but this new report in the monthly
00:01:43 --> 00:01:45 notices of the Royal Astronomical
00:01:45 --> 00:01:47 Society suggest that part of this
00:01:47 --> 00:01:49 appearance may actually be an artifact
00:01:49 --> 00:01:51 caused by the way the image was put
00:01:51 --> 00:01:54 together the study's lead author miosi
00:01:54 --> 00:01:55 Makoto from the national astronomical
00:01:55 --> 00:01:58 Observatory of Japan says their new
00:01:58 --> 00:02:00 image is slightly more Elon gated in the
00:02:00 --> 00:02:02 east west Direction and the eastern half
00:02:03 --> 00:02:05 is brighter than the Western segment
00:02:05 --> 00:02:07 Moto says this appearance means the
00:02:07 --> 00:02:09 accretion dis surrounding the black hole
00:02:09 --> 00:02:11 is rotating at about 60% the speed of
00:02:11 --> 00:02:14 light he hypothesizes that the Ring
00:02:14 --> 00:02:16 image resulted from errors during the
00:02:16 --> 00:02:18 event Orizon telescopes Imaging analysis
00:02:19 --> 00:02:21 and that part of it was an artifact
00:02:21 --> 00:02:23 rather than the actual astronomical
00:02:23 --> 00:02:25 structure The Event Horizon telescope
00:02:25 --> 00:02:27 observed Sagittarius AAR in
00:02:27 --> 00:02:30 2017 they used a network of eight
00:02:30 --> 00:02:32 groundbased radio telescopes using a
00:02:32 --> 00:02:34 technique known as radio interferometry
00:02:35 --> 00:02:36 to combine the results of these various
00:02:36 --> 00:02:39 telescopes into a single image the
00:02:39 --> 00:02:41 results of all these observations were
00:02:41 --> 00:02:43 then published in
00:02:43 --> 00:02:46 2022 it showed an image of a bright ring
00:02:46 --> 00:02:48 structure surrounding a central dark
00:02:48 --> 00:02:50 region indicating the presence of a
00:02:50 --> 00:02:52 black hole now in contrast to typical
00:02:52 --> 00:02:54 photography data from these observations
00:02:54 --> 00:02:57 linking several widely separated radio
00:02:57 --> 00:02:59 telescopes contain gaps and that
00:02:59 --> 00:03:01 requires special algorithms to construct
00:03:01 --> 00:03:04 a complete image from the available data
00:03:04 --> 00:03:06 in the new analysis M and colleagues
00:03:06 --> 00:03:08 applied more traditional methods to the
00:03:08 --> 00:03:10 event horizon data although the
00:03:10 --> 00:03:12 appearance of Sagittarius AAR put
00:03:12 --> 00:03:14 forward in the new paper differs from
00:03:14 --> 00:03:16 the results of the Event Horizon team
00:03:16 --> 00:03:18 both are plausible structures derived
00:03:18 --> 00:03:20 from the data using their respective
00:03:20 --> 00:03:24 methods this is spacetime still to come
00:03:24 --> 00:03:26 a new study looking at data from Nas's
00:03:26 --> 00:03:28 Cassini spacecraft suggests that
00:03:28 --> 00:03:30 Saturn's moon Titan has an insulating
00:03:30 --> 00:03:33 methane Rich crust which could be up to
00:03:33 --> 00:03:35 10 km thick and nessa's released its
00:03:36 --> 00:03:38 latest update on the size of Earth's
00:03:38 --> 00:03:40 ozone hole all that and more still to
00:03:40 --> 00:03:49 come on
00:03:49 --> 00:03:56 [Music]
00:03:56 --> 00:03:59 SpaceTime a new study looking at data
00:03:59 --> 00:04:01 from Mass Cassini spacecraft suggest
00:04:01 --> 00:04:03 that Saturn's moon Titan could have an
00:04:03 --> 00:04:06 insulating methane Rich crust which
00:04:06 --> 00:04:09 could be up to 10 km thick Titan has a
00:04:09 --> 00:04:12 special place in our solar system you
00:04:12 --> 00:04:14 see it's the only World other than Earth
00:04:14 --> 00:04:17 which is a thick atmosphere and where
00:04:17 --> 00:04:19 rain falls onto the ground forming
00:04:19 --> 00:04:21 streams and rivers which eventually flow
00:04:21 --> 00:04:24 into lakes and seas but because Titan's
00:04:24 --> 00:04:26 extremely cold the liquids there aren't
00:04:26 --> 00:04:29 water but rather hydrocarbons like
00:04:29 --> 00:04:32 methane and ethane and on Titan water is
00:04:32 --> 00:04:34 frozen solid forming the planet's
00:04:34 --> 00:04:37 Bedrock the new findings reported in the
00:04:37 --> 00:04:39 planetary science journal revealed that
00:04:39 --> 00:04:41 methane gas may also be trapped within
00:04:41 --> 00:04:43 the ice forming a distinct crust up to
00:04:44 --> 00:04:46 10 km thick which warms the underlying
00:04:46 --> 00:04:49 ey shell and may also explain Titan's
00:04:49 --> 00:04:51 methane Rich atmosphere the new
00:04:51 --> 00:04:53 observations are based on a fresh
00:04:53 --> 00:04:55 analysis of Titan's impact crators which
00:04:55 --> 00:04:57 it turns out are hundreds of meters
00:04:57 --> 00:05:00 shallower than expected also only 90
00:05:00 --> 00:05:02 impact craters has been identified on
00:05:02 --> 00:05:06 Titan now this is a world some 5 km
00:05:06 --> 00:05:09 wide that's 50% larger than the Earth's
00:05:09 --> 00:05:12 moon and 80% more massive in fact Titan
00:05:12 --> 00:05:14 the second largest moon in the solar
00:05:14 --> 00:05:16 system after Jupiter's moon ganim and
00:05:17 --> 00:05:19 it's larger than the planet Mercury so
00:05:19 --> 00:05:22 why does it only have 0 craters where
00:05:22 --> 00:05:24 places like the moon and mercury a smack
00:05:24 --> 00:05:27 bang full of thousands of craters the
00:05:27 --> 00:05:29 study's lead author luren schum from the
00:05:29 --> 00:05:31 University of Hawaii says this was a
00:05:31 --> 00:05:33 very surprising result because based on
00:05:33 --> 00:05:35 other moons one would expect to see far
00:05:35 --> 00:05:37 more impact craters on the surface and
00:05:37 --> 00:05:39 the craters should also be much deeper
00:05:39 --> 00:05:42 than what are observed on Titan all that
00:05:42 --> 00:05:44 suggests something unique is happening
00:05:44 --> 00:05:46 on Titan which must firstly be making
00:05:46 --> 00:05:48 the creators shallower and then making
00:05:48 --> 00:05:50 them disappear relatively quickly so
00:05:50 --> 00:05:52 shumay and colleagues develop computer
00:05:52 --> 00:05:54 models to see how the Topography of
00:05:54 --> 00:05:56 Titan might relax and then rebound after
00:05:56 --> 00:05:59 an impact event if the ey shell was
00:05:59 --> 00:06:00 covered with a layer of insulating
00:06:00 --> 00:06:03 methane clathrate ice a kind of solid
00:06:03 --> 00:06:05 water ice with methane gas trapped
00:06:05 --> 00:06:07 within the crystalline structure now
00:06:07 --> 00:06:09 since the initial shape of Titan's cred
00:06:09 --> 00:06:11 is is unknown the author modeled and
00:06:11 --> 00:06:14 compared two plausible initial depths
00:06:14 --> 00:06:15 based on Fresh looking cred is of
00:06:15 --> 00:06:18 similar size on the similar sized icy
00:06:18 --> 00:06:20 Moon gany made they were able to
00:06:20 --> 00:06:22 constrain the methane clathrate cross
00:06:22 --> 00:06:25 thickness to between 5 10 km because
00:06:25 --> 00:06:27 simulations using that thickness produce
00:06:27 --> 00:06:29 crater depths that best match the observ
00:06:29 --> 00:06:33 ations shumi says the methane clathrate
00:06:33 --> 00:06:35 crust warms Titan's interior that causes
00:06:36 --> 00:06:38 a surprisingly rapid topographic
00:06:38 --> 00:06:40 relaxation and that results in creat a
00:06:40 --> 00:06:42 shallowing at a rate similar to that of
00:06:42 --> 00:06:45 fast moving warm glaciers on Earth
00:06:45 --> 00:06:47 estimating the thickness of the methane
00:06:47 --> 00:06:49 Isel is important because it may help
00:06:49 --> 00:06:51 explain the origin of Titan's methane
00:06:51 --> 00:06:53 Rich atmosphere and it helps researchers
00:06:53 --> 00:06:55 understand Titan's carbon cycle liquid
00:06:55 --> 00:06:58 methane-based hydrological cycle and
00:06:58 --> 00:07:01 changing climate shumaya says Titans a
00:07:01 --> 00:07:03 natural laboratory to study how the
00:07:03 --> 00:07:05 greenhouse gas methane warms and Cycles
00:07:05 --> 00:07:07 through the atmosphere Earth's Own
00:07:07 --> 00:07:09 methane clate hydrates found in the
00:07:09 --> 00:07:11 permafrost of Siberia and below the
00:07:11 --> 00:07:13 Arctic seaf Flor are currently
00:07:13 --> 00:07:16 destabilizing and releasing methane now
00:07:16 --> 00:07:18 methane is four times worse as a
00:07:18 --> 00:07:21 greenhouse gas than carbon dioxide and
00:07:22 --> 00:07:23 as Earth is heating up more and more
00:07:24 --> 00:07:27 methane is being released so lessons
00:07:27 --> 00:07:28 from Titan can provide important
00:07:28 --> 00:07:30 insights into into the process which is
00:07:30 --> 00:07:32 happening here on Earth and the
00:07:32 --> 00:07:35 topography scene on Titan makes sense in
00:07:35 --> 00:07:37 the light of these new findings
00:07:37 --> 00:07:38 constraining the thickness of the
00:07:38 --> 00:07:40 methane clathrate ice crust indicates
00:07:40 --> 00:07:43 the Titan's interior is likely warm not
00:07:43 --> 00:07:45 cold rigid and inactive as previously
00:07:45 --> 00:07:48 thought you see methane clathrate is
00:07:48 --> 00:07:50 stronger and more insulating than
00:07:50 --> 00:07:52 regular water ice a clathrate crust
00:07:53 --> 00:07:55 insulates Titan's interior making the
00:07:55 --> 00:07:57 water eyes shell very warm and ductile
00:07:57 --> 00:07:59 and implies that Titan's eye shell is or
00:08:00 --> 00:08:02 at least was slowly convecting and
00:08:02 --> 00:08:05 that's important because if life exists
00:08:05 --> 00:08:07 or ever has existed in Titans oceans
00:08:07 --> 00:08:09 under its thick ey shell any biomarkers
00:08:09 --> 00:08:11 would need to be transported up through
00:08:11 --> 00:08:13 Titan's ey shell to the surface where
00:08:13 --> 00:08:15 scientists could more easily access it
00:08:15 --> 00:08:18 or at least view it with future missions
00:08:18 --> 00:08:20 with NASA's dragonfly Mission the Titan
00:08:20 --> 00:08:22 scheduled to launch in July 2028 with
00:08:22 --> 00:08:25 arrival on the saturnian moon in 2034
00:08:25 --> 00:08:27 researchers will have an opportunity to
00:08:27 --> 00:08:29 make up close observations of this Moon
00:08:29 --> 00:08:32 and further investigate its icy surface
00:08:32 --> 00:08:36 needless to say we'll keep you informed
00:08:36 --> 00:08:39 this is spacetime still to come NASA
00:08:39 --> 00:08:41 provides its latest update on Earth's
00:08:41 --> 00:08:43 ozone hole and later in the science
00:08:43 --> 00:08:45 report new Antarctic core sample
00:08:46 --> 00:08:48 suggests planet earth has already passed
00:08:48 --> 00:08:52 1.5° C of global temperature rise above
00:08:52 --> 00:08:54 pre-industrial levels all that and more
00:08:54 --> 00:09:12 still to come on SpaceTime
00:09:12 --> 00:09:14 a new study has found that the annual
00:09:14 --> 00:09:16 ozone Hall that opens up above Earth's
00:09:16 --> 00:09:18 South Pole Antarctic region every year
00:09:18 --> 00:09:20 was relatively smaller this year
00:09:21 --> 00:09:22 scientists with NASA and the national
00:09:22 --> 00:09:24 oceanographic and Atmospheric
00:09:24 --> 00:09:26 Administration Noah suggests that at
00:09:26 --> 00:09:28 this present rate the oan layer could
00:09:28 --> 00:09:30 fully recover by
00:09:30 --> 00:09:32 2066 during The Pick of the ozone
00:09:32 --> 00:09:34 depletion season between September the
00:09:34 --> 00:09:37 7th and October the 13th the 2024 area
00:09:37 --> 00:09:39 of ozone Hall ranked the seventh
00:09:39 --> 00:09:42 smallest since recovery began in
00:09:42 --> 00:09:44 1992 that's when the Montreal protocol
00:09:44 --> 00:09:46 Landmark International agreement to
00:09:46 --> 00:09:48 phase out ozone depleting chemicals
00:09:48 --> 00:09:51 began to take effect at almost 20
00:09:51 --> 00:09:54 million square kilomet the monthly
00:09:54 --> 00:09:56 average ozone depletion region in the
00:09:56 --> 00:09:58 Antarctic this year was still nearly
00:09:58 --> 00:10:01 three times the size of Australia the
00:10:01 --> 00:10:03 hole reached its greatest one-day extent
00:10:03 --> 00:10:05 for the year on September the 28th when
00:10:05 --> 00:10:08 it was 22.4 million square kilm
00:10:08 --> 00:10:11 scientists describ the ozone hole as the
00:10:11 --> 00:10:13 area in which the ozone concentrations
00:10:13 --> 00:10:14 have dropped below the historical
00:10:14 --> 00:10:19 threshold of 220 Dobson units in 2024
00:10:19 --> 00:10:20 the concentration reached its lowest
00:10:20 --> 00:10:23 value of 109 Dobson units on October the
00:10:23 --> 00:10:26 5th the lowest value ever recorded over
00:10:26 --> 00:10:29 the South Pole was 92 Dobson units back
00:10:29 --> 00:10:32 in October 2006 the Improvement is due
00:10:32 --> 00:10:34 to a combination of continuing declines
00:10:34 --> 00:10:36 in the use of harmful
00:10:36 --> 00:10:38 chlorofluorocarbons or cfc's along with
00:10:38 --> 00:10:40 an unexpected infusion of ozone carried
00:10:40 --> 00:10:42 by air currents from north of the
00:10:42 --> 00:10:45 Antarctic in previous years NASA and no
00:10:45 --> 00:10:47 have reported the ozone hole ranking
00:10:47 --> 00:10:50 using a time frame dating back to
00:10:50 --> 00:10:52 1979 that's when scientists began
00:10:52 --> 00:10:54 tracking Antarctic ozone levels using
00:10:54 --> 00:10:57 satellite data using that longer record
00:10:57 --> 00:10:59 this year's hole ranked as the 20th
00:10:59 --> 00:11:02 smallest in area across 45 years of
00:11:02 --> 00:11:04 continuous observations the chief of
00:11:04 --> 00:11:07 earth scientists Paul Newman from NASA's
00:11:07 --> 00:11:09 G out space flight center in greenb Belt
00:11:09 --> 00:11:11 Maryland says the gradual improvements
00:11:11 --> 00:11:13 seen over the past two decades shows
00:11:13 --> 00:11:15 that International efforts to curb ozone
00:11:15 --> 00:11:18 deputing chemicals are working and
00:11:18 --> 00:11:20 that's important you see the ozone Rich
00:11:20 --> 00:11:22 layer high in the Earth's atmosphere
00:11:22 --> 00:11:24 acts as a planetary sunscreen helping to
00:11:24 --> 00:11:26 Shield the Earth from harmful
00:11:26 --> 00:11:29 ultraviolet radiation from the Sun areas
00:11:29 --> 00:11:31 with depleted ozone allow more
00:11:31 --> 00:11:33 ultraviolet radiation to reach the
00:11:33 --> 00:11:36 Earth's surface and that results in
00:11:36 --> 00:11:38 increased cases of skin cancer and
00:11:38 --> 00:11:40 cataracts excessive exposure to
00:11:40 --> 00:11:42 ultraviolet light can also reduce
00:11:42 --> 00:11:44 agricultural yields and it can damage
00:11:44 --> 00:11:47 aquatic plants and animals in vital
00:11:47 --> 00:11:50 ecosystems by the mid 1980s the ozone
00:11:50 --> 00:11:52 layer had been depleted to such an
00:11:52 --> 00:11:54 extent that broad areas of the Antarctic
00:11:54 --> 00:11:56 Stratosphere are essentially devoid of
00:11:56 --> 00:11:59 ozone by early October each year sources
00:12:00 --> 00:12:02 of damaging cfc's included coolants in
00:12:02 --> 00:12:04 refrigerators and air conditioners as
00:12:04 --> 00:12:06 well as aerosols in Hairspray
00:12:06 --> 00:12:09 antiperspirant and spray paints harmful
00:12:09 --> 00:12:11 chemicals were also released in the
00:12:11 --> 00:12:14 manufacturing of insulation foam and as
00:12:14 --> 00:12:15 components of industrial fire
00:12:15 --> 00:12:18 suppression systems scientists rely on a
00:12:18 --> 00:12:20 combination of different systems to
00:12:20 --> 00:12:23 monitor the ozone layer these include
00:12:23 --> 00:12:25 instruments aboard NASA's Ora satellite
00:12:25 --> 00:12:28 the Noah 20 and Noah 21 satellites and
00:12:28 --> 00:12:31 the suomi NPP satellite which is jointly
00:12:31 --> 00:12:33 operated by NASA and Noah Noah
00:12:33 --> 00:12:35 scientists also released instrumented
00:12:35 --> 00:12:37 weather balloons from the South Pole
00:12:37 --> 00:12:39 Baseline atmospheric Observatory to
00:12:39 --> 00:12:42 monitor ozone concentrations directly
00:12:42 --> 00:12:46 overhead this report from NASA
00:12:46 --> 00:12:49 TV have you ever heard that something
00:12:49 --> 00:12:51 called the ozone layer is thinning or
00:12:51 --> 00:12:53 that your aerosol hairspray is what's
00:12:53 --> 00:12:55 causing it or that it leads to more
00:12:55 --> 00:12:58 severe sunburns Nu UV rays this is
00:12:58 --> 00:13:00 referring to the ozone hole but what
00:13:00 --> 00:13:02 exactly does it all mean welcome to
00:13:03 --> 00:13:05 Ozone
00:13:06 --> 00:13:08 101 the ozone hole's proper name is
00:13:08 --> 00:13:10 actually the Antarctic ozone hole
00:13:10 --> 00:13:13 because when it forms it forms over
00:13:13 --> 00:13:15 Antarctica but before we get into what
00:13:15 --> 00:13:17 that is let's first talk about what
00:13:17 --> 00:13:21 ozone itself is Ozone is a gas comprised
00:13:21 --> 00:13:24 of three oxygen atoms about 90% of the
00:13:24 --> 00:13:26 Earth's ozone exists in the stratosphere
00:13:27 --> 00:13:28 the layer of the atmosphere that extends
00:13:28 --> 00:13:31 from 8 to about 30 Mi above the earth's
00:13:31 --> 00:13:33 surface in fact the stratosphere is
00:13:33 --> 00:13:36 often referred to as the ozone layer
00:13:36 --> 00:13:38 ozone acts as a sunscreen around the
00:13:38 --> 00:13:41 earth filtering out harmful ultraviolet
00:13:41 --> 00:13:43 radiation or UV rays which are mainly
00:13:43 --> 00:13:46 absorbed in the stratosphere without an
00:13:46 --> 00:13:49 ozone layer UV radiation would sterilize
00:13:49 --> 00:13:51 the Earth with a damaged but still
00:13:51 --> 00:13:53 present ozone layer there would be more
00:13:53 --> 00:13:55 sunburns more skin cancer cases
00:13:56 --> 00:13:57 increased cases of eye damage the
00:13:58 --> 00:14:00 wilting and loss trees and plants and
00:14:00 --> 00:14:02 significantly lessened crop yields
00:14:02 --> 00:14:04 suffice it to say ozone is pretty
00:14:04 --> 00:14:07 important for the planet so what causes
00:14:07 --> 00:14:10 the ozone hole there are several major
00:14:10 --> 00:14:12 factors that together lead to the
00:14:12 --> 00:14:15 destruction of ozone thus creating the
00:14:15 --> 00:14:19 ozone hole those factors are one very
00:14:19 --> 00:14:21 strong winds around the South Pole or
00:14:21 --> 00:14:25 the polar vortex two the sun's Rays
00:14:25 --> 00:14:28 three chlorine and bromine compounds
00:14:28 --> 00:14:32 from ozone depleting substances and four
00:14:32 --> 00:14:35 cold temperatures below -19° F in the
00:14:35 --> 00:14:38 stratosphere which form a specific kind
00:14:38 --> 00:14:40 of cloud polar stratospheric
00:14:40 --> 00:14:43 clouds the polar vortex forms in the
00:14:43 --> 00:14:45 southern hemisphere Stratosphere during
00:14:45 --> 00:14:47 the winter as temperatures drop and when
00:14:47 --> 00:14:49 sunlight returns to Antarctica in late
00:14:49 --> 00:14:51 winter and early spring temperatures are
00:14:51 --> 00:14:53 still cold enough to form polar
00:14:53 --> 00:14:55 stratospheric clouds and now there's
00:14:55 --> 00:14:58 also sunlight chemical reactions take
00:14:58 --> 00:15:00 place on on the cloud particle surfaces
00:15:00 --> 00:15:02 converting unreactive forms of chlorine
00:15:03 --> 00:15:05 and bromine into reactive
00:15:05 --> 00:15:08 chemicals The Vortex acts as a sort of
00:15:08 --> 00:15:10 container confining the contents of the
00:15:10 --> 00:15:12 Antarctic Stratosphere within its bounds
00:15:12 --> 00:15:14 allowing the reactive chlorine and
00:15:14 --> 00:15:17 bromine compounds to destroy ozone
00:15:17 --> 00:15:19 molecules that's when depletion can
00:15:19 --> 00:15:22 occur on a large scale with the presence
00:15:22 --> 00:15:24 of sunlight the reactive chlorine and
00:15:24 --> 00:15:26 bromine compounds produced during winter
00:15:26 --> 00:15:28 begin to deplete ozone molecules by
00:15:28 --> 00:15:30 stealing one of their oxygen atoms
00:15:30 --> 00:15:33 leaving just oxygen gas or O2 in its
00:15:33 --> 00:15:36 wake as long as the polar stratospheric
00:15:36 --> 00:15:38 clouds are present these reactions will
00:15:38 --> 00:15:40 occur over and over again until the
00:15:40 --> 00:15:43 ozone is nearly gone this forms what we
00:15:43 --> 00:15:45 call the ozone hole but that's really a
00:15:45 --> 00:15:49 misnomer it's actually more of a thinned
00:15:49 --> 00:15:52 layer in mid to late spring The Vortex
00:15:52 --> 00:15:54 begins to break up and the polar air
00:15:54 --> 00:15:56 depleted of ozone is mixed back in to
00:15:56 --> 00:15:59 the rest of the southern hemisphere
00:15:59 --> 00:16:02 the ozone hole is gone ozone depletion
00:16:02 --> 00:16:05 has still occurred it's just no longer
00:16:05 --> 00:16:07 all concentrated in one small area it's
00:16:08 --> 00:16:10 spread around the atmosphere so why is
00:16:10 --> 00:16:12 the ozone hole bigger and longer lasting
00:16:12 --> 00:16:15 in certain years well it all comes down
00:16:15 --> 00:16:17 to weather just like some Winters are
00:16:17 --> 00:16:19 colder and longer than others on the
00:16:19 --> 00:16:21 Earth's surface the same goes for
00:16:21 --> 00:16:23 weather in the stratosphere if the
00:16:23 --> 00:16:25 Antarctic Stratosphere stays cold the
00:16:25 --> 00:16:28 polar vortex and the ozone hole within
00:16:28 --> 00:16:31 it will persist and in years with cold
00:16:31 --> 00:16:33 Springtime temperatures the polar vortex
00:16:33 --> 00:16:35 and the ozone hole are
00:16:35 --> 00:16:38 large make no mistake ozone depletion is
00:16:38 --> 00:16:41 not a natural thing it stems from Human
00:16:41 --> 00:16:43 emissions of chemicals called
00:16:43 --> 00:16:45 chlorofluorocarbons or
00:16:45 --> 00:16:48 CFCs in the early 1900s refrigerators
00:16:48 --> 00:16:51 used toxic gases like ammonia and methyl
00:16:51 --> 00:16:53 chloride as refrigerants unfortunately
00:16:53 --> 00:16:55 this led to fatalities as the toxic
00:16:55 --> 00:16:58 gases leaked out of the appliances so
00:16:58 --> 00:17:00 the search began for a non-toxic and
00:17:00 --> 00:17:02 non-flammable chemical that could be
00:17:02 --> 00:17:04 used as a refrigerant thus the CFC was
00:17:04 --> 00:17:07 born there are many types of cfc's but
00:17:07 --> 00:17:11 the two most common are cfc1 and CFC
00:17:11 --> 00:17:14 12 in the 1930s the production and
00:17:14 --> 00:17:17 consumption of cfc's began to
00:17:17 --> 00:17:20 Skyrocket by the early 1980s over 300
00:17:20 --> 00:17:23 million pounds of cfc1 alone were being
00:17:23 --> 00:17:27 released into the atmosphere each year
00:17:27 --> 00:17:30 then in 1985 British researcher Joe
00:17:30 --> 00:17:32 farman and his colleagues published
00:17:32 --> 00:17:34 their research on large seasonal ozone
00:17:34 --> 00:17:36 losses over Antarctica thanks to the
00:17:36 --> 00:17:38 combined efforts of the quick acting
00:17:38 --> 00:17:40 science Community industry and policy
00:17:40 --> 00:17:43 makers the Montreal protocol was signed
00:17:43 --> 00:17:46 in 1987 restricting the production and
00:17:46 --> 00:17:49 consumption of cfc's Every Nation on
00:17:49 --> 00:17:50 Earth has now signed the Montreal
00:17:50 --> 00:17:53 protocol so for the record your
00:17:53 --> 00:17:55 hairspray in aerosol deodorant hasn't
00:17:55 --> 00:17:57 been harming ozone since these laws went
00:17:57 --> 00:18:00 into effect in the 80s
00:18:00 --> 00:18:02 but why do we still see an ozone hole
00:18:02 --> 00:18:06 today first cfc's have lifetimes of 50
00:18:06 --> 00:18:08 to 100 plus years and it will take some
00:18:08 --> 00:18:10 time for the concentration of CFCs in
00:18:10 --> 00:18:13 the atmosphere to drastically decline
00:18:13 --> 00:18:15 second there are still CFCs being
00:18:15 --> 00:18:17 released into the atmosphere today for
00:18:17 --> 00:18:20 example as an old refrigerator or air
00:18:20 --> 00:18:22 conditioning unit deteriorates in a
00:18:22 --> 00:18:25 landfill the CFCs within are slowly
00:18:25 --> 00:18:28 released from the time a CFC is released
00:18:28 --> 00:18:30 into the air it takes about 5 years for
00:18:30 --> 00:18:32 its impact to be felt over Antarctica
00:18:32 --> 00:18:35 where depletion will occur the CFC is
00:18:35 --> 00:18:37 emitted at the surface eventually rise
00:18:37 --> 00:18:40 into the tropical Stratosphere the ozone
00:18:40 --> 00:18:42 in the stratosphere blocks most of the
00:18:42 --> 00:18:45 Sun's UV radiation so the CFCs have to
00:18:45 --> 00:18:47 rise above most of the ozone layer
00:18:47 --> 00:18:49 before sunlight can then break them
00:18:50 --> 00:18:52 down once they get high enough solar
00:18:52 --> 00:18:54 radiation releases the chlorine most of
00:18:55 --> 00:18:56 which eventually goes into ozone safe
00:18:56 --> 00:18:58 forms like hydrochloric acid and
00:18:58 --> 00:19:01 chlorine nitrate when these compounds
00:19:01 --> 00:19:03 make their way to Antarctica those
00:19:03 --> 00:19:05 chemical reactions start up and if
00:19:05 --> 00:19:07 you're wondering why Antarctica these
00:19:08 --> 00:19:09 reactions are unique to the polar
00:19:09 --> 00:19:11 regions because of their extreme low
00:19:11 --> 00:19:13 temperatures and presence of polar
00:19:13 --> 00:19:14 stratospheric
00:19:14 --> 00:19:17 clouds one chlorine atom can destroy
00:19:17 --> 00:19:19 thousands of ozone molecules and
00:19:19 --> 00:19:22 millions of tons of CFCs were pumped
00:19:22 --> 00:19:24 into the atmosphere from the 1920s
00:19:24 --> 00:19:26 through the early
00:19:26 --> 00:19:29 1990s as CFC concentr ations in the
00:19:29 --> 00:19:31 atmosphere continue to decline the ozone
00:19:31 --> 00:19:33 hole is expected to gradually become
00:19:33 --> 00:19:36 less severe and scientists expect the
00:19:36 --> 00:19:38 Antarctic ozone to recover back to
00:19:38 --> 00:19:43 healthy levels around the year 2070 this
00:19:43 --> 00:19:57 [Music]
00:19:57 --> 00:19:59 SpaceTime and and time now to take
00:19:59 --> 00:20:00 another brief look at some of the other
00:20:00 --> 00:20:02 stories making news and science this
00:20:02 --> 00:20:05 week with the science report a new study
00:20:05 --> 00:20:07 looking at Antarctic Ice core samples
00:20:07 --> 00:20:09 has suggested that planet earth has
00:20:09 --> 00:20:13 already passed the 1.5° C Global
00:20:13 --> 00:20:15 temperature rise attributable to human
00:20:15 --> 00:20:18 induced climate change the findings
00:20:18 --> 00:20:19 reported in the journal Nature
00:20:19 --> 00:20:21 geoscience used ice cord data to
00:20:21 --> 00:20:23 estimate how Global surface temperatures
00:20:23 --> 00:20:25 and atmospheric carbon dioxide levels
00:20:25 --> 00:20:28 have changed over the past 2 years
00:20:28 --> 00:20:30 researchers say that from their
00:20:30 --> 00:20:32 estimates human induced warming likely
00:20:32 --> 00:20:36 reached 1.49 de C in 2023 compared to a
00:20:36 --> 00:20:38 pre-industrial baseline level from the
00:20:38 --> 00:20:40 1300s to the
00:20:40 --> 00:20:42 1700s preventing global temperatures
00:20:42 --> 00:20:45 from exceeding 1.5° Celsius of warming
00:20:45 --> 00:20:47 has been a key goal of the Paris
00:20:47 --> 00:20:49 agreement made at the United Nations
00:20:49 --> 00:20:51 climate change conference in
00:20:51 --> 00:20:54 2015 the agreement however is faulty as
00:20:54 --> 00:20:57 it allows two of the world's largest CO2
00:20:57 --> 00:21:00 producers namely China and India to
00:21:00 --> 00:21:01 continue polluting the air with
00:21:01 --> 00:21:03 greenhouse gases until
00:21:03 --> 00:21:05 2030 in fact the World Meteorological
00:21:05 --> 00:21:07 organization says China Remains the
00:21:07 --> 00:21:09 world's biggest carbon dioxide polluter
00:21:10 --> 00:21:11 producing a third of the total Global
00:21:12 --> 00:21:14 output that amounts to more than 10.2
00:21:14 --> 00:21:17 million tons annually that's double that
00:21:17 --> 00:21:18 of the United States which is the
00:21:18 --> 00:21:20 world's second worst polluter and four
00:21:20 --> 00:21:24 times that of India which holds third
00:21:24 --> 00:21:27 place a new study claims exposure to
00:21:27 --> 00:21:29 outdoor lighting at night could be
00:21:29 --> 00:21:31 increasing Alzheimer's prevalence more
00:21:31 --> 00:21:33 than any other risk factor for people
00:21:33 --> 00:21:35 aged under
00:21:35 --> 00:21:37 65 the findings reported in the journal
00:21:37 --> 00:21:40 frontiers of Neuroscience studied light
00:21:40 --> 00:21:43 pollution maps for 48 US states and
00:21:43 --> 00:21:44 Incorporated medical data about
00:21:44 --> 00:21:46 variables known or believed to be risk
00:21:46 --> 00:21:49 factors for Alzheimer's they found that
00:21:49 --> 00:21:51 for people aged under 65 Alzheimer's
00:21:51 --> 00:21:53 prevalence was more strongly linked to
00:21:53 --> 00:21:55 NightLight pollution than just about any
00:21:56 --> 00:21:58 other disease Factor including alcohol
00:21:58 --> 00:22:00 abuse use chronic kidney disease
00:22:00 --> 00:22:02 depression and obesity only disease
00:22:02 --> 00:22:04 factors such as diabetes high blood
00:22:04 --> 00:22:06 pressure and stroke were more strongly
00:22:06 --> 00:22:09 linked to alzheimer's than light
00:22:09 --> 00:22:11 pollution scientists have discovered
00:22:11 --> 00:22:13 that adding LED lights to surfboards and
00:22:13 --> 00:22:16 wet suits could be a simple way to
00:22:16 --> 00:22:19 prevent attacks by great white sharks
00:22:19 --> 00:22:20 the study reported in the journal
00:22:20 --> 00:22:22 current biology shows that the lights
00:22:22 --> 00:22:24 act as a type of camouflage confusing
00:22:24 --> 00:22:26 the silhouette which white pointers
00:22:26 --> 00:22:29 normally search for some marine species
00:22:29 --> 00:22:31 emit light from their undersides as a
00:22:31 --> 00:22:33 camouflage strategy because any
00:22:33 --> 00:22:34 Predators below them looking for a snack
00:22:34 --> 00:22:36 would be searching for a shape
00:22:36 --> 00:22:39 illuminated by sunlight from above so
00:22:39 --> 00:22:41 scientists from aquari University tested
00:22:41 --> 00:22:44 a similar strategy by fitting LED lights
00:22:44 --> 00:22:46 on sealed decoys towed behind the boat
00:22:46 --> 00:22:48 to see if different brightness levels
00:22:48 --> 00:22:50 would impact Predator attacks they found
00:22:50 --> 00:22:52 sharks were far more likely to interact
00:22:52 --> 00:22:54 with sealed decoys that didn't have LED
00:22:54 --> 00:22:56 lights attached and the brighter the
00:22:56 --> 00:22:58 light the less likely sharks were to
00:22:58 --> 00:23:01 interact with the fake seals the authors
00:23:01 --> 00:23:03 say that because white poters have poor
00:23:03 --> 00:23:05 visual accurity anyway and they also
00:23:05 --> 00:23:07 lack color vision the strategy is
00:23:07 --> 00:23:10 especially likely to work on
00:23:10 --> 00:23:12 them Nord have just released their
00:23:12 --> 00:23:14 latest Global survey of people's
00:23:14 --> 00:23:17 passwords and the results shocking with
00:23:17 --> 00:23:19 the details we're joined by technology
00:23:19 --> 00:23:22 editor Alex Sahara Roy from Tech advice.
00:23:22 --> 00:23:24 live yeah this is their sixth year of
00:23:24 --> 00:23:25 doing this and they're saying that look
00:23:25 --> 00:23:27 the passwords people are choosing are
00:23:27 --> 00:23:30 still really bad so they've analyzed a
00:23:30 --> 00:23:34 2.5 terabyte database of publicly
00:23:34 --> 00:23:35 available sources obviously they didn't
00:23:35 --> 00:23:37 hack anything themselves they saw what
00:23:37 --> 00:23:39 the passwords were out there that people
00:23:39 --> 00:23:42 were using and look globally the number
00:23:42 --> 00:23:45 one password that people use is 1 123 4
00:23:45 --> 00:23:48 5 6 which is just ridiculous I mean if
00:23:48 --> 00:23:50 this is the password you use you
00:23:50 --> 00:23:52 obviously don't really care about your
00:23:52 --> 00:23:53 digital security I mean would you leave
00:23:53 --> 00:23:55 your house unlocked would you leave your
00:23:55 --> 00:23:57 car unlocked this is also one of the
00:23:57 --> 00:23:59 passwords that people people are using
00:23:59 --> 00:24:00 in business settings and Nord was able
00:24:00 --> 00:24:03 to determine both consumer addresses and
00:24:03 --> 00:24:05 business addresses because well business
00:24:05 --> 00:24:06 name as part of the email address
00:24:06 --> 00:24:08 generally indicates it's from a business
00:24:08 --> 00:24:10 and in Australia the number one password
00:24:10 --> 00:24:13 for both consumers and for businesses is
00:24:13 --> 00:24:16 the word password which is no security
00:24:16 --> 00:24:19 at all well I use nonsequential letterss
00:24:19 --> 00:24:21 numbers and symbols what obviously you
00:24:21 --> 00:24:23 should be using complicated passwords
00:24:23 --> 00:24:25 but the more complicated passwords you
00:24:25 --> 00:24:27 have the harder it is to remember you
00:24:27 --> 00:24:28 want to write them down on a little book
00:24:28 --> 00:24:29 book you wor people are going to take
00:24:29 --> 00:24:31 the book and know your passwords so you
00:24:31 --> 00:24:34 use a password manager now Nord has one
00:24:34 --> 00:24:36 of those Norton 360 has one of those
00:24:36 --> 00:24:39 there's the one password app your phone
00:24:39 --> 00:24:41 whether it's Android or iPhone your
00:24:41 --> 00:24:43 browser they have these in there they
00:24:43 --> 00:24:45 can generate passwords for you and if
00:24:45 --> 00:24:48 you use a password app you only have to
00:24:48 --> 00:24:50 remember one password to be able to get
00:24:50 --> 00:24:51 into that app and then normally those
00:24:52 --> 00:24:54 apps will then fill the passwords in for
00:24:54 --> 00:24:55 you but there's another way where you
00:24:55 --> 00:24:58 can use your device as a pass key so
00:24:58 --> 00:25:00 here you don't have to remember any
00:25:00 --> 00:25:02 passwords at all except one to give to
00:25:02 --> 00:25:05 your phone and then your phone or your
00:25:05 --> 00:25:08 computer can be the actual second or
00:25:08 --> 00:25:10 even third factor of authentication so
00:25:10 --> 00:25:12 in the future we'll have no passwords at
00:25:12 --> 00:25:14 all it'll be your devices it'll be both
00:25:14 --> 00:25:16 a biometric or password to get into the
00:25:16 --> 00:25:18 phone and then your phone itself is the
00:25:18 --> 00:25:20 password so this is a problem of the
00:25:20 --> 00:25:23 current time and I would suggest don't
00:25:23 --> 00:25:25 use really simple passwords that uh give
00:25:25 --> 00:25:27 the bad guys an opportunity to try that
00:25:27 --> 00:25:29 password every else in your life that's
00:25:29 --> 00:25:35 Alex Sahara Roy from Tech advice.
00:25:35 --> 00:25:47 [Music]
00:25:47 --> 00:25:50 live and that's the show for now
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