WEBVTT 1 00:00:00.560 --> 00:00:05.200 This is Spacetime Series twenty seven, episode sixteen, or broadcast on the fifth 2 00:00:05.240 --> 00:00:10.480 of February twenty twenty four. Coming up on Space Time, the Earth's Moon 3 00:00:10.560 --> 00:00:18.839 is shrinking and that means moonquakes for astronauts. NASA's analysis confirms World Meteorological Organization 4 00:00:18.960 --> 00:00:24.320 figures showing that twenty twenty three was the war misteir on record, and a 5 00:00:24.399 --> 00:00:30.120 new study indicates that stars travel more slowly around the edge of the Milky Way. 6 00:00:30.879 --> 00:00:37.320 All that and more coming up on space Time Welcome to Space Time with 7 00:00:37.600 --> 00:00:58.640 Stuart Gary. A new study has confirmed earlier research showing that the Earth's Moon 8 00:00:58.759 --> 00:01:03.239 is shrinking and that it's causing landslides, instability, and moonquakes around the lunar 9 00:01:03.400 --> 00:01:10.920 South Pole. Scientists say the findings will have consequences for the astronauts destined to 10 00:01:11.000 --> 00:01:15.239 explore and ultimately colonize this part of the lunar's surface. The study, reported 11 00:01:15.239 --> 00:01:19.239 in the Planetary Science Journal As shown that the Moon shrank more than forty six 12 00:01:19.359 --> 00:01:26.400 meters in circumference as it's called gradually cooled over the last few hundred million years, 13 00:01:26.439 --> 00:01:30.040 in much the same way as a grape will wrinkle as it shrinks down 14 00:01:30.120 --> 00:01:34.640 to become a raisin. The Moon also develops creases as it shrinks, but 15 00:01:34.879 --> 00:01:38.280 unlike the flexible skin on a grape, the moon surface is brittle, causing 16 00:01:38.359 --> 00:01:45.079 falseter form where sections of crust pushed past one another. Importantly, scientists of 17 00:01:45.200 --> 00:01:49.400 Nardis covered evidence that this shrinking of the Moon's surface has led to notable surface 18 00:01:49.480 --> 00:01:55.640 warping near the lunar South Pole. That's the region where NASA plans on landing 19 00:01:55.719 --> 00:02:00.200 its manned Artemis three mission in two years time. In fact, because of 20 00:02:00.239 --> 00:02:04.640 the South Pole's easy access to water, although in a frozen state deep on 21 00:02:04.680 --> 00:02:08.759 the floors of permanently shaded craters, the South Pole will become the likely main 22 00:02:08.879 --> 00:02:15.520 colonization point for future lunar missions to the lunar surface. The problem is fault 23 00:02:15.560 --> 00:02:21.280 formation caused by the moon shrinkage is often accompanied by searsmic activity like moonquakes, 24 00:02:21.319 --> 00:02:25.199 and locations within or in these such fault zones could post dangers for future human 25 00:02:25.280 --> 00:02:30.280 exploration efforts. The authors have already linked one group of forts located near the 26 00:02:30.280 --> 00:02:35.879 moon south Pole region to one of the most powerful moonquakes ever recorded by the 27 00:02:35.919 --> 00:02:42.159 Apollo seismometers more than fifty years ago. Using models to simulate the stability of 28 00:02:42.199 --> 00:02:46.840 surface slopes within that region. Site has found that some areas were especially vulnerable 29 00:02:46.840 --> 00:02:52.560 to landslides from seismic shaking. The studies lead author Thomas Waters from the National 30 00:02:52.599 --> 00:02:57.759 Air and Space Museum set for Earthen Planetary Studies, says the modeling suggests that 31 00:02:57.919 --> 00:03:02.039 shallow moonquakes capable of bridge using strong ground checking in the South Pole region are 32 00:03:02.120 --> 00:03:07.840 possible from slip events on existing faults or the formation of new thrust faults. 33 00:03:07.439 --> 00:03:12.960 He warns that the lunar global distribution of young thrust faults, their potential to 34 00:03:13.000 --> 00:03:16.439 be active, and the potential to form new thrust faults from ongoing global contraction 35 00:03:16.719 --> 00:03:22.759 should be considered when planning the location and stability of permanent outposts on the Moon. 36 00:03:23.479 --> 00:03:27.400 The study suggest that shallow moonquakes occur near the surface of the Moon, 37 00:03:27.639 --> 00:03:31.360 just one hundred of circular meters deep into the crust. Similar to earthquakes, 38 00:03:31.439 --> 00:03:36.439 shallow moonquakes are caused by faults in the lunar interior, and they can be 39 00:03:36.520 --> 00:03:40.319 strong enough to damage buildings, equipment, and other human made structures. But 40 00:03:40.520 --> 00:03:45.800 importantly, unlike earthquakes, which tend to only last a few seconds or minutes, 41 00:03:46.000 --> 00:03:50.919 shallow moonquakes can last for hours, even a whole afternoon. It means 42 00:03:50.960 --> 00:03:54.919 if we're not careful, shallow moonquakes could devastate any future human settlements on the 43 00:03:54.960 --> 00:04:00.280 Moon. These new findings will help prepare humans for it awaits them when they 44 00:04:00.319 --> 00:04:03.479 do move to the Moon, and that needs to include engineering structures so they 45 00:04:03.520 --> 00:04:11.240 can better withstand Luna seismic activity, thereby protecting people in the danger zones this 46 00:04:11.759 --> 00:04:17.879 space time still to come. A new NASA analysis confirms the World Meteorological Organization's 47 00:04:17.920 --> 00:04:24.240 figures that show twenty twenty three was the warmest Yuron record, and a new 48 00:04:24.279 --> 00:04:29.160 study shows that stars tend to travel more slowly along the outer edge of the 49 00:04:29.199 --> 00:04:33.079 Milky Way Galaxy. All that and more still to come on space time. 50 00:04:49.839 --> 00:04:57.000 A new NASA analysis has confirmed data by the World Meteorological Organization that planetarth average 51 00:04:57.000 --> 00:05:01.920 surface temperature in twenty twenty three was the stone record. Their data shows global 52 00:05:01.959 --> 00:05:08.079 temperatures last year were around one point two degrees celsius above the average for NASA's 53 00:05:08.079 --> 00:05:13.600 baseline period, which is between nineteen fifty one and nineteen eighty. NASA Administrator 54 00:05:13.639 --> 00:05:17.160 Bill Nilson says the studies by both NASA and NOAH. The National Oceanographic and 55 00:05:17.160 --> 00:05:25.000 Atmospheric Administration clearly confirms that planet Earth is facing a climate crisis. In twenty 56 00:05:25.040 --> 00:05:29.639 twenty three, hundreds of millions of people around the world experienced extreme heat, 57 00:05:29.800 --> 00:05:33.600 and each month from June through to December last year set a new global record 58 00:05:33.680 --> 00:05:40.079 for that respective month, and July ended up being the hottest month ever recorded. 59 00:05:40.800 --> 00:05:44.920 Overall, planet Earth was about one point four degrees celsius warmer in twenty 60 00:05:44.959 --> 00:05:48.839 twenty three than it was during the late nineteenth century average that's when modern record 61 00:05:48.920 --> 00:05:54.759 keeping began. Meanwhile, the director of NASA's god At Institute for Space Studies, 62 00:05:54.800 --> 00:05:59.240 Gavin Schmidt, says the exceptional warming isn't something that we've seen before in 63 00:05:59.360 --> 00:06:03.519 human history. He says it is being driven primarily by fossil fuel emissions, 64 00:06:03.759 --> 00:06:09.399 and we're seeing the impacts of this in heat waves, intense rainfall, and 65 00:06:09.480 --> 00:06:14.959 coastal flooding. Those scientists have conclusive evidence that the planet's long term warming trend 66 00:06:15.120 --> 00:06:18.680 is driven by human activity. They're still examining other phenomena that could be affecting 67 00:06:18.839 --> 00:06:24.759 yearly or multi yearly changes in climate, such as el Nina aerosols and pollution, 68 00:06:25.040 --> 00:06:30.439 and volcanic eruptions. Now typically, the largest source of yety of variability 69 00:06:30.439 --> 00:06:34.839 on Earth is the Al Nino Southern Oscillation Index. It's a climate pattern based 70 00:06:34.879 --> 00:06:41.079 around the Pacific Ocean. The pattern has two phases, El Nino and Lininia. 71 00:06:41.720 --> 00:06:46.480 During these phases, see surface temperatures in the Pacific along the equator tend 72 00:06:46.560 --> 00:06:50.959 to switch between warmer average and cool at temperatures. Now, what's been unusual 73 00:06:50.959 --> 00:06:56.000 of late is that between twenty twenty and twenty twenty two, the Pacific Ocean 74 00:06:56.040 --> 00:07:00.959 saw three consecutive Linina events, which tend to cool global temperatures. Then, 75 00:07:01.040 --> 00:07:05.519 in May twenty twenty three, the ocean transition from La Nina to El Nino, 76 00:07:05.720 --> 00:07:11.160 which often coincides with the hottest Jees on record. However, the record 77 00:07:11.199 --> 00:07:15.240 temperatures in the second half of twenty twenty three occurred before the peg of the 78 00:07:15.279 --> 00:07:18.759 current El Nino event, and scientists say they now expect to see the biggest 79 00:07:18.759 --> 00:07:23.839 impacts of El Nina over the next three months. But it's not just El 80 00:07:23.959 --> 00:07:29.480 Nino. Scientists have also been investigating the possible impacts of the January twenty twenty 81 00:07:29.519 --> 00:07:33.839 two eruption of the Hunger tonguahunga Ape under sea volcano, which blasted water, 82 00:07:33.959 --> 00:07:40.519 vapor, and fine particles and aerosols high into the stratosphere. A recent study 83 00:07:40.560 --> 00:07:44.839 found that the volcanic aerosols, by reflecting sunlight away from the Earth's surface, 84 00:07:45.120 --> 00:07:48.360 actually led to an overall slight cooling of the planet by about zero point one 85 00:07:48.360 --> 00:07:54.920 degree celsius that was mainly restricted to the southern hemisphere. Immediately following the eruption, 86 00:07:55.759 --> 00:08:00.800 Nasaus symbols at surface temperature records using air temperature data colling did from tens 87 00:08:00.839 --> 00:08:05.560 of thousands of meteorological stations. There's also sea surface temperature data acquired either by 88 00:08:05.680 --> 00:08:11.959 ship or booy based instruments. All this data is then analyzed using methods that 89 00:08:11.040 --> 00:08:16.680 account for varied spacing of temperature stations around the globe and for things like the 90 00:08:16.800 --> 00:08:22.759 urban heat effect, they could be skewing calculations. Independent analyzes by NOAH and 91 00:08:22.879 --> 00:08:26.160 by the Hadley Center, which is part of the United Kingdom's Met Office, 92 00:08:26.319 --> 00:08:31.319 have also concluded that global surface temperatures for twenty twenty three were the highest since 93 00:08:31.399 --> 00:08:35.000 modern record keeping began. Now, while these scientists are all using the same 94 00:08:35.039 --> 00:08:41.440 temperature data in their analysis. They're using different methodologies, yet they're arriving at 95 00:08:41.480 --> 00:08:46.960 the same conclusions. Although rankings can be slightly different between the records, they're 96 00:08:46.960 --> 00:08:52.240 still all in broad agreement and they clearly show that some ongoing, long term 97 00:08:52.320 --> 00:08:58.600 warming is taking place and has been doing so over recent decades. This report 98 00:08:58.759 --> 00:09:05.480 from NASTV twenty twenty three was the hottest year on record by a large margin. 99 00:09:07.039 --> 00:09:09.840 But why does NASA, a space agency, even look at Earth's temperature 100 00:09:09.879 --> 00:09:31.720 record. Let's start from the beginning. NASA's Goddard Institute for Space Studies or 101 00:09:31.799 --> 00:09:37.679 GIS, creates the global temperature record using land and ocean surface data collected from 102 00:09:37.799 --> 00:09:41.159 thousands of instruments and boobies around the world. But this critical data set of 103 00:09:41.200 --> 00:09:46.799 Earth's temperature has an origin story that starts one hundred million miles away on planet 104 00:09:46.879 --> 00:09:54.639 Venus. It's nine hundred degrees hot of the surface, has powerful high altitude 105 00:09:54.679 --> 00:09:58.360 winds, and is blanketed by a dense carbon dioxide. The GARDIS Suit for 106 00:09:58.399 --> 00:10:03.960 Space Study here in New York was set up in the early nineteen sixties to 107 00:10:03.039 --> 00:10:09.320 provide a connection between NASA and the academic community, and so it was very 108 00:10:09.399 --> 00:10:13.840 much an ideas shop, and so we spent a lot of time with the 109 00:10:13.879 --> 00:10:18.399 formation of galaxies and black holes and panetary program and Voyager, and we were 110 00:10:18.440 --> 00:10:24.960 involved very early on in some of the missions to Venus and Jupiter. Back 111 00:10:24.000 --> 00:10:28.399 then, when GIFs researchers were studying the weather on Venus, scientists noticed something 112 00:10:28.480 --> 00:10:33.399 fascinating. A thick atmosphere made up of clouds and carbon dioxide was trapping heat, 113 00:10:33.879 --> 00:10:37.120 so much heat that Venus had a surface hot enough to melt lead. 114 00:10:37.840 --> 00:10:43.240 This trapping of heat is known as the greenhouse gas effect. One of the 115 00:10:43.279 --> 00:10:48.240 lead Venus researchers, I guess doctor James Hansen, realized that greenhouse gases were 116 00:10:48.240 --> 00:10:52.240 also building up an Earth's atmosphere, so he switched his sights to his home 117 00:10:52.279 --> 00:10:56.039 planet and pledged to model the changing atmosphere of Earth and to verify our ground 118 00:10:56.039 --> 00:11:00.879 truth. As model, he needed real world measurements over time, so he 119 00:11:00.960 --> 00:11:05.759 began keeping track of Earth's global temperature record dating back to eighteen eighty When there 120 00:11:05.799 --> 00:11:11.960 was a sufficient amount of data to pull from, we used our expertise in 121 00:11:11.120 --> 00:11:18.559 understanding literally the clouds of Venus and the clouds and dynamics of Jupiter, and 122 00:11:18.600 --> 00:11:22.120 then we took that and we started to think about how you would do the 123 00:11:22.159 --> 00:11:26.639 same thing for the Earth. Since then, Guests has kept at sights on 124 00:11:26.679 --> 00:11:31.720 the global temperature record, and that was the birth of Gifts as a climate 125 00:11:31.799 --> 00:11:37.840 modeling institution, and scientists have seen a clear trend in that record rising temperatures, 126 00:11:39.320 --> 00:11:43.519 and they know why. The key difference between say, this decade and 127 00:11:43.559 --> 00:11:48.679 the decade before and the decade before that, is that the temperatures have been 128 00:11:48.759 --> 00:11:56.039 rising because of our activities, because of principally the burning of fossil fuels. 129 00:12:00.320 --> 00:12:03.519 Without the presence of humans, Earth's temperature would rise and fall due to a 130 00:12:03.559 --> 00:12:09.440 complex array of natural drivers. With human presence, however, the temperature just 131 00:12:09.519 --> 00:12:16.440 continues to rise. We know that by observing temperature anomalies. Measuring temperature anomalies 132 00:12:16.639 --> 00:12:22.320 means that we look at the change over time rather than absolute temperatures. The 133 00:12:22.440 --> 00:12:26.759 data map isn't showing that the Arctic style warmer temperatures than the tropics. It's 134 00:12:26.799 --> 00:12:30.720 saying the Arctic was that much warmer than the Arctic has been in previous years, 135 00:12:31.120 --> 00:12:33.879 which is an anomaly in Arctic temperatures. But how do we get those 136 00:12:33.879 --> 00:12:41.600 anomaly measurements Let's say you want to track if apples these days are generally larger, 137 00:12:41.799 --> 00:12:46.279 smaller, or the same size as they were twenty years ago. In 138 00:12:46.320 --> 00:12:50.879 other words, you want to track the change over time. Imagine each person 139 00:12:50.919 --> 00:12:54.519 on your apple measuring team has their own food scale. Person A measures apple 140 00:12:54.559 --> 00:13:00.000 one and their food scale rates six ounces. Person B measures the same apple, 141 00:13:00.480 --> 00:13:05.039 but their scale reads seven ounces. Since these scales are calibrated differently, 142 00:13:05.200 --> 00:13:09.120 your team ended up with two different recorded weights for the same exact apple. 143 00:13:09.799 --> 00:13:13.600 There's some imprecision in the measurements, and to account for that when you compare 144 00:13:13.639 --> 00:13:16.039 this apple's measurement to the apples growing next year, you'll need to look at 145 00:13:16.039 --> 00:13:20.720 their difference rather than absolute weights, focusing on the anomaly, or how much 146 00:13:20.720 --> 00:13:26.960 heavier or lighter than next apple is from year to year. So for temperatures, 147 00:13:26.200 --> 00:13:30.600 while it would be great to have the same exact scale or thermometer all 148 00:13:30.600 --> 00:13:33.399 over the world measuring the temperature in the same exact way, we don't. 149 00:13:35.000 --> 00:13:39.360 Instead we focus on how much warmer or colder the temperatures are in each place, 150 00:13:39.519 --> 00:13:43.919 based on their own instruments. Another factor to consider is, since you're 151 00:13:43.960 --> 00:13:46.759 tracking apples from all over the globe, there are differences in baseline weights. 152 00:13:48.279 --> 00:13:52.320 Let's say apples grown in Florida are generally larger than apples grown in Alaska. 153 00:13:52.799 --> 00:13:56.240 Like in real life, how Floridian temperatures are generally much higher than Alaskan temperatures. 154 00:13:56.919 --> 00:14:01.200 So how do you track the change in apple size is from apples grown 155 00:14:01.279 --> 00:14:05.440 all over the world while still accounting for their different baseline weights by focusing on 156 00:14:05.480 --> 00:14:11.440 the difference within each area rather than the absolute weights. So when it comes 157 00:14:11.519 --> 00:14:16.200 to the temperature record, scientists aren't comparing temperatures in Bermuda to temperatures in Greenland 158 00:14:16.519 --> 00:14:20.919 and averaging them together for net warming. Instead, they're comparing the change in 159 00:14:20.960 --> 00:14:26.679 temperatures in Bermuda to the change in temperatures in Greenland. Again, we look 160 00:14:26.720 --> 00:14:31.320 at the anomaly measurements to track the change over time. Now let's scale this 161 00:14:31.399 --> 00:14:35.600 example up. If you have a weather station that's say here in New York 162 00:14:35.639 --> 00:14:39.679 City, and you compare it to a weather station in Washington, d C. 163 00:14:39.159 --> 00:14:43.720 Or Montreal, they tell very different stories about the absolute temperature. Right, 164 00:14:43.759 --> 00:14:48.039 So Montreal is colder and the Washington d C Is often warmer. But 165 00:14:48.159 --> 00:14:52.919 when they move up and down, when there's a month that is warmer or 166 00:14:52.960 --> 00:14:56.039 colder, it's basically the same in all three locations. And so by looking 167 00:14:56.039 --> 00:15:01.720 at the anomalies how much warmer it is than normal for that particular point, 168 00:15:03.720 --> 00:15:05.879 and then you look at those anomalies at all those different points and you can 169 00:15:05.919 --> 00:15:11.039 average those. It turns out that you can fill out the gaps much more 170 00:15:11.039 --> 00:15:18.039 effectively. This big picture global temperature is comprised of much smaller concentrated data points 171 00:15:18.080 --> 00:15:22.720 from all over the world. So while globally temperatures average out to be record 172 00:15:22.759 --> 00:15:28.759 hot, it wasn't record hot in every single location around the world. But 173 00:15:28.840 --> 00:15:33.200 why did twenty twenty three see record heat? Well, to put it simply, 174 00:15:33.360 --> 00:15:37.559 a combination of high greenhouse gas emissions and the transition out of three consecutive 175 00:15:37.600 --> 00:15:43.120 years of Lannina conditions and into al Nino conditions led to record breaking heat, 176 00:15:43.440 --> 00:15:48.360 But the year was in some respects still surprisingly hot, and NASA is continuing 177 00:15:48.399 --> 00:15:52.399 its research on why. Typically the largest cause of short term year to year 178 00:15:52.440 --> 00:15:58.639 differences in temperature is usually La Nina and al Nina weather patterns. Laninia generally 179 00:15:58.639 --> 00:16:03.039 cools things down while warms them up. The largest cause of long term decade 180 00:16:03.080 --> 00:16:08.519 by decade differences in temperature is greenhouse gas emissions and the subsequent trapped heat by 181 00:16:08.600 --> 00:16:12.879 greenhouse gases. So while we don't expect every year to be a new record 182 00:16:12.919 --> 00:16:18.039 like twenty twenty three, we do expect new records as long as we continue 183 00:16:18.039 --> 00:16:22.759 to increase greenhouse gas emissions. The key thing to take away from all of 184 00:16:22.799 --> 00:16:32.440 this is that the long term trends are pretty much relentlessly up. We're going 185 00:16:32.519 --> 00:16:38.039 to continue to have records be broken because that baseline is moving all the time, 186 00:16:38.360 --> 00:16:42.039 and then the weather is sitting on top of that, and so when 187 00:16:42.039 --> 00:16:45.519 the weather is warmer than normal, then we're going to get these records. 188 00:16:45.679 --> 00:16:48.360 But even when it's cooled in the normal, we don't go back to what 189 00:16:48.440 --> 00:16:57.399 it was. And in that report from That's a TV, we heard from 190 00:16:57.440 --> 00:17:03.720 Gavin Schmidt, the director of NASA's got Out Institute for Space Studies, this 191 00:17:03.400 --> 00:17:10.640 space Time Still to Come a you study show stars travel more slowly around the 192 00:17:10.759 --> 00:17:14.319 edge of the Milky Way galaxy, and later in the science report, your 193 00:17:14.359 --> 00:17:18.640 research shows that people who sit for long periods of time at work have a 194 00:17:18.680 --> 00:17:22.720 sixty percent higher risk of death. All that are more still to come on 195 00:17:22.799 --> 00:17:44.680 space time By clocking the speed of stars throughout the Milky Way Galaxy, physicists 196 00:17:44.720 --> 00:17:48.839 have discovered that stars further out on the galactic disc are traveling more slowly than 197 00:17:48.920 --> 00:17:55.000 expected compaired to stars that are closer to the galaxy center. The findings, 198 00:17:55.119 --> 00:18:00.000 reported in the Monthly Notices of the Royal Astronomical Society's Journal, erasing the possible 199 00:18:00.000 --> 00:18:04.200 ability that the Milky Wate gravitational core may be lighter in mass and contain less 200 00:18:04.279 --> 00:18:10.119 dark matter than previously thought. The new results are based on an analysis of 201 00:18:10.279 --> 00:18:15.519 data taken by both the GYA and APERGE instruments. GIA is an orbiting space 202 00:18:15.640 --> 00:18:21.559 telescope run by the European Space Agency. It's tracking the precise location, distance 203 00:18:21.640 --> 00:18:26.759 and motion of more than a billion stars throughout the Milky Way Galaxy. Meanwhile, 204 00:18:26.759 --> 00:18:32.240 APERGY is a ground based survey telescope. The physicist analyzed GUIAS measurements of 205 00:18:32.279 --> 00:18:36.119 more than thirty three thousand stars, including some of the furthest stars in the 206 00:18:36.160 --> 00:18:41.880 galaxy, and they determined eight stars circular velocity. Now, circular velocity is 207 00:18:41.920 --> 00:18:45.319 how fast the star is circling the galactic disc given the stars distance from the 208 00:18:45.359 --> 00:18:52.160 galactic center. The authors then plotted each star's velocity against its distance to generate 209 00:18:52.200 --> 00:18:57.240 a rotational curve. It's a standard graphic astronomy representing how fast matters rotating at 210 00:18:57.279 --> 00:19:02.279 at given distance from the center of a galaxy. The shape of this curve 211 00:19:02.400 --> 00:19:06.759 and gives scientists an idea of how much visible and dark matter is distributed throughout 212 00:19:06.799 --> 00:19:10.519 the galaxy. One of the studies authors, Lena A. KiB from the 213 00:19:10.559 --> 00:19:15.319 Massachusetts Institute of Technology MIT, says what really surprised the authors was that this 214 00:19:15.559 --> 00:19:19.880 curve remained flat, and it continued to stay flat all the way out to 215 00:19:19.920 --> 00:19:26.279 a certain distance, and then it suddenly started tanking away. This means the 216 00:19:26.319 --> 00:19:30.599 outer stars of the galaxy are rotating a little slower than expected, which is 217 00:19:30.640 --> 00:19:34.799 a very surprising result. The authors then translated this new rotational curve to a 218 00:19:34.839 --> 00:19:41.279 distribution of dark matter that could explain the outer stars slow down. They found 219 00:19:41.279 --> 00:19:45.880 the resulting map ended up producing a lighter galactic core than what was expected. 220 00:19:45.599 --> 00:19:49.480 In other words, the center of the Milky Way galaxy might be less dense 221 00:19:49.599 --> 00:19:55.200 with less dark matter than what astronomers had always thought. The new results, 222 00:19:55.240 --> 00:20:00.079 therefore, are in clear tension with other measurements. The authors say there's something 223 00:20:00.119 --> 00:20:03.880 fishy going on somewhere. Like most galaxies in the universe, our milky Way 224 00:20:04.000 --> 00:20:07.880 spins, I guess sort of like water at a whirlpool, and its rotation 225 00:20:08.039 --> 00:20:12.400 is driven in part by all the matter that's swirling within the disk. It 226 00:20:12.519 --> 00:20:18.759 was back in the nineteen seventies when astronomer Verra Ruben became the first to observe 227 00:20:18.960 --> 00:20:22.279 that galaxies rotate in a way that cannot be purely driven by their visible matter. 228 00:20:23.000 --> 00:20:27.240 Ruben and colleagues measured the circular velocity of stars and found that the resulting 229 00:20:27.359 --> 00:20:33.079 rotational curves were surprisingly flat. That is, the velocity of the stars going 230 00:20:33.079 --> 00:20:37.200 around the center remained the same throughout the galaxy, whether or not they were 231 00:20:37.200 --> 00:20:41.240 close to the center or out near the edge. Their rotational curves weren't dropping 232 00:20:41.279 --> 00:20:47.720 off with distance. Rubon and colleagues concluded that some other type of invisible matter, 233 00:20:47.920 --> 00:20:51.960 stuff we now call dark matter, must be acting on distant stars to 234 00:20:52.000 --> 00:20:56.359 give them an additional push. In this regard, Ruben's work in rotation curves 235 00:20:56.519 --> 00:21:00.799 was one of the first strong pieces of evidence for them in the existence of 236 00:21:00.880 --> 00:21:04.880 dark matter, an invisible, unknown entity which we know exists and must make 237 00:21:04.960 --> 00:21:10.559 up more than three quarters of all the matter in the universe. Since then, 238 00:21:10.680 --> 00:21:15.599 astronomers have observed similar flat curves in other far off galaxies, further supporting 239 00:21:15.680 --> 00:21:19.839 dark matters presence. But only recently of astronomers attempted to chart the rotation curve 240 00:21:19.839 --> 00:21:25.160 in our own galaxy with stars, and it turns out it's a lot harder 241 00:21:25.200 --> 00:21:29.680 to measure the rotational curve when you're actually sitting deep inside the galaxy. Back 242 00:21:29.720 --> 00:21:33.920 in twenty nineteen, Anachristina Elliots from MIT worked to chart the Milky Way's rotation 243 00:21:34.079 --> 00:21:38.640 curve using an earlier batch of data release by Geyer. Now that data release 244 00:21:38.680 --> 00:21:42.920 included stars as farret as twenty five Killer Parssex, which is about eighty one 245 00:21:44.039 --> 00:21:48.440 thousand light years from the galaxy center. Now, based on these data, 246 00:21:48.559 --> 00:21:52.759 Elliots observed that the Milky Way's rotation curve appeared to be flat, although with 247 00:21:52.839 --> 00:21:56.279 a mild decline, similar to other far off galaxies, and by inference, 248 00:21:56.799 --> 00:22:00.759 our galaxy likely bore a high day density of dark matter at its core. 249 00:22:02.480 --> 00:22:06.079 But this view is now shifted as guys released a new batch of data, 250 00:22:06.160 --> 00:22:10.160 this time including stars as far at as thirty kilo Parssex. That's almost one 251 00:22:10.200 --> 00:22:15.480 hundred thousand light years from the galaxy's core. Now these distances, astronomers are 252 00:22:15.480 --> 00:22:18.119 looking right at the edge of our galaxy, the place where stars are starting 253 00:22:18.119 --> 00:22:22.559 to peter out. No one's ever explored how much matter moves around in this 254 00:22:22.680 --> 00:22:29.319 outer galaxy region. It's where we're really starting to touch the nothingness of intergalactic 255 00:22:29.400 --> 00:22:33.519 space. So as you can imagine, the studies authors jumped on Guys' latest 256 00:22:33.559 --> 00:22:37.480 data at least late last year, looking to expand on at least initial rotation 257 00:22:37.680 --> 00:22:41.720 curve. To refine their analysis. They complemented the gay A telescope data with 258 00:22:41.839 --> 00:22:48.119 measurements by APERGEY, the Apergey Point Observatory Galactic Evolution Experiment. It's measuring extremely 259 00:22:48.200 --> 00:22:52.240 detailed properties of more than seven hundred thousand stars in the Milky Way, such 260 00:22:52.240 --> 00:22:57.000 as their brightness, their temperature, and their elemental composition. The data is 261 00:22:57.039 --> 00:23:02.880 then fit into an algorithm try and learn connections that can give scientists a better 262 00:23:03.000 --> 00:23:07.720 estimate of a star's distance. The authors use this data to establish a precise 263 00:23:07.799 --> 00:23:11.119 distance system more than thirty three thousand stars, and use these measurements to generate 264 00:23:11.160 --> 00:23:15.279 a three dimensional map of the stars scattered across the Milky Way out to around 265 00:23:15.359 --> 00:23:21.680 thirty kilo Parssex. They then incorporated this vast map into a model of circular 266 00:23:21.759 --> 00:23:26.119 velocity in order to simulate how fast any one star must be traveling given the 267 00:23:26.160 --> 00:23:30.440 distribution of all the other stars in the galaxy. They then plotted each star's 268 00:23:30.519 --> 00:23:34.079 velocity and distance on a chart in order to produce an updated rotation curve of 269 00:23:34.119 --> 00:23:40.480 the whole Milky Way itself, and that is where the weirdnesses come in. 270 00:23:40.480 --> 00:23:44.960 Instead of seeing a mild decline like previous rotation curves, the authors observed that 271 00:23:45.039 --> 00:23:48.759 this new curve get far more strongly than expected at the utter end. Now, 272 00:23:48.759 --> 00:23:53.319 this unexpected downturn suggest that while stars may be traveling just as fast out 273 00:23:53.359 --> 00:23:59.319 to a certain distance, they then suddenly slow down beyond this distance. When 274 00:23:59.319 --> 00:24:03.440 the team transition this rotation curve to the amount of dark matter that must exist 275 00:24:03.440 --> 00:24:07.920 throughout the galaxy, they found that the Milky Waiste core must contain far less 276 00:24:07.000 --> 00:24:11.920 dark matter than what they had previously estimated. The result is clearly intension, 277 00:24:12.000 --> 00:24:18.920 with other measurements. Really understanding the meaning of this result will undoubtedly have debrief 278 00:24:18.920 --> 00:24:22.440 percussions. This could simply be leading to more hidden masses just beyond the edge 279 00:24:22.480 --> 00:24:26.599 of the galactic disk, or could mean a total reconsideration of the state of 280 00:24:26.680 --> 00:24:32.200 the equilibrium of our galaxy. You can be sure of one thing, whatever 281 00:24:32.319 --> 00:24:52.240 unfolds will be fascinating. This is space time. Time out to take a 282 00:24:52.240 --> 00:24:56.440 brief look at some of the other stories making use in science this week with 283 00:24:56.519 --> 00:25:00.079 a science report. A new study has shown that people who sit for prolonged 284 00:25:00.079 --> 00:25:04.359 periods of time at work wind up having a sixteen percent higher risk of death 285 00:25:04.359 --> 00:25:08.960 from any cause and a thirty four percent higher risk of heart disease. The 286 00:25:10.039 --> 00:25:14.640 findings were reported in the Journal of the American Medical Association, based on research 287 00:25:14.680 --> 00:25:18.839 which followed almost five hundred thousand people over thirteen years. The study looked at 288 00:25:18.839 --> 00:25:23.039 how much the participants sat at work, how much they exercised in their free 289 00:25:23.079 --> 00:25:27.000 time, as well as their health outcomes and any deaths over the thirteen year 290 00:25:27.079 --> 00:25:33.039 period. The researchers say those who sat all day at work but exercise for 291 00:25:33.119 --> 00:25:37.079 fifteen to thirty minutes a day outside work had a similar risk of death to 292 00:25:37.119 --> 00:25:41.400 people who weren't sitting at work remained inactive during their free time. The researchers 293 00:25:41.440 --> 00:25:45.759 say their study supports the evidence that their jobs can be harmful to health. 294 00:25:47.440 --> 00:25:52.319 Reducing the amount of time you sit at work and exercising more outside working hours 295 00:25:52.480 --> 00:25:59.799 can help reduce the risks. A new Australian led study claims average global temperatures 296 00:26:00.000 --> 00:26:04.079 they already have risen by one point five degrees celsius above pre industrial levels. 297 00:26:04.720 --> 00:26:10.599 Aiming to limit temperature rises to one point five degrees celsius or below was the 298 00:26:10.640 --> 00:26:15.920 goal of the Paris Climate Agreement struck in twenty fifteen. While previous estimates of 299 00:26:15.039 --> 00:26:19.720 warnings based on sea surface temperature records, these only date back to the mid 300 00:26:19.839 --> 00:26:25.680 nineteen hundreds, these new findings, reported in the journal Nature Climate Change, 301 00:26:25.680 --> 00:26:30.039 are very different. They're based on data from species of long lived sea sponges. 302 00:26:30.680 --> 00:26:36.880 These primitive animals contain hundreds of years of data and chemical changes within their 303 00:26:36.920 --> 00:26:41.440 skeletons, and this can be used by scientists to estimate temperatures from March earlier. 304 00:26:42.079 --> 00:26:47.440 So the researchers used samples of these sponges from species from the Eastern Caribbean 305 00:26:47.519 --> 00:26:52.079 in order to explore temperatures over the last three hundred years, and they say 306 00:26:52.079 --> 00:26:56.000 their estimates show that one point five degrees celsius of warming relative to pre industrial 307 00:26:56.119 --> 00:27:03.759 levels has already been reached. A new study warns that outdoor artificial lighting at 308 00:27:03.880 --> 00:27:07.680 night could be linked to an increased risk of macular degeneration, a leading cause 309 00:27:07.720 --> 00:27:14.039 of irreversible blindness. A report in the Journal of the American Medical Association looked 310 00:27:14.039 --> 00:27:19.119 at some four thousand and seventy eight patients newly diagnosed with age related macular degeneration, 311 00:27:19.519 --> 00:27:23.039 as well as one hundred and twenty two three hundred and forty people without 312 00:27:23.039 --> 00:27:27.799 the disease, all over the age of fifty. After estimating people's exposure to 313 00:27:27.920 --> 00:27:33.720 artificial outdoor light at night using satellite data from around their addresses, the authors 314 00:27:33.720 --> 00:27:37.240 found higher levels of outdoor artificial lighting at night was linked to a higher risk 315 00:27:37.279 --> 00:27:44.880 of developing age related macular degeneration. While this kind of research can't confirm whether 316 00:27:45.000 --> 00:27:48.279 lighting at night courses blindness, the researcher say the findings do add to a 317 00:27:48.319 --> 00:27:53.200 body of research showing how much artificial light at night could be impacting your health. 318 00:27:55.920 --> 00:28:00.279 It's been revealed that the sleepy eastern English county of Bedfordshire, often described 319 00:28:00.319 --> 00:28:06.880 as the country's most boring place is actually a hotbed of pagan satanic activity. 320 00:28:07.559 --> 00:28:11.480 The title is England's most boring county is based on the twenty eighteen Yugov poll 321 00:28:11.559 --> 00:28:15.640 of forty two thousand people. But what's not so well known is that the 322 00:28:15.799 --> 00:28:22.359 same area is regarded as the nexus of sorts. There are deconsecrated churches, 323 00:28:22.720 --> 00:28:27.839 strange ancient rock monuments, modible claims of demonic visitations, and a long history 324 00:28:27.880 --> 00:28:33.160 of witch trials and Wickerman festivals. Even today, it's claimed many villages in 325 00:28:33.200 --> 00:28:38.079 the area still have regular black masses and at least two or three practicing witches. 326 00:28:38.880 --> 00:28:42.759 Thousand year old May festivals still take place in the region, and one 327 00:28:42.839 --> 00:28:48.880 village even has a bizarre pancake day witch listening. Tales of the devil stealing 328 00:28:48.000 --> 00:28:53.599 children and the souls of the wicket abound. Timendum from Australian skeptics who actually 329 00:28:53.640 --> 00:28:56.799 lived in this county for some time, since the area was part of the 330 00:28:56.880 --> 00:29:02.559 Viking ruled Dane Law and as a longer pagan history than Anglo Saxon Wessex, 331 00:29:02.720 --> 00:29:07.440 with Celts practicing the Druid religion once common throughout the county. In fact, 332 00:29:07.480 --> 00:29:11.680 lived in Bedfordshire for about a year, yes, so, which proves what 333 00:29:11.720 --> 00:29:15.440 a hot beta is actually of everything. Bedford Shire is in the middle of 334 00:29:15.480 --> 00:29:18.680 England, sort of lower middle. The biggest town is Luton, famous for 335 00:29:18.720 --> 00:29:22.400 the Luton Girls Choir, which doesn't exist anymore. It's not the most exciting, 336 00:29:22.480 --> 00:29:25.200 I'm told, the most boring county in England. Yeah, aparently there 337 00:29:25.240 --> 00:29:27.880 was a survey people, so I don't know how many people in Bedfordshire decided 338 00:29:27.960 --> 00:29:30.880 that. But there's a lot of hidden secrets in Bedfordshire. It is an 339 00:29:30.880 --> 00:29:33.599 old county and there's a lot of old buildings in it. I think that 340 00:29:33.680 --> 00:29:36.960 was one of the ones I lived in. Was pretty old and certainly elite. 341 00:29:37.000 --> 00:29:40.279 But what they have tanners? One person described as sort of that. 342 00:29:40.359 --> 00:29:44.799 Bedfordshire is known for two things, hack making and Satanism. Right, interesting 343 00:29:44.799 --> 00:29:48.960 combinations you'd normally put together, are they? Well? I don't know what 344 00:29:48.000 --> 00:29:52.160 Satans wear on their head. Maybe they have particular hats that you only get 345 00:29:52.160 --> 00:29:57.039 in bed Also the horns, wouldn't you that's right. I'm sure every county 346 00:29:57.200 --> 00:30:00.680 in England, Scotland, Whale wherever, and a lot of other places as 347 00:30:00.720 --> 00:30:06.880 well have their fair share of ghosts and haunted houses and halted castles and churches, 348 00:30:07.000 --> 00:30:11.480 run down churches, and strange occurrences. So what they stand out. 349 00:30:11.559 --> 00:30:14.480 There's a whole range of sort of strange people who have lived there in the 350 00:30:14.519 --> 00:30:18.160 past, well more than other places, I don't know. There's characters who 351 00:30:18.200 --> 00:30:22.920 are involved in witchcraft and witch hunters and witches and people who supposedly had evil 352 00:30:22.000 --> 00:30:26.039 powers over other people, and strange occurrences, people coughing up needles and pins 353 00:30:26.079 --> 00:30:29.440 and all sorts of stuff. It was actually home, I don't know if 354 00:30:29.440 --> 00:30:32.759 it's in Bedfordshire or in neighboring county, which was the hell Fire Club, 355 00:30:32.799 --> 00:30:36.720 which was the famous other sort of gentle members of the late seventeen hundreds early 356 00:30:36.720 --> 00:30:41.240 eighteen hundreds who used to do all sorts of stranger They used to do it 357 00:30:41.279 --> 00:30:45.079 for the hell of it, and they were notorious for being the baut they're 358 00:30:45.079 --> 00:30:48.720 seen to be. There's a lot of watch pitlets of time anyway in that 359 00:30:48.960 --> 00:30:52.200 ere pit, with more money than there and plenty of time to do stuff. 360 00:30:52.240 --> 00:30:55.920 One of the interesting things is that they actually refer to that one of 361 00:30:55.960 --> 00:30:57.640 the small towns that I lived in there was a town called Layton Buzz. 362 00:30:57.680 --> 00:31:00.400 It's the one little name for Tanning and the people think it actually comes from 363 00:31:00.480 --> 00:31:03.960 Latin voters are and that was quite sure. But Layton Bosa sounds good, 364 00:31:03.960 --> 00:31:07.799 which has a church called Old Saints Church which is in the middle of the 365 00:31:07.880 --> 00:31:12.559 market town actually and it's got ancient graffiti of a basilisk cover and a demon 366 00:31:12.640 --> 00:31:17.599 cart into the stoneworks. Now there was another church in the in vetrity which 367 00:31:17.599 --> 00:31:21.559 actually has the devil's footprints in the front step. Trouble is they renovated the 368 00:31:21.640 --> 00:31:23.480 church and they were really fact I thought there was strange That would have been 369 00:31:23.480 --> 00:31:27.200 a great tourist thing. But anyway, Bedfordshire, regarded by the survey as 370 00:31:27.200 --> 00:31:32.319 the most boring county in England, does have its fair share of strange occurrences 371 00:31:32.319 --> 00:31:34.920 and things, and I think that should be celebrated. That's Timendum from Austria 372 00:31:36.039 --> 00:31:56.319 in Skeptics and that's the show for now. 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