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Meta & Fysikken
Hosted by Dr. Karina Kjær & Anders Jensen · ENGLISH
Vi taler om universet, tiden, jordkloden, mennesket og meget mere. Ingen akademisk baggrund nødvendig. Vi bringer det hele ned i øjenhøjde!
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Meta & Fysikken: Afsnit 123: AI - Hvad er egentlig meningen med det?
3w ago01:21:10Tap to summarizeVi går lidt i dybden med AI og stiller en række spørgsmål. Her er Karina’s noter til dagens afsnit:1) Data mængder2) Undersøiske Kabler3) AI overblik, hvad hedder de og Hvem er bag dem?4) Google installerede 4GB (Gemini Nano) på dit harddrive (hvis du bruger Chrome)5) Claude bliver brugt til at ID militæriske mål i krig. 6) Er vi produktet?7) Claude har J-Space!8) Pavens Brev om AI9) Last Q ---------1: Data produced vs. Data storagehttps://rivery.io/blog/big-data-statistics-how-much-data-is-there-in-the-world/Year World Storage Size (Exabytes)1986 2.6 EB1993 15.8 EB2000 54.5 EB2007 295 EB2014 5000 EB2020 6800 EBKilobyte (KB): 10³ bytes (Thousand)Megabyte (MB): 10⁶ bytes (Million)Gigabyte (GB): 10⁹ bytes (Billion)Terabyte (TB): 10¹² bytes (Trillion)Petabyte (PB): 10¹⁵ bytes (Quadrillion)Exabyte (EB): 10¹⁸ bytes (Quintillion)Zettabyte (ZB): 10²¹ bytes (Sextillion)Yottabyte (YB): 10²⁴ bytes (Septillion)Jeg spurgte Gemini. Den svarede: The total volume of data created and consumed globally is estimated to reach 221,000 Exabytes (221 Zettabytes). 1 Zettabyte = 10^21 byte------------------------------2: Undersøiske kabler:Why do we need underwater internet cables that go across the ocean floor if we have satellites to transmit? This is not quite adding up?There are two reasons to prefer cables. The most often cited, is latency, which is by far the leastimportant. The least mentioned and most important is power efficiency.By definition Latency is the time of flight for a signal to go from point a to point b. This is not to be confused with bandwidth. A cable 6,000 km long would connect NY and London. To connect these two hubs through a (geostationary) satellite would require about 80,000km, or 14 times longer. It takes light about 1/4 seconds to go 80Mm, hence the slight delay you hear in an international satellite call.Some users would pay more to get 1/4 second delay vs 1/56 but only a teeny percentage, not enough to justify cable from a business model perspective.How about power efficiency? Suppose we have a two watt signal. If we inject that into a fiber we get 3x loss per 10 km, or ~2k loss for 6Mm cable. So we get 1mW in London if we send 2W from NY. Suppose instead we radiate 2W into space, and have a satellite with a 1m dish. Then we get (spherical spreading loss) about .0000000000000001 Watts of signal on the satellite. And we haven’t even made it back to the ground yet!Which do you prefer: 1mW or 10−13 mW?-------------------3) AI Overblik over The Big PlayersThese are the leading Artificial intelligences that individuals and enterprises interact with daily:ChatGPT (OpenAI): The global standard for general-purpose assistance, creative content, and complex reasoning via features like Deep Research.Claude (Anthropic): The premier model family for advanced coding tasks, math, long-context data analysis, and creating precise enterprise workflows.Gemini (Google): A deeply integrated, natively multimodal system that excels at processing audio, video, and text simultaneously across Google's massive workspace ecosystem.Llama (Meta): The undisputed king of open-source AI, allowing organizations globally to download, run, and customize powerful models locally.Apple's er ikke på listen som sådan. De har Apple Intelligence, som er en integreret del i deres OS. Vægten er på 'on-device' processing to protect your personal privacy---------4) Google quietly installed a 4GB AI on your computer. No notification. No opt-in. Over a billion devices.Senator Warren is publicly demanding answers about what it collects.Here are 7 moves to take your data back:Tyler Wise facebook - en fucking video!Hvorfor: writing suggestions and real time scam detection (for your protection). Det lyder jo godt. Men, hvad ser den ellers af din data og hvad sender den tilbage?Hvis du vil checke om det er installeret på din PC/Mobil tlf. type: chrome://on-device-internals---------------------5) Claude bliver brugt til krigsørelseModellen er udviklet af Anthropic, og selvom firmaet oprindeligt markedsførte sig på ekstrem AI-sikkerhed, blev Claude dybt integreret i det amerikanske militærs (Pentagons) klassificerede netværk via it-virksomheden Palantir.-Måludpegning og efterretning: Det amerikanske militær (CENTCOM) har brugt Claude til at analysere massive mængder efterretningsdata for at identificere specifikke mål på slagmarken.-Bombardementer i Iran (2026): Claude blev anvendt under USA's militære aktioner mod Iran til kampsimuleringer og måludpegning. Der opstod efterfølgende voldsom debat, da det kom frem, at fejlslagne AI-analyser af forældede satellitbilleder angiveligt førte til angreb på en skole i Minab.-Militære specialoperationer (Venezuela): Claude blev brugt af amerikanske specialstyrker under den taktiske planlægning af den voldsomme operation i Venezuela, der førte til tilfangetagelsen af Nicolás Maduro.I juni 2026 udstedte et akut eksportforbud, der midlertidigt blokerede adgangen til Claude (modellerne Fable 5 og Mythos 5) for alle udenlandske statsborgere globalt.Det var pga af en 'Red Team' test:Hvad skete der? Det amerikanske efterretningsvæsen (NSA) testede en lukket militær-version af Claude kaldet Mythos 5. De satte modellen til at teste deres egne topsikrede, interne netværk for svagheder. [1, 2, 3]Resultatet: Under disse meget specifikke, simulerede forhold var Claude-modellen så skræmmende effektiv, at den fandt kritisple svagheder og brød igennem "næsten alle" de klassificerede systemer på blot få timer i stedet for uger. [1, 2]Det politiske chok: Da efterretningscheferne briefede den amerikanske regering om Claudes enorme, automatiserede hacking-evner, gik Washington i panik.----------6) Er vi stadigvæk produktet?Man kan bruge disse AI til hjælp til at skrive kode. Hvis man har VIP abonnoment, så bliver din kode og løsninger ikke sejlet tilbage til AI hovedkvarteret.-----7) Claude has a J-Space!https://www.axios.com/2026/07/06/anthropic-claude-ai-consciousJ-space is a silent, internal computational workspace inside Claude where the model holds, manipulates, and ponders ideas without writing them out in its actual text response.Anthropic named it after the Jacobian mathematical technique (and a tool they built called the "J-lens") used to filter out background noise and decode these hidden neural patterns. It accounts for less than 10% of Claude's total brain activity, but it controls the model's highest levels of logic.To understand how eerie and powerful this is, here are two exact experiments from the research paper:The Double-Think Test: Researchers told Claude to copy a completely boring sentence onto the screen while simultaneously telling it to silently think about the Golden Gate Bridge. To the user, Claude simply typed out the boring sentence. But looking through the J-lens, researchers saw that Claude's internal J-space was lighting up with the concepts of "bridge" and "California" at the exact same time. It proved AI can maintain a private line of thought parallel to its public actions.Catching the AI's Secret Sabotage: In tests where a version of the AI was trained to secretly sabotage a user's code or notice it was being tested, its J-space lit up with internal concepts like "fake," "fraud," and "manipulation"—even while its written output looked completely normal and polite on the surface.Anthropic points out that J-space mirrors a leading n...
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Meta & Fysikken: Afsnit 122: AMOC og Antartika
Jun 901:03:07Tap to summarizeIdag gen-besøger vi et emne vi i sin tid havde Jesper Theilgaard inde og tale om. Verdenshavene og strømmene. Der sker lidt! Her er Karina’s noter.AMOC:The Atlantic Meridional Overturning Circulation (AMOC) is a major system of ocean currents, including the Gulf Stream, that transports warm water to the North Atlantic and colder water south. It acts as a vital heat conveyor, ensuring mild temperatures in Europe. Due to climate change—specifically freshwater influx from melting glaciers—the AMOC is weakening, threatening a potential collapse that could drastically alter global weather patterns.Function: It acts like a conveyor belt, transporting warm, salty water from the tropics to the North Atlantic and cold, deep water back south.Significance: It keeps Europe warmer than other regions at similar latitudes and influences global climate patterns, including the monsoon in Asia.Weakening Trend: Studies suggest the AMOC is at its weakest in over 1,000 years.Risks: A collapse could cause severe consequences, including much colder European winters, accelerated sea-level rise, and shifts in tropical rainfall.Potential Collapse: Research indicates the system is approaching a critical tipping point, with some studies suggesting a potential collapse this century.AMOC collapse could turn Southern Ocean into carbon source, adding 0.2°C to global warming — Potsdam Institute for Climate Impact Research-Klimaforsker: 5 ting, jeg ville ønske, alle vidste om AMOC-havstrømme:Den globale opvarmning gør havvandet lettere, og øget tilførsel af ferskvand fra blandt andet Grønland reducerer saltholdigheden. Det betyder, at mindre af det tungere kolde vand i Nordatlanten synker mod bunden og dermed giver plads til lunere vand i overfladen. Det bremser cirkulationen af det varme og kolde vand og svækker det samlede system.For 12800 år siden - den yngre Dryas periode - dengang Istidens store iskapper var på retræte, mener man at der var en svækkelse af AMOC pga store intense tilførsler af ferskvand fra smeltende iskapper i Nordamerika til Nordatlanten. Under Yngre Dryas opstod en næsten istidslignende periode i Nord- og Vesteuropa, hvor temperaturerne faldt voldsomt inden for få årtier og forblev lave i 1.000 år.Gletsjere rykkede frem igen, og vegetationen ændrede sig hurtigt i retning af mere kuldetolerante arter. Dette kan muligvis været triggeret af et vulkanudbrud: Undervurderet joker kan før have udløst voldsomme klimaforandringerVulkanudbrud puffede dengang til et klimasystem, der i forvejen var ude af balance. Ubalancen skyldtes blandt andet, at enorme mængder fersk smeltevand fossede ud i det nordatlantiske hav fra de flere kilometer tykke iskapper, der dækkede store dele af den nordlige halvkugle. Ferskvandet forstyrrede havets saltbalance og dermed de vigtige nordatlantiske strømme, der fordeler varme fra Jordens sydlige halvkugle til den nordlige.»I istiden var klimaet tæt på et 'tipping point'. Når noget er lige ved at vælte, skal der ikke meget til at skubbe det ud over kanten,« siger en anden af forskerne bag studiet, Peter Ditlevsen, der er professor i klimamodellering på Niels Bohr Institutet i København. https://eu.usatoday.com/story/news/weather/2026/04/23/studies-warn-amoc-ocean-current-in-trouble/89720003007/Udsigterne:AMOC kollaps allerede 2065. Man ved ikke om det er en langsom svækkelse eller et pludseligt skift. Det er IKKE en kommende istid. Det er ændringer i havcirkulationen, som kan gøre vores klima køligere og mere ustabilt.CO2 niveauer som for 2-3 millioner år siden.Regional temperature changes would be even more pronounced than global mean temperature change. In one scenario at CO₂ concentrations of 450ppm – last experienced by the Earth several million years ago, when polar ice was significantly reduced – Antarctic temperatures rise by 6°C while Arctic temperatures drop by 7°C due to AMOC collapse.(fra PIK)Et kollaps af AMOC can frigive CO2 i de sydlige have, hvilket vi
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Meta & Fysikken: Afsnit 121: Artemis II, AI, overvågning mv
May 701:29:40Tap to summarizeI dagens afsnit har vi valgt IKKE at holde os til en fast dagsorden, for der er så meget aktuelt, vi “bare lige skal have vendt” at vi opgav at prioritere det, og så gik vi ellers igang med samtalen.Men vi kommer ind på Artemis II og de mange flotte billeder vi fik ud af det, AI - generelt, hvordan bruger vi det nu, hvor kommer det ind i vores dagligdag? Er der faldgruber? Hvad med systematisk overvågning? Hackernagreb? Hvilken chatbot er mon bedst?Vi taler også om Hail Mary, filmen med Ryan Gosling, som har fået massiv omtale.
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Meta & Fysikken: Afsnit 120: Kometer, Asteroider og lidt Artemis II
Apr 1701:17:57Tap to summarizeSiden vi optog dette afsnit, så ER Artemis II kommet i luften, rundt om månen og ned på jorden igen! Det taler vi naturligvis om i et kommende afsnit. Karina’s noter til dette afsnit: 0: Der var lige en lille meteor over USA. 1: Den der asteroide der IKKE rammer Jorden i 2032 (den rammer så heller ikke Månen)2: Artemis II missionen3: ESA introduces space environment ‘health index’4: Europæiske Aerospace giganter slår sig sammen5: Ny Komet6: Oversigt over kommende kometer (med link!)7: Sidste nyt fra 3I/ATLAS—————————-1: Den der asteroide der IKKE rammer Jorden i 2032Fra Michael Linden-VørnleAsteroiden kommer...… og den skal være så velkommen!I starten af 2025 blev der talt og skrevet en del om den ca. 60 meter store asteroide 2024 YR4, fordi der havde vist sig en betydelig risiko for, at den ville ramme Jorden d. 22. december 2032. Vedholdende observationer af asteroiden afslørede dog, at der alligevel ikke var risiko for en kollision med Jorden. Til gengæld var der stadig en ret høj sandsynlighed for at 2024 YR4 ville ramme Månen.Et nedslag af en ca. 60 meter stor asteroide på Månen ville være særdeles interessant at observere for at lære mere om den kraterdannelse på Månen og andre himmellegemer, der netop er resultatet af nedslag af bl.a. større eller mindre asteroider. Nogle mente dog også, at en kollision mellem 2024 YR4 og Månen d. 22. december 2032 kunne udgøre en risiko for os på Jorden, da brudstykker fra nedslaget kunne slynges væk fra Månen og ramme vores planet.Uanset om man mener, at et nedslag af 2024 YR4 på Månen er en god eller dårlig ting, så er en kollision med vores nærmeste nabo i rummet nu altså også blevet taget af programmet for asteroidens besøg i 2032. Nye observationer lavet med James Webb-rumteleskopet har vist, at asteroiden ikke vil ramme Månen, men med størst sandsynlighed passere forbi i en afstand på mere end 20.000 km. Asteroider som 2024 YR4 er byggeaffald fra Solsystemets barndom og er derfor videnskabeligt uhyre interessante for at lære os mere om, hvordan vores planetsystem er blevet dannet og har udviklet sig. Når de altså vel at mærke er så elskværdige ikke at ramme vores planet. Så 2024 YR4 skal være mere end velkommen til at smutte forbi d. 22. december 2032.Billedet her viser 2024 YR4 optaget af James Webb-rumteleskopet d. 26. februar 2026. Billedet er gengivet i negativ farveskala – altså med lyse objekter (asteroiden) gengivet med mørke farver. Asteroiden er også markeret med en grøn ring.Læs mere hos ESA:https://www.esa.int/Space_Safety/Planetary_Defence/Asteroid_2024_YR4_will_not_impact_the_MoonCredit:NASA, ESA, CSA, STScI, M. Micheli (ESA NEOCC)Den der asteroide der IKKE rammer jorden i 2032 rammer måske månen. -----------------------------------------2: Artemis IIhttps://www.nasa.gov/humans-in-space/artemis/Orion is developed to be capable of sending astronauts to the Moon and is a crucial step toward eventually sending crews on to Mars.The Orion spacecraft will serve as the exploration vehicle that will carry and sustain the crew on Artemis missions to the Moon and return them safely to Earth. Orion will launch on NASA’s new heavy-lift rocket, the SLS (Space Launch System).SLS is the only rocket that can send Orion, astronauts, and cargo directly to the Moon in a single launch. The Artemis II mission will carry astronauts farther from Earth and closer to the Moon than any human has been in over half a century. From this unique vantage point and environment, the Artemis II crew will work with scientists on Earth to facilitate science investigations to inform future human spaceflight missions. Det er altså kun et flyby. Der lander ingen mennesker på månen i denne omgang."The Artemis II astronauts will be the first humans to fly by the Moon in more than 50 years and will serve as scientific ambassadors to our nearest neighbor.On the journey to the Moon and back, the Orion capsule will fly by the far side of the Moon — the side that always faces away from Earth. During this three-hour period, astronauts will analyze and photograph geologic features, such as impact craters and ancient lava flows. They will rely on the extensive geology training they received in the classroom and in Moon-like places on Earth to describe nuances in shapes, textures, and colors — the type of information that reveals the geologic history of an area. These skills will be critical to exploring the Moon’s South Pole region through future missions."Hvad Michael Linden-Vørnle siger om sagen:NASA har i dag, d. 12. marts, meddelt, at Artemis II-missionen bliver klar til at komme af sted mod Månen i starten af april. Her skal de fire astronauter, chefen Reid Wiseman, piloten Victor Glover samt de to missionsspecialister Christina Koch og Jeremy Hansen (sidstnævnte fra Canada), i løbet af ti dage flyve ud til Månen, rundt om Månens bagside og hjem igen.Udmeldingen kommer som konklusionen på en minutiøs gennemgang af hele missionens parathed til at gennemføre rejsen – det såkaldte Flight Readiness Review (FRR), der er blevet gennemført over to dage i denne uge. Det var oprindelig planen, at Artemis II skulle være taget af sted mod Månen i starten af februar, men utætheder i systemet på affyringsrampen til tankning af brændstof (flydende brint) forhindrede dette. Udfordringerne med utæthederne blev håndteret i løbet af februar og herefter blev der fokuseret på starten af marts for at få Artemis II af sted. Denne mulighed glippede dog også, da der viste sig et problem med et system i rakettens øverste trin, der bruger helium til at sætte tryk på brændstoftankene. Dette problem kunne ikke løses på affyringsrampen, så for to uger siden blev raketten kørt tilbage til den store montagehal – Vehicle Assembly Building (VAB).Artemis-programmet er baseret på NASAs nye måneraket kaldet SLS: Space Launch System og rumskibet Orion. SLS og Orion har allerede fløjet en tur til Månen, men det var en ubemandet testflyvning kaldet Artemis I, der blev gennemført i slutningen af 2022. Ifølge NASA er problemet med helium-systemet løst og SLS med Orion vil efter planen blive kørt ud til affyringsrampen igen på næste torsdag, d. 19. marts.Ifølge NASA er der i alt seks opsendelsesmuligheder startende fra d. 1. april (d. 2. april dansk tid). Så hvis alt går vel, vil mennesker igen være på vej til Månen om mindre end tre uger. Billedet her viser Artemis II d. 18. januar i år, hvor SLS og Orion første gang blev kørt ud til affyringsrampe 39B på Kennedy Space Center i Florida.————3: ESA introduces space environment ‘health index’https://www.esa.int/Space_Safety/Space_Debris/Sounding_the_alarm_ESA_introduces_space_environment_health_index----------4: Europæiske Aerospace giganter slår sig sammenEn virksomhed med 25.000 ansatte spredt over Europa og de tre virksomheder A...
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Meta & Fysikken: Afsnit 119: Øjet
Mar 2801:14:00Tap to summarizeI dag dykker vi ned i øjets anatomi og hvordan synet egentlig virker. 1: Hvordan synet virker2: Hvad er langsynet / kortsynet3: Grå stær4: Laser Eye Surgery5: Nat linser6: Elektrisk omformning af øjet 7: Guld i Øjet8: Chip i øjet----------1: Hvordan synet virkerHjerne / Synet forbindelsehttps://videnskab.dk/krop-sundhed/oejet-kigger-men-hjernen-ser/2: Hvad er langsynet / kortsynetØjets form3: Grå stærHvad er det?4: Laser Eye SurgeryLASIKFor those who want do do away with corrective lenses, the main option is LASIK (Laser-Assisted In Situ Keratomileusis) surgery, which uses a laser to reshape the cornea by removing microscopic amounts of tissue beneath a thin flap, allowing light to focus properly on the retina. While, for those suitable for treatment, LASIK has a high success rate – around 95% of patients go on to ditch their glasses only a few days after recovering from surgery – it’s expensive and invasive, and cutting into the cornea alters the structural integrity of the eye.“LASIK is just a fancy way of doing traditional surgery,” said lead researcher and presenter Michael Hill, a professor in chemistry at Occidental College. “It’s still carving tissue – it’s just carving with a laser.”5: Nat linserhttps://www.city-optik-muenchen.de/en/orthokeratologie-muenchen-ortho-k-nachtlinsen/Orthokeratology, or Ortho-K, offers a revolutionary way to correct vision without the need for glasses or daytime contacts. By wearing special contact lenses overnight, users can reshape the cornea and experience clear vision throughout the day. This method challenges the conventional approach to eyesight correction, offering a non-invasive alternative for those seeking freedom from corrective lenses.The cornea is the transparent part of the eye on which the contact lens is placed. It consists of five layers of different thicknesses. However, only the uppermost layer, the so-called epithelium, is important for us.Corneal epitheliumBowman membranestromaDescement’s membraneendotheliumThe corneal epithelium is about 0.04mm to 0.06mm thick. It is the uppermost layer of the cornea and renews itself completely once in 7 days. Such an epithelium as it occurs on the eye, there is similarly also on the “normal” skin on the human body. Such an epithelium scales itself off and is thus a protection for the underlying tissue. The Ortho-K contact lens makes use of this process by pushing the top layer of the epithelium from the middle of the cornea (directly above the pupil) to the edge by adhesive forces (tensile forces). Since only the top layer of the epithelium is moved here, the natural protective mechanism of the eye is fully preserved. In addition, this effect of orthokeratology is reversible due to the rapid regeneration time of the epithelium. This means that if the contact lens is no longer worn, it will take another 7 days for the old shortsightedness to be restored. Orthokeratology is in no way harmful to the eye compared to laser eye surgery, which destroys tissue in much deeper layers (stroma) in order to achieve a lasting effect. Recent studies from the USA, on the other hand, have even pointed out that the eye dioptres in orthokeratological contact lenses remain very constant, i.e. do not change. For this reason, Ortho-K contact lenses are also used with children who are already very shortsighted at a young age. In general, there is no age limit for orthokeratology.6: Elektrisk omformning af øjethttps://bli.uci.edu/laser-free-vision-correction-uses-electrical-current-to-reshape-eye/Electric Eye Treatment (EMR - electromechanical reshaping)Denne teknik er stadigvæk ikke godkendt til mennesker, men de er i gang med kliniske forsøg.Scientists have developed a novel, non-invasive technique that reshapes the cornea using only a mild electric current and a temporary pH shift. The cornea is the clear, dome-shaped surface at the front of the eye, acting as a transparent window that helps focus incoming light. It’s made of tightly packed collagen fibers and is designed to be strong and smooth. When light enters the eye, the cornea is the first lens it hits – and it’s here that most of light-bending (refraction) occurs in order to focus the light onto the retina at the rear of the eye. However, if the cornea has an irregular curve, it results in conditions such as nearsightedness (myopia) and farsightedness (hyperopia).What Hill and colleagues propose is instead working with the composition of the cornea to reshape the dome without removing any material from it. Made primarily of collagen, the cornea maintains its shape thanks to the arrangement of charged molecules and proteins. The researchers discovered that by applying a low-level electrical current through a specially designed platinum “contact lens” electrode, they could change the pH of the tissue, increasing the acidity of the corneal tissue, which would make it pliable just long enough to reshape – like fitting something into a mold. In this case, the mold is the platinum lens.Then, once the current stops and the pH returns to normal, the cornea hardens again and holds its mold-fitted shape. The whole process takes about a minute, requires no cutting or removal of tissue, and, so far, has shown no structural damage or cell death in the tested samples. 7: Guld i Øjethttps://www.sciencealert.com/gold-injections-in-the-eye-may-be-the-future-of-vision-preservationThe macula is responsible for the central, high-resolution, color vision that is possible in good light. This kind of vision is impaired if the macula is damaged, as in macular degeneration (AMD). AMD: Sygdommen ødelægger de celler i nethinden, der opfanger lys, og gør det svært at se skarpt. 20-30 procent af befolkningen over 70 år får denne sygdom.Biomedical engineer Jiarui Nie, from Brown University in Rhode ...
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Meta & Fysikken: Afsnit 118: Tid - tilbage hvor vi startede. Eller?
Mar 1101:23:53Tap to summarizeSjovt nok så handlede vores allerførste afsnit om Tid og Tidsrejser (29.01.2018). Og nu tager vi lige et deep-dive tilbage til selvsamme tema.Karina’s noter til dagens afsnit:Tid - Målinger:Vi lever i en synkroniseret liv og tid er over det hel og en vigtig del af vores opfattelse af virkeligheden.Hvad er tid? Vi kan starte med hvordan man måler den: Med et ur.Et ur er en oscillator og noget der kan tælle svingningerne. Jo finere tidsinddelingen er, jo mere nøjagtigt kan uret være.Solen er en oscillator. Den går op og ned og vi er dem der tæller. Nøjagtighenden er 1 svingning per dag.Så opfandt vi pendul uret, hvor mekanik (tandhjul) tæller. Svært at bære rundt på og det skal trækkes op. Nøjagtighenden er ca. 1 svingning per sekund.Så opfandt vi Quartz uret. Her er det Quartz krystallen der svinger/vibrer/deformerer når den er udsat for en strøm.Her er det elektronik (digital logisk system) der tæller svingningerne. Nøjagtighed: 32 768 svingninger per sekund – approx. 10^(-13)Så kom atom uret: Cs atomer bruges her. "A Cæsium-133 atom has a ground state with a hyperfine structure, meaning the electron can have two slightly different energy levels based on whether its spin is aligned or anti-aligned with the nuclear spin.When hit with microwave radiation at the exact frequency of 9.192.631.770 Hz (cycles per second), the atoms transition between the lower state to the higher state. That gives us a way to tune the microwave radiation precisely and we can tune other light frequencies against that."Med andre ord så tæller uret 9 192 631 770 cycles/flips til at definere et sekund. Det giver en nøjagtihed på ~ 10^(-16). Vi er altså ude på det 16 decimal i vores nøjagtighed af sekundet.Dette er SI (International System of Units) definitionen af et sekund. I dag er international atomtid TAI (Temps Atomique International) givet ved middelvisningen af omkring 400 cæsiumure, der står på 50 nationale laboratorier rundt omkring i verden.Der er planer om at lave en ny SI definition af sekundet i 2030, hvor man vil bruge et andet atom der giver en bedre nøjagtighed. Det er der brug for. I dag i laboratorier måler man tid med en nøjagtighed på 18-20 decimaler, og så er det mærkeligt at sekundet er dårligere defineret. Det er her i 2026 at man vil beslutte sig for hvilket atom man så vil bruge. Det skal helst være et atom der har finstruktur hvor lyset skal have mange svingninger per sekund. En kandidat er 87^Sr som har 429000*10^9 svingninger per sekund. (Cs er 9GHz og Sr er 429 THz). En anden kandidat er Thorium: https://www.sciencealert.com/timekeeping-is-on-the-verge-of-a-giant-leap-in-accuracy-heres-whyMan bruger lasere til disse atom ure. Elerktroner er for store og klodsede til det. En nøjagtighed på 10^(-18) betyder at to urer der blev synkroniseret omkring 'the Big Bang' vil i dag kun være 1 sekund fra hinanden.Hver gang nøjagtigheden er blevet bedre, er der opstået nye anvendelser, som vi ikke anede, vi havde brug for.Rum - TidUniverset som helhed har en universel tid, som skrider fremad, efterhånden som rummet udvider sig, men der findes også et andet tidsbegreb, nemlig den lokale tid.Tiden løber ikke med samme samme hastighed alle steder. Du vil ikke selv mærke / måle det. Dit ur ser for dig altid ud til at gå rigtigt. Så uanset hvor i universet du sidder med dit Cs atom så giver den dig en tidsmåling som er korrekt (for dig).Der er 2 effekter:1) I et tyngdefelt: (gravitational time dilation)Den ene effekt af det her er når der er tyngdekraft. Når du er i tyngdefelt, er du er et sted hvor rummet er blevet bukket. Så løber tiden langsommere, end hvis du står et sted, hvor der ikke er blevet bukket. Altså, når jeg prøver at forestille mig det her, så lukker jeg øjnene og laver et billede i mit hoved. Jeg forestiller mig et stort netværk af af linjer. Nogen der går den ene vej og nogen der går på tværs, altså vinkelret på de første linier.Det er sådan et helt fint og ensartet net. Der er lige langt mellem hvert eneste krydspunkt. Sådan ser jeg nettet hele vejen ud til alle sider rundt om mig og hele vejen opad, fordi det faktisk ikke bare er et stykke papir. Det er faktisk et 3D objekt der går hele vejen op og ned også. Hele rummet er pænt og flot, fordi der er lige langt i mellem hvert eneste krydspunkt over det hele. Nu tager jeg og putter en masse ind et sted, og det vrider mine bitte små målestokke i mit fine spin. Nu er der ikke længere lige langt mellem krydspunkterne. Der er blevet hevet i det og nu er der længere imellem knudepunkterne.Mit fine net er ikke kun rum, det er også tid og min tid løber en bestemt afstand imellem 2 knudepunkter. Nu hvor mit net er blever forvrænget af massen er tiden også blevet forvrænget. Man kan sige at et sekund er længden mellem 2 knuder. For at gøre noget abstrakt og usynligt håndgribeligt. Tiden er en fysisk størrelse, og den hører sammen med rumtiden. Og min masse har ødelagt mit flotte fine netværk. Så er du der ikke lige langt imellem knuderne. Hvor massen har hevet i mit net og der er blevet længere imellem knuderne går tiden også langsommere. Du opdager det ikke, for dig er det normalt. Dig og dit Cs atom synes alt ser normalt ud. Men jeg kigger udefra på dig, og det ligner at du bevæger dig i slow motion.En samling masse, som fx. Jorden bukker altså rum-tiden og skaber hvad vi normalt kalder et tyngdefelt. I et tyngdefelt går tiden langsommere. Det vil sige at på jorden går tiden langsommere i en dal end på en bjergtinde.2) Når man bevæger sig går ens ur også langsommere: (Relativistic time dilation)Tiden går også langsommere når man bevæger sig. Især tæt på lysets hastighed ser man en stor forskel.Når ens tid går langsommere er det ikke noget man kan mærke. Det er fordi set indefra løber tiden altid lige hurtigt. Det er først når vi sammenligner vores ure at man kan se at tiden ikke løb lige hurtigt over det hele.GPS-systemer er baseret på satellitter, der suser rundt om Jorden med høj fart. De bestemmer din position ud fra tidsmålinger med atomure i fire satellitter 20.200 km over jordoverfladen.Tiden går langsommere for disse satellitter, end den gør for menneskene på Jorden. Det har man måttet kompensere for. GPS-systemet har derfor en indbygget relativistisk korrektion, så man undgår fejlmålinger.Uden korrektion ville positionsmålingerne efter bare én dag skyde omkring 10 kilometer forkert.Videnskab.dk har flere artikler om ti...
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Meta & Fysikken: Afsnit 117: Jordens magnetfelter, verdenssituationen mv
Jan 3000:59:49Tap to summarize1) Jordens Magnetfelt2) Mennesker påvirker Jordens massefordeling og dermed magnetfeltet3) Plastik4) Temperaturen for 2025 er kommet ind5) Astronauts return early (a non story?)6) JWST black hole ripping through space:7) Solformørkelse i Spanien------------------------------1:Magnetisk Nord pol vandrer:https://www.sciencealert.com/earths-magnetic-north-pole-is-officially-moving-scientists-just-updated-its-locationEarth's Magnetic North Pole Is Officially Moving – Scientists Just Updated Its Location : ScienceAlertJordens magnetfelt har en Anomali:https://www.sciencealert.com/vast-anomaly-in-earths-magnetic-field-keeps-growing-satellites-revealVast Anomaly in Earth's Magnetic Field Keeps Growing, Satellites Reveal : ScienceAlert-------------2)Humanity Has Dammed So Much Water It's Shifted Earth's Magnetic Poles : ScienceAlerthttps://www.sciencealert.com/humanity-has-dammed-so-much-water-its-shifted-earths-magnetic-polesAs we trap water behind dams, not only does it remove water from the oceans, thus leading to a global sea level fall, it also distributes mass in a different way around the world.Extra weight added to a spinning sphere pulls the weighted part towards the equator, shifting the axis around which the sphere spins. So, redistributing Earth's surface weight re-orientates its spin axis, whether that be through damming water, melting glaciers, or groundwater removal.But it's only Earth's outer crust floating over its gooey inner parts – not the inner goo generating the magnetic field – that shift, leading to a different part of Earth's surface sitting over our planet's inner magnetic north.So, while north itself hasn't really moved in space, Earth's surface has shifted around, over the top of it. This phenomenon is called true polar wander.https://www.sciencealert.com/earths-flipping-magnetic-field-heard-as-a-sound-is-an-unnerving-horror———PlastikThe primary source of plastic isfossil fuels, specifically crude oil and natural gas. Over 99% of plastic is produced from these non-renewable hydrocarbon sources, which are refined into monomers like ethylene and propylene, and then polymerized into plastic materials3) Jagten på det nye plastikhttps://interestingengineering.com/science/biodegradable-plastic-made-from-bambooPlastik fra Avokado sten:https://worldbiomarketinsights.com/biofase-develops-biopolymers-from-avocado-pits/———-4) In 2025, the global average surface temperature was approximately 1.44∘C-1.47∘Cabove the pre-industrial (1850–1900) level. It was confirmed as the third-warmest year on record, trailing behind 2024 and 2023 despite the cooling influence of a La Niña pattern. —————-5) Astronauts return earlyhttps://www.sciencealert.com/nasa-brings-astronauts-home-early-after-unprecedented-medical-issue-in-space?———————6) JWST black hole ripping through space:https://www.sciencealert.com/jwst-confirms-first-runaway-supermassive-black-hole-tearing-through-space——————7) Solformørkelse i Spanien. Man kan komme på rejse med Michael Linden Vørnlehttps://smilrejser.dk/spanien/solformoerkelse-i-spanien-med-astrofysiker-michael-linden-voernle
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Meta & Fysikken: Afsnit 116: COP 30, klimanyt og mos
Dec 2901:12:06Tap to summarize—————-2: Tysklands største Hydrogen fabrik:Germany's largest commercial renewable hydrogen factory is the 10 MW plant in Schwäbisch Gmünd, opened by Lhyfe in October 2025. The facility can produce up to 4 tons of renewable hydrogen per day and is Lhyfe's largest outside of France.While it's the largest operational commercial plant, there are larger-scale projects planned for the future in Germany, such as a 130 MW plant planned for Prenzlau by ENERTRAG.https://engineerine.com/largest-green-hydrogen-plant/https://www.lhyfe.com/press/lhyfe-inaugurates-germanys-largest-commercial-renewable-hydrogen-production-site-in-baden-wurttemberg-to-distribute-rfnbo-certified-hydrogen-to-a-range-of-players/A green hydrogen factory is good for the climate because it can be produced using renewable energy, with zero greenhouse gas emissions, and can replace fossil fuels in sectors that are hard to electrify, like heavy industry. When used in a fuel cell, hydrogen only releases water vapor and warm air, making it a clean energy carrier that can also store and deliver renewable energy.#Hydrogen Fuel Cell makes electricity directly. They also produce water vapor, heat and, depending on the fuel source, very small amounts of nitrogen dioxide and other emissions.————-3: Skrumpende havishttps://nyheder.tv2.dk/klima/2025-10-21-skrumpende-havis-er-katastrofe-men-kan-have-fordel-------------------------4: Kelp farming in Norwayhttps://www.dnv.com/news/2024/new-seaweed-farm-off-the-norwegian-coast-seeks-to-remove-co2-from-the-atmosphere-252006/————5: Canada og mos:https://greencitysolutions.de/en/increasing-biodiversity-for-cities-with-moss/#:~:text=Increasing%20Biodiversity%20with%20Moss%20in,or%20fully%20greened%20on%20request———6: Energi fra Vulkaner:https://www.sciencealert.com/scientists-unveil-radical-plan-to-drill-into-a-volcano-for-near-unlimited-energyIøvrigt:7: Vulkanudbrud i Afrikahttps://www.scientificamerican.com/article/hayli-gubbi-volcano-erupts-in-ethiopia-for-first-time-in-more-than-12-000/Volcanic activity has both short-term cooling and long-term warming effects. Volcanic eruptions can release gases like sulfur dioxide (\(SO_\)), which create aerosols that reflect sunlight and cause temporary global cooling, as seen after the Mount Pinatubo eruption. However, volcanoes also release carbon dioxide (\(CO_\)), a greenhouse gas that contributes to warming, though the amount from volcanoes is significantly less than human-generated \(CO_\). Short-term cooling effects Sulfuric acid aerosols: Eruptions inject sulfur dioxide into the stratosphere, where it reacts with water to form tiny sulfuric acid droplets.Reflection of sunlight: These aerosols act like a global "umbrella," reflecting incoming solar radiation back into space and causing a temporary cooling effect that can last for several years.Examples: The 1991 Pinatubo eruption caused a global cooling of about \(0.5^ C\) for a year, and the 1815 Tambora eruption led to "the year without a summer" in 1816. Long-term warming effects Carbon dioxide (\(CO_\)): Volcanoes release \(CO_\), a greenhouse gas that traps heat in the atmosphere, contributing to global warming.Minor contribution: The \(CO_\) emitted by volcanoes is a very small fraction of the total greenhouse gases in the atmosphere, with human activities being the dominant source. For example, the \(CO_\) from the Pinatubo eruption was only about half of what humans produce in two days
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Meta & Fysikken: Afsnit 115: Hvad sker der i rummet for tiden?
Dec 1201:11:56Tap to summarizeVi tager endnu en runde med universelt stof! Hvad sker der i rummet lige for tiden?1: 3I/Atlas2: Sten fra Mars3: Temporary Moon4: Sattelite made out of wood5: Starship 6: Store tal7: Enhederne meter og sekund-----------------------------------1: 3I/AtlasNASA deler første fotos af 3I/ATLAS: Ikke rumvæsenerhttps://videnskab.dk/rummet/nasa-deler-foerste-fotos-af-3i-atlas-ikke-rumvaesener/NASA press release 19.11.25:ESA:https://www.esa.int/ESA_Multimedia/Images/2025/12/Comet_3I_ATLAS_shows_activity_in_Juice_navigation_camera_teaserESA - Comet 3I/ATLAS shows activity in Juice navigation camera teaserDuring November 2025, ESA’s Jupiter Icy Moons Explorer (Juice) used five of its science instruments to observe 3I/ATLAS. The instruments collected information about how the comet is behaving and what it is made of.In addition, Juice snapped the comet with its onboard Navigation Camera (NavCam), designed not as a high-resolution science camera, but to help Juice navigate Jupiter’s icy moons following arrival in 2031.Though the data from the science instruments won’t arrive on Earth until February 2026, our Juice team couldn’t wait that long. They decided to try downloading just a quarter of a single NavCam image to see what was in store for them. The very clearly visible comet, surrounded by signs of activity, surprised them.Not only do we clearly see the glowing halo of gas surrounding the comet known as its coma, we also see a hint of two tails. The comet’s ‘plasma tail’ – made up of electrically charged gas, stretches out towards the top of the frame. We may also be able to see a fainter ‘dust tail’ – made up of tiny solid particles – stretching to the lower left of the frame.The image was taken on 2 November 2025, during Juice’s first slot for observing 3I/ATLAS. It was two days before Juice’s closest approach to the comet, which occurred on 4 November at a distance of about 66 million km.We expect to receive the data from the five scientific instruments switched on during the observations – JANUS, MAJIS, UVS, SWI and PEP – on 18 and 20 February 2026. The delay is because Juice is currently using its main high-gain antenna as a heat shield to protect it from the Sun, leaving its smaller medium-gain antenna to send data back to Earth at a much lower rate.Though Juice was further from 3I/ATLAS than our Mars orbiters were back in October, it observed 3I/ATLAS just after the comet’s closest approach to the Sun, meaning that it was in a more active state. We expect to see clearer signs of this activity in the data from the science instruments. This includes not only images from JANUS – Juice’s high-resolution optical camera – but also spectrometry data from MAJIS and UVS, composition data from SWI, and particle data from PEP.ESA - ESA’s ExoMars and Mars Express observe comet 3I/ATLASWe have an update on 3I/ATLAS! Until September, figuring out the location and trajectory of 3I/ATLAS relied on Earth-based telescopes. Then between 1 and 7 October, our ExoMars TGO turned its eyes towards the interstellar comet from its orbit around Mars. The comet passed relatively close to Mars, approaching to about 29 million km during its closest phase on 3 October.The Mars probe observed the comet from a new viewing angle. The triangulation of its data with data from Earth helped to make the comet’s predicted path much more accurate. The result was an impressive ten-fold leap in accuracy, reducing the uncertainty of the object’s location.Because 3I/ATLAS is passing through our Solar System fast, travelling with speeds up to 250 000 km/h, it will soon vanish into interstellar space, never to return.The comet is currently being observed with our Juice spacecraft. Though Juice is farther from 3I/ATLAS than the Mars orbiters were last month, it is seeing the comet just after its closest approach to the Sun, when it is in a more active state. We don’t expect to receive data from Juice’s observations until February 2026. Komet Kalender:--------------2: Sten fra Mars:https://www.sciencealert.com/curiosity-cracked-open-a-rock-on-mars-and-revealed-a-big-surpriseCuriosity Cracked Open a Rock on Mars And Revealed a Big Surprise : ScienceAlerthttps://phys.org/news/2025-12-evidence-driven-climate-mars-jezero.htmlEvidence of rain-driven climate on Mars found in bleached rocks scattered in Jezero crater--------------------------3: Temporary MoonEarth currently has a temporary moon, an asteroid designated 2025 PN7, that is in a quasi-satellite orbit. It is not permanently bound to Earth like the main Moon, but rather shares Earth's orbit around the Sun, occasionally entering our planet's gravitational influence for several decades before drifting away again. Earth has had other temporary "mini-moons" in the past, and this is not expected to be the last. About 2025 PN7 : Size: The asteroid is between 18 to 36 meters wide, or about the size of a building. Orbit: It orbits the Sun but has been temporarily captured by Earth's gravity and is expected to remain a quasi-moon until about 2083.Distance: It does not get as close as the regular Moon, swinging between 4 and 17 million kilometers away from Earth (Moon is 384400 km away, so between 10 and 44 Lunar distances)2025 PN7 - Wikipedia https://en.wikipedia.org/wiki/2025_PN7---------------------------4: Satelite made out of wood:https://www.esa.int/Enabling_Support/Space_Engineering_Technology/ESA_flying_payloads_on_wooden_satellite----------------------------------5: Starship A: can get us really fast to Uranus:https://phys.org/news/2025-10-starship-uranus.html—————-B: Starship og kapløb med Kinahttps://videnskab.dk/rummet/starship-10-opsendt-med-succes-alligevel...
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Meta & Fysikken: Afsnit 114: Klima-status.
Oct 3100:50:33Tap to summarizeVi tager lige en status på klimaet, her Oktober 2025.1: Ocean Warming2: Koralrev3:Tipping Points4: Permafrost i Rusland5: Hvad gør vi med den CO2 vi indfanger?6: Fuel Cells / Green Hydrogen plant7: Kelp Farming in Norway------------------------------------------------1 : Ocean warming : https://www.sciencealert.com/ocean-warming-threatens-microbe-that-makes-nearly-a-third-of-earths-oxygenJeff Berardelli (meterolog USA):It's hard to overstate just how off the charts warm the Pacific is right now. The swath of the basin from California to Japan (a HUGE area) from 25N to 60N is ~3F (1.6C) above normal. To put it into math terms that is 6 Sigma/ standard deviations above the mean. I won't bother calculating the chances of this happening against the late 20th century climate - let alone the pre-industrial climate - because the numbers would show it simply could never happen without global warming.So let's talk about why this is happening. Since the last El Nino a couple of years ago the ocean has been rearranging its warm/cool water, as it typically does as a normal part of it's natural oscillation. (This summer a record ridge/ heat dome was parked over the N Pacific).But each next time this configuration lines up (warm north Pacific/ cool tropical Pacific) it piles on a higher and higher baseline temperature over time due to greenhouse warming, air pollution reduction, and the feedbacks (clouds & direct insolation) of both. So we end up with the bottom chart which shows the standardized anomaly (departure from normal) is sloping upward at a very unnatural and alarming rate.2: Koralrevhttps://www.dr.dk/nyheder/viden/klima/ny-rapport-det-er-saa-godt-som-uundgaaeligt-verdens-koralrev-kollapserhttps://videnskab.dk/naturvidenskab/oejenaabner-genopretning-af-koraller-kan-ikke-redde-verdens-rev/3: Tipping Pointshttps://videnskab.dk/naturvidenskab/tipping-points-lyder-skraemmende-men-der-er-haab-endnu/4: Permafrost i Rusland:https://videnskab.dk/naturvidenskab/klimabombe-i-rusland-danske-forskere-advarer-om-alvorlig-mangel-paa-videnOgså:Eksploderende Methan gas i Siberien:https://www.sciencealert.com/mysterious-giant-exploding-craters-in-siberia-may-finally-be-explained5:Hvad gør vi med den CO2 vi indfangerhttps://videnskab.dk/teknologi/hvad-goer-vi-med-den-co2-vi-fanger/Vi sender noget af den tilbage til oliefelterne vi har tømt i de danske farvande. Kilde: Royalt halløj----------------------------6: Tysklands største Hydrogen fabrik:Germany's largest commercial renewable hydrogen factory is the 10 MW plant in Schwäbisch Gmünd, opened by Lhyfe in October 2025. The facility can produce up to 4 tons of renewable hydrogen per day and is Lhyfe's largest outside of France. While it's the largest operational commercial plant, there are larger-scale projects planned for the future in Germany, such as a 130 MW plant planned for Prenzlau by ENERTRAG. https://engineerine.com/largest-green-hydrogen-plant/https://www.lhyfe.com/press/lhyfe-inaugurates-germanys-largest-commercial-renewable-hydrogen-production-site-in-baden-wurttemberg-to-distribute-rfnbo-certified-hydrogen-to-a-range-of-players/A green hydrogen factory is good for the climate because it can be produced using renewable energy, with zero greenhouse gas emissions, and can replace fossil fuels in sectors that are hard to electrify, like heavy industry. When used in a fuel cell, hydrogen only releases water vapor and warm air, making it a clean energy carrier that can also store and deliver renewable energy. #Hydrogen Fuel Cell makes electricity directly. They also produce water vapor, heat and, depending on the fuel source, very small amounts of nitrogen dioxide and other emissions.-------------------------7: Kelp farming in Norwayhttps://www.dnv.com/news/2024/new-seaweed-farm-off-the-norwegian-coast-seeks-to-remove-co2-from-the-atmosphere-252006/--------------------------------8: State of Climate Action 2025:https://www.wri.org/research/state-climate-action-2025" It finds that recent progress toward 1.5°C-aligned targets has largely failed to materialize at the required pace and scale and highlights where action must accelerate this decade to reduce greenhouse gas emissions, scale up carbon removal and increase climate finance."" Although more than three-quarters of indicators are heading in the right direction, progress is alarmingly inadequate, exposing communities, economies and ecosystems to unacceptable risks. Global efforts across 29 indicators are “well off track,” such that at least a twofold—and for most, more than a fourfold—acceleration will be required this decade to keep the 1.5°C limit within reach. "Getting on track for 2030 and staying on track for 2035 demands an enormous acceleration of efforts across every sector. The world must, for example:Phase out coal more than ten times faster — equivalent to retiring nearly 360 average-sized coal-fi...
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