11 ms·
Earth’s magnetic field is acting up
- feniv 8y agoEarth's magnetic pole has been known to switch sides in the past. https://en.wikipedia.org/wiki/Geomagnetic_reversal https://en.wikipedia.org/wiki/Geomagnetic_reversal "183 reversals over the last 83 million years... A brief complete reversal, known as the Laschamp event, occurred only 41,000 years ago during the last glacial period. ... Geologists first noticed that some volcanic rocks were magnetized opposite to the direction of the local Earth's field.".
- darkerside 8y agoWhen this happens, does the magnetism "rotate" around the Earth, or does it fade out and fade back in reversed?
- idbehold 8y agoCloser to fading out and back in.
- michaelg7x 8y agoDoes this mean anything for the protection the planet receives from cosmic rays or solar wind?
- AndrewDucker 8y agoDefinitely https://m.phys.org/news/2012-11-cosmic-rays-reveal-event-earth.html https://m.phys.org/news/2012-11-cosmic-rays-reveal-event-ear...
- deleted 8y ago[deleted]
- techas 8y agoIndeed. Some people believe these “unshielded” periods might had some influence on the evolution of the species. Without those, the rate of change is just not enough to get to humans...
- DoctorOetker 8y agoI'm not contesting but merely interested in references.
- feniv 8y agoHere's a gif from a 1995 supercomputer simulation of the reversal process - https://imgur.com/a/jgpZZBF https://imgur.com/a/jgpZZBF "The tubes represent magnetic field lines, blue when the field points towards the center and yellow when away." Original source: https://www.psc.edu/science/glatzmaier.html https://www.psc.edu/science/glatzmaier.html It took them a year of computing on a CRAY C90 and 2000 hours of processing.
- deleted 8y ago[deleted]
- falcolas 8y agoOddly enough, this has a sizable impact to general aviation. Heading is typically measured using a gyro, but the heading values are calibrated to magnetic north (typically via a magnetometer or manually against a compass). The creep of the magnetic field is noticeable in particular in the numbering of runways - they are numbered according to their heading. Some runways that have existed for a few decades are, accordingly, off by a few degrees. An older runway numbered "35" may have an actual approach heading of 340 (340 degrees from magnetic north). Not a huge problem when flying by eye, but it has the capability of causing some confusion when flying using instruments. Alternately, the runway numbers can even change. As for GPS, this won't solve the problem either, since GPS can give you a "true" flight path using the movement over time, which with wind will not always match the actual heading of the aircraft due to wind.
- fh973 8y agoThat's why runway designations are updated periodically to reflect the magnetic change.
- joeseeder 8y agoYup, quite a few were renumbered last year in UK
- deleted 8y ago[deleted]
- souprock 8y agoThis is pretty sad. For at least decades, maybe even centuries, there have existed compasses that let you rotate the "north" indicator to match the current local magnetic declination. Adjusting as you travel is no different than the pressure adjustments that pilots make for altimeters. There is no good reason we couldn't have all of the airports using geographic north. That one is far more resistant to change, with continental drift and Earth axis wobble being far slower than magnetic pole movement.
- aeternus 8y ago
- thangalin 8y ago"Pottery jugs from between the eighth and second centuries B.C. bear administrative stamps that changed with the political situation. Unbeknown to the people firing these jugs, the act of heating locked information about the Earth's geomagnetic field into minerals present in the clay. Because the stamps provide precise information about when the pots were fired, the study allows a detailed look at geomagnetic changes over 600 years." https://www.livescience.com/57868-earth-magnetic-field-spike-ancient-times.html https://www.livescience.com/57868-earth-magnetic-field-spike...
- ryanmercer 8y agoDouble pottery awesomeness today between that and this post https://news.ycombinator.com/item?id=18869653 https://news.ycombinator.com/item?id=18869653
- medius 8y agoThis is one of the most amazing things about humans to me. I marvel at how it's possible to get so much information about our universe by observing so little. Astronomy is another field that I'm really impressed with. It's possible to infer things about galaxies, stars, planets, etc. just buy observing some light coming from them to our little blue planet. Absolutely crazy. How many such techniques we haven't even discovered or technology is not there to observe such things? I really enjoyed reading Our Mathematical Universe by Max Tegmark that explores such things.
- olivermarks 8y agoArticle linked is truncated, last sentences lifted from here https://www.nature.com/articles/d41586-019-00007-1?utm_source=twt_nnc&utm_medium=social&utm_campaign=naturenews&sf205680051=1 https://www.nature.com/articles/d41586-019-00007-1?utm_sourc...
- NeedMoreTea 8y agoThat's a much better article, free of claims of scientific bafflement. :)
- sctb 8y agoThanks! We've updated the submission from https://www.newsweek.com/earth-magnetic-field-baffle-scientists-north-pole-siberia-canada-world-1286507 https://www.newsweek.com/earth-magnetic-field-baffle-scienti..., which points to this.
- NeedMoreTea 8y agoI've read a number of pieces over the years that a geomagnetic reversal might be near, and there have been flips as short as a couple of hundred years. Where "near" may be in my lifetime or in the next 500 years. So we may not know why it's moved more than model, but I don't think we should be unduly surprised. Here's one recent piece implying a switch could be sooner rather than later: https://www.extremetech.com/extreme/192522-earths-magnetic-field-could-flip-within-our-lifetime-but-dont-worry-we-should-be-ok https://www.extremetech.com/extreme/192522-earths-magnetic-f...
- ams6110 8y agoSo what exactly does that mean? If I'm driving from Chicago to Milwaukee will my compass say I'm heading South?
- bjelkeman-again 8y agoThe flip can possibly happen in a lifetime, but it probably takes thousands of years. But we have never observed it so we don’t really know how, but we know that it happens. https://en.m.wikipedia.org/wiki/Geomagnetic_reversal#Character_of_transitions https://en.m.wikipedia.org/wiki/Geomagnetic_reversal#Charact...
- cartsagis 8y agoFun fact, the earth Northern Magnetic pole (ie the magnetic pole in the northern hemisphere) is actually the south pole of the magnetic dipole. So your compass actually is already telling you that you're heading south. But yes, the compass you have today will point south instead of north, but this can be solved by repainting which pole of the compass is red :)
- faissaloo 8y agoI'd guess it would cause the mass death of animals that use the poles to navigate.
- Tharkun 8y ago
- exabrial 8y agoBeing a son of a geologist, I found it fascinating we could tell from geologic history how many times the earth's magnetic field has flipped. Turns out we're long overdue for a reversal.
- golemotron 8y agoIt was foretold: https://www.imdb.com/title/tt0298814/ https://www.imdb.com/title/tt0298814/
- ComputerGuru 8y ago> Update, 9 January: The release of the World Magnetic Model has been postponed to 30 January due to the ongoing US government shutdown. This article isn't much without the accompanying model.
- peterwwillis 8y agoSince the US is on extended winter vacation, maybe China or Russia can maintain the world magnetic model?
- macawfish 8y agoSo it begins
- angelic 8y agoMajor geological changes like this take many centuries to play out. This is an absolute nothingburger.
- phkahler 8y ago>> In 2018, the pole crossed the International Date Line into the Eastern Hemisphere. It is currently making a beeline for Siberia. I knew Putin was a super villain. Now he's stealing the north pole!
- lostmsu 8y agoOn the picture, the movement of the pole slightly resembles a pendulum: it is slow at the beginning far from the geographic pole, and it speeding up as it nears it. Makes perfect sense, actually.
- chiefalchemist 8y ago> "On 15 January, they are set to update the World Magnetic Model, which describes the planet’s magnetic field and underlies all modern navigation, from the systems that steer ships at sea to Google Maps on smartphones." Boggles the mind to think that Mother Nature is the foundation for such significant technology. If only the Twilight Zone was still around to do an episode on the magnetic north suddenly going MIA. It has gone south (literally) a couple times I believe.
- vanattab 8y ago"Boggles the mind to think that Mother Nature is the foundation for such significant technology." As best I can tell Mother Nature is the foundation of ALL technology...
- petre 8y agoMads Faurschou Knudsen and Peter Riisager, Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK. Pages 71-74. Based on an observed correlation between the Earth's magnetic dipole moment and oxygen isotope paleo-precipitation records from caves in Oman and southern China, Knudsen and Riisager suggest that the Earth's magnetic field may have influenced the amount of rainfall in low-latitude regions during the past 5000 years. The physical mechanism that underpins the geomagnetic-climate link is provided by the cosmic-ray-climate theory, which suggests that galactic cosmic ray (GCR) particles entering the atmosphere influence the formation of low-altitude clouds and, in turn, climate. The geomagnetic field shields the Earth from GCR particles and, according to the cosmic-ray-climate theory, it therefore has the potential to influence cloud formation, rainfall, and climate. Since the amount of GCR particles entering the atmosphere is also modulated by the Sun, the cosmic-ray-climate theory is central to the ongoing scientific debate regarding the role of the Sun in climate change. Knudsen and Riisager lend support to the notion that variations in the Earth's magnetic field may influence the climate of our planet. They also deliver independent support for certain aspects of the cosmic-ray-climate theory. https://www.eurekalert.org/pub_releases/2009-01/gsoa-jgm010809.php https://www.eurekalert.org/pub_releases/2009-01/gsoa-jgm0108...