[HN Gopher] Digitized Continuous Magnetic Recordings for the 185...
       ___________________________________________________________________
        
       Digitized Continuous Magnetic Recordings for the 1859 Carrington
       Event
        
       Author : simonebrunozzi
       Score  : 134 points
       Date   : 2024-04-23 19:50 UTC (1 days ago)
        
 (HTM) web link (agupubs.onlinelibrary.wiley.com)
 (TXT) w3m dump (agupubs.onlinelibrary.wiley.com)
        
       | TheAmazingRace wrote:
       | I'm amazed that the scientific community of the time happened to
       | have some kind of equipment to measure this phenomenon... all
       | right before the time of the American Civil War.
        
         | pvg wrote:
         | _happened to have some kind of equipment_
         | 
         | Maxwell's _A Dynamical Theory of the Electromagnetic Field_ was
         | published in 1865 - it 's mostly your perception of the history
         | of the relevant science that might be a few decades off.
        
           | iyn wrote:
           | Why so snarky? The paper you refer to was published _after_
           | the event. I 'm also amazed that it was possible to record
           | such event at that time.
        
             | pvg wrote:
             | I'm not sure where you got snarky, I'm just giving a little
             | info on the state of scientific development of that
             | particular field at the time. You need plenty of previous
             | work to get to a theory of electromagnetism, as Maxwell
             | did. If you prefer something a little earlier and more
             | experimental Faraday published his seminal result in 1831.
             | It took him about 10 years of fiddling with wires and
             | magnets.
             | 
             |  _I 'm also amazed_
             | 
             | Which is wonderful! So were 19th century scientists,
             | though, and they also figured it out.
        
             | tanseydavid wrote:
             | The comment you are responding to, does not seem at all
             | snarky to me. Just sayin'.
        
         | BobbyTables2 wrote:
         | London had an earlier version of the Underground while we were
         | busy burning things and shooting at each other in the swamps...
        
         | aardvark179 wrote:
         | They didn't just happened to have experiments set up to measure
         | the magnetic field, improving navigation is really important if
         | your power comes from trade so this sort of thing is funded.
        
           | Roark66 wrote:
           | And yet they were saving money by reusing photographic
           | plates, bacause (as the article said) the observatory was
           | constantly in danger of running out of funding. I guess
           | science has always been underfunded.
        
       | xattt wrote:
       | Given the topic, is it possible for a solar flare to happen that
       | is so large that aurora reach sea level? Or does it turn to
       | Cherenkov light at that point?
        
         | yummypaint wrote:
         | Given the energy range of protons from the sun, it seems that
         | the only way they can reach sea level is if much of the
         | atmosphere were already swept away by some huge event.
        
       | londons_explore wrote:
       | A big open question appears to be "how often do storms of this
       | magnitude occur"
       | 
       | If we wanted answers to that, I think we could inspect chunks of
       | iron containing mudstone deposited anytime in the past few
       | million years. By looking at the magnetic alignment of iron
       | particulates, you will learn the magnetic field when the particle
       | was laid down. With particles being so small, it seems likely one
       | could reconstruct 5 minutely magnetic field angle, albeit with a
       | big linearity error on the time axis due to the uncertainty in
       | rate of silt deposits.
       | 
       | However, such a measurement should still give a good estimate of
       | the frequency and magnitude of geomagnetic storms.
        
         | jameshart wrote:
         | Are you suggesting this because you have some knowledge of the
         | field and are aware that this work hasn't been done? It seems
         | like if it were so simple someone might have taken a look.
         | Magnetic analyses of rock deposits are after all how we know
         | about things like the timing and frequency of magnetic pole
         | flips.
         | 
         | The Carrington event lasted about 2 weeks. How much silt is
         | deposited in that time?
        
           | londons_explore wrote:
           | I suspect it hasn't been done because there was no obvious
           | value to such data, and the effort of figuring out the
           | precise position and magnetic orientation of trillions of
           | iron particles would be pretty high...
        
             | exogenousdata wrote:
             | Lloyd's of London is a large insurer and is very interested
             | in the potential liability that they are exposed to from
             | the various insurance policies that they've underwritten.
             | 
             | In 2013, they published a report[0] considering the effects
             | of solar storm risk to the North American electric grid.
             | 
             | tldr; it's all about the transformers
             | 
             | [0] - https://assets.lloyds.com/assets/pdf-solar-storm-
             | risk-to-the...
        
         | entropic88 wrote:
         | They look for carbon 14 isotope spikes in ancient tree rings,
         | and compare to beryllium 10 and chlorine 36 in ice cores
         | 
         | We've developed a fairly decent record of events back to 14,000
         | years ago
         | 
         | Look up 'Miyake events'
        
           | nicbou wrote:
           | https://en.wikipedia.org/wiki/Miyake_event
           | 
           | This keeps getting more interesting!
           | 
           | > Six diverse historical occurrences, from archaeological
           | sites to natural disasters, have thus been dated to a
           | specific year, using Miyake events as benchmarks and counting
           | tree rings. For example, wooden houses in the Viking site at
           | L'Anse aux Meadows in Newfoundland were dated by finding the
           | 993 CE Miyake event and then counting tree rings, which
           | showed that the wood is from a tree felled in 1021 CE.[
        
             | stainforth wrote:
             | 13000 years ago seems like a special moment for a few
             | events. Is it possible that say a volcano eruption, or a
             | meteor strike saturates the atmosphere and normal cosmic
             | ray interaction with soot and so on can attribute to what
             | they detect in trees?
        
           | hansjorg wrote:
           | According to Wikipedia:
           | 
           | > At present, five significant events are known (7176 BCE,
           | 5259 BCE, 660 BCE, 774 CE, 993 CE)
           | 
           | Seems like the Carrington event wasn't strong enough to be
           | considered a Miyake event.
        
           | pyinstallwoes wrote:
           | Interesting one is 12k years ago around Younger Dryas
        
         | shzhdbi09gv8ioi wrote:
         | > I think we could inspect chunks of iron containing mudstone
         | deposited anytime in the past few million years. By looking at
         | the magnetic alignment of iron particulates, you will learn the
         | magnetic field when the particle was laid down.
         | 
         | This method has been used to identify the reversal of the
         | magnetic pole. [1]
         | 
         | Generally tho, such solar storm lasts for way too short amount
         | of time to leave permanent evidence in the rock layers.
         | However, I believe they have studied deviations in tree trunk
         | rings.
         | 
         | 1: https://en.wikipedia.org/wiki/Geomagnetic_reversal
        
           | zh3 wrote:
           | And to prove the theory of continential drift (through
           | Paleomagnetism [0]). Shame that Wegener [1] didn't live to
           | see his theory vindicated.
           | 
           | [0] https://en.wikipedia.org/wiki/Paleomagnetism
           | 
           | [1] https://en.wikipedia.org/wiki/Alfred_Wegener
        
       | netrap wrote:
       | I found the software they used for digitization to be
       | interesting: https://markummitchell.github.io/engauge-digitizer/
        
         | neuronexmachina wrote:
         | Something similar which is more recently-maintained:
         | https://github.com/automeris-io/WebPlotDigitizer
        
       | hasmanean wrote:
       | If they had used polygonal mirrors instead of flat ones they
       | would not have lost any data.
        
       ___________________________________________________________________
       (page generated 2024-04-24 23:02 UTC)