| General > General Technical Chat |
| Time, Standards, and Dog-Shit... what could it mean?? |
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| GlennSprigg:
I'll get to the 'strange' title in a minute... haha... 8) I, like most other humans, have THOUGHT we understood about 'GMT'. It seems we dont!!!... "GMT" stands for 'Greenwich Mean Time', but this has little to do with how things are dealt with today. It all started when refs were made to a particular Astronomical Telescope, 0 degrees of longitude on the line marking the prime meridian at the Royal Greenwich Observatory in London, England. Here's a photo of the line in London!!!... Since then 'scientists' have decided/agreed that although this 'line' does indeed mark the position of the Royal Greenwich Observatory, it is no longer relevant to the science/knowledge of Today!! Navigation systems such as GPS now use the IERS Reference Meridian (IRM), which is a DOUBLE acronym for the letter 'I' meaning the "International Earth Rotation and Reference Systems", with the 'RM' (Reference Meridian) which runs about 334 feet (102 meters) east of that observatory!!. This new spot, is about 1 second out, for out known/past 'calculations'... One big difference though, is that what we used to call 'GMT', is no longer a 'Standard' for 'Time', but just a time zone as opposed to the now UTC. People however, think it is strange that there is NO specific marked POINT/PLACE which is presently 102 Metres away?? Until...... Certain scientific Nerds & stirrers, noticed that, (using Google Maps & other sophisticated calculations, that a Dog Litter Bin in Greenwich Park, 102 Metres East of the Observatory, is pretty much exactly where the new/now globally used meridian should-be/is the 'marker' for the new standard!!!! ^-^ Un-'official' or not, I like that!! Many things get 'named' for the most obscure reasons... FOR EXAMPLE!!! Do you remember the 'old' name for a Computer/Printer/Scanner interface, called 'TWAIN'. :D At the time of it's discovery and on a Test-Bench, they originally called it... A "Tool Without Any Important Name"... and it stuck! I love that! |
| greenpossum:
It's a meridian so there there is an infinity of points on that meridian. However for a particular latitude there is that DLB. |
| GlennSprigg:
Oops, i forgot to post this link... (one of many!)... https://www.timeanddate.com/geography/prime-meridian-wrong.html |
| greenpossum:
Apropos of something related. Something big happened last May 20. From that day the kilogram is no longer defined in terms of a physical object, the big K in Paris. It is now defined by the fixed value of the Planck constant. Here's one of many simplified explanations: https://www.vox.com/science-and-health/2018/11/14/18072368/kilogram-kibble-redefine-weight-science And a commentary from me: If only we could all co-operate like scientists and engineers do. |
| GlennSprigg:
You are right. 'Standards' are no longer based on physical objects, but is beyond the scope of the 'discussion' here in this post. My post was not to discuss the rate of vibration of a Cesium atom to reset an atomic clock etc... but just a play on events & locations. Start a new topic, and we will take it to the stars!!! :-+ |
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