Jan 9, 2018 10:59 PM
Rewritable paper goes technicolor
https://cen.acs.org/articles/96/web/2018...color.html
EXCERPT: The paper industry has a significant environmental impact, from cutting down trees for raw material to consuming large amounts of energy and water to process that material. To curb that impact, chemists have been working on rewritable paper technologies that would allow people to print on a sheet of paper with special inks and then erase them to reuse the paper. A team now reports a form of rewritable paper that can display multicolored images and text for months, before being erased and reused time after time...
Very Low Frequency Radio Waves Protect Earth?
https://engineering.curiouscatblog.net/2...ect-earth/
Very low frequency or VLF [...] is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and for secure military communication. Since VLF waves can penetrate at least 40 metres (120 ft) into saltwater, they are used for military communication with submarines.
EXCERPT: . . . these waves [...] also extend out beyond our atmosphere, shrouding Earth in a VLF bubble. [...] the outward extent of the VLF bubble corresponds almost exactly to the inner edge of the Van Allen radiation belts, a layer of charged particles held in place by Earth’s magnetic fields. Dan Baker [...] speculates that if there were no human VLF transmissions, the boundary would likely stretch closer to Earth. Indeed, comparisons of the modern extent of the radiation belts from Van Allen Probe data show the inner boundary to be much farther away than its recorded position in satellite data from the 1960s, when VLF transmissions were more limited....
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https://cen.acs.org/articles/96/web/2018...color.html
EXCERPT: The paper industry has a significant environmental impact, from cutting down trees for raw material to consuming large amounts of energy and water to process that material. To curb that impact, chemists have been working on rewritable paper technologies that would allow people to print on a sheet of paper with special inks and then erase them to reuse the paper. A team now reports a form of rewritable paper that can display multicolored images and text for months, before being erased and reused time after time...
Very Low Frequency Radio Waves Protect Earth?
https://engineering.curiouscatblog.net/2...ect-earth/
Very low frequency or VLF [...] is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and for secure military communication. Since VLF waves can penetrate at least 40 metres (120 ft) into saltwater, they are used for military communication with submarines.
EXCERPT: . . . these waves [...] also extend out beyond our atmosphere, shrouding Earth in a VLF bubble. [...] the outward extent of the VLF bubble corresponds almost exactly to the inner edge of the Van Allen radiation belts, a layer of charged particles held in place by Earth’s magnetic fields. Dan Baker [...] speculates that if there were no human VLF transmissions, the boundary would likely stretch closer to Earth. Indeed, comparisons of the modern extent of the radiation belts from Van Allen Probe data show the inner boundary to be much farther away than its recorded position in satellite data from the 1960s, when VLF transmissions were more limited....
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