SpaceX Punched a Hole in the Ionosphere

Re:SpaceX Punched a Hole in the Ionosphere by eqvinox on Friday July 28, 2023 @08:28PM (#36915361)

"molecules from the rocket exhaust produce photons at a wavelength of 6300 Å – the same color as red auroras."

Anyone else have this use of Ångström trigger an exception in their brain? The unit of default for wavelength is nm, not Å… (1nm=10Å)

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Re:SpaceX Punched a Hole in the Ionosphere by samstave on Friday July 28, 2023 @09:29PM (#36915820)

my trigger is from like the 1980s or 1990s where angstrom was a computer I couldnt afford...

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Re:SpaceX Punched a Hole in the Ionosphere by throwaway4837 on Friday July 28, 2023 @10:30PM (#36916222)

Angstroms are used pretty commonly in molecular/nuclear physics.

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Re:SpaceX Punched a Hole in the Ionosphere by dermesser on Saturday July 29, 2023 @01:31AM (#36917245)

If you look in another field, the default wavelength (wave number) unit is 1/cm. Meaning, there's not really a default wavelength unit.

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Re:SpaceX Punched a Hole in the Ionosphere by dguest on Saturday July 29, 2023 @01:58AM (#36917362)

I don't know if there's a "default" unit, but most people I interact with would use SI units (i.e. km, m, cm, mm, micron, nm, pm). Maybe more to your point, 630 nm is the same number of characters and a slightly more familiar unit. Writing a wavelength as 6300 angstroms is a bit like saying a marathon is 421,950 cm.

Anecdotally I've only really heard angstroms used in material science / condensed matter physics, where most small structures are small integer numbers of angstroms across.

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