4 ms·
To do so is to redefine the second on the moon. That redefines the Watt, the Joule, the Newton, the Ampere, the Pascal, the Becquerel, etc. It even makes a vol
by ISL 3y ago
To do so is to redefine the second on the moon.
That redefines the Watt, the Joule, the Newton, the Ampere, the Pascal, the Becquerel, etc.
It even makes a voltmeter read incorrectly.
Moon-meters would be different from Earth-meters.
Careful.
- doublerabbit 3y agoHow many moon metres equate to 10 space football fields?
- 8338550bff96 3y agoThe size of football fields might need to change as well to accommodate the change in play style. You probably don't want quarterbacks dunking a touchdown in one flying leap from the 50-yard line.
- kube-system 3y ago> You probably don't want quarterbacks dunking a touchdown in one flying leap from the 50-yard line. That’s exactly what I want! takeMyMoney.jpg
- dmd 3y agoJon Bois has you covered
- non-chalad 3y agoIs that moon yards, or space yards?
- saalweachter 3y agoIs it space feet, or space survey feet?
- Findecanor 3y agoIt has been speculated that humans evolved in lower gravity would grow taller, getting longer finer features than humans on earth. If an independence movement on Luna gets hold, it might want to differentiate Luna from Earth, and introduce a "lunar foot" based on lunar people.
- brummm 3y agoIt would redefine the meter too since the speed of light is defined as a constant and the meter derives from it.
- looperhacks 3y agoThe meter is defined by the speed of light in a vacuum, that doesn't change on the moon
- ZiiS 3y agoMeter is defined as how far the light travels in a vacuum in 1/299792458th of a second. The actual speed of the light in a vacuum is fixed, so unless you have identical seconds the distance of the meter changes. If you have identical seconds in lower gravity, then you get less of them.
- seanhunter 3y agoGood luck landing a craft built by multiple teams with possibly differing definitions of Newtons. Kinda feels like agreement on the definition of the Newton would be the difference between "guidance and propulsion systems worked perfectly" and "debris was scattered across the landing zone".[1] [1] Not an astrodynamicist, but have done enough problems with inclined planes, pulleys, springs etc to know it's quite important to get the magnitude of the forces right.
- adrian_b 3y agoIt would have been easy to avoid the redefinitions of all other units by defining the second based on the frequency of an atomic clock that works in a null gravity field. This would have required to apply a relativistic correction to the measured frequency of any atomic clock, but it would have provided unit definitions independent of the position in the Universe. However, before contemplating the idea of time keeping on other celestial bodies it was decided to define the second based on an atomic clock that works on the surface of the geoid. I believe that this was a big mistake, because it ties all the SI units to the Earth and especially because it does not really avoid the use of relativistic corrections. Now the precision of the atomic clocks is so great that for most of them it is necessary to apply relativistic corrections depending on the altitude of the laboratory.
- ISL 3y agoGeneral Relativistic time differences come primarily from differences in gravitational potential, not field-strength. Thus, it is impossible to perform the suggested procedure. We don't (and probably can't) know what zero potential looks like. Furthermore, we would probably measure those potential differences using clocks that rely upon the SI as presently defined.