Timeline for How to convert Joules to units where the speed of light is 1
Current License: CC BY-SA 4.0
14 events
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| Apr 19, 2021 at 21:32 | comment | added | Bill Watts |
You solution of UnitConvert[Quantity[10, "Joules"]/(Quantity["SpeedOfLight"])^2] // N is right on the money since you are essentially dividing Joules by $1^2$, but I'm not quite sure what you mean about problems with the editor.
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| Apr 19, 2021 at 3:33 | history | edited | larry | CC BY-SA 4.0 |
added 275 characters in body
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| Apr 18, 2021 at 10:10 | answer | added | Roman | timeline score: 1 | |
| Apr 18, 2021 at 7:05 | comment | added | Roman |
As an example of the aforementioned solution, the command unitConvert[Quantity[10, "Joules"], makeUnitSystem[{"SpeedOfLight", "PlanckConstant", "ElectronMass"}]] gives a conversion to $1.221432857\times10^{14} m_e c^2$. The need for a mass unit (here, the electron mass; but could be anything) becomes explicit.
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| Apr 18, 2021 at 6:54 | comment | added | Roman | As @JohnDoty points out, you need to fix an entire system of units, not just one (speed of light). In SI units, we choose kilograms, meters, and seconds as the three base units for dynamics. You can choose any three you like; but they have to be three in number (for dynamics). So choosing the speed of light as a base units is fine but needs to be complemented by two others, for example the kilogram and the meter, or Planck's constant and the electron's mass, or really any other pair. See this answer for more examples. | |
| Apr 18, 2021 at 1:33 | history | edited | larry | CC BY-SA 4.0 |
sped -> speed
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| S Apr 18, 2021 at 1:25 | history | edited | larry | CC BY-SA 4.0 |
sped -> speed
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| S Apr 18, 2021 at 1:25 | history | suggested | Gert | CC BY-SA 4.0 |
sped -> speed
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| Apr 18, 2021 at 1:07 | comment | added | John Doty | To define an energy unit based on c, you must also choose a unit of mass, either explicitly or implicitly. | |
| Apr 17, 2021 at 22:20 | comment | added | Bill Watts |
I think by setting c = 1 = 299792458 m/s , the OP wants a second to meter conversion or vice versa. With that conversion you can eliminate either meter or second for the joule conversion
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| Apr 17, 2021 at 21:54 | review | Suggested edits | |||
| S Apr 18, 2021 at 1:25 | |||||
| Apr 17, 2021 at 20:54 | comment | added | Adam |
What's wrong with UnitConvert[Quantity[10, "Joules"]/Quantity["SpeedOfLight"]]?
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| Apr 17, 2021 at 20:03 | comment | added | CA Trevillian | What have you tried so far? Can you, please, include this code in your question? | |
| Apr 17, 2021 at 19:47 | history | asked | larry | CC BY-SA 4.0 |