Timeline for How can length be a vector?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
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| Apr 11, 2017 at 16:07 | comment | added | Robin Ekman | @R.M. If you are a little pedantic, we do have a separate term for the vector quantity, since the quantities that appears in the differential form of Maxwell's equations are, strictly speaking, the charge and current densities. That's an additional three syllables though, so it's understandable that we get sloppy. | |
| Apr 11, 2017 at 15:53 | comment | added | ZeroTheHero | @R.M. That's a good way to put it. | |
| Apr 11, 2017 at 15:48 | comment | added | R.M. | @RaghavSingal Current is a scalar in the same sense that speed is a scalar ... Only with speed/velocity we have a different word for the scalar version (i.e. "speed") and the vector version (i.e. "velocity"), whereas for current we use the same word for both the scalar and vector form. (Sort of like some English plurals: One goose, two geese, but one moose, two moose.) - And like speed/velocity, the vector version of current becomes more important than the scalar one for advanced physics. | |
| Apr 11, 2017 at 13:58 | comment | added | Robin Ekman | @ZeroTheHero I completely agree, and I think another example is Bohr's model of the atom, which also causes need for lots of unlearning. One way of fixing it would to just stick everyone with Landau and Lifschitz, but I can see there being ... other issues with that. :D | |
| Apr 11, 2017 at 13:57 | comment | added | ZeroTheHero | @RobinEkman Yeah... it's a pity in a way because it is an "error" that is repeated and the source of genuine confusion. Students in upper level courses have to "unlearn" this and re-adjust. But we are slaves to history in this matter. | |
| Apr 11, 2017 at 13:54 | comment | added | Robin Ekman | Maxwell's Treatise is only 144 years old, you can't expect textbooks to have caught up yet. :^) | |
| Apr 11, 2017 at 13:48 | comment | added | ZeroTheHero | Yes but this is historical because of circuits, as explained above. Your confusion is completely understandable, and your textbook (as all other textbooks) follows the convention of history rather than logic. I wish I could say it better but the only other (illogical) comment would be to say that current "magically" becomes a vector in 2d and 3d... but we can agree this is pretty absurd... Sorry for the historical tradition but we're stuck with it. | |
| Apr 11, 2017 at 13:47 | comment | added | Matt | But according to university phys8cs it says current is a sacalar . | |
| Apr 11, 2017 at 13:45 | history | answered | ZeroTheHero | CC BY-SA 3.0 |