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Parallel without qualification should not imply direction?
by getcrunk 2y ago
Parallel without qualification should not imply direction?
- K0balt 2y agoMmmmm I don’t think you would say that two cars going opposite directions on a road , in opposite lanes, are on a parallel path, you would say they were on an opposite path, I would think. But if those two cars were traveling the same direction, in the same two lanes, they would be properly described as following a parallel path. from a line vs ray perspective parallel and opposite are equivalent, but when they are rays and not lines, directionality matters.
- getcrunk 2y agoEverything you added is context I.e. qualifications
- digging 2y agoContext is indeed what narrows the meaning of a word with various or broad meanings.
- theoreticalmal 2y agoMaybe the car metaphor breaks down sooner than you’d hoped?
- robertlagrant 2y agoJust like a real car.
- danwills 2y agoI don't think it does, but rather says whatever direction the first one is pointing in is exactly the same as the direction the second one points in.
- PittleyDunkin 2y agoParellelism doesn't imply directionism at all.
- gus_massa 2y agoFrom a mathematical point of view: no, no directionism at all. From a physicist working with spins point of view: yes, parallel has the same direction and antiparallel the oposite. Each area create their own jargon. Sometimes it's confusing to ousiders and when you pick a book from another area you must double check that the worlds mean what you think their mean.
- gilleain 2y agoFor what it's worth, protein structural biochemistry uses similar terminology for sheets. Since a strand has a direction (N to C), sheets are 'parallel' when neighbouring strands are pointing (roughly) in the same direction, and 'antiparallel' when pointing in opposite directions.
- phantomathkg 2y agoI think in this case as they are talking about force, it is a vector and implicitly imply direction. So antiparallel really means that the two force are pointing to opposite direction.
- PittleyDunkin 2y agoYou'd think they'd include a term that signaled this is about vectors then! I foolishly assumed this was a new term for "orthogonal", but words don't really need to be meaningfully related to their roots to be meaningful themselves.
- ajkjk 2y agoIt is a very standard term in physics at the undergraduate level.
- PittleyDunkin 2y agoSuch definitions may not make sense but it's still worth accepting them.
- seanhunter 2y agoIf you’re talking Euclidian geometry of infinite lines on a plane definitely yes. If you’re talking about vectors then you need an additional concept to capture the way the case of two vectors which fall on lines which in the Euclidian sense are parallel but point in opposite directions is clearly different from two vectors which point in the same direction also. This is like the difference between cars in parallel lanes on one side of a multi-lane highway and the oncoming traffic which would be antiparallel.