5 ms·
I'm not following how "uncertainty" principle is a bad way of putting it. No matter what we do, we cannot know the position and velocity precisely at the same
by EnFinlay 10y ago
I'm not following how "uncertainty" principle is a bad way of putting it. No matter what we do, we cannot know the position and velocity precisely at the same time. If you know position precisely, velocity is uncertain. From what I understand it's not a matter of velocity is "as yet undetermined", if we know the location precisely, then the velocity has many values and will collapse to one value if observed precisely (at which point position will have gone from precise to many valued).
Or should I not be physics-ing in the morning.
- dnautics 10y agoI thought exactly the same thing. ΔpΔv > k is exactly "the uncertainty in p and the uncertainty in v cannot be zero.
- rubidium 10y agoI agree. Uncertainty principle is a great word for it. Not sure the authors points are really valid, and the "mongolian" language metaphor he used is a stretch. VERY capable physicists have been happy using the term uncertainty principle just fine in English and have no misunderstanding of what that means.
- klodolph 10y agoThe article's problem with "uncertain" is that it has connotations of some intelligence comprehending the observed value. When I say, "velocity is uncertain" it seems to mean something like "I am uncertain what the velocity is", but when I say that "velocity is undefined" or "velocity is fuzzy" then it is more clear that I am talking about the velocity itself. I think "uncertain" is fine. Of course, the particular words are not really that important if you just tell people to read the definitions and equations used in the theory.
- dnautics 10y ago"undefined" has a very specific scientific and mathematical meaning that would place it at risk of being very, very wrong if conflated.
- klodolph 10y ago"Uncertain" also has a meaning outside the uncertainty principle. When we say that a measurement has uncertainty, we usually mean that it has some fixed value, but our tools are not capable of measuring it beyond some limit. Almost all terms in mathematics and science are overloaded in ways like that. For example, what is the "basis" for a mathematical space?
- dnautics 10y agoGood point. Uncertainty colloquially does admit the possibility of "no true value" embarrassingly as a scientist, I forgot the stat definition.
- Manishearth 10y agoIt sort of is a bad way in that "uncertain" means that an answer exists but we don't know it, whereas the answer really doesn't exist. However, this is a really minor nitpick and since statistics is used all the time with QM "uncertainty" is just fine. The article is making a mountain out of a semantic molehill.
- tgb 10y agoI have encountered people, in person, that spout new-agey nonsense based largely on the word "uncertainty" in this uncertainty principle. I'm sure they would latch onto other things were it not there, but this definitely feeds into that stuff.
- acqq 10y agoYes, "unsharp" or "the principle of non-sharpness" or something like that, inspired by some German terms used, would be much less prone to misunderstandings and myths. "It's not sharp, but it's OK." Can't be reduced to "stupid scientists are so uncertain."
- EnFinlay 10y agoUnwinnable battle, that one.
- eternalban 10y ago> new-agey nonsense One of these hippie types went so overboard that he even made a "hand wavy" coat of arms to go along with his lateral comments about Buddha and Laotze [1] and question our very ability to fully comprehend an objective reality. [1]: https://upload.wikimedia.org/wikipedia/commons/thumb/d/da/Coat_of_Arms_of_Niels_Bohr.svg/2000px-Coat_of_Arms_of_Niels_Bohr.svg.png https://upload.wikimedia.org/wikipedia/commons/thumb/d/da/Co...
- Manishearth 10y agonew agey nonsense comes out of every popsciification of physics, this isn't new. Its also still a minor thing IMO.
- Florin_Andrei 10y ago"Uncertainty" suggests that the position might, in some way, be defined with 100% precision, but it's us, the observers, who are uncertain what the actual value is. "Unschärferelation" suggests the value coming out of the system (position, impulse, etc) is in a fundamental way not pinned on a single value fixed with 100% precision, but instead it's spread out over a distribution function.
- EnFinlay 10y agoOh, I got it. It's the difference between "I am uncertain" and "It is uncertain". That makes sense. First discussion that happens in an undergrad quantum mechanics class. Teacher: "It is uncertain" Student: "Can't we measure it better?" Teacher: "No, it is unknowable, no matter what" Student: "Wtf?"
- emsy 10y agoUnscharf (the adjective to Unschärfe) can be translated to "out of focus" or "blur", which kind of describes the phenomenon figuratively.