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People have this strange idea that Einstein destroyed objectivity in physics and validated all their pet postmodern theories. It isn't true. In relativity, tim

People have this strange idea that Einstein destroyed objectivity in physics and validated all their pet postmodern theories. It isn't true. In relativity, time is a variable that is different for each observer, but it is still objective. It's not a matter of opinion for each observer. There are formulas that determine how all the variables change, and any observer can know what the other observers' variables are by watching how they move through space and using the formulas. While some naive Newtonian concepts such as a single universal time metric stop working, there's no wiggle room for observer A and B to be inconsistent with one another based on their personal opinions. There is one objective reality and one objective way to quantify it mathematically. Time isn't a single universal quantity in relativity, but it's still objective. Einstein didn't turn physics into cultural anthropology.

morelisp 5y ago
People have this strange idea that "subjective" means something equivalent to "unknowable" or "an opinion" or "as I please". It isn't true. > a variable that is different for each observer This is literally what "subjective" means - different dependent on the subject.
- civilized 5y ago
  Google subjective and copy the definition you see here. Here's what I see: subjective: based on or influenced by personal feelings, tastes, or opinions.
  - morelisp 5y ago
    First result is Wikipedia entry for "Subjectivity" which says... - Something being a subject, narrowly meaning an individual who possesses conscious experiences, such as perspectives, feelings, beliefs, and desires. - Something being a subject, broadly meaning an entity that has agency, meaning that it acts upon or wields power over some other entity (an object). - Some information, idea, situation, or physical thing considered true only from the perspective of a subject or subjects. The third being the only obvious applicable one. It's also hypocritical to demand an adherence to an anti-common-sense physics-based formal definition of "time" while refusing the same courtesy towards formal definitions of "subjective."
    - civilized 5y ago
      But it's not applicable, because an "observer" in relativity is not a subject having perspectives, feelings, beliefs, etc. It is an abstract mathematical point moving through space. "Reference frame" is really the proper term, not observer or subject. And the proper time that passes in a given reference frame is an objective fact in relativity, even though that measurement cannot be directly applied to other reference frames without transformation. "Objective" doesn't mean "experienced from all perspectives in the same way". Two different observers of a cube will get two different perspectives of the cube. The cube is still a single, objective, observer-independent reality. The same applies to relativistic time. It's a single reality (part of the spacetime manifold) that is measured differently in different reference frames. The different measurements must be consistent with one another according to a system of formulas. Just as different perspectives of a cube must be consistent with one another based on (1) the cube's objective existence in space and (2) the formulas of optics which determine the perspective each observer will receive. It may be helpful to think about a more mundane example. Google search results for a given search term depend on who searches, which makes them relative. But they don't depend on the feelings of the searcher and hence are not subjective.
- Taywee 5y ago
  It's more what you'd call "relative". You could probably call it "subjective" if the meaning of the word weren't so loaded.
  - civilized 5y ago
    Not sure why you are being downvoted for this, it's very helpful. We should draw a distinction between relative and subjective. A measurement of time only makes sense relative to a given reference frame, but that doesn't mean that time measurement is subjective (i.e. depending on a subject's opinion, or only true from the perspective of a conscious subject). "X time passed in reference frame Y" is an objective fact in relativity. It may be helpful to think about a more mundane example. The results Google returns for a given search term depend on who searches, which makes them relative. But they don't depend on the feelings of the searcher and hence are objective, not subjective.
- PeterisP 5y ago
  It's not different dependent on the subject, it's different for different inertial reference frames, but identical for every subject existing in the same reference frame. In Einstein's thought experiments with trains moving at relativistic speeds, every observer on that train has the same time.
  - deleted 5y ago
    [deleted]
robwwilliams 5y ago
Love your last line after reading Napoleon Changon on cultural anthropology in the 1960s to 1990s. What a fight he had.
- civilized 5y ago
  I would agree that cultural anthropology could benefit from an objective lens as well ;) I just read a review of his "Noble Savages" book in the NYT and it's one of the worst things I've ever read. The author said almost nothing about the book and spent the entire time gossiping about the author, occasionally backing the gossip with tiny snippets of the authors' writing. This one was somewhat better; https://www.npr.org/2013/02/16/171918973/noble-savages-a-journey-to-break-the-mold-of-anthropology https://www.npr.org/2013/02/16/171918973/noble-savages-a-jou...

morelisp 5y ago

People have this strange idea that "subjective" means something equivalent to "unknowable" or "an opinion" or "as I please". It isn't true. > a variable that is different for each observer This is literally what "subjective" means - different dependent on the subject.

civilized 5y ago
Google subjective and copy the definition you see here. Here's what I see: subjective: based on or influenced by personal feelings, tastes, or opinions.
- morelisp 5y ago
  First result is Wikipedia entry for "Subjectivity" which says... - Something being a subject, narrowly meaning an individual who possesses conscious experiences, such as perspectives, feelings, beliefs, and desires. - Something being a subject, broadly meaning an entity that has agency, meaning that it acts upon or wields power over some other entity (an object). - Some information, idea, situation, or physical thing considered true only from the perspective of a subject or subjects. The third being the only obvious applicable one. It's also hypocritical to demand an adherence to an anti-common-sense physics-based formal definition of "time" while refusing the same courtesy towards formal definitions of "subjective."
  - civilized 5y ago
    But it's not applicable, because an "observer" in relativity is not a subject having perspectives, feelings, beliefs, etc. It is an abstract mathematical point moving through space. "Reference frame" is really the proper term, not observer or subject. And the proper time that passes in a given reference frame is an objective fact in relativity, even though that measurement cannot be directly applied to other reference frames without transformation. "Objective" doesn't mean "experienced from all perspectives in the same way". Two different observers of a cube will get two different perspectives of the cube. The cube is still a single, objective, observer-independent reality. The same applies to relativistic time. It's a single reality (part of the spacetime manifold) that is measured differently in different reference frames. The different measurements must be consistent with one another according to a system of formulas. Just as different perspectives of a cube must be consistent with one another based on (1) the cube's objective existence in space and (2) the formulas of optics which determine the perspective each observer will receive. It may be helpful to think about a more mundane example. Google search results for a given search term depend on who searches, which makes them relative. But they don't depend on the feelings of the searcher and hence are not subjective.
Taywee 5y ago
It's more what you'd call "relative". You could probably call it "subjective" if the meaning of the word weren't so loaded.
- civilized 5y ago
  Not sure why you are being downvoted for this, it's very helpful. We should draw a distinction between relative and subjective. A measurement of time only makes sense relative to a given reference frame, but that doesn't mean that time measurement is subjective (i.e. depending on a subject's opinion, or only true from the perspective of a conscious subject). "X time passed in reference frame Y" is an objective fact in relativity. It may be helpful to think about a more mundane example. The results Google returns for a given search term depend on who searches, which makes them relative. But they don't depend on the feelings of the searcher and hence are objective, not subjective.
PeterisP 5y ago
It's not different dependent on the subject, it's different for different inertial reference frames, but identical for every subject existing in the same reference frame. In Einstein's thought experiments with trains moving at relativistic speeds, every observer on that train has the same time.
- deleted 5y ago
  [deleted]

robwwilliams 5y ago

Love your last line after reading Napoleon Changon on cultural anthropology in the 1960s to 1990s. What a fight he had.

civilized 5y ago
I would agree that cultural anthropology could benefit from an objective lens as well ;) I just read a review of his "Noble Savages" book in the NYT and it's one of the worst things I've ever read. The author said almost nothing about the book and spent the entire time gossiping about the author, occasionally backing the gossip with tiny snippets of the authors' writing. This one was somewhat better; https://www.npr.org/2013/02/16/171918973/noble-savages-a-journey-to-break-the-mold-of-anthropology https://www.npr.org/2013/02/16/171918973/noble-savages-a-jou...