Physics is established, so one can defer to existing authorities and get right answers about physics. Starting a well-run laundromat is also established, so ditto. Physics and laundromat-running both have well-established feedback loops that have validated their basic processes in ways third parties can see are valid.
If a research area has reached a dead end and further progress is impossible except perhaps if some extraordinary path-breaking genius shows the way, or in an area that has never even had a viable and sound approach to begin with, it’s unrealistic to expect that members of the academic establishment will openly admit this situation and decide it’s time for a career change. What will likely happen instead is that they’ll continue producing output that will have all the superficial trappings of science and sound scholarship, but will in fact be increasingly pointless and detached from reality.
Arguably, some areas of theoretical physics have reached this state, if we are to trust the critics like Lee Smolin. I am not a physicist, and I cannot judge directly if Smolin and the other similar critics are right, but some powerful evidence for this came several years ago in the form of the Bogdanoff affair, which demonstrated that highly credentialed physicists in some areas can find it difficult, perhaps even impossible, to distinguish sound work from a well-contrived nonsensical imitation.
This is fair; I had in mind basic high school / Newtonian physics of everyday objects. (E.g., “If I drop this penny off this building, how long will it take to hit the ground?”, or, more messily, “If I drive twice as fast, what impact would that have on the kinetic energy with which I would crash into a tree / what impact would that have on how badly deformed my car and I would be if I crash into a tree?”).
basic high school / Newtonian physics of everyday objects. (E.g., “If I drop this penny off this building, how long will it take to hit the ground?”
This is tricky: basic high school physics lies to you all the time. Example: it says that a penny and a large paper airplane weighting the same as the penny will hit the ground at the same time.
In general, getting the right answers from physics involves knowing the assumptions of of models used and at which points they break down. Physics will tell you, but not at the high school level and you have to remember to ask.
Depending on which parts of physics one has in mind, this seems possibly almost exactly backwards (!!). Quoting from Vladimir_M’s post Some Heuristics for Evaluating the Soundness of the Academic Mainstream in Unfamiliar Fields:
The reference to Smolin is presumably to The Trouble With Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next . Penrose’s recent book Fashion, Faith, and Fantasy in the New Physics of the Universe also seems relevant.
This is fair; I had in mind basic high school / Newtonian physics of everyday objects. (E.g., “If I drop this penny off this building, how long will it take to hit the ground?”, or, more messily, “If I drive twice as fast, what impact would that have on the kinetic energy with which I would crash into a tree / what impact would that have on how badly deformed my car and I would be if I crash into a tree?”).
This is tricky: basic high school physics lies to you all the time. Example: it says that a penny and a large paper airplane weighting the same as the penny will hit the ground at the same time.
In general, getting the right answers from physics involves knowing the assumptions of of models used and at which points they break down. Physics will tell you, but not at the high school level and you have to remember to ask.