Recent content by Keith Koenig

That may be a matter of semantics. A quick google search for "fundamental properties of physics" gives this as the first hit: https://www.texasgateway.org/resource/13-language-physics-physical-quantities-and-units#:~:text=In physics, there are seven,of substance, and luminous intensity. My...

I don't think I am at all confused. I am concerned with the definition of the units of fundamental quantities, from which the units of all derived quantities are obtained. To stick with mechanics and leave out charge, the fundamental units are defined to be length, time, and mass. Fundamental...

Wait, seriously? Can you cite a textbook that directly converts kg to ##m^3/s^2## and back, not as part of the solution of an equation, but directly. Like in a conversion table between English and Metric. I'm pretty sure that will be a difficult search [Mentors' note: a digression into a...

My point is there is no need to use anything other than ##G##. Forgive the lengthy post but my wife asked me to explain my point using a T.V. show. This was my reply: Tony Beets and Parker Schnabel are crew members of the aforementioned hypothetical interstellar ship, and work in a very large...

I like it! But what are the units on the readout? kg? g? I would bet a month's pay they are not ##m^3/s^2##.

OK, I'll give you that, but it could be that caesium is extremely rare elsewhere in the universe but certainly a choice can be made using a similar oscillation. And let's give the period and wavelength of the chosen oscillation values of 1. This uniquely determines the value of all speeds in...

OK, my bad, frankly I did not carefully translate wrt to "with respect to", at which point it becomes clear you are thinking relativistically, in which case I agree, with the caveat that it applies most at large velocities. It is interesting that your concern is with defining the value of 0...

To answer your question, and a very good one at that, just watch an air bubble rise. It quickly reaches a terminal velocity, where the force from friction equals the accelerative force. The same is true on the opposite extreme - free fall. Skydivers quickly reach terminal velocity, after...

Having a common value of zero for anything is meaningless. I could claim a quantity exists called "smeorf" that has a default value of zero, but if you multiply your velocity at any point by the proper value of smeorf you obtain another quantity that is proportional to the meaning of life.

That may seem like a silly question, but suppose the crew of an interstellar vessel wanted to measure the mass of their ship, perhaps to estimate remaining resources. Unless they have very well calibrated thrust and a very well calibrated accelerometer, the only option is to do so...

I get that, but I was trying to provoke a bit of introspection on basic assumptions that physics makes. Always a good idea, and fun imho.

We think of length and time as the first fundamental quantities and velocity as the first derived quantity but any two determine the third so we would be completely justified in defining velocity as a fundamental quantity and one of length or time as the other, with the remaining being the first...