4 ms·
> Also the part about mass being generated by motion and how it seems to be an established fact. That's what they mean by relativistic speed. When effects from
by squeaky-clean 4y ago
> Also the part about mass being generated by motion and how it seems to be an established fact.
That's what they mean by relativistic speed. When effects from special relativity become large enough that you need to account for them in your math and measurements. There is a difference between invariant mass (aka rest mass) and relativistic mass, which depends on the object's velocity relative to the observer.
https://en.m.wikipedia.org/wiki/Relativistic_speed https://en.m.wikipedia.org/wiki/Relativistic_speed
- tsimionescu 4y agoWhile your description of what relativistic speeds means is accurate, this has nothing to do with the mass. Instead, composite "particles" have mass mostly because of the energy of their components. This is a famous observation (the most famous by far) in general relativity: E=mc². E here can be the kinetic energy of the constituent particles, or some other kind of energy (for example, a polar molecule like water owes some of its mass to the electrical energy of the bond; and its mass will increase or decrease if placed in a strong electric field, depending on the orientation of the field). This has nothing to do with the concept of "relativistic mass", which is anyway not commonly used in modern physics anymore. Mass almost always refers to "rest mass", and observer-dependent "relativistic mass" is accounted for only through differences in observer-dependent time and position measurements. That is, instead of saying "as an objects speed approaches the speed of light, its relativistic mass approaches infinity", the preferred interpretation is "as an object approaches the speed of light, time passes more slowly for it, so it takes longer for it to accelerate even if pushed with a constant force".