Recent content by Logic Cloud

I'm trying to understand the various different ways in which we can 'formulate' theories in physics and I am finding it somewhat hard to obtain a bird's-eye view. I hope someone here can help clear up some ambiguities. I apologize in advance for the 'sketchy' ways I put matters in my...

The physics-mathematics relation has been discussed quite extensively in the philosophy of science using a number of different approaches and from a number of different perspectives. In one approach, the applicability of mathematics to empirical phenomena is, very roughly, represented as a kind...

Thank you all for your replies. I believe I understand the general idea. What confused me initially was that I wanted to equate my "property X" with the flatness of spacetime in non-GR theories. But this does not seem quite correct, since even in flat spacetime we might still require...

Ah yes, I was afraid using "vector" might lead to confusion (which is why I wrote "full tensor calculus"). My question would then be why we need only this special fragment of tensor calculus for CM, whereas we need the general tensor concept in GR. As for your other comment, isn't what you're...

In explanations of the importance the tensors I often see people refer to transformation properties, general covariance and the like. Now, I have also often read that in principle any physical theory, e.g. classical mechanics and special relativity, can be written in a generally covariant form...

I am looking for books/papers pertaining to symmetry principles in physics. I am particularly interested in literature aimed at deriving physical theories from their underlying symmetries, but all recommendations are welcome. I already know of the books Symmetries in Fundamental Physics by...

I have come to understand that phosphorylation plays a significant role in the (de)activation of certain proteins. I'm now trying to understand this mechanisms in more detail. Specifically, how the addition of a phosphate group can regulate protein activity. Can anyone point me to a source where...

I'm trying to understand the nature of coordinate transformations in physics. In classical mechanics, we can transform to a different coordinate frame by means of a Galilean transformation. In special relativity, this is replaced by a Lorentz transformation. I am now wondering whether there...

State-space trajectories in classical mechanics can be used to nicely represent the time evolution of a given system. In the case of the harmonic oscillator, for instance, we get ellipses. How does this situation carry over to quantum mechanics? Can the time evolution of, say, the quantum...

Say we have two separated observers which have a velocity relative to each other and are both looking at a system. By a system, I mean simple systems as encountered in mechanics. They want to determine if they are looking at the same system or not. They can perform measurements on the system...

I am looking for literature on a certain topic in mathematics inspired by string theory of which I have heard bits and pieces. Since I am not at all familiar with string theory and haven't found anything online, I was hoping someone more knowledgeable might recognize some of the keywords I...

In classical mechanics we can get a nice overview of the dynamics of a system by looking at its position-momentum phase space. Is there a useful analogue of this concept in special relativity? Can the dynamics of a relativistic system be represented by its phase space in the same way as is done...

I have so far encountered the notion 'state' in classical mechanics, thermodynamics and quantum mechanics. I have, however, not seen this notion in the context of electrodynamics. Is there such a thing as a state in electrodynamics? My guess is it would be a pair consisting of an electric field...

I see. So there really isn't any need for the concept of phase space for describing physical systems, since the trajectory can be found by just solving the equation of motion directly. My question was motivated by the classical variant of the Dirac-Von Neumann axioms where a classical system is...

To what extent do phase space trajectories describe a system? I often see classical systems being identified with (trajectories in) phase space, from which I get the impression these trajectories are supposed to completely specify a system. However, if you take for example the trajectory...