Space Definition and 1000 Threads

The minimal necessary math to describe the potential path of an electron expands over time. Second by second, the space necessary to describe the possible positions of the electron expands. . Does that imply expansion of physical space? And does that shift the explanation of the expansion of...

I'm a complete rookie in this field so please correct me where I go wrong, I just really want a better understanding of this subject. So as far as I am aware, mass causes the space surrounding it to curve or bend. What I want to know is how much does it bend the space? is the bending of space...

Homework Statement Given ##\hat{x} =i \hbar \partial_p##, find the position operator in the position space. Calculate ##\int_{-\infty}^{\infty} \phi^*(p) \hat{x} \phi(p) dp ## by expanding the momentum wave functions through Fourier transforms. Use ##\delta(z) = \int_{\infty}^{\infty}\exp(izy)...

Homework Statement Problem- Determine if the set of all function y(t) which have period 2pi forms a vector space under operations of function addition and multiplication of a function by a constant. What I know- So I know this involves sin, cos, sec, and csc. Also I know that a vector space...

Two stationary masses will attract each other. That is, they start moving towards each other. For example, a stationary apple will fall to earth. I can see bent space affecting the trajectory of a moving object. ...but how does bent space explain that stationary objects start moving?

A question arose over a simplification I wrote on another subject. My i information say's that matters antimatter pairs are generated in what is known to be very empty space such as the voids within the cosmic web. When I read about this it was considered anomalous but definitely verified. Now...

Right now, I am studying Advanced Calculus (proof based), and it is hard thinking through some of the definitions without first thinking about it concretely (meaning how to visualize it better geometrically, if that makes any sense?). I need help with this definition. Definition Let X be a...

Why do we see the dimensions of our universe as 3 dimensions of space and time instead of space, time, and matter? (Or another variation)

I am currently solving a problem where I need to find the gravity in the ISS (distance 400km from Earth with Radius 6371km). I am using the formula g=GM/R^2 . One way to solve it would be to find GM by multiplying g(which is 9.81) and R^2 (which is known) and then to use it in GM/(R+400)^2 and...

We have a simple table , for example a kitchen table, with some objects on it. If we consider the table having two dimension (1) does the table with objects represent an affine space ? Why ? I want to do some calculation, so i choose a point as origin and i place a vector space in the affine...

Imagine that the CMB did not exist. What observational evidence exists to support the theory of the metric expansion of spacetime, as opposed to having a static spacetime and it's the matter distribution that is expanding - as it would in an explosion?

Homework Statement Homework EquationsThe Attempt at a Solution Substituting x = ## r \cos{ \theta } ## and y = ## r \sin \theta ## into the equation y = 3x +2, I got r = ## \frac { -3 \cos{\theta} \pm \sqrt{ 4 – 31 ( \cos{\theta} )^2 } } { 10 ( \cos{\theta} ) ^2 – 1} ##Plotting...

Homework Statement a) research the space elevator concept. Consider the environment in which the cable must operate. Recommend two physical and one chemical property that the cable should have. Justify your choices. b) Based on what you have learned about bonding and forces in solids, which...

Please, moderator, just delete this question if it is too silly. I am wondering what is happening in anyone point in the SpaceTime field. That's what it is called, I think? Because my simple understanding is that we see colours/light because of propagated electromagnetic radiation at...

Does space have its own density? i.e. a mass density distinct from the mass density of 'particles' in it? or may it have a uniform density of some kind of vast particle(s)? If so, would the effect on observable masses largely cancel out? One answer from...

Evaluate $\displaystyle \int_C(x+y)ds$ where C is the straight-line segment $x=t, y=(1-t), z=0, $ from (0,1,0) to (1,0,0) ok this is due tuesday but i missed the lecture on it so kinda clueless. i am sure it is a easy one.

Good afternoon, I'm trying to search only based on bibliography or numerical and theoretical calculations the change of the thermal optical properties, namely the solar absorptivity, of a polyimide-based plastics (VESPEL SP-1) in space conditions (considering radiation, atomized oxygen atoms...

how do you describe the speed of an object in momentum space (energy, momentum as the 2 axes) where there is no distance or time? Can you give an example?

Just want to get a poll out there about what people think this is going to be like compared to the movie. I think it will be really good.

Hi all, This is my first time posting on this forum. I'm not sure if this is the right place to ask this question so apologies in advance. Perhaps someone could recommend a more appropriate forum for me to post this on. I'm working on creating documentation for a simulation. It's an Apollo...

Massive Space Structures Have Surprising Connection to Quantum Mechanics Math Reading my daily science news I came across an interesting article that talks about how massive space objects have unexpected relationships to quantum mechanical mathematics. I was quite surprised to hear this, as I...

Can momentum space also able to handle spin and polarizations? I'm understanding it that in QM, you have position, momentum, spin, polarization as observables. Position and momentum can be equivalent via Fourier transform. So if you use momentum space instead of position, how do you handle...

Regarding the expansion of space... In one book I've read the diameter of the universe is more than 100B light years across, even though the age of the universe is only roughly 14B years old. This is due to accelerated expansion of space. In another book it says that space is expanding in a...

I am no smart person like the rest of you, but I find it fascinating about how physics works. I am deeply motivated to know about how we would solve this problem about gravity and space flight. Would a particle accelerator be used to help solve this problem or am I way off base?

I am reading "Multidimensional Real Analysis I: Differentiation by J. J. Duistermaat and J. A. C. Kolk ... I am focused on Chapter 1: Continuity ... ... I need help with an aspect of Lemma 1,1,7 (iv) ... Duistermaat and Kolk"s Lemma 1.1.7 reads as follows...

I am reading "Multidimensional Real Analysis I: Differentiation by J. J. Duistermaat and J. A. C. Kolk ... I am focused on Chapter 1: Continuity ... ... I need help with an aspect of Lemma 1,1,7 (iv) ... Duistermaat and Kolk"s Lemma 1.1.7 reads as follows: At the start of the proof of (iv)...

as we know light travel in vacuum because of oscillation of electric and magnetic field and both are perpendicular to each other. But i don understand how these electric and magnetic fields get generated in vacuum. as electric filed can vary by oscillating charge and that generate varying...

$\textsf{An advertisement claims that a centrifuge takes up only $0.127 m$ of bench space}$ $\textsf{but can produce a radial acceleration of $4100 \, g$ at $6830 \, rev/min$}$ $\textsf{a. Calculate the requested radius of the centrifuge}$ OK the only thing I can guess here is...

When I see stuff on Netflix (yes not real), and yet I look stuff up on the Net (real) and they try and create a spaceship capable of travellng anywhere else in the solar system, they always come up with standard missile design and go "new and improved.." When they then show failure to actually...

Hi PF! A text states that the following two functions $$ \psi^o_k = \sin(\pi(k-1/2)x)\cosh(\pi(k-1/2)(z+h)): k\in\mathbb{N},\\ \psi^e_k = \cos(\pi kx)\cosh(\pi k(z+h)): k\in\mathbb{N} $$ each form complete orthogonal systems in two mutually orthogonal subspaces, which compose the Hilbert...

Does space contract when one observes the space from the frame which is moving with relativistic velocity?

Entangled states are only separable relative to certain basis states. So does that mean that reference frames have importance beyond those in spacetime?

hi I am studying algebra and i have a question. why is important that something is a vector space?, i mean, what implications have? matrix, complex numbers , functions , n-tuples. What do these have in common, apart from being a vector space? why is so important that a certain set of...

Hello, Hola, hajimemashite physics family, Well do you know what It takes to start a space exploration company such as making cubesats , satellites or launching vehicles? :wideeyed:o_O:woot: Give your suggestions please :oldeyes::oldbiggrin::angel: Regards.

NASA decided to stop *WFIRST and concentrate on Mars project (send humans to Mars). What do you think about it? In my opinion, since a lot of ventures have begun space developments such as SpaceX and this proves that rockets make money, NASA should tackle WFIRST. Generally, we cannot earn...

I believe the electric flux within a closed space can be found with the equation phi = Q/ε0. Can this be used for volume and area, or just volume? Also what good does this do. Why would I want to know the electric flux of something?

What is the practical feasibility of changing the International Space Station's orbital inclination to match the orbit of the Moon? Major future missions beyond the Earth-Moon system (ie: space colonization) will likely require in-orbit assembly of components from multiple launches. And...

Sorry for the possible double post. I really need help with this...anyway let's assume we have chances of winning "something" anything...can be the lotto or whatever. We have A, B, C, D, E and each have a different chance of winning. We will also give them each a value, and the chance of winning...

In trying to explain the concept of curved space, many books use the example of the surface of a sphere, which can be considered as a curved 2D space embedded in a higher dimensional, 3D space. I could derive, starting from ##a^2=x^2+y^2+z^2##, that the metric, or the line element, on the...

I have some questions about the curvature of space (NB not of spacetime) near a planet like Earth. Unambiguously defining space curvature requires choice of a coordinate system, so I choose the Swarzschild system. Here are my questions: Would constant-time hypersurfaces under the Swarzschild...

Homework Statement [/B] The International Space Station (ISS) has a mass of 400,000 kg and orbits 408 km above the Earth’s surface. The ISS is 109 m across. Homework Equations : [/B] R=a(semimajoraxis) cubedroot(m2/3M1)The Attempt at a Solution : [/B] ive tried multiple ways with multiple...

Homework Statement Derive, using the canonical commutation relation of the position space representation of the fields φ(x) and π(y), the corresponding commutation relation in momentum space.Homework Equations [φ(x), π(y)] = iδ3(x-y) My Fourier transforms are defined by: $$ φ^*(\vec p)=\int...

Has the spectrum of light that is reflected off planet Earth ever been measured from outer space? (In the same sense that we measure spectra of the light emitted/reflected from other celestial bodies in astronomy). If so, would it be possible that there could be dips in the spectrum resulting...

Homework Statement So I have these two Matrices: M = \begin{pmatrix} a & -a-b \\ 0 & a \\ \end{pmatrix} and N = \begin{pmatrix} c & 0 \\ d & -c \\ \end{pmatrix} Where a,b,c,d ∈ ℝ Find a base for M, N, M +N and M ∩ N. Homework Equations I know the 8 axioms about the vector spaces. The...

the problem: Say we have the entire space uniformly charged. Then, the E field experienced by any point is zero, from symmetry.* But, it means that for any Gaussian surface, the flux though it is zero even though the charge enclosed is clearly not. Gauss' law seems to disagree with symmetry, but...

I am trying to follow modern QFT by Tom Banks and I am having an issue with literally the first equation. He claims that beginning from ## |p_1 , p_2, ... , p_k> \: = \: a^\dagger (p_1) a^\dagger (p_2) \cdots a^\dagger (p_k)|0> ## with the commutation relation ##[a (p),a^\dagger (q)]_\pm \: =...

Hello In our Quantum Mechanics lecture we have been discussing a simplified model of the Stern-Gerlach experiment. Let ##|+>## and ##|->## denote an electron that is "spin up" and "spin down" (with respect to ##\hat{z}##), respectively. Our professor then asserted that ##|+>## and ##|->## acted...

Regarding curvature of spacetime/space: At some given point in a gravitational field, spacetime is curved at that point and this is a constant. (I'm assuming this is true). Although we can talk about the curvature of spacetime, I never hear anyone talking about the curvature of space. Can...

Homework Statement A 50 g, 420 mw laser pointer is floating in outer space (don’t ask how it got there) at rest with respect to an observer. The laser pointer is turned on and let go. If the battery runs continuously for 250 hours before dying, what is the final speed achieved by the laser...

Hey I'm new to Physics. I have a question. Is it possible to use the force generated when air entera a vacuum tube to launch something into space? Can anybody throw some light on this in simple words please. Thank You.