Space Definition and 1000 Threads

I am considering making a small studio space for a video I want to make. It will have to hold a cubic meter of space in which I will have very small fluorescent objects 1 mm cube (see previous thread). Since I am not expecting to have the most flaming hot UV light driving the fluorescence I...

NASA just announced a solar probe to travel quite close to the Sun, about 3.7 million miles from the solar surface: Nasa’s hotly anticipated solar mission renamed to honour astrophysicist Eugene Parker. Renamed the Parker Solar Probe to honour solar astrophysicist who predicted high speed solar...

Hi. I'm working on a science fiction story about colonization of the solar system. Asteroid way stations are an important part of the story. I want to construct a realistic scenario about how we could convert the Eros asteroid into a shuttling habitat in it's current orbit (or something close...

Do any of you have pictures of space objects, planets, moons, galaxies that have not been enhanced?

I've been messing around with some circle theorems and found that you couldn't possibly take a picture of a full Earth from a single shot. Is this impossible? Is their some math to prove otherwise, I'm really stuck.

I've read that when two pieces of the same kind of metal touch in space, they will fuse because there is no way for the electrons to "know" that they are in different pieces of metal. What would happen if two different metals were to touch in space? Would electrons still flow freely between...

Light can get red-shifted due to expansion of space, this leads to a loss of energy. Would it be possible that this energy is what's causing the universe to expand in the first place?

Would you explain when the space should be left when backslash, \, is used? For example some codes using backslash. \ \displaystyle a=\frac{dv}{dt} \ : This one works good because there is space between the first two backslashes. But if the space between the first backslash is removed the code...

What happens to sound when it hits a vacuum? Because there is nothing for the sound wave to vibrate against, what happens to the energy?

I am interested in looking at the metric where time is everywhere normal to space, so gta=0 everywhere, where t is the time coordinate and 'a' is any of the space coordinates. I'm finding it hard to look up in the literature: does it have a name that I can search for? My main interest is in...

Does Geometry of space Changes?

Homework Statement Hello All, I am experiencing Adventures in Topology. So far, so good, but I have an issue here. In the topological space (Real #s, U), show that 1 is not an element of Cl((2,3]).Homework Equations The closed subsets of our topological space are the converses of the given...

Edit: Disclaimer, this post contains faulty ideas I'm a 'pedestrian' to physics trying to wrap my mind around various concepts of relativity, and one of those is a visualization of two, say, planets, say each starting at rest. By my understanding, their mass causes space to relatively...

We are told that space is expanding and that the rate of expansion is speeding up. However, as relativity shows that space and time are inextricably linked, does this mean that time is expanding too?

Hi all! How is humidity related to temperature in a system where temperature is constant in time but not in space? As an example: If we have humid air trapped between two parallel walls with T1 and T2 respectively, how does humidity behave along the line from one to the other wall? Is absolute...

how do we know light stays consistent when traveling through the "not nothingness of space"? how do we know the rate at which light degrades as it travels through the medium that has to be there?

Consider the function $$f(x) = - \frac{1}{2}a^{2}x^{2} + \frac{1}{4}bx^{4} + d^{4}\cos(x/c),$$ where ##a##, ##b##, ##c## and ##d## are arbitrary parameters. For some region(s) of the parameter space, there are oscillations in the function. My goal is to identify these regions of the parameter...

I am doing some mathematical exercises with 3D anti-de sitter face using the metric ds2=-(1+r2)dt2+(1+r2)-1+r2dφ2 I found the three geodesics from the Christoffel symbols, and they seem to look correct to me. d2t/dλ2+2(r+1/r)*(dt/dλ)(dr/dλ)=0...

It's generally understood that nothing can be accelerated up to the speed of light, and that nothing can surpass it. That being said, the expansion of space itself can exceed this "universal speed limit," as the Universe is expanding so fast that light can't catch up to it. Regarding the...

Hello! (Wave) I want to find the solution of the following Cauchy problem and determine the space in $\mathbb{R}^2$ where the initial condition defines the solution. $$u_t+ u_x=4, u|_{t=0}=\sin{x} \text{ for } |x|<1$$ I found that the solution of the above initial value problem is...

From the book, I did not understand, 1. Why does fields coming inwards the sphere contradicts the Gauss law ? 2. I am unable to connect the potential picture and electric field picture. Why does the point P must have lowest or highest potential than neighbouring particles ? 3. I understand...

Homework Statement The question asks me to express the system shown in the image in state-space form, firstly by using the transfer function which was fine but the second part asks to express in state-space form by using the components A,B,C,D as the states x1,x2,x3,x4 Homework Equations U(s)...

We say that in big bang, a highly dense point like structure exploded and expanded. In what did it expand? If so, universe and space would be different entities. Please elaborate.

Hi guys, I am a little confused on the difference between an Algebra and a vector space. I´m guessing there´s a fairly simple distinction. Any guidance would be much appreciated, I accept both hand wavy and hardcore axiom based responses :) Cheers

If a particle can potentially be transported to any place in space limited only by the speed of light, does that potential amount to an expansion of space? And another question: Does it make sense to define space as any place a particle could go to?

Please help me flesh this out: You share a "long haul" freighter with six-ten other people. Everybody can have one pet that runs lose (cats, ferrets, etc.) or more that are permanently confined to the person's private living space. (Gold fish would be an example of the latter.) Tribbles are...

<Mentor's note: moved from general mathematics to homework. Thus no template.> Prove subspace is only a subset of vector space but not a vector space itself. Even a subspace follows closed under addition or closed under multiplication,however it is not necessary to follow other 8 axioms in...

Would it be possible to craft a carbon based life form throw dna manipulation and selective breeding that could live in the cold vacuum of space?? Also if I posted the thread in the wrong place I'm sorry I didn't know where else to place it. Once again thank you to anyone that will tack the time...

Is it possible for Low Frequency to distort the fabric of space? If so, how?

how can the universe be expanding if matter nor mass can be created?

I set eyes on the next formulas: \begin{align} E_{\alpha \beta \gamma \delta} E_{\rho \sigma \mu \nu} &\equiv g_{\alpha \zeta} g_{\beta \eta} g_{\gamma \theta} g_{\delta \iota} \delta^{\zeta \eta \theta \iota}_{\rho \sigma \mu \nu} \\ E^{\alpha \beta \gamma \delta} E^{\rho \sigma...

Hi all, If I have a hot object in space (not a star but say an oven or just a hot gas as would be on Earth < 10,000 degrees Kelvin) glowing at a temperature T and I want to know long it takes to come to equilibrium with the vacuum of space around it, how can I calculate such a time? I could...

If $ r<s<t $ then for any $ ϵ>0 $there exists $ C>0 $ such that $ ∥f∥_{(s)}≤ϵ∥f∥_{(t)}+C∥f∥_{(r)} $for all $f∈H_t $ Can you please tell me how to start thinking of this problem? I really feel stuck and don't know where to start!

Hi. I'm trying to prove that [\Omega] = \int dq \int dp \, \rho_{w}(q,p)\,\Omega_{w}(q,p) where \rho_{w}(q,p) = \frac{1}{2\pi\hbar} \int dy \, \langle q-\frac{y}{2}|\rho|q+\frac{y}{2}\rangle\,\exp(i\frac{py}{\hbar}) is the Wigner function, being \rho a density matrix. On the other hand...

Homework Statement Consider the vector space that consists of all possible linear combinations of the following functions: $$1, sin (x), cos (x), (sin (x))^{2}, (cos x)^{2}, sin (2x), cos (2x)$$ What is the dimension of this space? Exhibit a possible set of basis vectors, and demonstrate that...

<Incorrect link deleted. See post below.> For a start the solar cells do not look big enough to power the craft.

Homework Statement Homework Equations equivalent tension coefficient tDE= applied force/distance between points D and E = 17/SQRT(1[^2+2^2+4^2) = 3.7097 The component of the 17kN in the x-direction = Δx X tDE = -1...

Homework Statement In a lab that I did in Physics we calculated the magnetic field of a solenoid while constantly increasing the number of time the wire was wrapped around the electromagnet. After I obtained all the values, plotted it in a graph and found the line of best fit, the slope came...

Since NASA is currently under way with the deep space Ion drive, they plan on using xenon to power this propulsion system. My question is could they harness the already existing radioactive particles in space to power it? If they could then there would be almost an unlimited supply of fuel for...

I just read something that I do not want to misinterpret. If there are two orthonormal basis that span the same space, which I think implies that each basis can be written in terms of the other basis, then measurements made with respect to each basis will not commute? Does this mean that...

Another Doubt Guys, I was watching this video on youtube. it is about weightlessness in space. it states that the astronauts inside a spaceship fly in space not due to zero gravity but due to centripetal force with which the satellite is revolving the earth. My question is "then why the...

Hi all, I need an algorithm that fills a 3d lattice from any point, always expanding (no return allowed as in ref. http://msl.cs.illinois.edu/~lavalle/papers/KufLav09.pdf). The cells must be visited just once. My efforts are contained in the attached file. It works ***almost*** correct. Some...

Two questions, underlined: I have read that the universe began with a singularity. Then space began expanding. How can space expanding affect a singularity? Has this conundrum been resolved? If time was speeding up, is would act the same as space expanding, but it would affect a singularity...

Some posts in another thread lead me to a search which ended when I read the following "kets such as ##|\psi\rangle## are elements of abstract Hilbert Space". That lead me to this paper. http://www.phy.ohiou.edu/~elster/lectures/qm1_1p2.pdf "The abstract Hilbert space ##l^2## is given by a...

Is it possible to compress the space without gravity?

I always had this doubt,but i guess i never asked someone. What's the main difference between the Classical phase space, and the two dimensional Hilbert Space ?

Sorry new here trying this question. From the perspective of a light particle leaving its star that particle would arrive everywhere in the universe instantly since it is traveling at the speed of light. But we trust our perspective of time and distance in light years to describe what we are...

Homework Statement Consider the subspace $$W:=\Bigl \{ \begin{bmatrix} a & b \\ b & a \end{bmatrix} : a,b \in \mathbb{R}\Bigr \}$$ of $$\mathbb{M}^2(\mathbb{R}). $$ I have a few questions about how this can be decomposed. 1) Is there a subspace $$V$$ of...

Are there STEM related careers in the space industry which are different from Aerospace or Mechanical Engineering? If so, what are they?

If you have two different containers filled with two different gasses at the same temperature, would they have less pressure when connected to each other? Dalton's law states that each of the gases behave independently when it comes to pressure as they fill the space as if they were the only gas...