Space Definition and 1000 Threads

I have heard this before many times, ‘we can’t reach some parts of our universe because of expansion’ but can we launch a massive rocket and then launch a rocket from the first rocket in the same direction and then again and again? Due to relativity.

Hello everyone, I am a second-year Electrical Engineering student, and my ultimate goal and dream is to work in space exploration. During my studies, I’ve realized that I am much more drawn to theoretical fields involving physics and mathematics than to technical fields like circuits and...

Hi everyone, I’m Pavel! I’ve always been fascinated by space exploration and innovative engineering solutions. Lately, I’ve been working on some ideas to improve efficiency in space-related projects and would love to hear the thoughts of people with experience in this field. I’m here to learn...

In ever space science friction involving a light speed or near light speed or even beyond when they engage warp drive or drop out of warp drive they persons on board hardly twitch yet if an aggressive ship fires upon them or some gravitational wave hit them suddenly they are all thrown all over...

Suppose you have space with time and four perpendicular Euclidian dimensions. Assume that atoms exist and the laws of physics are the same. This doesn't seem likely, it's just intellectual exercise. Then assume things on Earth have the same number of atoms they have in 4D. The main result...

Hello, my name is Fernando, let's talk about thinkable and unthinkable things about space.

I was scrolling through YouTube and saw this video: The video showcases the Project Orion rocket. Project Orion was a theoretical spacecraft propulsion concept which uses nuclear explosions to propel a rocket. Opening the comment I further learned that it was discontinued due to Nuclear Test...

I was recently reading that the space of 3d rotations should have the topology of a real projective space. For confirmation, see wiki, https://en.wikipedia.org/wiki/3D_rotation_group. It seems to me that when we assign coordinates to this space (I was thinking of using the Euler angles, but...

TL;DR Summary: I'm an upcoming 3rd-year Aerospace Engineering student preparing to start my dissertation. Unfortunately, I was not allocated to a personal project due to capacity issues and my university has a lack of organisation. As a result, I'm proposing my own project because the rest of...

If you and your frame are following a square path in space, and the Universe is the other frame, each leg of the square path instantly changes every photon in the Universe to suit your dimensional perspective of speed, length, frequency, and time. Is this new light situation actually different...

I am the mother of a 6 year old who has been asking questions such as, “What caused the Big Bang?” and “What causes a star to lose its gas and become a black hole?” since he was 4. His curiosity is now focused on black holes, the concept of white holes and worm holes, and the expanding universe...

For those of you who haven't read the book, it is a science fiction story in which a man named Dr Ryland Grace travels to Tau Ceti. The star is approximately 12 light years from Earth, and he got there in about 13 years, which for him was a 3 year journey. He is accelerating at 1,5g constantly...

I have a question that I have been unable to find an answer to. The question is does matter "create" space? Some places I read that space "just is", and matter fills it and creates its gravitational curving. But that something "just is" is supremely unsatisfying as far as answers go. Another...

I had an idea about a spacetime drive that *seems* as though it is an FTL drive while trying to outline a plot for a series of sci-fi short stories set in the late 22nd-early 23rd century (possibly later as well). Instead of working with warping space ala Star Trek or utilizing a hyperdrive to...

From Hydrogen line in cosmology Is it possible to calculate Hydrogen speed in the outer space based on the observed frequency range considering the mix of Doppler effect and the gravitational redshift?

In section 10.1 of "A First Course in GR" by Schutz, in the paragraph directly above equation 10.5, Schutz says "we must have that a line ##r## = const., ##\theta## = const., ##\phi## = const. is also orthogonal to the two-spheres. Otherwise there would be a preferred direction in space. This...

Consider 3 elbows. One extremity is connected to a plane surface and may rotate 360° freely. The available extremity may be connected to another elbow only if the both faces "face" each other (normal vector aligned). Once one connect a second elbow, a second liberty degree is added, since one...

Let's say we have an egg-shaped (for better drag) 1500 kg cargo container and a acceleration system that accelerates that container and launches it at sea level to reach 160 km on its own without any engine. What speed should be applied to this 1500 kg container at sea level, so it reaches 160...

If one were to demonstrate gravity independent of earth's constant gravity, how could it be done? Assuming this would need to be done in space, what minimum proportions of mass would be required to demonstrate gravitational pull to a human's naked eye?

V is a vector space and W is a subset of V. could W be a vector space but not a subspace of V?

I know it is an homework excercise but I already tried all the isoentropic relations, the problem is not the Isp, I can't find a relation to calculate the thrust as I am missing some important parameters, such as Ae, At, mdot, and thrust. This is the text of the excercise: A bipropellant rocket...

Hi I am an aircraft maintenance engineer reading about Aviation ,space and physics ( very amateurish level) are my hobbies

Please excuse my ignorance I hear some people say that space is flat. What exactly do they mean by this?

Dark side of the moon! I can understand that Selena Gomez I've been down the darkest alleys Saw the dark side of the moon in Wolf or Transformer movie use that phrase, But this is US Space Force, of all people! US Space Force

Can the expansion/creation of space in the universe affect the speed of light over long distances? (dividing the space traveled (including expanded space) by the travel time). If the Hubble constant is valid throughout the universe, it follows that from a certain Megaparsec of distance, galaxies...

I assume that a space station like portrayed in 2001 A Space Odyssey could either be fixed in rotation, or contra-rotating. Is there an advantage of one over the other?

Hi everyone! I love science, am constantly interested in news in various fields, and have even done my own amateur research in physics and psychology, but I am an artist. And that’s why I most like to popularize scientific and technological progress, as well as highlight related issues through...

Hi Someone told me that to hit the target, they just shoot the ICBM up the space in the right latitude, then wait for the earth to rotate until the target is right below the ICBM, then just drop down to hit the target. That sounded strange, but seems doable. But I would think it's a lot faster...

How can space expand when space is not a physical thing? I’ve heard some say that is not expanding but rather it is getting less dense, which to me implies the same thing.

Space must have properties, it's not just empty nothing, and one of those properties is distance. When an object moves through space at a velocity V information has to be transferred between the object and space. The object has the information that it is moving at velocity V which is...

I wanna be checking homogeneity of space(only interested in vertical) for simplicity and example we can do is "ball is dropped". To check homogeneity, we use either passive or active transformation and I'm interested in lagrangians. I heard that we can write lagrangians such as: ##L =...

Here is the definition of spacetime? “In physics, spacetime is any mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum.” But if space is literally the absence of matter or physical properties, and time has no...

Imagine experiment is such as I drop a ball from some height vertically only. What’s the right way to do 2nd experiment in order to check homogeneity of space. Way 1: I move a little bit and drop the ball (same height, it’s just I moved - ball as well, but not in terms of height) Way 2: We...

Hello, Im a student in astrophysics and space technology!

As background, I grew up in a working class neighborhood where few parents went to school. In 1962, John Glenn came back from space. I was told this. I am not sure what the adults believed back them. "Space" was new. It would be 4 years before star trek, and even then,Space was labeled the...

Movement isn't required to achieve gravity, even the artificial kind. Standing on a rotating body requires you to be actually physically standing on it. How is this achieved? Well, by gravity of course. Unless you are tied/stuck to the rotating body, but in that case there is no gravity pushing...

From: https://www.physicsforums.com/posts/6925227 Can I stop space and enter from toggling my checkbutton? My brain intially parsed that as: Can I stop Space and (then) enter (it) by toggling my checkbutton?" 🤪🤪

To kickstart the discussion, I am thrilled to share with you the first idea: NASA's Shapeshifting Mars Rover Wheels, which can adapt their shape to navigate various terrains on the Red Planet

Can anyone tell me if this would be correct? Would Earth not be seen flashing from space like a lighthouse to a distant planet when it reflects oceans and then DMS as the sons reflection per perspective travels across land then back to Ocean then back to land? I'm sure it probably says that...

I have no expertise in this area, other than rudimentary concepts. The following might apply if the visualization of space, as depicted below, represents actual reality, but I don't know for sure. Please help me understand better, you guys! 2-dimensional space The curvatures deform into the...

I encounter a function that I don‘t know in the calculation of Relativistically invariant 2-body phase space integral: in this equation, ##s##is the square of total energy of the system in the center-of-mass frame(I think) I don't know what the function ##\lambda^{\frac{1}{2}}## is. There are...

Saturn reclaims 'moon king' title with 62 newfound satellites, bringing total to 145 https://www.space.com/saturn-moon-king-62-newfound-satellites Astronomers have discovered 62 new moons orbiting the ringed planet Saturn, bringing to total to 145 Moons, with 121 irregular moons and 24 regular...

I got this watch nearly a year ago and love it. It is a celebration of the Apollo 11 moon landing. The planets orbit to tell you the time. The stars and planets glow in the dark as well!

Hi again, I've found interesting video. Roller homopolar motor : Roller Motor Do you think the motor from 1:08 min Will self rotate in Vacuum/Space (No other forces : Gravitational or Other type.) Thank you in advance.

For this problem, , The four points are, ##P(8,2,6)## ##R(-2,16,-2)## ##Q(3.9,2)## ##S(\frac{14}{3}, \frac{20}{3}, \frac{10}{3})## And the solution is, However, does someone please know what in the proportion 2:1:3 mean? Many thanks!

Li = Lrf +Ltf Iωo = Iωf + mvRsinθ I = MR^2 (MR^2)ωo = (MR^2)ωf + mvRsinθ ωf = (MR^2ωo -mvRsinθ)/MR^2 = 3.99

Do the people on this forum support manned (staffed) space exploration? I would like to know? Or would we be better off with simply robots exploring space for us. What is your opinion?

From NASA: https://www.nasa.gov/feature/goddard/2023/hubble-sees-possible-runaway-black-hole-creating-a-trail-of-stars "We think we're seeing a wake behind the black hole where the gas cools and is able to form stars. So, we're looking at star formation trailing the black hole," said Pieter...

Awhile back there was a discussion about the following scenario: an astronaut sets free into space outside his window a round magnet so it just sits there a distance away ensuring the spaceship has no effect on the experiment. Then he wafts out gently a large pail of tiny iron filings and dust...

According to Maxwell’s Equations, the speed an EM plane wave in free space, far from its source, is determined by the electric constant, ε0, and the magnetic constant, μ0, such that c = 1/√( ε0 μ0). The units of ε0 are capacitance per unit length and the units of μ0 are inductance per unit...