Hi, folks.
There's a somewhat popular hypothetical situation that involves a person falling into a hole dugg all the way through the Earth or any planet, passing straight to its center. Now, I understand quite well that the resulting motion would be periodical and the reasoning behind it. My...
Say for instance me and another person were 1 light hour away from each other. Now at my position I am subjected to a much greater gravitational field and thus, due to time dilation, 1 hour for me is 2 hours for him (at his current position).
If I were to send a beam of photons at him...
Hypothetically, a particle p of mass M is sitting at velocity v. Assuming M = 0, and the vi of p is 0 m/s, 0 seconds passes and vf 100 m/s is reached. Since time t is 0, acceleration cannot exist, as no t has passed between the vi and vf states. And, knowing that a = (vf - vi)/ Δt, a = (100 -...
So I was sitting around pondering about forces, and I found myself thinking about shock-waves. Whether they're caused by supersonic travel, or explosions, the pressure at the front of the wave-bow shock pressure is a force.
So I started thinking of a way to generate them without having to go...
[don't know whether i is the correct thread prefix, will change if requested/possible]
Now I will start off by saying I'm only an interested lay person, and haven't studied this but was thinking about time dilation and it's correlative effects with gravity. Higher gravity, time slows down...
imagine a hypothetical star composed of gluon stars, color neutral on whole, consisting solely of gravitationally bound glueballs. what would be its expected physics ? i.e for the mass of the sun, what would its radius be? would it emit radiation and if so what spectrum? would it be stable or...
What would happen if all of the empty space of the universe from the small to the vast, were replaced with the gases that make the Earth's atmosphere while neglecting gravity from any massive object?
Suppose there was a universe that was small, and flat, but globally it was connected like a torus. Basically, pac-man's universe (except special relativity is in effect). The space ##(\mathbb{R} \pmod{1})^3##.
Does this assumed universe have a distinguished inertial frame where the...
Hello!
I have a question about grand piano action design. As a quick primer, the way a piano works is basically that each key is a lever mounted on a fulcrum, so when a player presses a key, the other end of that lever rises. A hammer is attached to the other end of the key, and when that end...
Disclaimer: I am an aeronautical engineer with a background in fluids. My knowledge of cosmology only extends to articles and things I read before I go to sleep.
So, here is my question:
I have though about time travel, as many other people have. Currently we think it may not be possible, as it...
I found the thread "SR, LET, FTL & Causality Violation", looked through through all of it and read large parts. I believe I found my answer there, but to make sure, I'm asking the question here:
Suppose we had some "magical" black-boxes that allow us to communicate information in both...
Right, on the huge hypothetical atom I asked about before; what I'm really after is how the electric field from a point charge is quantized at a macroscopic distance of several centimeters? Let's say that you charge a metal electrode with C Coulombs of negative charge and then use that electric...
Solution to Schroedinger Equation for a huge hypothetical atom?
Let's say you have hypothetical atomic nucleus with a very large Z, say a million times of the most highly charged ones; what would be the solution to the SE at very large n's i.e. at very large distances, say several centimeters...
Hypothetical question here. If someone were to develop a system for navigating the galaxy what would be the best way to determine a position and direction assuming no prior information about location (but access to things like star locations from our solar system's perspective). I'm assuming a...
Excuse the simplified question title. I have very little knowledge in the world of organic chemistry, and chemistry alone.
If I looked at the composition of banana (atomically), and then I got a little jar full of every element that is necessary to a banana's composition, could I make a...
1. Consider a closed loop which already has a current ##I## running through it while the resistance of this loop is ##R=0##. I now suddenly start tuning on a homogenous magnetic field through the loop which gives raise to an emf in the loop ##\epsilon=-\frac{d\Phi}{dt}##. What will happen?
My...
I have a problem that is completely hypothetical and revolves around the speed of a non-existent aerial vehicle. Using the following specifications, what speed can this hypothetical flying vehicle move?
Standard weight: 43.4 metric tons
Max Acceleration: 0.93 G
Rocket Thrusters: 2 x 24000 kg...
The Scenario:
Let's say one could have a lot of cations produced from a gas in a single plane contained in a 1 square foot area (like a fence around sheep). This plane of cations is over another one that is on the ground. So basically two layers of Cations in a tall hollow cube like...
Homework Statement
A hypothetical magnetic field existing in a region is given by ##\vec{B}=B_o\vec{e}_r##, where ##\vec{e}_r## denotes the unit vector along the radial direction. A circular loop of radius a, carrying a current ##i##, is placed with its plane parallel to the X-Y plane and the...
Lay person here...
If there was a new metal that was discovered with extremely high electrical conductivity and corrosion resistance but no thermal conductivity, what do you image its industrial uses might be?
If aliens collapse a previously stable traversable wormhole that is situated at roughly the location where the ISS is located, and that wormhole then becomes a black hole, how long would it take for the Earth to be drawn into its singularity and utterly destroyed?
Also, let's say humans have...
Homework Statement :
There is tank with a certain depth with water that is exposed to air. There is a hole at the bottom of the tank. Using Bernoulli's equation, we can find the efflux speed. density of the water * gravity * depth = 1/2density of water * velocity ^2.
This will give us the...
Would there be any way to get the energy from the rotation of a planet, which is an Earth like planet in material, sized like Jupiter, and seems to have a 24 hr day.
I am just starting to get into real Physics, So I am not even sure where to start getting the numbers to work with, and I would...
I had an argument at my university about it, since experiments at LHC aren't 100% confirmed.
I mean, gauge theories are.. theories and Goldstone bosons are theorems.
Someone share some light plese?
Alright, so there's a RP website I'm on that has a fairly detailed description of their solar system. However, they have no details on their planet's moons. This is something I've been trying to work out, as I want to introduce a lunar calendar of sorts to a nation I RP there. I've managed to...
I know of Project Daedalus, Project Icarus, and Project Orion. These basically utilize pulse propulsion. In Daedalus and Icarus helium 3 and deuterium are combusted by a laser to create thrust. And in Orion nuclear bombs explode behind the craft to get it moving. All of these designs only reach...
Hello,
Due to all the buzz by Mars One, my friend and I have been discussing hypothetical possibilities for long term colonization of Mars. He suggests the only long term solution is to extract O2 from the Ice on Mars and give the planet a breathable atmosphere. he did the math and calculated...
Hi everyone,
I want to discuss the following question:
What would happen to the distance between two objects with masses M and m with M >> m if the central mass M was time-dependent (e.g. the moon's orbit if the mass of the Earth would increase slowly)?
My theory goes like this:
The...
Hello physics forums,
Say you had a hollow steel sphere of thickness 1 mm and diameter of 1 meter (from outside to outside)?
Inside the sphere is gas at 1 atm pressure. Outside is 1 atm of pressure. How much gas would I have to remove from the inside until the sphere collapsed from...
If you could create a small space on Earth in which a person could fit that was totally unaffected by gravity, or that was sheltered from the gravitational affects of external sources of gravity, what sort of affect on time dilation would be observed? Both for the person in the pocket, and for...
This is only hypothetical, but bare with me.
I did some searching on the interweb and found out that a drop of water has about:
1.67 × 10^21 molecules
(Source: http://wiki.answers.com/Q/How_many_water_molecules_are_in_one_drop_of_water)
Also, the amount of protons and neutrons that can...
Hi there,
I have a hypothetical question which is prima fascia more than a little ridiculous, but it relates to a science fiction book I'm working on writing. I'm hoping that one or more of the general smart folks here can weigh in on it and give me some realistic answers about a very...
Hi everyone,
I am humbly here to ask a question. I have no EE training or education (as will become apparent) but I couldn't sleep and my head was churning and now I need to know:
Can you operate a city or country on solar power generated on the other side of the globe? i.e. Could solar...
Ok, so I have had a lot of spare time and started pondering the things of the universe. Mainly problems looking at time dilation, mass dilation, length dilation and gravity. So one day I came up with a question that I have been unable to answer and I wonder if it is answerable or if there are...
Let's say that you leave Earth at 75% the speed of light (c). You travel out and back for a minute. And when you come back an hour has passed on Earth. (I understand this is not accurate; I'm just using it for the sake of this hypothetical) You leave again at 99% of c, again for a minute. When...
How would they look like?
Being more specific and less speculative: would higher atmospheric pressure (ex. 5 atm) mean that it is easier to fly/glide because lower wingspan would allow to achieve the same lift? Or it would be actually harder, because denser atmosphere would mean higher drag...
Hi,
I have been pondering about a hypothetical distance between consecutive real numbers. It seems a bit of a paradox, though I expect it will be shown to be a consistent picture. I'll be using recently-learned terminology which hasn't completely set in mind yet, so please have patience with...
So we are doing problems involving potential energy of electrons, wave functions, and all that jazz, but I am utterly lost on how to do this problem... The professor threw it at us, and I am completely lost on how to even begin. Please help me
In a different universe from ours the spin...
Here is a brief detail on the planet i created.
Mass .218 Earth's, density 5.62 g/cm3, radius .60 Earth's, surface gravity is .602 Earth's
It has 1 moon that has 5% the mass of the main world orbiting 300,000 miles above the surface.
It orbits a sun like star, same luminosity and mass every 342...
Would it be possible for a truck, measuring 5ft tall when stationary, to pass under a 4ft barrier by accelerating towards the speed of light?
If so what would a spectator see if standing next to the barrier, would the spectator see the truck shrink? What would you see of the barrier from the...
Hello,
Imagine that we have a fluid heated up by solar energy (every day during sunlight). Due to higher temperature it would undergo thermal expansion and do some mehanical work while expanding, right? And during night it would cool down and hence compress and do some negative mechanical...
How will light switched on from a space-craft moving faster than c appear( hypothetical space-craft) to a ground observer??
I am new to this forum and i am unfamiliar regarding threads, but some guy locked my previous thread, its absolutely unfair,citing the reason space-craft can't travel...
I thought of a question and its been causing some debate with my collegues. Its completely hypothetical and possibly ridiculous but I'm looking for somebody's more educated take on it.
Here goes:
Say you could theoritically drill a large hole between the poles of the Earth, large enough...
A spaceship has managed to accelerate to 86.6% of lightspeed. Focusing on special relativity would fuel consumption remain the same, better, or worse as opposed to traveling at non-relativistic velocities, what about breathable air?
I understand that the rate of fuel consumption would...
I found a couple of threads on the subject, but they didn't really give me the answers I was looking for.
I'm working on a project where Earth has become a global desert. The statue of liberty surrounded by wasteland, New York City barren and covered with sand, same story everywhere else on...
I am writing a science fiction book that includes the idea of a planet orbiting within the habitable zone of Alpha Centauri A and I'm hoping this is a good place to get some questions answered. It's science fiction, so I'm perfectly fine with stretching the limits of possibility, here, just...
Homework Statement
Consider the following energy levels of a hypothetical atom.
E4 -1.0 10-19 J
E3 -5.0 10-19 J
E2 -10 10-19 J
E1 -15 10-19 J
(a) What is the wavelength of the photon needed to excite an electron from E1 to E4...
From what I understand, space (not matter) can expand at a speed faster than that of light, and when it does, it goes in all directions. Would it be possible to create a controlled expansion of space behind a vehicle along a single path, like a corridor, that would change your position in space...