Not how many Tsar Bombas, but the size / mass of one single bomb.
I'm only writing this post because I myself have falsely fancalc'd the energy required to destroy/bust planets as the GBE of the planet before.
It's off by a factor of ten thousand for almost all planetary destruction feats in fiction, as I recently realized after looking at the formula for escape velocity. It turns out the gravitational binding energy of an object is exactly 0.6 times the kinetic energy of the same object moving at it's own escape velocity.
What does that mean? If you blast Earth with an attack that has 2.2 x 10^32 joules you will overcome its GBE, but the fragments of Earth will only move apart at a speed of about 11 kilometers per second. That's practically nothing if you look at the entire planet from the outside and it's not what happens in fiction 99.9% of the time.
Look at Alderaan being destroyed or this planet blowing up in Stargate for example. The planets are flying apart at thousands of kilometers per second. And going a hundred times as fast takes ten thousands times the energy, so yeah, the explosions absolutely dwarf the GBE.
Fancalcs aren't really that prevalent here, so this probably isn't very interesting for most people on the sub. It's not some profound insight or anything either, but it still absolutely blew my mind. I've equated planet busting with overcoming the GBE of the planet for years now without even thinking about it, turns out that's wrong in most cases.
For instance, could a neutron star blow itself apart if it was spinning fast enough?
How do i compute for the gravitational binding energy given two charges, one positive, one negative, and a distance?
I have an ideal monoatomic gas of N particles, each of mass m, is at thermal equilibrium at absolute temperature T, confined inside a cubical box of side L, whose top and bottom sides are parallel to the earthβs surface. The eο¬ect of the earthβs uniform gravitational ο¬eld on the particles should be considered, the acceleration due to gravity being g.
I wish to understand if I need to account for the gravitational field on the KE of each particle? I know this gas has 3 d.o.f., each contributing 1/2 KT, so the average KE without gravity is 3/2KT.
Also how do I then find the average potential of each particle? Since they are ideal monoatomic, I presume they have no interactions, so usually (without gravity) the potential would be 0. How to account for this ccorrectly in this case?
Thanks!
I am doing a physics course on Khan Academy and am currently on a section about Newton's Law of Universal Gravitation. In the practice section I got this problem:
Two identical spacecraft start out at rest 150,000m apart. The spacecraft then move so that they are again at rest, now 2,500m apart. Both spacecraft must fire their rockets to stay at rest.
How did the spacecraftsβ change in position affect the gravitational potential energy of the system?
The answer I chose was, "The gravitational potential energy increased because the spacecraft moved closer together". However this is apparently wrong. The correct answer was, "The gravitational potential energy decreased because the spacecraft are closer together".
The explanation given for the correct answer was, "The gravitational force from each spacecraft pulls them toward each other. So, when the spacecraft did move toward each other, the potential energy decreased".
In the video about gravity, it was explicitly stated that objects closer together will have a greater gravitational force and objects further apart will have a smaller gravitational force, so how am I wrong? The only difference I see is the answer references gravitational energy, not gravitational force.
Note: The video on this section only covered gravitational forces and fields, so if potential gravitational energy is different, then how was I supposed to connect what was taught to gravitational energy? (Which if there isn't anything wrong with the answer, then I'm assuming that's what I was supposed to do.)
Or is a 'filament' just the end result of temporary gravitational pull from the galaxies creating the appearance of an distinct object? I saw this article: https://www.universetoday.com/151553/the-largest-rotating-objects-in-the-universe-galactic-filaments-hundreds-of-millions-of-light-years-long/amp/
and got to thinking about how if rotation is happening on these super large scale structures, other forces could be acting on them as well.
Can such a wave be generated naturally?
I have noticed that there are some mountains with an unused steep railway on them. For example this one in Longyearbyen or this on in Pyramiden (bot are far away from me but there are some nearby). I live in a country where electricity prices can vary 3-fold within a week or so.
I look at at the first one on a map, it provides a ~280 meters height difference. The second one seems be on the same order of magnitude.
I thought about using a similar setup: let's say I can get my hands on a similar pair of tracks to ~200 meters height, at a 45 degree angle. If I have a (let's say) 1000 kg minecart, I could use cheap electricity to pull it up, and generate electricity by releasing it when electricity is expensive.
This company seem to be working on a similar setup. They claim to have 90%+ round-trip efficiency. Energy Vault is trying to achieve a similar thing with cranes: they claim to have efficiency between 80 & 90%.
Amount of potential energy I could store with pulling up & releasing a single cart: 200m*1000kg*10m/sec^(2) = 2 MJ = 0.55 kWh. When accounting for efficiency, significantly less.
I am interested in creating such a device mostly for fun. I would like to use the same electric device for pulling up the cart and for generating electricity when it is released. What is the name of this device I am looking for? What details of such a device should I consider if I'd like to buy one?
About my background: I have a degree in Astrophysics, so I know quite a bit of math/physics/coding, but I am a complete noob when it comes to real world electronics. If you could take this into account, I would appreciate it a lot.
EDIT1: This is my first post here, I see I have to include where I am from if not US: Norway.
EDIT2: at least one of the companies I linked seems to be consisting of scammers/idiots. Sorry everyone.
I wonder if the gas in the accretion disk could be so hot and compact that there could be a range near the event horizon where nuclear fusion could happen much as it does in a star? What about in the relativistic beam? Any fusion there?
I was reading an article on the observation of an intermediate black hole consuming a star, and how gravitational waves would ripple out. Within a galaxy, there would be numerous events creating ripples , and so we'd expect waves generally to move outwards from galaxies (assuming there would be some degree of both constructive and destructive interference, but that generally the waves would not cancel out), then surely this would exert and outward force that would push neighbouring galaxies away. And could some sort of gravitational wave resonance account for a part of dark matter, holding galaxies together for faster rotation?
Sort of like how salt poured onto a surface with sound frequencies arranges itself in clumps and patterns, similar to star in galaxies and galaxy clusters. "Gravitational resonance" of sorts....
Mass and energy are the same thing so if youβre moving at a significant portion of lightspeed you are also carrying a great deal of kinetic energy, so does your mass also increase?
Could you move close enough to c that light with distort around you like how it distorts around other supermassive objects like galaxies or black holes?
If lensing does happen, then are there issues with communicating with a spaceship moving close to c?
http://au.finance.yahoo.com/news/magnis-energy-technologies-limited-mns-225800416.html
About who Traxys is: https://www.traxys.com/upload/cms/brochure/TraxysBrochure.pdf
Carlyle Group is a major investor/owner of Traxys
Iβm going off of this video here. I have zero background in this kind of thing, just curious.
https://youtu.be/Xo232kyTsO0
Seems to me if one blocked stacked on top of another block has more mass because itβs higher up, that an object much further away would have even more mass due to its greater potential energy.
