Hypothetical Definition and 192 Threads

I’m trying to keep a master list of all the theoretical “things” in physics that were once postulated to exist but probably don’t, like magnetic monopoles. Could anyone help me out?

I was watching a video on YouTube and while the channel is very credible; it said the often-believed-erroneous-belief that quantum entanglement can allow FTL travel or communication. I left a respectful comment saying that this is incorrect but many other people actually do believe QE is FTL...

I remember one of the Ant-Man movies had time travel enabled by shrinking down to an incredibly small size. This seemed silly to me at first but then I realized that a second is much closer to the age of the universe than a Planck time is to a second. This is mind-boggling and the human brain...

I watch John Michael Godier on YouTube. He is a futurist and makes fantastic videos where he speculates on many things. Todays video was about primordial black holes and he speculated about Planet 9 not being visible because it may actually be a black hole born in the dawn of the universe. He...

I recently read that there is enough hydrogen in the human body to lift 195 lbs off the ground. I know this sounds super-silly but if we ever develop nanites; could they manipulate the hydrogen and allow us to float?

I recently watched History of the Universe and they talked about the Giant Arc, a large scale structure that spans 3.3 billion light years long, exceeding the hypothetical limit of 1.2 billion. The Arc was discovered last year. https://en.wikipedia.org/wiki/The_Giant_Arc They said if the Giant...

Say one was to create an artificial stable isotope of Promethium as it has predicted applicable properties. What would it’s number have to be? I know Promethium-147 is semi-stable.

Hi all, I've been thinking about a hypothetical circuit with (say) a 6V cell of negligible internal resistance, a 4V cell of negligible internal resistance, and a resistor in parallel with each other, and I can't figure out what the potential difference across the resistor would be. I've tried...

Did Max Tegmark talk about his Mathematical Universe hypothesis at this event (https://www.zimbio.com/photos/Brian+Cox/Michio+Kaku/rAcvFyE88Ul/World+Science+Festival)? And if that's the case, what was the opinion of Michio Kaku?

As seen in the summary, my question is purely hypothetical and I understand that it would most likely be impossible to happen (or I just haven't read enough). The concept that quarks and leptons are the fundamental particles of the universe has existed for a while now - therefore we know that...

Hi everyone! :) While i watched rc jet exhibitions on youtube, i find that the most fast of this RC reached +700 Km/h. When i browse more information about the tourbine, i realized that for a hypothetical supersonic RC the mechanical system of the tourbine must have a complete air compressor...

Let us consider a hypothetical scenario, where we are able to translate any mass at a constant speed of 10m/s w.r.t to a given frame of reference. For simplicity, we are going to assume that the object is at rest initially. Case 1 - Now, consider 2 points A and B at a distance of 10m, and our...

Given a bug that's walking counterclockwise around on the surface of a lazy susan (which itself is sitting on frictionless bearings), wouldn't the the friction between the bug and the lazy susan (which is needed to be able to walk) apply torque (no matter how negligible) that accelerates the...

I was just reading up about the Earth's three motions, and it was written that the 'wobbling motion' (precession) exhibited by the Earth, could be compared to that of a spinning top. Intuitively, I guessed that a spinning top wobbles because of the Earth's gravity, and I found out that the...

Hi there. I'm writing a sci-fi story for a video game. At some point in time an advanced civilization from the future, say 4010, creates a wormhole for a not so advanced civilization spacecraft in the past, say 2050, to travel through. The idea is for the not so advanced civilization...

Hello all, My second hypothetical question for the day (and last). Suppose you drilled a hole from the surface of the earth, through the Earth's core, and out the other side. The sides of the hole are reinforced preventing any of the hot stuff from escaping the Earth's core, in fact this hole...

Hello all, Suppose you created a 20x20 foot hollow sphere at the most central point of the earth’s core. This sphere is protected from the heat and oxygenated, in fact it’s a perfect 22 degree C inhabitable environment for a human. What kind of gravitational forces would one experience in this...

Ok, so I have long been fascinated with magnetic fields and their mysterious nature. I've been wondering what would happen when the magnetic field of Earth gets bent/disturbed/rippled by some extraneous force. I am aware the extent of effects that magnetic fields have on a planet is great, but I...

Hypothetical: Approximately how far from Earth would a star the size of the sun have to be for an object the size of a quantum particle to cause a total eclipse of that star when orbiting the Earth at a distance equal to that of Earth to the center fro the moon?

This might be total nonsense, but the thought popped into my head while I was trying to get to sleep, so I thought I see if I could find any advanced help with the following hypothetical: If light were instantaneous, how far from Earth would the sun have to be to cause a quark orbiting in place...

At 100m: (a) 0.03315 W/m (b)4166 W Since E is inversely proportional to 1/r^2, then E at 150m is 2.22 V/m. (a) 2.22/377= 0.00654 W/m (b) 4*pi*r^2*Wrad= 1665 W Is this reasoning correct?

Assuming that both the Earth and Mars's atmospheric pressure follows an exponential curve, how many kilometers deep would the average bore-hole on Mars need to be in order to arrive at a depth where the atmospheric pressure was 0.35 bar or approximately 5 psi? What about 0.7 bar?

I would like to know about the hypothetical properties of hypothetical negative energy--most especially the properties that would be useful for a science fiction writer to know. If such energy existed, could it be used in a drive for space craft? An FTL drive? For a weapon? A safety...

I’ve read many Legends and Canon Star Wars books and I always take away stuff on their limits of technology and science. Over the years; here are some things they said science can’t do. 1.) Cybernetic liver- In Lost Stars, it was said Ciena’s liver could not be replaced as it was one of the...

Just wondering about this (as I have a ridiculous $7,000 health insurance deductible - I basically have a non-employer catastrophic plan): Say you are a young, healthy person, who makes $50,000/year (assume an average American city COL) and you have to buy your health insurance on your own...

Does this violate conservation of momentum or some other law? It claims to take advantage relativistic mass increases to achieve propulsion https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190029657.pdf

I know that the standard mantra of physicists who view themselves and their work as mainstream believe its never aliens. After all, as Carl Sagan reminded us, "extraordinary claims require extraordinary proof, " as it should rightly be. But, recently, some pretty extraordinary proof has made its...

I was watching videos on YouTube and this question suddenly popped into my head: If I was able to push a sub-atomic particle (proton, electron, etc...) a distance of 1 Planck length. Excluding all the quantum interactions and uncertainties, is it possible to measure/calculate how fast the...

is there any sci-fi that would rerate a life based on ammonia or silicon or any other type of life?

I have a hypothetical universe where the distance between two points in spacetime is defined as: $$ds^2 =−(\phi^2 t^2)dt^2+dx^2+dy^2+dz^2$$Where ##\phi## has units of ##km s^{-2}##. The space in this universe grows quadratically with time (and, as I understand it, probably isn’t Minkowski...

Looking for existing examples of or guidance on building computer simulations of simple N-bodies in relativist situations. Of particular interest is the simulation of a planet orbiting a star whilst that trivial solar system is caught in a dark flow of relativist velocity; maybe .8 or .9 C. Not...

Hi there. I wanted to direct this question to all of you (and am especially interested in hearing from @Vanadium 50 , given his often harshly realistic views). I wanted to present an hypothetical scenario. Suppose a student a student is finishing his/her BS in physics with an admittedly weak...

Hi everyone. I wanted to pose an hypothetical question. Suppose we have a student who is a graduate from a physics program in a Canadian university (e.g. University of Toronto, University of Waterloo, McGill University, University of British Columbia, University of Calgary, University of Guelph...

Hello, this is my first posting on this forum. I enjoyed Chemistry in high school, though the arts were where my abilities drew me. I've learned that a ratio of 2 hydrogen to 1 oxygen, when ignited by a certain amount of heat, will create a small amount of water. I will give a brief outline on...

If the coordinates x = rsinθcosφ, y = rsinθsinφ, z = rcosθ represent a Sphere, then what does the coordinates x = rsinθcosφ, y = rsinθsinφ, z = rcosθsinφ represent? @fresh_42 @FactChecker @Infrared @WWGD

I'd like to ask about a hypothetical situation. A human, wearing a jetpack, for example, accelerates forward with 200,000 m/s^2 and therefore, experiencing extreme g-force of roughly 20,408 g. If there will be a hypothetical device that will be able to redirect the gravity force (g) to elswhere...

During a random conversation with a friend, we got onto the subject of dropping a 6ft cubed cube of Hardened-Steel from the height of 100 meters. I ended up getting really curious about the energy it would cause, as well as the potential impact/destruction it would cause on the area...

I know this won't work, I'm having trouble explaining why to someone who thinks it will. Make a ring around a planet. Give it low walls. Fire countless pellets at hypersonic speeds around the inside of the ring. The pellets are moving at super-orbital speed, pushing the ring outward, making it...

Hypothetical question that came up in World Building stack exchange. The question asked for what the longest reasonable day length would be. I thought that a 100 hour day: * Afternoons in what are now hot deserts would be uninhabitable. * Frost traps in more polar climates would be...

Hi all, It has come to my attention this article on PF (https://www.physicsforums.com/insights/can-gene-editing-eliminate-alzheimers-disease/) about a genetic approach to prevent Alzheimer's disease, based on applying gene-editing techniques on human embryos. In short (so not to be...

Hi All, First time poster here, and I've got a couple questions. Straight up, I'm writing a sci-fi story where antimatter is utilised as fuel (feel free to laugh at the cliche), and I want to portray it as realistically as possible. To that end, I've come up with a storage method and I want to...

Not saying that there is another universe. But if there were, would the laws be the same? I've heard Leonard Susskind explain that extraneous solutions of string theory could represent the environment in regions very far "away". So is it just small things like the physical constants being...

Hi What strange hypothetical objects in space do you know of? Example: Magnetar, pulsar, black hole. As I am currently writing a sci fi book for children, I am trying to probe the universe of your mind in search of extraterrestrial objects.

Homework Statement Imagine another planet with an acceleration of 10.00 m/s^2 at its equator when ignoring the rotation of the planet. The radius is 6.2 x10^6 m. An object dropped at the equator yields an acceleration of 9.70 m/s^2. Determine the length of 1 day on this planet. Homework...

Let's say for example, there was a dye in which any number with any amount of digits could be scored. You also had an equal chance of scoring every number. Which means that you have the same chance of rolling a 1 as you do 5 billion. If you rolled that dye, how many digits would that number...

Imagine I have 2 constant-volume, constant-temperature containers. Container A has a volume of 10 L and one Container B has a volume of 5 L. My hypothetical gases Ideal Gas A and Ideal Gas B have the same properties as each other (temperature, mass, energy, heat capacity, blah blah blah). If I...

Hi all, So the (hypothetical) question I have is about the range of the Earth's length of orbit (number of days) within the Sun's habitable zone which could sustain human life. I.e. what would the length of the shortest 'habitable' year be, and the longest (in days)? What would our living...

Hello everyone! I am a fiction writer with a hypothetical question. For my work I have a new planet, the same size as Earth, with a moon with just a very slightly longer mean orbit (a few days). I have been reading about tidal locking which ensures that observers on the planet only see the...

I was helping someone with his fanfiction where a system didn't have the same gravitational constant that exists within the rest of the universe.There was a throw-away line given by Q on the Star Trek episode, "Deja Q", where Q was asked how would he fix the problem of a moon falling out of...

I'm not entirely sure how to clarify this question, so instead I'll pose another one that should serve the same purpose. If, hypothetically, someone in the future devised a way to travel back in time (which to my understanding has never been shown to violate any laws of physics) after...