Universe Definition and 1000 Threads

So Coulomb's law is this simple formula for calculating the force between two charges. Kq1*q2/(r^2) (Disclaimer: I know this computation is not actually possible I was just wondering if it would give the correct result) I was wondering if it is valid to sum the force vector from every charge...

I can basically explain everything, why the Universe exists, what it's doing, Dark Matter and connecting the forces together. I worked all this out when I was trying to make a spaceship and explore the Universe. I have mathematical proof which connects gravity to Quantum Mechanics etc. Or I had...

I would like to ask some questions about an interesting paper that was written back in the late 90's (https://arxiv.org/abs/astro-ph/9701131) There, the authors propose how the universe may evolve from the near future to extremely far time scales Near the end of it (Section VI, D.), they...

Suppose we have a simulated universe in which the observable portion (a collection of galaxies) is climbing out of a gravitational well at a very high fraction of the speed of light. The gravitational well is caused by a very large, accreting black hole outside of the observable portion. The...

Here's one that is very easy to find and that I definitely recommend. Steven Weinberg, The First Three Minutes. (paperback) Amazon $31.19, I'm asking $15 with free shipping at media rate ($10 plus shipping if shipping is less than $5)...

This pop up on anyone radar? Electron mass different throughout the universe? I don't see how this section could have passed peer review: The masses of electrons, muons, and tau can be explained by the different curvatures of universe, galaxy, and solar system, respectively. I've seen crazy...

Sagan describes this on page 207 of his book (1995 reprint hardback edition). In the context of the page he is discussing accelerating at 1g for half the journey and decelerating the other half for trips to Barnard's Star, the center of the Milky Way and the Andromeda galaxy. Then he talks about...

Hi. If the early universe did not undergo rapid expansion but rather a more controlled growth like the human body, how old would the universe be given its present size? thanks

I would like to ask a question about an interesting paper [1] back from the late 90's There, the authors propose how the universe may evolve from the near future to extremely far time scales Near the end of it (Section VI, D.), they discuss entropy and heat death: They indicate that contrary...

Apparently, among the options for the fate of the universe, the universe reaching heat death in the extremely far future is the most likely one, after the last black holes would have evaporated (https://en.wikipedia.org/wiki/Heat_death_of_the_universe) But, even if objects in extremely long...

Cosmologists say that the observable universe has a diameter of 93 billion light years. Does this mean the universe has a center?

Hello everybody! Although I'm joining this forum, my field of studies is not science, it's linguistics. Despite that, I've always been fascinated by the universe and its laws, I've consumed countless media about the topic ever since I was in elementary school, when I brought a study about the...

If the universe is infinite and if it started out of a finite singularity, how did it make this step ? From finite to infinite ? This looks a hard thing to do ?

Liddle (2015, p.67) writes: "From the crude estimates that a typical galaxy weighs about ##10^{11}M\odot## and that galaxies are typically about a megaparsec apart, we know that the Universe cannot be a long way from the critical density." Was this fact (i.e. that the actual density is likely...

what would the universe look like if its a manifold with boundary? what would it look like at the boundary? and what happens if u try to touch the boundary? is it just a black wall that's unbreakable?

it requires less energy to impart acceleration to an object than to the entirety of the universe, This would break the principle of relativity since the amount of energy to move an object should be the same as the amount of energy to move the rest of the universe. This observation implies a...

If big bang existed, than universe must be sphere, because explosion expand in all direction.. I read that universe is maybe flat so how this is possible? Why can we with telescope determine shape of universe?

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...

The age of the universe is said to be about 13.8 billion years. But, since time depends on the observer, would it be the same for a possible inhabitant of a planet in a galaxy about 10,000 million light years away that is separating from us at 60% of the speed of light?

We think the age of universe is 13.8 billion years old . I think we are wrong. Let’s pretend we can go outside of our observable universe. Also, let’s say we can go so far out that we do not even see a spec of light from our universe. We see nothing at all, total darkness. When they finally do...

(pop science) It seems like the mass in the universe at the point of origin was way higher and the size way smaller than required to form a black hole, so why didn't our universe just sit forever as a single black hole? From a figure for the mass of the universe you could calculate the event...

Astronomer - have built and used lots of stuff for ground and space based astronomy, and worked on top of countless mountain tops across many continents; studying the radio Universe from the deserts of New Mexico, taking pictures from mountain tops in Chile, Hawaii, La Palma, listening to the...

hi, how do we calculated the number of atoms at the start of universe i.e, after big bang?

My understanding is when a star creates new matter it has an affinity towards iron? Does the universe on a whole favor certain elements based on the laws in place? Certain complexity level and certain physical characteristics are ideal and the farthest from those things the stronger the force to...

Hi I am trying to reconcile the concept of the Big Bang of occurring "everywhere" (an infinite Universe) - v - the concept of the origin of the Big Bang occurring in a particular compressed state and then expanding? Thanks Martyn Arthur

I am curious to understand how the universe works. I love to imagine if I were the universe or a particle why would I behave the way it does. It's a fun exercise. I am currently preparing for IIT JAM exam. I am glad to be part of this community. I am looking forward to getting to know you...

Professor Brian Cox was on the TV last night. He stated that eventually everything will end up in black holes. When there is nothing left to absorb they will start evaporating via Hawking radiation until eventually they all disappear in a small flash of light and then there will be eternal...

There is an interesting paper by Arkani-Hamed and collaborators (https://arxiv.org/abs/1607.06821) to address the hierarchy problem. There, they consider many possible models of fundamental particle physics where they all have an exact copy of the Standard Model but with different Higgs...

Hello everybody. I have been having a lingering question about the State of the Universe. As humans, we view the Universe's expanse as historical from the vantage point of Earth. For example, 10,000 light years away would have occurred 10,000 years ago. On that same logic, looking at Earth from...

I cannot find an answer online. Help please.

How can there be galaxies in the unobservable universe when The CMBR which precedes all galaxies is observable?

Hello! I am a highschooler looking to learn more about physics and looking to hear a lot of feedback on my thoughts about physics.

so I've started doing a few equations involving time dilation due to gravity and have been told it changes depending on if its spinning or not (like with a black hole), how different is it, and whether there is any time something won't be spinning and it needing the altered calculations

I believe in the Big Bang but I struggle with something. If the Big Bang happened and universe is expanding there has to be something (or really nothing) there for the universe to be expanding into. Any thoughts?

Everything that I’ve researched into this seems to suggest that we know absolutely nothing about the universe at the beginning of the Big Bang event. Could it be that just nothing is there? Could everything in the universe be described by cause and effect, yet cause and effect does not apply...

https://www.theatlantic.com/science/archive/2023/01/astrophysics-fusion-experimentation-supernovas/672625

Yes, I understand that once white dwarfs get cold enough, they aren't luminous enough to get observed, so my question could be interpreted as "when did the earliest white dwarf evolve, and how cold is it now"? This is the article that motivated this question...

The earth is a sphere. I can stand anywhere on its surface and look up directly above my head at the night sky and see lots of stars many light years away. I see this view wherever I stand on the earth's surface although the stars will be different ones, depending on where I'm standing...

Physicist Grigory Volovik has put forward some ideas about the universe undergoing a topological phase transition (especially in the early stages of the universe). He published a book called "*The Universe in a Helium Droplet*" where he explained his ideas. You can find a brief discussion here...

I apologize in advance if this is a stupid question but... According to some scenarios about the beginning of the universe (namely cosmological inflation), in layman's terms, everything was born out of a quantum fluctuation which caused a violent expansion. In this case, since an expanding...

The GR predictions for the universe's size are those of fig.a. Whereas the Hubble expansion is exponential, fig.b. How are the two reconciled?

I am frequently contemplating the size of the universe. Logic tells me that existence cannot is end as there really can’t be anything as anti-existence but if the universe loops back on itself; it may not be an issue. Is there a possible way in the far future to semi-accurately measure its size...

If universes can collide to make universes and split to make new ones, where did the first universe come from? Do we have any ideas? Any help would be appreciated.

Does anyone know where I can find the map animation of the galaxy / nearby galaxy cluster that illustrate the geometry between Earth and M87 at the 29th minute in the Netflix show ? Alternatively if that's not a public source, can anyone recommend a publicly available "map of the universe", I'd...

I have heard that some types of inhomogeneties and topological defects (like cosmic strings) in cosmology have been proposed to be able to break fundamental symmetries of nature such as the Poincaré, Lorentz, diffeomorphism CPT, spatial/time translational...etc symmetries... However, I have not...

Perhaps this is a stupid question but, if Lorentz symmetry and time translational symmetry are not global in an expanding universe, wouldn't that mean that is possible that other Hubble spheres outside our observable universe could have other symmetries or an absence of the Lorentz symmetry? I...

According to the Planck 2018 results, the curvature component of the density parameter of the universe is Ωκ=0.001±0.002. From this data, would it be possible to determine the greatest possible positive curvature of the universe and the radius of the corresponding 3-sphere?

As of now, it appears the ΛCDM can accommodate this new data but new data is needed to be sure. https://www.quantamagazine.org/standard-model-of-cosmology-survives-jwsts-surprising-finds-20230120/

Wikipedia states the following in their article about the expansion of the universe: If the cosmological principle was discovered to be false in our universe, i.e. our universe was discovered to be inhomogeneous or anisotropic or both on very large scales and the FLRW metric does not hold for...

TL;DR Summary: I'm interested in constructing an artificial universe and discussing its properties and behaviors. I would like to construct an artificial universe somewhat akin the Conway's Game of Life and discuss its behavior and properties. Is that allowed? Is this the place to do that...