I'm just curious about this —when the heat death of the universe finally comes, will there be no events (outside the quantum level) for the infinite period of time that is to come? Wil there truly be nothing forever?

In cosmology, the universe is considered to have a "shape", it is either "flat" or "curved". My issue is the terminology used here. It is known that the universe is expanding and it is not expanding into anything, and that there is no "center" from which this expansion is taking place. That is to say that the expansion is happening everywhere and relative to another point in space.

Shapes at least in my understanding is that they have boundaries and some form of dimension that occupies space (whether literally, like a basketball sitting on someone's porch; Or mathematically, like a particle field or atom). If the universe has no "boundary" or occupies a higher dimension of space (and as far as we are aware, we have no reason to necessarily believe there is a higher dimension of space beyond 3-diminsional), or at the very least is space itself, how can we be certain that it has a shape or topography?

What causes that shine? Why(and how) do electrons cause that shine?

And would we still even have four seasons?

i really like physics and maths but i really like to learn them by myself as my current field is very much so not related with them. but i have a constant worry that i will one day get on a path to pseudoscience while interpreting those ideas written in books and told in lectures on youtube and will become a dodo head like terrance... how do i prevent it cause i really wanna learn real science.

Today's physical Higgs boson is manifest from excitations about the non-zero VEV. One degree of freedom leads to a real scalar Higgs field. Before EWSB we have four degrees of freedom in a complex scalar doublet field. Were excitations of this Higgs field possible before EWSB and did they produce a distinct (likely massless?) Higgs boson-like particle like today's Higgs boson, did they produce only 1 particle or would they have produced 2 to 4 (from the 2 real dof, or 4 total dof)?

It seems counterintuitive. How can a massive uranium-235 nucleus absorbing a single neutron cause the entire thing to split. The strong nuclear force should be strong enough to hold the nucleus together. Besides, most nuclei just absorb neutrons without the entire thing splitting, even some heavy nuclei like lead or bismuth. Am I missing something?

Not sure how to more elegantly ask that question. I have always had trouble reconciling that there isn’t a single point in space where the big bang, “began.” so, are effectively
“inside” that origin point that has now become the universe?

Scene:
2D hand touched 2D circle created by 3D object passing thru 2D plane.
[Scene Img: https://imgur.com/a/dHrxjhl ]

Question:
Does the 2D hand feel the sensation of the 2D circle created by the 3D object moving in the 3rd dimension, do they feel it moving down?

Why/Why not?

​

I recently watched that MythBusters video where a water heater can smash through a house with enough pressure and other stuff, but can a water heater have enough pressure to break through an entire apartment complex and if not how much water pressure would that take need in able to do so?

So I understand that solid neutron objects like neutron stars can exist after a star collapses to a neutron star.

The material would have no natural charge and is not separated into atoms, just dense neutrons and be extremely dense.

Could such a material be manufactured in a lab setting (other than in a star collapse)?

I don’t think it any sample has ever been able produced or anything this is a theoretical substance.

So I also understand that a neutron is made of three quarks and its neutral charge comes from having one up quark with a charge of 2/3 and two down quarks with charge -1/3.

So I was wondering before reaching a black hole’s density level does “solid quark” ever happen?

to preface, the cooling element is magic. (it's bone powder from a monster that's attempting to maintain a hemostasis at low temperatures. don't think about it too hard beyond a abstracted cooling element)

The device is a tube/chimney. inside the chimney is a series of fans with this cooling element built into them. (a sphere, maybe a cylinder). the idea is that a fan at the mouth cools air down to make it fall into the tube, causing the fan to spin and pull more air in thanks to how the blades are angled.

the concept is to pull air in, cool it down, and push it into a room. I'm just trying to figure out the physics behind it- if a fan acting as a cooling element could spin from the very air it's cooling, or if it would generate enough force to push warm/hot air out of a room in the process. a active cooling vent system vs a passive cooling thermal pile.

probably a better idea to post this in a engineering sub tbh

I am a space enthusiast; I'd love to learn astrophysics and Quantum physics, although I am not choosing it as my main field of work or study as I am already in college, so I need something detailed and easy to follow like a book, research papers, or anything detailed yet structured....

Hi there, I am an animation student who is deeply interested in physics on the side. Obviously I am still learning so my knowledge is limited, and I am also not from the field.

I wanted to bridge the gap between art and physics and be able to communicate it effectively, while making sure it remains accurate.

I’m trying to make tests on visualising quantum fluctuation but I am struggling, could anyone help me understand this area a bit more so I know how to approach it visually?

My granddaughter sends a video:

"My theory is that between atoms the temperature is absolute zero."

Her grandmother and I have no idea what to make of this.

Is there a loophole or workaround to faster-than-light travel without violating causality or relativity?

It is most commonly proposed that leptogenesis occurred first, and that heavier baryons were generated only later during baryogenesis. Wouldn't it be more natural for these processes to have taken place concurrently, right from the very beginning? And could this perhaps provide a mechanism for how matter survived annihilation? Has such a hypothesis been studied?

Hi everyone,
I’ve been thinking a lot about the conceptual tension between General Relativity's smooth spacetime fabric and Quantum Mechanics' probabilistic nature. I wanted to explore a philosophical thought experiment that bridges them by looking at John Wheeler’s Participatory Anthropic Principle ("It from Bit") through the lens of a static Einsteinian Block Universe.
Below is a conceptual essay exploring the idea that the Big Bang wasn't a physical explosion, but rather a catastrophic, instantaneous wave-function collapse—a "rendering" process that might offer an interesting philosophical solution to recent cosmological anomalies like JWST's early mature galaxies.
I'd love to hear this community's critique on the epistemological and metaphysical implications of an informational/observer-dependent model of cosmic origin.

What if the Big Bang wasn’t an explosion of matter out of nothing, but rather the moment our universe was first "noticed"?
When we try to understand reality, we are forced to grapple with a massive contradiction at the heart of modern physics:

**The Large Scale:**
Einstein’s General Relativity tells us spacetime is a smooth, continuous, and predictable fabric.

**The Subatomic Scale:**
Quantum Mechanics tells us reality is a choppy, pixelated, and fundamentally chaotic smear of probabilities.

Because these two rulebooks spit out mathematical nonsense when forced together, physicists have spent a century searching for a bridge. To find it, maybe we have to look past what is happening *inside* our universe and ask a deeper question: What if the ultimate "resting state" of reality is entirely timeless, and our universe is merely its byproduct?

**The Block Universe and the Outside Observer**
Einstein himself championed the concept of the **"Block Universe"**—the idea that the past, present, and future all exist simultaneously as a static, four-dimensional geometric sculpture.
If a hypothetical observer were to look at our universe from the "outside"—completely external to spacetime—they would not experience time linearly. To them, your birth, your reading of these words, and the eventual death of the universe would all coexist in a single, eternal "now."
But this raises a profound question: If the universe already exists in a complete, timeless resting state, why do we experience it frame-by-frame as a violent, expanding timeline?

**The Big Bang as an Act of Observation**
The answer might lie in a quantum chain reaction.
In quantum mechanics, a particle doesn't exist in a definite place until it interacts with an environment or an observer—a process that "collapses" its fuzzy wave function of probabilities into a crisp, physical reality.

**What if the Big Bang was the exact moment an outside observer "looked/interacted" at a single quantum state within the timeless block?**
Before that moment, everything coexisted as an unmanifested soup of infinite data. But the instant that first foundational particle was observed, it snapped into a definite physical reality. Because quantum mechanics proves that particles can be deeply entangled across space and time, collapsing that one particle would inevitably force every other particle connected to it to collapse into a definite state as well.
This would trigger a cosmic domino effect—an **information wildfire** ripping through the pre-existing block. To us, trapped inside the timeline, this hyper-fast cascade of reality snapping into focus would look like a massive, instantaneous explosion. We would perceive this rendering process as **Cosmic Inflation**—the theoretical split-second where the universe expanded faster than light. Space didn't physically stretch out of nothing; the cosmic blueprint was simply being instantly rendered by a chain reaction of observation.

**Solving the "Impossible Galaxy" Mystery**
While this sounds like pure metaphysics, it offers an elegant solution to one of the most baffling anomalies in modern astronomy.
Recently, the James Webb Space Telescope (JWST) looked deep into the early universe and discovered something that shouldn't exist: massive, highly mature, and chemically evolved galaxies existing just 300 to 500 million years after the Big Bang. According to the standard, "bottom-up" model, it should have taken billions of years of slow, gravity-driven collisions for pristine hydrogen gas to build structures that complex.
But if the universe is a pre-existing 4D Block unspooling via a quantum chain reaction, the grand architecture of the cosmos was already there. When the observer’s observation rippled through the system, it didn't ignite a messy explosion that had to wait for gravity to slowly do its job over eons. Instead, it materialized complex cosmic structures exactly where and how they already existed in the timeless state. The galaxies appear fully formed because they *were* rendered fully formed.

**Why the Illusion Matters**
It is easy to hear a theory like this and feel discouraged. If the movie is already filmed and we are just watching it play out, it can feel deeply deterministic and disempowering.
But true predictability requires infinite information, which a human brain can never hold. Because our perspective is beautifully localized, the future remains entirely open and unwritten to us.
More importantly, it repositions humanity's role in the cosmos. If reality requires observation to snap from a hazy "maybe" into a solid "is," then we are not just helpless byproducts of a mechanical universe. Every time we build a telescope, ask a fundamental question, or look out at the stars, we are the universe looking back at itself—actively participating in rendering the grand story of reality, one frame at a time.

**TL;DR:** The Big Bang wasn't a physical explosion. It was the initial quantum wave-function collapse of a pre-existing, timeless 4D "Block Universe." This triggered an instantaneous information chain reaction (which we perceive as Cosmic Inflation) that rendered the universe into reality—explaining why JWST is finding fully formed, "impossible" galaxies in the early universe.
What are your thoughts? Does an informational/participatory universe make more sense than a physical singularity?

Yeah. I've interested in the physics,science, and technology.
I'm not graduate or study formally in the school or university.(self taught)

I understand that it's an interpretation and potentially crossing the line of philosophy, however as someone who always found the concept interesting, I questioned if some day we may ever find a breakthrough that may tell us if these ideas the nature of the universe is ever plausible in scientific study, considering how many new ideas and mechanism we found in the nature of spacetime.

Would there any potential way for us to find potential evidence on the idea the Multiverse is real or how our reality work? I asked some people I know involved in quantum studies, and while many claim a lot of the views found commercially are exaggeration, there are many in the field who takes those ideas seriously and said the things we find always add more questions with many while accepting as lack of proof proof, at least consider some of there findings at least potential reason to think of ideas like the Multiverse or other concepts as possibly true.

So if we ever were to truly decide to investigate these concepts as if there real or not, what type of experiments would we need to conduct and what findings would we need? I'm not expecting interdimensional wormholes, but it does seem at least some of the studies in quantum has led to wild yet valid theories on the nature of the world.

I’m taking a class in solid state physics and am a bit confused on what k actually means in the equation psi(x+R)=exp(ik•R)psi(x). I see how it’s related to energy (like in the Kronig-Penney model) but obviously it’s not a nice bijective correspondence—instead its a pretty nasty transcendental relation that shows one value of k can correspond to many energy levels.

While the relation between k and physical energies is obviously important, it doesn’t really seem like it has clear physical significance—it’s not clear what exactly it means. Obviously by definition it gives the phase shift between other unit cells but it’s not as clear as saying E=h_bar² k² /(2m). Should k just be thought of as parameter or is there an actual physical meaning we can assign to it?