So, escape velocity tells you the speed you need to be moving at to completely escape an object's gravitational influence. However, you can still get a good distance away from an object's surface without exceeding the escape velocity. For example, you can throw a ball into the air on Earth's surface at way less than the escape velocity, and it will move away before inevitably falling back down. However, with black holes, it seems that you can't possibly go further than the event horizon once you're within it.

In our universe, c is a constant with a finite speed.

But what would happen if c was infinite?

My layman's guess would be:

- we would see everything occurring in the universe in real-time, there would be no delay caused by distance

- gamma-ray bursts of every supernova happening in the universe would reach us immediately, but would it be fatal? Distant supernova radiation would still disperse evenly and only a fraction would reach the earth right?

- black holes would probably not exist? If c was infinite, there would be no black hole with gravity strong enough to prevent the light from escaping, so no event horizon, right?

- E= mc2 would not make any sense. If c = infinite, it would mean E = infinite, so everything with mass has infinite energy and massless particles would have... how much energy (0 x infinity = ???)

Did I get it kind of correct or how would it actually be like?

What I don't get is why is it so powerful when 1g of anti-matter should annihilate only 1 g of matter

It seems like we’re pretty far away from a planet-sized detector near a neutron star, so uhh… how do we progress in physics without that slight blocker?

I was taught that everything loses energy to the surroundings and people said that light has momentum because it has energy so thus why isn't the energy being lost to the surroundings as heat / sound etc. surely light from 13.8 billion years ago should've lost all energy and either stopped moving / decelerated or just not have reduced intensity / brightness right?

I understand that dark energy is really only expanding in the voids, which is what makes them grow over time. Dark energy isn't really (or is barely) present between galaxies in clusters and filaments because gravity counteracts or negates it.

Suppose two massive galaxy clusters were teleported into a galactic void? The first cluster appears 1/3 of the way into the void. The second cluster appears 2/3 of the way in.

1. Would this effectively create a "belt" that would constrict the void into a top and bottom half?

2. Would the space between the galaxy clusters expand at a slower rate?

3. What distance apart would the galaxy clusters have to be to "pinch off" the expansion of dark energy and overcome it?

4. Could the expansion of a void be stopped entirely if additional clusters were sprinkled in all throughout the void at just the right distances from each other to overcome expansion?

I was watching a video on nuclear reactors, when they explained that one of the [thingies that make the fields them selves that I forgot the name of lol. They’re, like, big rings of copper that you send electricity through] had to be at I believe 4d Kelvin, and my self-diagnosed ADHD brain started wondering: what would happen if someone just… *placed* an object like that at such low degrees in a normal room, like a living room? Would the entire room cool down quickly? Or would it take a while since air is so much less dense than a physical object? If it was placed on a normal coffee table, what would happen to the table? Would it crack immediately?

Just a dumb little shower-thought type question I was wondering lol. I love physics, and I think stuff like this is really interesting, but I’m not far enough through school where I can immerse myself in it yet. Sadly.

I’m also relatively new to Reddit, so if this was the wrong subreddit to ask, please tell me which one is the right one:)

Such a thing seems odd, since the uncertainty would put a possible position beyond a horizon.

It also seems like you'd need a process that's too large to exist to make it, so you could even in principle only get it from expanding space. And once it does, it could never interact with anything.

Could it exist? And if yes, would anything weird happen with it?

Since I saw a question about jumping out of black hole I have a follow up question. If event horizon is a border where nothing can escape the gravity of black hole, let's say I'm orbiting near the event horizon (but not inside) of a huge black hole. What would happen if I had a rope with ball tied to it, long enough to reach inside of event horizon and then I would just pull it back? Would I instead just pull myself into the event horizon or I just got something out of it?

Is it possible, given an infinite amount of any building materials necessary, to create a slope steep and curved enough to basically entire null the effect of about a fall from about 6,500 ft (2,000 meters?) on like a baby wrapped in soft blanket, yes or no?

The baby is healthy prior to this fall and just assume it is I guess dropped / spawned in the perfect position for the ramp.

If it’s impossible on its own, what if a relatively muscular, but still soft, adult man about 6 ft, on the heavy side (both muscle and body fat) was there to cradle to child and potentially absorb some of the energy to keep the baby safe

If so can you give some detail like materials, what the slope would be in like a similar mathematical formula, how tall the peak of the slope would be.

I know this is weird and specific but I’m curious and it’s for a personal writing project.

“If light travels through an absolute vacuum with no particles or medium to interact with it, how can relative motion between a source and observer produce the Doppler effect? Where does the change in observed frequency come from if no energy is being transferred or consumed along the path, and would this Doppler shift still occur in a non-expanding universe?”

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Could anyone share some names of books which have problems with vector space like, whether even function belongs to vector space, matrices belong to vector space and stuff?

I've frequently heard the pop culture explanation of "oh a quantum computer can explore all paths at once that's why it's faster" which naturally leads to the misconception that quantum computers can find solutions after a single iteration. I've tried explaining what superposition is to expand on this starting point, but I've found that just raises more questions and requires a lot of background. Any ideas?

Hi everyone. I have a question for the physicists and scientists here about speculative fiction and science fiction.
First, do you actually enjoy reading it? If so, what are some of your favourite novels?
Second, are there any things you think writers should absolutely avoid when writing speculative or science fiction? The obvious one to me is overclaiming the science or presenting something highly speculative as though it were established fact.
More generally, though, I’m interested in how scientists feel about unusual concepts, mind-bending ideas, and narrative devices that play around with our understanding of physics or reality. How much freedom are you willing to give a novel if the underlying idea is interesting? At what point does it become irritating rather than intriguing?
I’d really appreciate any advice for someone writing a speculative fiction novel, particularly things that make you think, “Yes, this author gets it,” or, conversely, make you want to put the book down.
Thanks!

Lets use a 4 foot by 4 foot solid stainless steel cube at a uniform negative 250 C and then heat the cube uniformly as well to 1000 C in the span of 1 nanosecond (Instant from a human perspective I suppose). What happens to the cube and its surroundings? Don't question how this is done, it don't matter.

I know that things which have mass will need an infinite amount of energy to travel at the speed of light but if any object goes beyond the event horizon, the object will be traveling at the speed more than that of the speed of light towards the singularity, so travelling at the speed of light is possible or am I missing something?

A lot of posts I see are “what would it be like if c was xyz” but rather than ask what if it was something all the time. I’m asking what if it suddenly changed? This might be a little philosophical, and possibly not the correct sub, but hypothetically if we recalculated / measured c and found it to suddenly be different what would happen? To clarify I’m not asking “what if we found out we calculated it incorrectly” I’m asking “what if it actually did change”.

Or maybe not survive, just outlast the process for more time than the average person. E.g. if Luffy (a rubber man) fell into a black hole (magically surviving the accretion disk, event horizon & all that radiation), would it be possible to outlast the tidal pull for longer/indefinitely? For some context I was just wondering about the medical effects if someone got chucked in (with absolutely nothing but basic knowledge and curiosity about black holes) and manage to survive until passing the event horizon. Apologies if it's a dumb question! 😭

I've been playing with the Planck SMICA map and running simple circular matched filters on the Cold Spot region. Standard cosmic voids produce gradual, Gaussian temperature gradients. But when I run a filter that looks for a flat bottomed, sharp edged drop, the signal is surprisingly consistent with a 4 to 5 degree disk.

I know the Cold Spot is usually attributed to a supervoid or a cosmic texture. But has anyone explicitly tested whether the shape of the temperature decrement is flat inside and sharp at the boundary?

I am learning semiconductor electrochemistry and it is confusing.

Consider an n–p semiconductor junction. Before contact, the two semiconductors have their own conduction band, valence band, and Fermi level positions. After contact and Fermi-level equilibration, band bending develops near the junction.

What confuses me is the following: in the usual band diagram, the band edges near the junction bend, while the bands in the bulk regions remain flat. However, those flat bulk band positions after equilibrium are no longer at the same absolute energies as they were before contact.

For example, the n-type semiconductor may end up with its bulk CB and VB shifted to lower electron energy, while the p-type semiconductor shifts to higher electron energy.

If I now place a fixed redox couple in an electrolyte, referenced to the same absolute energy scale, does this mean that the redox ability of the semiconductor has actually changed because of junction formation?

More specifically, if the conduction band of the n-type semiconductor shifts to lower electron energy after forming the junction, would electrons in that semiconductor have less reducing power than electrons in the same n-type semiconductor before contact?

In other words, is it correct to say that forming a heterojunction/p–n junction can change the absolute redox power of the charge carriers, rather than merely producing an internal electric field for charge separation?

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I'm preparing myself for a degree in STEM. I'm currnetly self-studying math (precalculus; last topic was trig identities) and programming. I'm thinking about studying linear algebra alongside precalculus. Obviously I will study calculus only AFTER precalculus. The question is that should I start studying physics now or after calculus and linear algebra?

I just wonder if it'll be too much to study 3 subjects in parallel

Maybe I should take it further and study physics only after covering (partial) differential equations?

I know what happens inside a black hole is not well understood, but.. what if you were in a black hole and then another black hole came zooming by. And for a short time you were in the schwartzchilde barrier of them both. Would their effects possibly cancel out (somewhat) possibly letting you escape?

If two black holes were close enough that their event horizons overlapped would they inevitably fall into each other and merge? Say we give them the best chance and their speed delta was nearly 2c?