I'm a HS senior and looking to go into applied physics for college and eventually become a quantum physicist. I've heard incredibly mixed things about going into physics as a major/career and wanted to hear other's opinions and/or advice.

I have been wondering about why do atoms even bother to make bonds and attain the electronic configuration of nearest noble gas. That seems to create imbalance between positive and negative charges and cause instability but that instead makes the atom stable. So, here's what I know and think. Please feel free to tell where I am right or wrong and further clarify and enhance my understanding.

1. Why atoms bother to make bonds and attain the noble gas electron configuration.

Every thing in the universe tries to be in the lowest possible state of energy. If it has high energy, it will strive to lower its energy. Atoms are no exception. When the electrons are as close to the atomic nucleus as possible, they have the lowest state of energy. That's why noble gases are stable because they have the lowest atomic radius that any other atom in their group (in the terms of periodic table). So, they are the most stable. Other atoms who have more atomic radius try to make bonds to lower their atomic radius and thus their energy by reaching the electronic configuration of nearest noble gas.

2. How covalent bonds lower atomic energy by getting the electrons closer to the atomic nucleus.

When two atoms make a covalent bond they are sharing their electrons which means the electron is spending some time with one atom and some with the other creating the effect that both atoms have gained an electron even though they have just shared one. This creates a cloud between the two nuclei in which the electron is most likely to be found. Let's use an analogy. Consider two hydrogen atoms who have made a covalent bond. Consider their electrons as ropes (not physically but by function) and the atomic nuclei as players of tug of war. They both attract the electron towards themselves. Since the electron functions as a rope, it pulls both the nuclei closer using their force. This reduces the space between the nuclei which houses the cloud of electron. So, the cloud gets smaller so, the electron gets closer to the atomic nuclei. Although the bond actually increase the atomic radii of the atoms due to the repulsion between two electrons, they are near the nuclei most if the time. So, the atom get stable.

3)How electrovalent bonds lower the atomic energy. Let's look at the cation and anion individually. In the cation, when it loses an electron, the nuclear charge becomes more than the electronic charge. So, the nucleus pulls the electrons harder causing the electrons to come closer and the atomic energy lowers. This creates imbalance between positive and negative charges causing some instability but is less than the stability obtained by getting the electrons closer. The atom continues to do so until it loses all the electrons on its penultimate shell. When it tries to give away the electrons in the lower shell, the instability caused by imbalance between positive and negative charges turns out to be more. So, they only give away a shell. Now let's look at the anion. It gains the electrons lost by the cation. The cation is more positively charged than normal so tries to attract the electrons gained by the anion. So, just like in the covalent bond, this creates a cloud of electrons between the cation and anion pulling them closer to each other and reducing the space for electrons to move getting them closer to the nucleus of the anion.

So, this is my understanding of atomic bonds on a quantum level. It includes some facts and some baseless theory. Feel free to share your knowledge and correct me.

hi, sorry if this is worded poorly because i don’t have a lot of knowledge of physics if any at all haha

so while not being religious, i’ve always felt a lot of spiritual (?) connection and comfort in the fact that my body at its smallest building blocks was connected to everything in the universe based on the fact that it has in some form existed since the Big Bang / forever, and will continue to exist in whatever form (whether that be mass or energy) even after the universe ‘dies’. (heat death or whatever other scenario)

i’ve been having a lot of trouble with this lately as i’m seeing differing answers on whether this is true- i see some say that the conservation of energy is always true, while others say otherwise.

so is it true that in some form (mass / energy or whatever it decays into) the particles and such that make up your body have existed/ will exist forever (to the best of our knowledge), or are they eventually completely destroyed out of existence?

Code for reconstructing the diagonal elements of a density matrix from its off-diagonal elements.
This is an unresolved problem in quantum information, but it seems to produce good approximations.

https://ideone.com/56hmuK

I am trying to understand the basic particles better. Is there a model of their property comparison? I know most of them aren't measured in size but atleast weight or wavelength so you could know their distinct place in the universe. What I am getting at is like, you know that atoms are bigger then that other stuff, so you assume they are smaller, but they are also distinct, is there a model showing that?

I know ahead of time that the following thought experiment is unconventional. It is not only unconventional, but it is aggressively anti-conventional. I know that. I'm not some lunatic. But here me out. What if quantum uncertainty actually does exist on the macro scale? What if even large objects like buses, trains, or entire cities exist as a probability cloud until observed? Where would that meta narrative absolutely, objectively break down?

I've been looking in an amateur-ish way into some theories and I want to understand which things made the proccessess which eventaully led us here, can anyone explain?

I have this job where I need to write 3 page articles every week (it's basically an internship so I don't get paid) and I chose Schrodinger's because it was pretty popular, I skimmed the Wikipedia page on it and now I'm supposed to write it but I'm slightly stumped. Please help, my deadline is in a few days and I really hope they don't basically fire me.

I’d like to learn about quantum physics from its most fundamental concepts but I’m unsure where to start.

Any resources / material recommendations would be appreciated.

To Start:

So basically, I have to make an animation following a flame lab we did in my science class, and I have so many questions. The animation consists of a simple Bohr model of a strontium atom going into a flame, however by the time I got to the point where I would animate the actual energy shift, I realized I didn't know how. I am on fall break right now so I cannot ask my teacher, and we didn't learn this yet. I understand there is likely a simpler route that doesn't necessitate this deep level of understanding, however now I'm just curious.

As some background info, we used the chloride molecule of each element.

Questions:

1. What actually is the mechanism by which the atom absorbs the energy from the flame? I know it's heat energy, but how? If it's Infared light/heat, how does that produce some of the higher energy purple lines seen on a spectrometer. I'm not trying to imply I believe that strontium chloride produces a purple flame when burned, just that spectral lines around 400nm are visible when burning strontium.
2. If energy levels are quantized, how is it that there are enough particles/photons with the PERFECT wavelength/frequency to have the EXACT energy needed to jump a whole number of shell(s) within millions if not many more atoms? e.g. say an atom were to only absorb light with a λ of 300nm, would light with a λ of 300.01nm be absorbed? how about light with a wavelength of lim n--->∞ (300 + (1/n) nanometers? If it is true that it only absorbs that singular wavelength with zero margin of error, how is it possible that there are enough particles that possess 4.132806433333333eV of energy to produce the significant amount of light seen in flame labs? Otherwise, wouldn't a photon with a wavelength of 300.0000000000001nm carry 4.132806433333332eV (save yourself the trouble of comparing the two energies, they are different by the last digit) of energy and not be able to push the electron to the quantized level?
3. Since electrons are so small, how can energy be transferred to it so easily. Does the energy carrying particle not have to hit the electron precisely? If that is true, how is the energy transferred within this approximation of the electron's position?
4. How is a particular electron within an atom 'chosen' to move up energy levels?
5. For my animation, how do I know the precise number of eV's required to move an electron from one subshell to another. In addition, since I have to represent two different wavelengths of light being produced by the atom, if I know a wavelength that strontium produces, say 650nm. how can I know which electrons to move where?

Conclusion:

I'm sorry for the potentially over complicated/long questions, however I am extremely grateful to anyone who replies. I am only 15 so I apologize if this is very elementary/I sound stupid for asking. Thanks so much again

INT. CLASSROOM - DAY

FADE IN

We fade into a dilapidated classroom. The classroom looks like it is taught out of an abandoned building (it is). There is a moldy chalkboard in the middle of the class that has "Quantum Physics." written in the middle. Above the chalkboard is a sign that says, "Smile, we're learning." and below the chalkboard is a desk with some rustled up papers, a rotten apple and a large box television facing towards the class.

PROFESSOR GENESIS enters this room with a solemn, eerie aura and looks like a cross between Batman's Hugo Strange and a humanoid cat. The professor goes up to the board and writes his name.

Professor genesis, "Hello class, my name is Professor Genesis. Welcome to day one of 'Quantum Physics 101'. Today’s lesson is on Quantum Physics and the theory made possible because of it - The theory of parallel universes.

Now, I know most of your other classes are theory focused, but here I would like a more practical, hands on, personal approach. One that will leave you left with no questions,"

From across the class the professor hears murmuring from one of the students in the back. It's vague, but we the audience can just make out hearing an unknown student saying, "*Murmur* please stop this *murmur*"

Professor Genesis, "Excuse me! Young lady in the back of the class, this is MY time, quiet please and thank you!"

The professor picks up the remote off of the desk.

Professor genesis, "Now... Earlier today, one of your class mates was kind enough to volunteer for our first demonstration. So eyes to the monitor and let us watch and... learn."

The black screen on the television turns on. The footage is shown from a security camera looking down in an empty, dim-lit, lab room and in the room there is a student tied down to a chair...

INT. LAB ROOM - DAY

The beaten male student is tied down on a chair with duct tape tightly wrapped around his wrists, ankles and mouth (there is a smile drawn with a sharpie on the tape of his mouth because 'Smile we're learning').

The door rapidly opens eight times.

The Professor walks in furious and towards the metal table on the other side of the room.

Professor Genesis, "All morning, I have had this annoyance vexing me. Constantly stirring in my conscious like an annoying little gnat, buzzing, buzzing, buzzing!!

And I have allowed it to take my beautiful bright morning and turn it into a gloomy fucking despair."

The professor stands in front of the table and looks down at the eight torture devices laying on top of it; some of the tools are traditional torture devices while others are everyday items, but, with a little imagination...

Professor Genesis, "You see, I got these eight new tools: The scalpel, a rat, pliers, a jar full of fire ants with a funnel, the heretic's fork, a battery charger, the pear of anguish and a tongue tearer.

You'd think I would be ecstatic to have these eight new tools right? Right?

Wrong. Because I don't see eight of you, which means seven of them will have to wait and I wouldn't consider myself the waiting type...no.

Takes a beat of silence as he looks at his tools. He then picks up the scalpel.

Professor Genesis, "But then I felt a sense of satisfaction as I thought about the idea of parallel universes and their connection to quantum physics.

You see, down at the subatomic level—the scale of the particles that make up our atoms, everything we're made of and that binds us together, has different physics than what we have here.

Here, Newtons apple falls, friction stops the ball, and one living thing can only be in one place at once... Right?"

The student is sweating profusely.

Professor Genesis, "The physics in the atom's world differs from ours or... Some may think.

A molecule's subatomic particles, such as electrons, are not confined to a single location but instead exist as a probability distribution, meaning they can theoretically be found in many potential locations at once until measured, but pay no attention to that for now, for now the importance is... Those particles would be in hundreds, thousand, millions, billions of places at once! Or even just... Eight.

Each molecule on the micro field lives on a different vibration level as the others, thus they never interact with each other and don't even know the existence of one another. Even though they're so, so, so, so, sub-atomically close together. They don't even know.

Now the big question is, why is the physics different down there from the physics up here in our world.

Well, to me, it just doesn't make sense that out of nowhere the physics completely changes... Or does it?

Is it possible, that just like the single molecule down there, we up here could be on a different vibrational levels to other versions of ourselves, all around us, we, just like the molecules, can't see the other versions of ourselves."

The student sees a fly start buzzing around his face.

Professor Genesis, "And if that is the case then I do, get some peace of mind knowing that in seven other realities I'll get to use, thoroughly, each and every one of these tools on you to the fullest satisfaction."

The professor walks up to the student and bends down to his level while saying...

Professor Genesis, "Hell, there's even a reality where I have a change of heart, cut you loose, smile and wave as you exit that door to your new awakened life… And oh, the infinite possibilities you could do from there. A new perspective on life."

The professor says with his eyes closed and a blissful smile on his face, imagining that possibility. The professor takes a deep breathe in and when exhaling out, he looks the student for the first time directly in the eyes.

Professor Genesis, "But that's not this reality."

The professor stabs into the student's chest and a montage begins - MONTAGE of the professor using each of the eight torture devices on the student to the professor's fullest satisfaction.

End on a peak of the student screaming at the top of their lungs and the professor laughing hysterically.

INT. CLASSROOM - DAY

Back at the security camera shot the audience sees the end result. A dismantled student still sitting in his chair while the Professor cleans his tools. The TV turns off as the professor addresses the class.

Professor Genesis, "Now does anyone have any questions?"

No response...

Professor Genesis, "Are you sure there is not one question?"

...

Professor Genesis, "Good! I'm glad the lesson stuck with each and every one of you then. So you all should have no problem writing an essay on what we have learned today.

The essay will be due next week and then we will continue our studies with the subject of next week's lesson being on the quantum leap. Do we have any volunteers for that demonstration?"

Finally we see the class revealed.

The classroom is undoubtedly held within an abandoned building with old thrown away broken school desks; and in those desks are a dozen college aged students all tied down and terrified. One student is shaking with fear as tears fall down his face, another student is drugged up and not coherent of what is going on around her, another student's leg can't stop fidgeting as piss runs down it, and another student is manically writing down a pattern of numbers in her notebook.

Professor Genesis, "Not one volunteer? Well then, I guess we'll have to leave it up to natural selection then. If your essay is the lowest in the class, then you have boughten yourself a one way ticket to volunteering for next weeks experimentation... So study hard, as I know each and everyone of you will. And until next class students, remember, smile, we're learning."

The professor says with the biggest smile on his face :)

[down below is a link to our comics for reference]

https://www.webtoons.com/en/canvas/the-children-of-ito-/list?title_no=997893&webtoon-platform-redirect=true

We make weekly short horror stories and in a few weeks we will release one called, "Quantum Physics." The premise is essentially this, a professor/serial killer teaches a class full of students (that he has imprisoned) about Quantum physics by showing them a video he made earlier in the day with one of their classmates.

In the video the student is tied to a chair and on the table nearby there are 7 torture devices and the professor is livid that he only gets to use one of the torture devices on him, but, then gets some satisfaction knowing that in 6 other parallel universes he gets to use each one thoroughly on him and this gives him some satisfaction.

Basically he describes in detail how it is possible for parallel universes to exist, as i would like the reader to walk away feeling like they've learned something, but I am not sure I describe it with a 100% accuracy. THUS i am here hoping someone would like to read my short script and help give some feedback.

If you are interested please put your email down below or send me a DM and would love to chat with you!

Here are our comics for reference:
https://www.webtoons.com/en/canvas/the-children-of-ito-/list?title_no=997893&webtoon-platform-redirect=true

I’d like some discussion and help understanding around the constant vibration of particles, even when nearing or at absolute zero.

Of course this is true, we’re literally hurtling at 500k km/hr and spinning at 1000+mph. Everything has inherent motion or vibration because it’s moving at a cosmic scale. We just never see that movement as humans.

Now apply this to the double slit. You’re shooting something ahead in space, at a minute scale. That’s where I get stuck, but I’m pretty certain there’s an overlooked connection (from what I’ve been able to find) on our constant motion through space and how we define particles as waves vs. particles. All particles act as waves because they are moving and “waving” through the universe at an absurd speed. They are also a particle, because well its matter.

That movement we experience feels like a constant but it’s not.

Any scientific articles or explanations to better understand would be great!

Hi, I am tying to understand the theory of Roger Penrose called  "Orchestrated Objective Reduction". But I don't understand it well. What is its affirmation between quantum oscilliation and human thoughts ?

There are several recent proposals arguing that the quantum nature of gravity might be more experimentally accessible than previous pessimistic assessments. This Quanta article outlines an approach that would (theoretically) provide evidence for the existence of quantized gravity (i.e., gravitons). This article by Carlo Rovelli argues it may be possible to measure interference effects that prove spacetime can exist in superposition.

I understand that the graviton detection experiment is controversial—some scientists believe a positive result provides no increased evidence of quantized gravity, because the exact same result would be observed given non-quantized gravity.

However, assuming you could run a loophole-free experiment that definitely proves gravitons exist, is this proof that gravity is a separate quantum field like the other quantum fields in the standard model? I understand that some quantized observations are based on pseudoparticles that do not represent a unique quantum field, despite a quantized effect (e.g., phonons). Also, I’ve seen arguments that spacetime might be an emergent property of the existing quantum fields (and not its own field). Would finding the graviton definitively prove that gravity is an independent quantum field?

I fully admit I have a lack of knowledge on this. It is entirely gained from...cough...tiktok...sorry. So this is why I am coming to this forum to ask hoping I can get some deeper understanding. What was watching the atoms? Was it a camera? Because I have heard talks of how they said let's discreetly unplug, suggesting power supply, the thing watching, but they don't make clear what it is. My question, and again I'm sorry if I sound dumb and I would like to think it has already been asked in the quantum physics community. My question is has anyone watched this with just their presence, woth human eyes? Or was it a camera watching the electrons? If it was could it be possible the EMF or whatever I don't know could have affected the electrons? Hopingyou guys can clear me of my ignorance and before any trolls start I am fully aware of it hence the question.

I read a paper a month ago that discussed how to extract energy from a vacuum/quantum field. It had circuit diagrams and everything. It is not https://arxiv.org/pdf/2409.03973. Sorry for the lack of details but I deleted it from my saves and now I can’t remember what it was. Thanks Edit: it also included the code to run the same program that was run on IBMs computer

How to store my Hamiltonian efficiently if it is sparse and time-dependent and pass it (sparse matrix) to 'mesolve' function of Qutip?

I am currently following a quantum optic class and I will ask the professor my question but I’d like to have an answer before the next class.

We talked about quantum sensors using interforemeters (such as LIGO) and their limits due to shot noise, coming from the fact that coherent states produced by lasers are a superposition of Fock states meaning that the number of photons is not well defined.

But can’t we produce directly a Fock state to send into the interferometer to get rid of the shot noise? Is it even possible to produce a Fock state other than a one photon-state?

All the diagrams I've seen suggest the fields are orthogonal to each other and mathematically two-dimensional (planar but traveling through our 4D space-time).

Is this accurate?

Hi all, I have looked through the FAQ/googled but I haven’t been able to find anything close to an answer. If this is a silly question, apologies in advance.

Because light has no reference frame, its relationship with space time is unclear to me. What is clear (I think), is that light does have a speed limit. An insanely high speed limit, but it does take time for light to get places.

So, if I were to hold a flashlight out in space and turn it on for one year, then turn it off, would there be a one lightyear long “segment” of light traveling away from me? I understand light to be a change in electromagnetic field, so perhaps the right phrasing would be a one lightyear long change in the field?

Or, because of lights relationship with spacetime, is there no such thing as a tail end of a light beam? If so, how does light terminate? Is that distance measurable in space?

I know that quantum strings can only vibrate at certin intervals but does the length of a quantum string change its frequency?

Hello, fellow quantum enthusiasts!

I’ve been pondering a thought experiment related to the delayed-choice quantum eraser and the role of which-path information in interference patterns. Specifically, I’m curious about scenarios where which-path data is recorded but rendered completely inaccessible before being destroyed.

Scenario:

Imagine conducting a double-slit experiment where we record which-path information by printing it out. This printed data is then placed in a time-locked incinerator set to destroy the information after a fixed period (e.g., 10 minutes). During this period, the data is physically present but impossible to access before destruction.

Questions: 1. Would the interference pattern emerge before the data is physically destroyed, given that the information is impossible to access before destruction? 2. Does the mere existence of which-path information, even if practically inaccessible, prevent the formation of an interference pattern? 3. Have there been any experiments or studies that explore the effects of inaccessible yet existent which-path information on quantum interference?

I’m interested in understanding whether the practical accessibility of information influences quantum outcomes or if the mere existence of such information, regardless of accessibility, determines the presence of interference patterns.

Looking forward to your insights and any references to related studies!

Thank you!

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