/r/Physics
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Mon | What are you working on? |
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/r/Physics
Dark matter and dark energy arise from a feedback mechanism between quantum processes and the large-scale structure of spacetime, facilitated by a holographic encoding of the universe’s quantum information on its boundaries. This feedback creates emergent gravitational effects and drives cosmic expansion without requiring new particles or fields.
Holographic Principle
Quantum Entanglement on Cosmological Scales
Feedback Mechanism and Cosmic Expansion
Emergent Gravity and Dark Matter
Galactic Dynamics
Cosmic Microwave Background (CMB) Anomalies
Expansion Rate Variability
Laboratory Simulations
This theory reimagines dark matter and dark energy as the natural consequences of a quantum feedback system intrinsic to the universe's holographic nature, opening new avenues for exploration in both cosmology and quantum physics.
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Formalizing the Quantum Holographic Feedback theory mathematically is a challenging task, as it involves synthesizing elements from quantum mechanics, general relativity, and the holographic principle. Below is an attempt to outline a preliminary mathematical framework that could underpin the idea:
1. Holographic Principle and Boundary Dynamics
2. Quantum Feedback Mechanism
3. Emergent Dark Matter Effects
4. Emergent Dark Energy Effects
5. Unified Framework
Galactic Rotation Curves:
Cosmic Expansion:
CMB Anomalies:
Numerical Simulations:
Comparisons to Observations:
Quantum Analog Systems:
Hi fellow physicists and science lovers!
Nuclear physics sometimes feel abstract and complex, but what if we could make it more accessible, and even fun, using LEGO?
Let me introduce the LEGO model of CROCUS, a real nuclear reactor used for teaching and research at EPFL, Switzerland. This unique model is designed to make nuclear science and reactor design more tangible and relatable.
🔍 How does it connect to physics?
As a university physics teacher, I've explored creative ways to teach nuclear concepts. This LEGO model has proven effective for:
🙋 What do you think?
(PS: If you're curious, the project is featured on LEGO Ideas to make it an official set, and and you can read more about it in this detailed article.)
I told him force is not same as speedm pulling something faster makes no sense.
And even if we consider GTR. The change of gravitational field will b e same as speed of light. How to give him a well articulate answer. Or am I being wrong. Also English isn't my strong suit so it is sometimes hard for me to explain something to others
So recently we put some lights for Christmas in our home. Right before i was going to school until the red light showed up, amd I wasn't seeing as much as i could see with blue and green. So i pulled out my phone, recorded it, amd came here to hopefully fin an answer to the question above.
Sorry for my english, It's not my first language
Hi, I'm currently in my 3rd year physics undergrad and I just finished our control systems class. I thought control theory is really fun. So now I'm thinking what if for my thesis (or graduate thesis) I study the applications of control theory on quantum systems?
What do you think of this? What is the research like in this field?
Any insights is welcome! Thank you.
PS. no one in my university does research in this field so i dont think I will do it for my undergrad
I am a 1st year Theoretical Physics but I am slowly realising I am bad at Physics and okay at Maths. Then, I wondered whether Mathematical Physics is more ideal for me.
Anyway, my question is: how exactly does it differ between a physicists and a mathematician doing maths?
Obviously we have different research topics but other than that, let's assume a physicist and a mathematician is approaching the same problem. What would the difference be? The obvious one I have in mind is how rigorous we are (my maths module lecturer from the physics department literally doesn't care about the modulus for , say, integral 1/x dx)
Hey guys! You all probably know what a cloud chamber is (if not, it's basically the simplest particle detector you can build at home, great for visualization and teaching), but If you ever tried to build one, you probably noticed just how different the instructions on Youtube and the internet might be. I recently worked on a project for school where I tried to improve the cloud chamber as much as possible, and wanted to share what worked for me and didn't. Note: though I tried to justify my results scientifically in the study, it still might be wrong and my suggestions might go against theory, in which case please correct me. Also, some of these tips might be already available online, and I don't claim to have invented them. Anyhow, here's a list of suggestions:
- For starters, check out the two following videos: 1) https://youtu.be/xky3f1aSkB8?si=VGAR5G1y6HTRyX3f and 2) https://youtu.be/eh3bxXHqF2U?si=zh_Ju3Gc150XQVr8 . I found these resources extremely helpful as the initial guide. The CERN one uses a metal sheet with grooves, however these are hard to find or do by yourself. So, follow ElectroBOOM's suggestion to make a silicon groove, it generally helps with the sealing and fixes the chamber container in place.
- Use glass or plastic for the chamber container. Some people suggested using plexiglass, which I ended up using, and do not recommend you do. Since we cool the chamber, the low temperature ended up cracking the container for me, leading to leaks at the bottom. Generally it's easier to get a ready container (from cooking sets or smth) rather than building you own, cause mine was imperfect and had gaps, which I had to glue together for some time.
- For the alcohol absorbent, use felt, not sponge. Felt can collect more alcohol and generally spreads it better than sponge. Also, the felt should cover the entire area of the top layer of the container, as it evenly spreads the alcohol. The felt layer should be quite thick (around 3-4 cm), as it allows to pour a sufficient amount of alcohol.
- Concerning the alcohol itself. It's best to use isopropanol, but for personal use different alcohols (methanol, ethanol, etc) are quite sufficient. I personally used ethanol because isoprop isn't sold in my region. Try to hit >90% purity - generally the higher you go the better the tracks. The cloud chamber has a specific limit of alcohol quantity where it actually operates, i.e if you poor too little or too much, it won't display tracks. If you have the time, try to play around with the volume of the vapor to see where this region lies for you - you will also see a change in the quality of the tracks, as some volumes produce a high number of tracks, others display them for longer. But if you're low on alcohol or just want to see the chamber work, the rule of the thumb is to cover the entire area of the felt and pour out the excess.
Also, the waiting time until the chamber actually starts displaying particles varies based on the amount of alcohol you add. So, for smaller volumes it took me about 10 minutes to start up, and 20 for higher volumes.
- For the metal sheet (which you place on top of your cold layer, where you actually see the tracks), try to find a black one. Aluminum, etc won't display as good and reflects light.
- The temperature gradient between the top and bottom layer plays a big role. It's best to get the bottom layer as cold as you can by using dry ice. Flaked ice worked best for me, as it covered the whole metal sheet area. Pellets work good as well. But if you plan to make more of a "perpetual" cloud chamber, go with Peltier coolers submerged in frozen salted water. This, however, will deteriorate the quality of your tracks, so judge based on your use. You can place hot water on your top layer, which will also improve your quality. I tried making a chain of resistors to heat the felt directly, but failed to do so. Maybe you'll be able to make it, but please be careful and look into it further because I'm not sure if it might actually ignite the alcohol :)
- If you want to produce more tracks rather than relying on cosmic rays, order smoke detectors with Americium-241 (I got them off of Aliexpress. Bought 10, only 3 produced decent results). Some recommend thorinated welding rods, but I went with the detectors. Remember radiation safety. Also, place the detector inside rather than trying to produce tracks from outside the container, plastic blocks off the particles.
___________________
Hope this helps! Have fun, I loved my experience with the chamber.
Edit: If you're concerned about the price of the chamber, the whole thing cost me around 30-40 usd, 20 of which went to the dry ice order. So shouldn't be too much
We were lucky enough to have Barry Barish speak at an informal round table event at Stony Brook University, and someone asked how to deal with imposter syndrome, feeling like every other student/physicist could do everything so much better than you, like you could never do anything significant next to them.
Barish explained that he felt particularly inadequate when he went to sign off on his Nobel Prize.
"Getting the Nobel Prize is this whole week long process, and I'd been doing well so far. The last day, they took us to get the money, take pictures, do all the important things. They came up to me with this nondescript, small book, and opened up this page that was blank except for '2017' at the top. 'Sign here,' they said. I signed my name, and flipped through the book. I saw Einstein, Feynman, all these fantastic physicists who changed the world... how could I be in this book? But I had already written in pen, so I couldn't erase my name."
I hope this brings you guys as much comfort as it did me, that even the most accomplished physicists feel this way at one point or another.
This is a thread dedicated to collating and collecting all of the great recommendations for textbooks, online lecture series, documentaries and other resources that are frequently made/requested on /r/Physics.
If you're in need of something to supplement your understanding, please feel welcome to ask in the comments.
Similarly, if you know of some amazing resource you would like to share, you're welcome to post it in the comments.
This is a dedicated thread for you to seek and provide advice concerning education and careers in physics.
If you need to make an important decision regarding your future, or want to know what your options are, please feel welcome to post a comment below.
A few years ago we held a graduate student panel, where many recently accepted grad students answered questions about the application process. That thread is here, and has a lot of great information in it.
Helpful subreddits: /r/PhysicsStudents, /r/GradSchool, /r/AskAcademia, /r/Jobs, /r/CareerGuidance
Hi all, not sure this post is allowed, in case not, feel free to remove it. I was thinking of buying a 2025 paper calendar as a decoration and I was looking for a science-themed one (preferably physics) do you know of a nice one? From a place that posts in Europe possibly.
This is similar to a previous question on fusion energy, which I'm really curious about the answers for quantum computing too.
I believe there's always some nuance involved in these fields dedicated to building these technologies that're hailed as breakthroughs, it's not all or nothing.
With all this research going into it, there's bound to be at least some useful research done that could benefit other fields right? Be it on the experimental or theoretical side?
This thread is a dedicated thread for you to ask and answer questions about concepts in physics.
Homework problems or specific calculations may be removed by the moderators. We ask that you post these in /r/AskPhysics or /r/HomeworkHelp instead.
If you find your question isn't answered here, or cannot wait for the next thread, please also try /r/AskScience and /r/AskPhysics.
Paper is open access - link to paper
Great Blog by Prof. Stacy McGaugh - The most recent post is about his and collaborators recent paper about JWST results and structure formation. Link to blog
Highly recommend the blog, whether you are interested in Galaxy dynamics or not, simply because it is great and McGaugh has all the hallmarks of a good guy and great communicator. As ever, judge the physics for yourself.
My reason for getting into and being interested in physics is quite odd now i look back on it, but i got interested in physics when a truck went past me going quite fast which generated a gust of air/wind
Then i started to think about how and why that happens, so i went home that day and started doing some research, and from that point on, i was hooked.
SUSY is an attractive (and natural) property to have for our world especially if we want to build a theory of quantum gravity (vis-a-vis, superstring theory, supergravity etc.). And I understand the basic motivation behind it too, why would nature, after all, not utilize spin 3/2 when she already utilizes the others (0, 1/2, 1, 2). However, for quantum gravity we only need SUSY at the Planck scale NOT at the Weak scale. So massively broken SUSY is not an issue for quantum gravity.
From my understanding the original motivation some 40 years ago for expecting Weak scale (slightly broken) SUSY was as follows:
(If I have understood these incorrectly or if you want to add more reasons, feel free to correct me!)
Now, from what I understand the non-detection of SUSY or WIMPs at the LHC and dark matter experiments (with XENONnT, LZ, etc., now hitting the neutrino floor), along with the growing limits on proton decay and EDM for SUSY models, we are reaching the limits of what SUSY was intended to fix in the first place!
So, my question is, am I missing something from this picture? Is there still any good motivation for Weak scale SUSY?
Graduated 8 years ago with a B.Sc and M.Sc in Physics and Chemistry Honours. I still reminisce about the late nights in labs, study groups, and the joy of learning with friends. I wanted to do a PhD but couldn’t stand the 7-year slog of academic bureaucracy. Recently, I’ve been diving back into my undergrad notes to relearn and keep my mind sharp. Feels good to reconnect with what I love.
I'm currently writing a report on the Ruchardt and Rinkel experiments I did in my uni labs, and while trying to look into the background of both, I found nothing about Rinkel, not even a first name beyond "R". I don't need anything more than the experiment for my report, but out of personal curiosity, does anyone know anything more about Rinkel?
I've started quantum mechanics. I know momentum and distance pair or energy time pair is significant in qm. But why is momentum*distance defines action? What does this quantity actually represent? And why is reduced planck const the minimum value of action?
This is a thread dedicated to collating and collecting all of the great recommendations for textbooks, online lecture series, documentaries and other resources that are frequently made/requested on /r/Physics.
If you're in need of something to supplement your understanding, please feel welcome to ask in the comments.
Similarly, if you know of some amazing resource you would like to share, you're welcome to post it in the comments.