Matter Definition and 1000 Threads

Hi all, I am trying to learn more about this field. Whether you work or have worked in this area or not, I would like to know where Soft Matter is going in terms of theory and applications. Thanks, A.D. *I apologize in advance if there are already many threads specifically addressing this...

Conceptually, at least, this is a simple question, although I recognize that it might be hard to calculate in practice from available data. The matter-energy budget of the universe is measured (in a model dependent way) to consist of a certain percentage of dark energy, a certain percentage of...

@vanhees71 reminds us that which suggests something I've wondered about for a while, whether dark matter might be adequately modeled by generalized free fields, which do not have asymptotic free states. Ray Streater, in Rep. Prog. Phys. 1975 38 771-846, "Outline of axiomatic relativistic...

I think mass as a form of potential energy and am always told that this is wrong. According to wiki: "In physics, potential energy is the energy possessed by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors." Why do this...

Scientists Thought All Galaxies Had Dark Matter, but They Just Found One Without It Could dark matter fill 'empty' space, strongly interact with visible matter and be displaced by visible matter? Could the reason for the mistaken notion the galaxy is missing dark matter is that the galaxy is...

A question arose over a simplification I wrote on another subject. My i information say's that matters antimatter pairs are generated in what is known to be very empty space such as the voids within the cosmic web. When I read about this it was considered anomalous but definitely verified. Now...

I did research on theoretical formulations in general relativity during my MSc studies. I look forward to pursuing PhD and have searched many universities and some research institutes for suitable research themes, but haven't found many research groups undertaking research consistent with my...

Just noticed this article. Wonder if anyone here has further info. Sounds very interesting. http://www.bbc.com/news/science-environment-43543195

Why do we need the theory of dark energy? I know the it is claimed that dark-matter has no affect on the electromagnetic spectrum. How do we know the affects attributed to dark-energy aren't affects caused by dark-matter? Dark-energy is claimed to be causing the universe to expand at an...

I was reading an article about the great Steven Hawking, and it seems to say that matter & anti-matter can be created in space, but that one of them can fall into a black hole, thus leaving the other around in a higher preponderance, which of course matter is. So it would seem that a good...

How do astrophysicists accurately account for all of the energy and pressure within a galaxy? How is it tabulated? My understanding of general relativity predicts that space-time curvature is a consequence of mass, energy, and pressure as expressed in the Energy-Momentum tensor. The accepted...

I have a question. Can energy exist by itself (without time and matter)? Or is it the case that if there is energy, then there must be matter (and therefore time)?

https://www.space.com/39837-first-stars-universe-fingerprints-dark-matter.html...

Do dark matter and energy affect on red shift phenomena? If yes, what, and what is the consequence of it?

Hi at all, I've the following question: How the fondamental particles (electrons, protons) are seen as matter waves, what shape and size should be these waves? They are wave-packets?

I searched through previous posts, but did not see this question posted - but I was wondering if mass and matter are different entities. I was reading a book that said something to the effect "if this entire paper clip was converted to energy using E=mc2"... but can a proton (what I see as...

Hydrogen and Helium are pervasive throughout our universe so their interaction with light is universal too. Dark Matter has been theorized to not interact with light but couldn't that be masked by the Helium and Hydrogen we already see?

I currently live in South Carolina and was thinking about going out of state to CU Boulder, but I'm concerned about tuition and really considering Clemson since it'll cost less. Do rankings for engineering really matter?

Hey! I have been wondering that is it true that matter can not be created or destroyed. I feel like it is a great question or that the idea is wrong because of couple of reasons... How do trees for from trees? Don't they just create more matter How can something change shape without destroying...

My plan right now is to study a program called 'engineering physics with materials science' when I enter university in the fall. What I want to work with is molecular nanotechnology and programmable matter. I want to contribute to creating stuff like "computronium", utility fog, self-healing...

I heard that energy is a form of matter in general relativity. If it is true, could you tell me any book about this phenomenon, please?

http://arxiv.org/abs/1801.04083 UV completion of a theory of Superfluid Dark Matter Andrea Addazi, Antonino Marciano (Submitted on 12 Jan 2018) We show that a model of superfluid dark matter, modifying the Newtonian potential and explaining galactic rotational curves, can be unitarized by the...

Why is the rough diamond in the following video held by a wire from above? Is it just so it will be easy to take the rock out of the water glass or is it to prevent the diamond from sinking to the bottom? If it is to prevent the diamond from sinking to the bottom, what is the reason for that ...

My query is really to find out what everybody thinks about 'empty space'. Does dark matter/energy exist and if so, it fills all voids in the universe? Where does it come from? Is it produced by some force? Without DM/DE, does space even exist? Say the supernovas, the collision of neutron stars...

Not the best at physics but trying to understand the standard model. So can someone please tell me if this is right or not and if not, can you explain me why? Higgs bosons reacts with everything that has mass. Electromagnetic force reacts with everything that has charge. Weak force reacts with...

I am about to teach some of an introductory course for bachelor students in the field of medical physics. More specifically the topic "Photon and charged particle interactions with matter" in respect to radiation therapy (again, medical physics). I know there are a lot of topics within radiation...

- I never quite understood , while people generally believe they must search for the reason of matter, anti-matter unbalance. I mean the big-bang was a violation of the energy conservation law. As far as I understand in the first moment there was only energy which later condensed into matter and...

Hi all, I was reading about the history of the early universe today, and there were some things that I did not understand. In particular, I do not understand the concept of "spontaneous symmetry breaking." After reading the Mexican Hat analogy many times, here is my best understanding of it...

Hello, So i wonder how elementary particles which are said to have no physical extension on a larger scale are able to form what is known to us as matter? Aka stuff with an observable physical extension.

Question 1: Do the calculations/models for galactic structure, the basis for the missing 6x mass problem that created the notion of "Dark Matter," include any factor/variable or set of variables that account for space-time dilation due to relativistic effects caused by the super-massive black...

On the podcast “Skeptics Guide to the Universe”, host, Steven Novella mentioned that astronomers can tell the difference between globular clusters orbiting the Milky Way Galaxy and satellite galaxies by looking to see if there is the gravitational effects of dark matter. Why would this be? That...

https://www.sciencedaily.com/releases/2017/11/171122113013.htm How plausible does this seem?

Hello everyone. I was watching this : and this question popped up in my mind ... could dark matter actually be visible, but it is so reflective on every electromagnetic spectrum that we cannot glimpse it from a distance .?. I would like to know if this question is in fact valid or totally...

Hi! I'm completely new to this website, and I have no background. I'm just a curious kid who googles stuff for the fun of it, and I've just had this burning question for a while now. I watched this interview with Michio Kaku on YouTube, and he discussed how we shouldn't exist. Anti-matter and...

I found an article https://arxiv.org/abs/1703.07365 and also it says that we should change current standart model about DM. Also I find this; "If this "wobbling" is not an unknown astrophysical phenomenon and in fact the result of the behaviour of dark matter, then it is inconsistent with...

Hi people! A may be philosophical question, in fact my doubt comes from epistemology class: Newton´s second law is a definition of force based on 2 previously defined things: momentum and time or is a relation found by Newton between 3 previously defined things: force; momentum and time? Thanks.

The gravitational potential energy of two massic points ##P_1## and ##P_2## with respective masses ##m_1## and ##m_2## is given by $$U = -G \frac{m_1 m_2}{|| P_2 - P_1 ||}$$ Now I was wondering how this formula could be applied to continuous matter. Let us imagine a very simple case where we...

Can someone explain why we are certain there is dark matter in our universe? I understood it like this. At some Point in our recent history we figured out, that according to our math galaxies (or sth like that) wouldn't have developed like they did or wouldn't even stay in 1 Piece since they do...

Managed to get through a Ph.D. in nuclear physics without covering nuclear matter calculations (or I just don't recall it). My question is does nuclear matter have any shear strength, or is it like an ideal gas? What little I see of elementary calculations it's like a fermi gas so one would...

I have been pulling my hair ought over this... I always see two responses to the above question. Some say energy is a property of matter and therefore the question is absurd. Its like saying "is matter made of height?" Others say things like "Yes, particles are just excitations of a thing we...

Today's APOD https://apod.nasa.gov/apod/ap171031.html shows a simulation picture of the developing universe involving galaxy formations and dark matter thin threads. I am wondering if any PF participant can answer the following questions: 1. Why does dark matter form thin thread structures...

Hello. I mean no challenge against current existing theories. I wanted to ask, how does the Big Bang model explain the creation of all the existing matter in the Universe? I read that the BB created matter but how how could matter be created? I think it should have been either infinitely...

https://www.sciencedaily.com/releases/2017/10/171026103110.htm Astronomers have discovered that the brightest galaxies within galaxy clusters 'wobble' relative to the cluster's center of mass. This unexpected result is inconsistent with predictions made by the current standard model of dark...

theory 'a' is we can cook all of our vegan food and heat our water with sunlight. what kind of difference would it make if i got a red painted pot? can you compare that to one painted black? and maybe also to a metallic one. please share some equations.

I forget the formulas I learned after a few weeks. I was wondering if it matters if I forget the formulas. Should I really have drilled the formulas into my head and remember how to do every single one?

What does quantum mechanics have to say about this aspect? Matter usually differs by antimatter having opposite charge. It is said that the Universe in the early stages should have created equal amounts of matter and antimatter. The total charge is conserved no matter the interactions and if...

for the matter+lambda universe why is Ω[Λ,o]=1-Ω[m,0]?

I have a curiosity. I saw recently how a team of researchers discovered two super massive black holes orbiting each other in a far off galaxy. (Google it if you didn’t hear, fascinating how they did it.). Anyway, I read a few things about unsolved mysteries of their formation and how SMBHs...

I just came across an August 2012 article that suggests possible first evidence for a disk of dark matter. https://phys.org/news/2012-08-plenty-dark-sun.html Here are some quotes. Astronomers at the University of Zürich, the ETH Zurich, the University of Leicester and NAOC Beijing have found...

Im doing a group presentation in one of my astrophysics papers this semester, and my part of the presentation is to research and outline the various theories for what dark matter could be. Does anyone on the pf know of any sites they may think will be helpful in my research, or any ideas on...