In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic particles, and in everyday as well as scientific usage, "matter" generally includes atoms and anything made up of them, and any particles (or combination of particles) that act as if they have both rest mass and volume. However it does not include massless particles such as photons, or other energy phenomena or waves such as light. Matter exists in various states (also known as phases). These include classical everyday phases such as solid, liquid, and gas – for example water exists as ice, liquid water, and gaseous steam – but other states are possible, including plasma, Bose–Einstein condensates, fermionic condensates, and quark–gluon plasma.Usually atoms can be imagined as a nucleus of protons and neutrons, and a surrounding "cloud" of orbiting electrons which "take up space". However this is only somewhat correct, because subatomic particles and their properties are governed by their quantum nature, which means they do not act as everyday objects appear to act – they can act like waves as well as particles and they do not have well-defined sizes or positions. In the Standard Model of particle physics, matter is not a fundamental concept because the elementary constituents of atoms are quantum entities which do not have an inherent "size" or "volume" in any everyday sense of the word. Due to the exclusion principle and other fundamental interactions, some "point particles" known as fermions (quarks, leptons), and many composites and atoms, are effectively forced to keep a distance from other particles under everyday conditions; this creates the property of matter which appears to us as matter taking up space.
For much of the history of the natural sciences people have contemplated the exact nature of matter. The idea that matter was built of discrete building blocks, the so-called particulate theory of matter, independently appeared in ancient Greece and ancient India among Buddhists, Hindus and Jains in 1st-millennium BC. Ancient philosophers who proposed the particulate theory of matter include Kanada (c. 6th–century BC or after), Leucippus (~490 BC) and Democritus (~470–380 BC).
Hi,
I have a question regarding decay of matter. Let's say I have a block of lead. Now imagine I sit it in a vacuum - given infinite time. What will happen to it - will it ever degrade or change. In another way does matter last forever?
Also what is the correct physics term for what I am...
This paper states that gravity gravitates, to me that is mind boggling, i can not even understand how these additive effects may alter cosmology.
arXiv:1509.06682
Let us start by recalling how interaction energies work in relativistic gravity. It is well known that gravity gravitates in...
This maybe a general science question but I'll put it here.
When we say that an element has so-and-so properties, how do we know those are the only properties it has.
For example:- We say an element has properties like electron affinity, electro-negativity etc. How do we know these are the only...
I'm wondering if someone can give a more detailed history of Dark Matter than what I've found on Wikipedia. How did Fritz Zwicky determine that a galaxy was in 'equilibrium' given the uncertainty of a line-of-sight measurement of velocity? How did he determine the mass given the variables of...
I have been looking into Dark Matter recently and how we know really little about it to even try to identify what it is clearly. But Dark Matter obiously has mass which means that in some way it must be interacting with the Higgs Field. So could studying the Higgs Boson and comparing its...
Given enough time Boltzmann freak structures will appear, assembled from drifting matter, in the maximum-entropy universe if it is static, I.E. not expanding to eventually sweep all matter into the far horizon.
In a lecture...
I have just been accepted to pursue an advanced degree (Masters) in Physics with a specialization in condensed matter.
I have some questions regarding this field (Google results are somewhat outdated).
(1) What exactly does a condensed matter physicist study? I know it is the study of...
Does the E8 theory that offered and posted by Antony Garrett Lisi,can explain the qualities and the source of the dark matter and dark energy in the universe?
As observed in published space maps, I have noted that dark matter is present only in those region which already have visible mass around them. Is this really a fact or just my wrong belief?
As opposed to antimatter, that is. The whole search for the asymmetry of matter vs antimatter seems to rest on the implicit assumption that what we observe is matter, not antimatter, no?
Is there a way of distinguishing from afar between the two?
I thought this paper is worth citing it gives a good overview of Dark matter, it maybe a little out of date but it is still a good readhttp://arxiv.org/abs/1006.2483
We know that in the Baryogenesis happened a asymmetry between baryons and antibaryons.Here Is matter only BM(baryonic matter) or BM+DM.
If its only BM so we have extra DM which its a matter.So the Baryogenesis solved ? (Here of course it can't be solved cause there's a big difference between...
Is there any dark matter where no baryonic matter (which here the galaxies).I mean are we observe dark matter only around the matter ? Or dark matter can be anywhere (In empty space which there's no baryonic matter around)
I am doing research and I need to find the dark matter density of Galaxies or dust clusters (It can be any type of thing) which the distance from Earth will be ≅4000 Mpc.Here the picture
Think the radius of sphere.
Dear Friends!
Probably more than a decade back understanding tells us : If the average matter density of the universe happens to be smaller than a critical value,then the galaxies will never come to a halt and turn back(Open Universe).Which will imply cold and lonely death.
If on the...
Hi,
I am approaching my A-levels in 1 time (currently in Year 11) , and so I would have to pick my A-level subjects which will then lead me on to my University (2 years later). I am practically obsessed with Theoretical Physics and I have already learned high-level mathematics and so on, not to...
I chose frame this question in this way because I was not convinced with the answers given for the question "What is Matter?" in this forum. We hear so much about how everything is made of matter, but the answer, more often than not, is just the common definition, as found in Wikipedia:
"The...
Hey, my name is Roy and I'm new to Physics Forums. I'm a retired medical and aerospace test engineer, now currently a freelance artist (kind of opposites right?) and I joined Physics Forums to hone my understanding of physics and ask the right questions in an ever expanding field of inquiry...
Some times I think space and Matter most to be different on others places and maybe equations need to be fit, but to find dark matter, what do we need to have here?
In this problem, they solve for i, and at first, it looks like it will be i*2* square root of 3... Then he puts 2 sqrt of 3 times i. Can it also be 2i sqrt of 3?
[Moderator's Note: This thread was split off from a previous thread because of a change of topic.]
It doesn't. Matter influences the curvature of spacetime locally; the curvature of spacetime propagates to distant locations; and the curvature of spacetime at those distant locations tells the...
basic question- neutrinos pass through matter because they are only subject to the weak interaction whereas photons interact with matter because they are subject to EM? Does the small mass of the neutrino contribute to this - if there was a neutrino with the mass of a proton how differently...
Dark matter particle candidates are being searched at CERN and the various dark matter models are being probed by cosmological simulations. The usual way to probe models via cosmology is to plug a candidate into a cosmological simulation and then compare the results with observations. Yet...
Preface: I have a B.S. in Applied Physics and minors in Biomedical Engineering and Mathematics. At this point my intention is to go into industry rather then academia. The project I am working on now, and might be able to turn into a M.S. thesis, is in bioinformatics, more specifically using...
What I have read about antimatter amounts to about this much:
-Each particle is paired with an antiparticle, and when they meet, they annihilate.
-When a particle and antiparticle annihilate, they produce energy and gamma rays.
-It is hypothesized that before the Big Bang, there was an equal...
There are not found the WIMPs until now. Ma be the effect of Dark Matter is because of a defect in topology otherwise than time dilation in General Relativity.
The lattice gauge theory formulated on a grid or lattice of points in space and time is successfully used in the quantum...
I was searching Dark Matter and I found this site is that can be true ? Dark matter can be a act like a pion ?
http://right.is/space/2015/07/deja-vu-new-theory-says-dark-matter-acts-like-well-known-particle-2117.html
This paper, http://arxiv.org/abs/1507.06282, The Duhem-Quine thesis and the dark matter problem, may be of interest to those curious about how and why dark matter has gained general acceptance by cosmologists
In general photons are not candidate for dark matter.
From the other hand stars constantly change matter into radiations (photons among them). And we can not measure radiation that does not hit us (although we can try to calculate it because radiation from star goes with same intensity in each...
I am told that even macroscopic objects like footballs obey the wave equations of quantum mechanics. Is there any experimentally based reason to believe this, or is it just said as a way of generalizing the theory?
In wikipedia says Physical baryon density: ##Ω_bh^2=0.02230±0.00014## and
Physical dark matter density:##Ω_ch^2=0.1188±0.0010##
Matter density:##Ω_m=0.3089±0.0062##
so If we collect baryonic matter density and dark matter density we...
<<Mentor note: Thread split from Is Dark matter homogeneous in Universe?>>
Not to be rude... but how do you know it even exists? Dark matter is a place holder used to make a hypothesis work mathematically with actual observations. Dark energy... Ditto. And the original hypothesis itself is...
I learned that dark matter distrubition is homogeneius and isotrophic in cosmic scales.
I searched some galaxies dark matter distrubition.And I am actually suprised.
Why cause every galaxy has a different ratio of dark matter baryonic matter distrubition.
In cosmic scales baryonic...
This the best description of Dark Matter i have come across, it uses the LCDM and MOND to create a best fit model.
arXiv:1507.03013 [pdf, other]
A Dark Matter Superfluid
Justin Khoury
Comments: 8 pages. To appear in the proceedings of the 2015 Rencontres de Moriond, "Gravitation: 100 years...
What is the interaction Lagrangian of matter and graviton fields?So(on the answer)we can say about the nonrenormalization.Why is the divergence of two gravitons diagram able to be the limit of the coincidence of the verties.So we can say about the nonrenormalization.
as you have learned about the states of matter in high school, there are three states of matter (just assume i know nth about plasma or any other things else first), and when change of states occur energy is supplied to the matter to increase its potential energy while keep kinetic energy...
Are there any high resolution observations of the gravitational lensing by dark matter, good enough to determine if dark matter is clumped or spread out at small scales?
[Moderator's note: Thread moved to Quantum Physics since it is more appropriate there.]
O.K., I'm confused: According to How Stuff Works http://science.howstuffworks.com/higgs-boson1.htm
"Can't matter just inherently have mass without the Higgs boson confusing things? Not according to the...
I've been reading on dark matter and I've never seen a satisfactory explanation as to why dark matter is expected to interact with the weak force. From what I gather, the only reason it's expected to do so is based on assumptions that dark matter had to be created after the electroweak epoch...
I have found this paper, it seems interesting although i haven't read it all yet arXiv:1507.00460 [pdf]
Dark matter, Mach's ether and the QCD vacuum
Gilles Cohen-Tannoudji
Subjects: History and Philosophy of Physics (physics.hist-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
I was recently reading an article that attempted to explain how the results of the Cronin-Fitch experiment illustrated CP violation. (http://hyperphysics.phy-astr.gsu.edu/hbase/particles/cronin.html) However, it wasn't very well explained. Could someone please explain this to me?
If there are 2 objects at the distance of 2 light years from each other exerting a pull of gravity on each other and one of them vanishes suddenly would the other feel the force instantly or 2 years later or after more time
Apologies for not doing too much research prior to asking this question; I suppose actually delving into the mathematics would reveal the answer I'm looking for but I haven't taken the time just yet.
Considering the concept of GR where matter/energy tells space how to curve and space tells how...
Dear PF Forum,
Can proton be annihilated by anti neutron?
Can proton be annihilated by positron?
Can neutron be annihilated by positron?
Does every particle has to match its antiparticle to be annihilated, example: Proton must be annihilated by anti-proton, not by anti neutron.
I've heard that...
Hi,
GR explains the perihelion precession of Mercury, the deflection of light and the gravitational redshift pretty accurately. However, predictions for larger scales seem to be quite wrong, and physicists introduce stuff like the cosmological constant, dark matter and energy.
Why are they...
Lets suppose we have a photon and it will going to create a particle particle mass is ##16.10^-29## kg.I used ##E=mc^2## to find the solution and I found 90 MeV but the answer is 180 where did I made wrong.
Thanks