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).
Hello! I'm having a bit of an issue here, and I came across this site while searching on how to dissolve plant matter. The thread I found had some ideas, but said a reason would be needed before any concrete advice could be given.
So here's my request - I need to instantaneously dissolve plant...
I'm a Physics student ending the bachelor degree in Physics. I'm strongly interested in Condensed Matter Physics (both theoretical and experimental), especially the quantum mechanical aspects that are linked to this field of studies.
I'm trying to choose where to study for a MSc in Physics...
Several articles I've read say that the basis for BBN is that we know how particles react here on earth, so we can extrapolate that and make precise predictions for the composition of the universe at a given energy level. For example, at 100 Billion K, we have a pretty good idea how neutrons...
Is this a ground breaking observation or does it agree with other observations?
atures and the Wing-Ford band, presented in a recent paper.
arXiv:1610.03854 [pdf, ps, other]
The observed spatial distribution of matter on scales ranging from 100kpc to 1Gpc is inconsistent with the standard...
Hubble Reveals Observable Universe Contains 10 Times More Galaxies Than Previously Thought
http://hubblesite.org/newscenter/archive/releases/2016/39/full/Change the data to fit model ?
I'm a bachelor student in Physics and I would like to continue with a MSc in the field of Condensed Matter Physics.
I have to choose between some courses at my university and, since I'm not already an expert in Condensed Matter I would like to have a suggestion. If you were in my situation and...
can dark matter explain Tully-Fisher relation, or is modified MONDlike gravity a better explanation for this?
new paper
The Radial Acceleration Relation in Rotationally Supported Galaxies
Stacy McGaugh, Federico Lelli, Jim Schombert
(Submitted on 19 Sep 2016)
We report a correlation between...
Hi.
If an electrically neutral, conducting rod is brought close to a (say negatively) charged object with one end, charges will separate due to electrostatic induction roughly as follows:
Let's now connect the rod to the (far-away) ground with a long cable. Does it make a difference whether...
Hi all,
Just did a little bit of (layperson) reading about Anderson localization and disorder in crystal structures. Here's my question: shouldn't all matter contribute to 'restricting' the wave function of e.g., an electron, whether it's in a crystal structure or not? That is, what's specific...
Is it conceivable that dark matter only interacts gravitationally? Is SUSY losing her charm? I truly want to know what the experts think. I'm not qualified to have an informed opinion about this subject.
I have been thinking at this for a couple of days now: why are stars grouped in the massive collections that we call galaxies?
I can assume that in the very early Universe, matter was grouped in these areas, that matter interacted thus resulting in the formation of stars. Then, the...
Hello,
Recently, I have been trying to work on some philosophy that I am developing, and the subject of measurement has come up.
My question goes a bit like this:
Suppose that it turned out that when you measure point A to point B as exactly 100cm (one metre), there are actually three...
It’s commonly held that left and right photons interact with matter in exactly the same way, because electromagnetism “conserves parity”. But we know that P-symmetry, in our world, is generally broken. Even according to the Standard Model, when light propagates through some media, it interacts...
Why gravitational force is attractive?
Some where it was written that gravitons are hypothetical particles which mediates the force of gravitation, and it has a spin of 2 , and Quantum field theory had proved that any particle of spin 2 characteristic will always mediate attractive force...
Can black holes convert dark matter into matter and vice versa?
Presumably, a black hole can gain its mass from eating normal matter, or dark matter, or light. Then, it will eventually evaporate into Hawking radiation. I guess the Hawking radiation should include light as well as both matter...
I am reading an articles introducing the Nobel Price on Bose-Einstein condensates from where I have further reading on Bosonic and Fermionic statistics on some texts. I know one of the mathematical difference is the +/- 1 term in the denominator of the distribution function as below
##f_{BE} =...
So, one of my friends posed this question to me, with some background on vibrations on the Higgs Field, But, he also said that doesn't explain why matter causes inertia. As, if that accepted theory is true, it should simply create big, choppy waves. I apologize if my writing is confusing, and I...
I'm a mathematician, not a physicist, so I apologise in advance if I'm just showing my ignorance here.
My only source of information on dark matter is popular science texts, like New Scientist. One thing that is never explained is how it gets to aggregate around galaxies. Lacking the ability...
My school has a 5 1/2 year masters program. You do a 4 year bachelors and you can a masters in 3 semesters instead of four. However, my school does not have many professors which specialize in what interests me, and there is another school nearby which has a lot of professors who specialize in...
Consider an object of mass 1kg moving with a speed of 1m/s. Theoretically , the de broglie wavelength associated with it is about 3.6x10-37. Now if we calculate the energy associated with this wave it comes out to be 3x1011. This is a huge amount of energy which could be very hazardous but it is...
As I understand it, the Universe is red-shifted (emission spectra) from any point of reference looking outwards. The Universe is expanding, but is matter being created at the same rate ? Does this mean that the density of matter in space is decreasing ? (density = mass / volume). What does this...
recent results on dark matter searches
LHC has produced no dark matter candidates, esp neutralinos
LUX/panda has found no candidate WIMP events
axion dark matter searches have come up empty
ice cube sterile neutrinos have come up empty
Ethan Siegel, Contributor
The null detection is...
Okay, this quite confuses me. "Energy" isn't anything physical. You can't point at energy. It's more of a property, like length. The definition of kinetic energy is ## ke = .5mv^2##.
Now, how can something like an abstract property turn into matter? An example being CERN, when new particles are...
At last a theory of Dark matter that can be tested, is there a fundamental reason why this theory may be true?
Recent findings indicating the possible discovery of a previously unknown subatomic particle may be evidence of a fifth fundamental force of nature, according to a paper published in...
this was widely reported in the past, but not commented on
here
https://www.sciencedaily.com/releases/2016/04/160422115320.htm
based on
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.161101
Search for Spectral Irregularities due to Photon–Axionlike-Particle Oscillations with...
I don't know if this question is even relevant, but I wonder about it so I'm asking it.
I understand from GR that matter and energy are essentially interchangeable, that matter can be converted to energy and vice versa.
I also understand that the earliest "snapshot" of our cosmos (via the...
I don't know if I've asked the right question, but here's what I want to know:
If I plunge my hand into a pool of water, which of the fundamental interactions is keeping the atoms in my hand separate from the atoms in the water?
I always thought it was the strong interaction, but then I...
I'm exploring quantum mechanics for fun and am in no way an expert.
I have a problem with understanding something:
If an atom would collapse if the electron acted like a particle and can only exist if the electron behaves as a wave (in a superposition) and if measuring an electron forces it to...
I majored in a science in college and a few years after college I think that engineering and applications are the only thing that make math and science relevant to society. I mean otherwise they're all just head knowledge and nothing justifies why society as a whole should keep them around...
The negative findings of the Large Underground Xenon (LUX) dark matter experiment, which is a 370 kg liquid xenon time-projection chamber that aims to directly detect galactic dark matter and which were published at the international dark matter conference in Sheffield, UK, raises questions...
How does the universe decide if transforming energy into matter or vice Versa?
Is there a particle or a field that decides so?
Is a probability process?
I went to an applied phd program in computational biology and got bored, so now I'm considering physics. Topological matter looks fancy/sort of interesting. Does it have anything to do with actual experiments (and I mean more than just insulators/superconductors) yet? I would assume that to...
widely reported in all science channels
LUX Dark Matter Experiment Ends With No WIMPs Found
what are the ramifications to SUSY QG string theory LQG MSSM dark matter etc based on this results?
how likely is dark matter WIMP hypothesis in light of this null result, and of neutralinos
Does this...
I have been to several job interviews nearly all of them have rejected me because i am 65, i have told them that i have at least another 5 years left in me but that does not wash.
I have plenty of skills, electrical, pnumatics, mechanics but even with thees skills i can not get a job, do you...
Hello Dear PhysicsForum members,
I am mechanical engineering MSc student. My undergrad gpa is 2.68/4 and my master gpa is 3.79/4. I would like to apply for PhD in USA to modest universities (not top one)Do you think my master gpa will offset my undergraduate gpa if i get good scores from...
I am a physics undergraduate student hoping to apply to grad school in the future. While my current research professor of a year is wonderful and will no doubt provide a great letter of recommendation, my previous research professor has a negative reputation around the department (I thought he...
The dark matter is described as something which can't be detected in any way except for its gravitational attraction.
My question is: may the dark matter be identified with gravitational field generated by the presence (for short times) of matter and anti-matter which is continually created and...
https://www.sciencedaily.com/releases/2016/06/160613144700.htm
Harnessing the shared wave nature of light and matter, researchers have used light to explore some of the most intriguing questions in the quantum mechanics of materials.
Just for discussion..
https://www.sciencedaily.com/releases/2016/06/160615134951.htm
From science daily
Date:
June 15, 2016
Source:
Johns Hopkins University
Summary:
When an astronomical observatory detected two black holes colliding in deep space, scientists celebrated confirmation of Einstein's prediction of...
We are using the following pump to measure the strain on a special tube.
http://www.instechlabs.com/Support/manuals/HABP.pdf
This special tube is connected on each side to another tube that is connected to one of the two connectors on the pump. (The two connectors of the pump were put parallel...
widely reported in the news is a second observation of 2 black holes gravitational waves. also reported are its implications
Science World Report-Jun 15, 2016
Astronomers have reportedly started to think that dark matter could be made up of primordial black holes. According to Alexander...
I read that the cold dark matter model best fits the cosmic background radiation spectrum. I am puzzled by why most of the mapping of the distribution of dark matter shows it to be in halos about galaxies, rather than evenly dispersed with ordinary matter. The question arises from this...