Questions tagged [matter]
The matter tag has no usage guidance.
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0answers
17 views
Neutrino oscillation in earths matter: electron-, proton- and neutron density
I want to incorporate an estimate of a matter effect in atmospheric neutrino oscillations into a model including active and sterile neutrinos. Since neutrinos are not only created in the atmosphere ...
5
votes
3answers
112 views
Cosmological Inflation: If Photon expands, why not other matter?
I keep repeatedly reading in many Stack Exchange and Quora questions that space of universe expands but particles (matter) don't, see e.g. this Phys.SE post. The reason given is that particles are ...
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0answers
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Clarification on Phase wave derivation in De Broglie's paper
De Broglie's paper refers to his theorem
A periodic phenomenon is seen by a stationary observer to exhibit the
frequency $ν_1=h^{-1}m_0c^2\sqrt{1-\beta^2}$ that appears constantly
in phase ...
6
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3answers
2k views
What is the meaning of “matter” in physics?
What is the meaning of matter in physics? By defining matter in terms of mass and mass in terms of matter in physics, are we not forming circular definitions? Please give a meaning of "matter" in ...
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5answers
113 views
In general relativity, is there a difference between matter-energy and spacetime?
This is the third time I try to formulate a question in a proper format so as to understand what is going on with gravitational waves at a physical level.
I am told that a spacetime oscillation and/...
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1answer
61 views
Could six copies of the universe exist only interacting by gravity? [closed]
The ratio of dark matter to matter is roughly in proportions $1:5.4$
This suggests that if there were about 6 Universes placed in the same space that were completely invisible to each other, except ...
2
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1answer
46 views
contradiction between total photon energy in the universe and early matter antimatter ratio
When looking at the energy count in the Universe, on one hand we are told dark energy 68%, dark matter 27%, regular matter 5%, neutrinos and photons a very small fraction (trace like).
https://en....
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0answers
15 views
If the universe is expanding, then the distance between the atoms must increase, which should result in decrease in density of everything [duplicate]
In the expansion of universe theory, it is already written that the scale of universe is itself expanding, which means the consequence for expansion of universe is not that atoms are growing in size, ...
1
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1answer
48 views
“Pure” Yang-Mills and the absence of light matter
I am researching various models of Neutral Naturalness which involve the addition of an additional gauge group whose matter content is uncharged under SM color. Many of these theories state that their ...
1
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0answers
74 views
Can we say there is literally nothing like vacuum [closed]
OK am trying to find out the meaning of vacuum since particle do exist everywhere even where all 'matter' has being removed am certain the definition of vacuum doesn't make sense with particles can ...
0
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1answer
31 views
When a solid is dissolved in a liquid, is it still a solid, what about individual atoms or molecules in a vacuum? [duplicate]
I am trying to gain a better understanding about states of matter, the last paragraph is the most important one to be answered.
It is my understanding that when a solid is dissolved into a liquid, ...
1
vote
1answer
26 views
What is the minimum amount of matter do I need to call it “bulk” matter?
I had been reading about bulk properties, but was confused what should the minimum amount of matter be for these properties to hold.
For eg: Intensive thermodynamic variables will not remain ...
0
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1answer
36 views
As space expands does the density of matter remain same or increase? [duplicate]
I learned that space is always expanding. Even between sun and earth, it's just gravity is stronger.
Imagine space as graph paper and there is a square object that fills it.
Space expands, 1x1 cell ...
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3answers
73 views
Why Neutrino is a ghost particle?
why neutrinos are called ghost particle.why it is not affected by strong magnetic field. why it does not interact with matter. why it does not interact with gravitational field? I am unable to ...
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5answers
136 views
Why are matter fields predominantly fermions?
Apart from the Higgs, all matter is made up of fermions. Is there any obvious reason why that is?
1
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1answer
58 views
Minimal quantity of substance to reveal its physical state properties
What is minimal quantity of matter required to reveal its physical state properties? I.e. number of particles/atoms when their collection can be considered as liquid, solid, gas or plasma.
I am aware ...
2
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1answer
42 views
Euler-Lagrange equations for electrodynamics: matter vs. gauge field change
I know how to derive Maxwell's equations from a Lagrangian density via the Euler-Lagrange equations, but I'm bothered by one little detail.
Variation of the Lagrangian seems only to be done with ...
1
vote
1answer
27 views
How quickly is momentum transferred through an object? [duplicate]
If there was a pole, that was a light year long, out in space. (Away from all physical interference.)
If we pushed one end of it, would the other end move instantly? And does it's speed depend on ...
0
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0answers
21 views
Do hydrogen and anti-helium annihilate one another? [duplicate]
So far I know that electron and positron annihilate each other completely and release energy, how about matter hydrogen atom with 1 proton and 1 electron come into contact with antimatter anti-helium ...
3
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2answers
54 views
Intuition for why matter dominated expansion is faster than radiation domination?
In a matter dominated universe $a_{\rm mat.}(t)\sim t^{2/3}$, while in a radiation dominated universe, $a(t)_{\rm rad.}\sim t^{1/2}$. Therefore, a matter dominated universe is expanding more quickly, ...
0
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2answers
61 views
Do antiparticles behave opposite of the particle?
If antiparticles have opposite charge to that of the particle, will their interaction be completely opposite?
For example, an electron and a proton are attracted to each other, will a positron and a ...
14
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2answers
1k views
Can matter be described as the result of the curvature of space, instead of vice versa?
Can matter be described as the result of the curvature of space, rather than the curvature of space being the result of matter, and energy being the cause of the curvature of space?
14
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5answers
2k views
Does a rock use up energy to maintain its shape?
A rock sitting on land, the ocean floor, or floating in space maintains its shape somehow. Gravity isn't keeping it together because it is too small, so I'm assuming it is chemical or nuclear bonds ...
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4answers
3k views
Could quantum fluctuations spawn real matter?
Would it be plausible for fluctuations in the QED vacuum to spawn actual matter (such as quarks, electrons the constituents of a hydrgen atom) given enough time and space?
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1answer
92 views
Are particles an abstraction of energy, or their matters do indeed exist?
I'm trying to understand from where the first particles in quantum mechanics came from, and while doing research I got this information from an article about the origin of matter:
In the beginning,...
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1answer
54 views
Probability of Photoelectric and Campton decrease as photon energy increases, WHY? [closed]
Why Probability of Photoelectric and Campton decrease as photon energy increases??
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1answer
73 views
What happen if an electron meets another electron? [duplicate]
A person give me an idea for my physical problem, and I think the answer of this question would be the next step for its answer
I only want to know what they are doing with each other if they meet ...
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1answer
77 views
If energy can't order itself, how did energy get ordered or made? [duplicate]
In the universe we see that hydrogen (bound up energy) is found in a highly concentrated ordered state in some places and it's highly dispersed in most other places. There is a natural progression ...
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2answers
49 views
What decides ductility of a substance- youngs modulus or the plastic limit of the substance? [closed]
Given two materials A and B such that a has higher young modulus as well as plastic
limit than B , which of the two is more ductile?
-1
votes
2answers
79 views
Are matter and energy dependent on each other? [closed]
If matter creates energy and energy creates matter can one exist without the other?
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2answers
119 views
How can 0-dimensional particles or 1-dimensional strings be 3D matter? [closed]
According to the latest information we got
String theory is a theoretical framework in which the point-like
particles of particle physics are replaced by one-dimensional objects
called strings....
1
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1answer
49 views
Working with Reciprocial Lattice
In solid matter physics the lattice structure can equivalently be described via standard Bravais modelling but also by considering it's reciprocial lattice. Mathematically the reciprocial lattice can ...
1
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2answers
91 views
Does dark-matter attract itself with gravity as light-matter does, and if so where are the dark stars and galaxies?
Does dark-matter interact with gravity like light-matter does, or does dark matter interact only with light-matter via gravity?
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1answer
70 views
Basic energy question
How do we know something contain energy or not?
P.S.: I don't really understand how energy should be interpreted. Until today I always thought that energy is some kind of magic that makes stuff ...
4
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2answers
75 views
Physical mechanism by which the body removes weight during long-term human weight loss [duplicate]
I'm trying to confirm the method by which the body physically loses weight during "long-term" weight loss. I'm specifying "long-term" here because obviously there are lots of ways to temporarily lose ...
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0answers
37 views
Acceleration from scalar-matter coupling in classical field theory
I have came across a text where an interaction term in a classical Lagrangian is presented that couples a matter density $\rho$ and a scalar field $\phi$ as
\begin{equation}
\mathcal{L}_{\text{int}} =...
3
votes
1answer
194 views
Temperature Required to give Particles of Matter Speed comparable to the speed of light
We know that at 0 K, particles of matter almost stop vibrating/moving completely. Also, as we increase temperature of the system, the particles gain energy (in the ...
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1answer
105 views
Could matter in the universe come from some process other than the decay of inflaton field?
Could matter in the universe come from some process other than the decay of inflaton field?
Do we have any theoretical reasons that support the idea that matter was created from the decay of ...
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1answer
47 views
Physics of Oil Stains - Why?
You accidentally put an oil stain on your clothes and try to wash it with cold water. Why is it difficult to do?
P.S.
This question was asked in class by my physics instructor, with a peculiar ...
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votes
1answer
120 views
Do photons apply gravity? [duplicate]
Matter curves space time . as its mass grows the curvature of space-time grows. This curvature procedure of space time is to my opinion what slows down and prevents from mass to reach the speed of ...
2
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1answer
54 views
How do liquid metals work?
So in solid metals they atoms give off electrons, which are delocalised and hold together all the metal atoms. But that's not the case in liquid metals, right? What holds together the individual atoms ...
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0answers
57 views
If matter cannot be transformed into information, why do we say that information about matter is lost when we talk about black hole paradox?
In this question it is said that matter cannot be transformed into information: Can matter be converted to information?
But when we talk about black hole information paradox, we say that matter ...
0
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0answers
38 views
Space expansion and conservation of energy [duplicate]
The phrase of 'expansion of universe' , as we are led to believe, is mostly referring to an expansion in space. But is space expanding in the sense that the space between two particles is increasing ...
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0answers
34 views
How do fabrics become stretchy? [closed]
What makes stretchyness happen? I know it has something to do with the way the threads are sewed together, right?
0
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2answers
104 views
Can't we stop the time? [duplicate]
Time is called as a measurement of difference between two or more incidents. So if we stop happening incidents can't we stop the TIME? Eventhough it's impractical, I mean if we reduce the temperature ...
3
votes
1answer
98 views
Baryon asymmetry still going on
I read these questions and answers and it made me curious.
Baryon asymmetry
Why do we believe baryon asymmetry?
Why does matter-antimatter asymmetry only refer to baryon asymmetry?
How does ...
3
votes
2answers
476 views
What kind of matter are black holes made of?
Imagine a black hole originally formed from, for example, Rubidium atoms. On the other hand, one made from, for example, Helium atoms. Will it be there any difference between the two? Or perhaps once ...
0
votes
1answer
44 views
Escaping a Blackhole
On reading hawking radiation, I know that either a matter or an anti-matter is able to escape a black hole, causing it to evaporate away soon.
On this thought, I am curious that would it be possible ...
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1answer
110 views
How does mass affect the expansion of space?
I'm a layman and I'm curious to understand how mass affects the expansion of space and whether the expansion of space is uniform everywhere in the universe.
From looking at redshifts it seems we have ...
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0answers
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Can strongly radiating matter cause dark matter to clump?
Ordinary matter clumps under gravitational attraction only when it loses energy through radiation. Dark matter supposedly doesn't clump since it can only exchange energy with itself and ordinary ...
