The property of an object that determines how much it responds to a force in Newtonian mechanics, and how much it interacts with gravity in the Newtonian framework. Mass also refers to the intrinsic energy of a particle in particle physics.
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134 views
Practical method to weigh human limbs with common household items?
What methods could be used to determine (or estimate within a reasonable margin of error) the mass of a living human's limbs, short of cutting them off? And more interestingly, how can this be done ...
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145 views
Impulse from absorbing a photon? Is there an increase in rest mass?
I'm going through A P French's special relativity. In one chapter (6) the following is set up:
Suppose that a stationary particle of mass $M_0$ is struck by a photon of energy $Q$, which is ...
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3answers
461 views
Why can't gauge bosons have mass?
Clearly, a mass term for a vector field would render the Lagrangian not gauge-invariant, but what are the consequences of this? Gauge invariance is supposed to be crucial for the renormalisation of a ...
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2answers
321 views
If quarks didn't have mass, could protons (and neutrons) exist?
I read here (mass of a proton) that the mass of a proton is mostly (99%) due to the energy of the strong nuclear force which binds the quarks together, and not the actual mass of the quarks. My ...
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2k views
Have I discovered how to calculate the proton's mass using only integers?
Could it be possible that the mass of the proton can be calculated by a series of integer sequences? Or is this just a curiosity?
$$\sum_{m=1}^{\infty } \frac{1}{10^{26}(m^2+1)_{2m}}=$$
...
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350 views
What's with the very slightly larger mass of the neutron compared to the proton?
Neutron mass: 1.008664 u
Proton mass: 1.007276 u
Why the discrepancy?
On a related note, how does one go about measuring the mass of a neutron or proton, anyway?
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2k views
How does Higgs Boson get the rest mass?
Higgs Boson detected at LHC is massive. It has high relativistic mass means it has non-zero rest mass.
Higgs Boson gives other things rest mass. But, how does it get rest mass by itself?
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249 views
How come a photon acts like it has mass in a superconducting field?
I've heard the Higgs mechanism explained as analogous to the reason that a photon acts like it has mass in a superconducting field. However, that's not too helpful if I don't understand the latter. ...
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214 views
Massive particles and speed of their propagation
Can one show that in quantum field theory at least some example massive particles propagate with speed less than speed of light, while massless travel at speed of light? Well, motion is a different ...
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3answers
114 views
Precision of Coulomb's law
Up to which precision has the coulomb law proven to be true?
I.e. if you have two electrons in a vacuum chamber, 5 meters appart, have the third order terms been ruled out? Are there any theoretical ...
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3answers
419 views
Infinite acceleration?
Why is acceleration regulated by mass? In a frictionless environment, why doesn't an object move at infinite acceleration if force is applied on it?
Force causes movement, so unless there is an ...
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3answers
278 views
Higgs-Boson/Graviton
The Higgs boson gives particles mass. And the graviton is the theoretical force-carrier of gravity. Gravity depends on mass. So if the Higgs Boson gives things mass, it therefore gives them gravity. ...
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4answers
303 views
Relativistic mass and imaginary mass
The (relativistic) mass of an object measured by an observer in the $xyz$-frame is given by
$$m = \frac{m_{rest}}{\sqrt{1 - \left(\frac{v}{c}\right)^2}}.$$
Mathematically $v$ could be greater than the ...
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2answers
201 views
Negative Mass and gravitation
Since Newtonian gravity is analogous to electrostatics shouldn't there be something called negative mass? Also, a moving charge generates electric field, but why doesn't a moving mass generate some ...
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3answers
181 views
Could we prove that neutrinos have mass by measuring their gravitational signature?
It is now said that neutrinos have mass. If an object has mass then it also emits a gravitational field. I appreciate the neutrinos mass is predicted to be small, but as there are so many produced ...
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1answer
84 views
Mass gap for photons
I am puzzled by the answers to the question:
What is a mass gap?
There, Ron Maimon's answer gives a clear-cut definition, which I suppose applies to any quantum field theory with Hamiltonian $H$, ...
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2answers
146 views
How can a pion have a mass, given it's a “field mediator” and created/destroyed continuously?
Maybe some of my assumptions here are basically wrong, but isn't it true that
pion is the "mediator" for the strong force field.
the quantum field theory basically says that there are no fields, ...
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3answers
98 views
Moment of Inertia (triangular plate)
I want to generalize the formula for the MOI of a triangular plate (sides $a,b,c$) about an axis passing through mid point of one sides and perpendicular to it's plane .
The mass of plate $M$ is ...
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76 views
Mass-energy equivalence and Newton's Second Law of motion
According to Einstein's Mass-energy equivalence,
$ E = mc^2$ OR
$ m = \frac E{c^2}$..... (1)
and According to Newton's Second Law of motion,
$ F = ma$ OR $m = \frac Fa$ ..... (2)
If we compare eq. ...
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4answers
624 views
Increasing mass' effect on the balance between centripetal force and centrifugal force
Okay, this is nothing more than a thought experiment which popped into my head while driving home from work today.
Take the case of a single body orbiting another, larger body, as in a planet and a ...
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1answer
148 views
Is there a theory which treats particles as classical point singularities?
Is there a published theory that looks at all matter as occupying no space and only being felt because of its gravitational pull?
We've been taught in school that matter has mass and occupies space. ...
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2answers
249 views
How to calculate the highest theoretical artificial hill?
The biggest peak in the world is Mount Everest.
Imagine someone starting to make an artificial hill (like pyramide) from soil (earth).
So, when starting with an 200x200 Km base area, with 45degree ...
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2answers
114 views
What is the mass distribution within the sun?
Jupiter is roughly 1/1000 the total mass of the sun. To get some idea of what effect Jupiter's gravity may have on the sun I'd like to know the approximate mass distribution of the sun. (i.e) the ...
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2answers
249 views
What is the relation between the Higgs field and chirality?
Wikipedia states that the spontaneous breaking of chiral symmetry "is responsible for the bulk of the mass (over 99%) of the nucleons".
How do the nucleons gain mass from the spontaneous breaking of ...
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1answer
70 views
How can we have massive states of strings and CFT on the string worldsheet at the same time?
Ok, so we can have conformal invariance on a string world sheet. However, it is well known that to preserve conformal symmetry we require states to be massless. So how is it that string theories ...
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1answer
155 views
Avogadro's number
Could I get an explanation of Avogadro's number and how it relates to determining the mass of a substance? My chemistry textbook only serves to confuse me and the Wikipedia article is aimed towards a ...
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1answer
81 views
How did Newton find out force has something to do with acceleration?
Its about Newton's second law of motion,
$$F=ma.$$
It says the acceleration of an object is directly proportional to the net force and is inversely proportional to the object's mass. Yes I can ...
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1answer
96 views
Soft Mass and Physical Mass in Softly-broken SUSY
In softly broken SUSY, the bare mass parameters may be specified at e.g. the GUT scale, and then we can run these down to another scale using RGEs, similar in form to the RGEs for gauge couplings, ...
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2answers
164 views
Does the Chandrasekhar Limit scale for a Black Hole?
No physicist/astrophysicist I; All I know about the Chandrasekhar limit is that it apparently limits the mass a star may survive, beyond which it degenerates to a neutron star, or a black-hole.
Does ...
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2answers
127 views
What is the meaning of negative mass (in a SUSY spectrum)?
I was playing around with SuSpect to generate some SUSY mass spectrums and I'm often encountering situations where I get a negative neutralino mass.
What is the physical meaning of this negative ...
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0answers
23 views
Classic mass predictions from Left-Right models with discrete symmetries?
I am covering the classic literature on predictions of Cabibbo angle or other relationships in the mass matrix. As you may remember, this research was a rage in the late seventies, after noticing that ...
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5answers
588 views
Does $E$ really equal $mc^2$?
I'm currently in a debate with a co-worker.
If mass is sped up to the speed of light, does the mass become energy?
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4answers
346 views
Does $p=mc$ hold for photons?
Known that $E=hf$, $p=hf/c=h/\lambda$, then if $p=mc$, where $m$ is the (relativistic) mass, then $E=mc^2$ follows directly as an algebraic fact. Is this the case?
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536 views
Relativistic momentum
I have been trying to derive why relativistic momentum is defined as $p=\gamma mv$.
I set up a collision between 2 same balls ($m_1 = m_2 = m$). Before the collision these two balls travel one ...
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2answers
601 views
Why do neutrino oscillations imply nonzero neutrino masses?
Neutrinos can pass from one family to another (that is, change in taste) in a process known as neutrino oscillation. The oscillation between the different families occurs randomly, and the likelihood ...
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1answer
383 views
How does a particle of light reach the max speed of light? [duplicate]
Possible Duplicate:
How can a photon have no mass and still travel at the speed of light?
First of all I am not a professional physicist. I was curious as to how a particle of light can ...
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3answers
256 views
Does Standard Model confirm that mass assigned by Higgs Mechanism creates gravitational field?
I am not comparing passive gravitational mass with rest inertial mass. Is there an evidence in Standard Model which says that active gravitational mass is essentially mass assigned by Higgs mechanism.
...
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1answer
382 views
What happens to a photon in a black hole?
Assume a photon enters the event horizon of a black hole. The gravity of the black hole will draw the photon into the singularity eventually. Doesn't the photon come to rest and therefore lose it's ...
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3answers
861 views
Is it possible to calculate weight of person with sensors found in today's smartphone?
Is it possible to calculate the weight of a person by only
using his smartphone, some action he must perform (jump, rotate etc.) and
some data like his height or age.
Current smartphones have the ...
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2answers
3k views
Do light and sound waves have mass
I have been reading Hawking's 'A Brief History of Time' and it has gotten me thinking about Einstein's theory of relativity, in that it assumes that an object must have infinite mass if it is to be ...
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2answers
226 views
Why are particles different sizes?
Is it correct in saying that a particles size is it's rest energy, and that particles don't actually have size (in the way you get different size objects)?
What defines what sizes a particle can be? ...
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2answers
298 views
What is the role of the vacuum expectation value in symmetry breaking and the generation of mass?
Consider a theory of one complex scalar field with the following Lagrangian.
$$
\mathcal{L}=\partial _\mu \phi ^*\partial ^\mu \phi +\mu ^2\phi ^*\phi -\frac{\lambda}{2}(\phi ^*\phi )^2.
$$
The ...
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2answers
495 views
Does Dark Matter interact with Higgs Field?
Dark matter does have gravitational mass as we know from its discovery. Does it have inertial mass?
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1answer
276 views
Why is mass renormalization insufficient to explain electron mass?
In the Standard Model, I understand that the mass of the electron is assume to arise from two effects:
A bare mass given by Yukawa interaction with the Higgs field, and
A mass correction from mass ...
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2answers
183 views
System of Particles and Moment of Mass
I recently came across the definition of the Center of Mass of a system as the point about which the first moment of mass is zero.
Further, it defined Moment of Inertia as the second moment of mass.
...
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3answers
595 views
Is there a finite amount of mass in the universe?
So, I'm not too physics savvy but I am curious to ask. Is there a finite amount of mass in the universe? or is there more and more being created from somewhere or something? If the universe is ...
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3answers
147 views
Charge Analog of the Higgs Boson?
Since mass can be given to particles via the interaction with the Higgs Field could there be a "Charger Field" that supplies particles with charge? Possibly this would require two different "charger ...
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2answers
411 views
What sort of “mass” is explained by the Higgs mechanism?
When I asked this question (probably in a less neutral form) to physicists, their answer was something along the lines that it's not gravity (i.e. unrelated to gravitons) but inertial mass. (So I ...
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4answers
582 views
What if we could give photons some mass?
I was reading an article and these paragraphs got me wondering...
Before I list the replies, here is some background. The Higgs mechanism describes an invisible field that, it is argued, split one
...
