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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Current known *lower* bounds to the neutrino masses?

I started a little bit of Googling around the topic, and found very few information. There are mainly upper limits. I found lower limits only to the rest mass differences of the different neutrino ...
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2k views

Why is Higgs Boson given the name “The God Particle”?

Higgs Boson (messenger particle of Higgs field) accounts for inertial mass, not gravitational mass. So, how could it account for formation of universe as we know it today? I think, gravity accounts ...
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Atomic mass of Copper-63?

This URL lists the mass of Copper-63 as 62.9295975(6) and this other URL lists the mass as 62.939598. These values differ by almost exactly 0.01 which seems hard to explain by experimental error. ...
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Why do neutrino oscillations imply nonzero neutrino masses?

Neutrinos can pass from one family to another (that is, change in flavor) in a process known as neutrino oscillation. The oscillation between the different families occurs randomly, and the likelihood ...
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604 views

Does lightning have mass?

My chemistry teacher/book states that lightning is just light, and therefore has no mass and takes up no space (we're not very far through the book yet, it's defining matter). However, I take issue ...
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3k 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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368 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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349 views

Nobel Prize 2013: What is it about? [closed]

I would really like to understand Higgs-Englert’s discovery that earned them the 2013 physics Nobel prize. I tried reading their work, but understood nothing of it unfortunately. The reason why I’m ...
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232 views

Why should it be allowed to set the einbein to unity?

The Polyakov action for a massive free point particle with worldline $\gamma$ is given by $$ S[\gamma] = \frac{1}{2}\int_\gamma e \biggl(\frac{1}{e^2}\dot{x}^2 - m^2\biggr)\mathrm{d}\tau $$ where ...
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336 views

What prevents photons from getting mass from higher order Feynman diagrams

The Higgs boson and gluons have no electric charge and photons couple to charge, so there is no tree level interaction between them and photons. But what prevents higher order diagrams from ...
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373 views

Can a mass matrix be asymmetric?

I am developing a mathematical model of a mechanical device consisting basically of coupled harmonic oscillators. It turns out that the system mass matrix is asymmetric. I seem to read somewhere that ...
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234 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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600 views

Does the Higgs field really explain mass or just reformulate it? What about charge?

The mass of a particle used to be considered a fundamental and intrinsic property of the particle; on the same level as other properties such as charge, spin, chirality/helicity. Due to the Higgs ...
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814 views

Planetary Gravity and its effects

This is my first question on the Physics portion of Stack Exchange. I was hoping to get some light on the topic of gravity. I don't have much background knowledge of physics so I might as well start ...
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3answers
242 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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5answers
7k views

What is Energy made of?

We have the famous equation $E = mc^2$, and we also believe that matter is made of particles. Then, What is the energy made of? If the two are interchangeable, there must be some common building ...
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369 views

bound states of massless fields?

Question: are they mathematically possible at all? physically? with finite mass systems, usually the binding energy contributes to the rest-mass of the system. It would seem that even if you could ...
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1answer
694 views

Why do some particles have a greater mass than others?

The property of mass that almost every particle possesses comes from the Higgs Field. It is this field, which permeates all of space, that particles interact with and hence obtain mass. But why do ...
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4k views

What is the difference between impulse and momentum?

What is the difference between impulse and momentum? The question says it all...I know the second of of them is mass * velocity, but what is the first one for, and when is it used? Also, what are its ...
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1answer
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What is the difference between pole and running mass?

For example, when we meassure Higgs boson mass to be 125 GeV, do we think about renormalized or pole mass? Should the mass of the Higgs change if it is produced at higher energies?
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1answer
331 views

Is this static mechanical balance possible without trickery?

On damnlol.com, I came across this picture: http://www.damnlol.com/hello-god-i-have-a-fault-to-report-7549.html My question is: Is this possible without glue? If not are there similar situations ...
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1answer
191 views

Question about Neutrino Flavor and Mass Eigenstates

I know the flavor and mass eigenstates are different, but are they related? What I mean is, in a process like fusion where electron neutrinos are created, do they start in the 1 mass eigenstate? My ...
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1answer
274 views

Relation of Higgs couplings to masses of fundamental particles

The standard model has 12 massive leptons and 2 massive bosons other than the Higgs. My understanding of the Higgs mechanism is at about the level of this article, which goes as follows. Start with ...
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3answers
2k 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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2answers
705 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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1answer
348 views

Mechanisms of mass generation for Dirac neutrinos

If neutrinos are Majorana particles, one way of explaining their small masses is the seesaw mechanism. Now say I'd like my neutrinos to be Dirac, for symmetry to the quark sector. What mechanisms ...
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1answer
335 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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147 views

Why is effective mass of holes positive?

i am trying to understand this. I know that the effective mass of electrons or holes is calculated as: $$m^* = \frac{h^2}{(4\pi^2)\frac{d^2E}{dk^2}}$$ Now,if i look at this plot for example: I ...
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1answer
313 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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864 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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Why do two bodies of different masses fall at the same rate (in the absence of air resistance)?

I'm far from being a physics expert and figured this would be a good place to ask a beginner question that has been confusing me for some time. According to Galileo, two bodies of different masses, ...
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2answers
941 views

Is my interpretation of how a gravitational wave is formed correct?

I'm sure many here are familiar with the following image showing the 2D representation of how the fabric of spacetime is warped by the presence of mass:- Can this fabric be interpreted as an ...
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5answers
773 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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278 views

For a particle to have physical mass, is it always necessary to have a mass term in the lagrangian?

Since the self-energy adds to the bare mass defined in the Lagrangian, is it possible to create a physical particle mass from the self-energy alone, with no mass terms occuring in the Lagrangian? On ...
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What is the optimal weight for a golf ball?

I am 32 now, and have forgotten the basic physics formulas we used in school. I am sitting with a question that is bugging me. If I had to hit two golf balls of different weight with the same force, ...
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1answer
534 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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2answers
7k 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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5answers
3k views

Does everything with mass or energy have a gravitational pull?

As small as it may be, does every 'thing' have a gravitational pull? That is, something with mass or energy. No matter how obsolete or negligible it may be, is it there? If so, how is it calculated? ...
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How does Higgs Boson get the rest mass? [duplicate]

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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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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2answers
204 views

Which is the lightest thing in this universe? Is that a photon or neutrino?

I hear a lot of people saying that neutrino is the lightest subatomic particle but according to me a photon must be the lightest as nothing can travel faster than light because it gets heavier and ...
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322 views

Calculating the Center of Mass

We have a homogeneous body that looks like this: I have tried dividing the body into different parts using the following definition: R g * A = R 1 * A 1 + ... R n * A n I was thinking I could ...
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3answers
110 views

Can mass be directly measured without measuring its weight?

From Wikipedia, http://en.wikipedia.org/wiki/Mass Inertial mass measures an object's resistance to being accelerated by a force (represented by the relationship F=ma). Active gravitational ...
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109 views

What would the gravity be like if Earth and the moon were touching?

What would the gravity be like if Earth and the moon were touching? Assuming the moon keeps its form and doesn't collapse on its own weight, would the area between it and the Earth (point B) have ...
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1answer
176 views

Is $E=mc^2$ false?

Recently I have found a Youtube video saying that $$E=mc^2$$ is false. It is said that the real one is $$ E^2=m^2 c^4 + p^2 c^2 $$ where $E$=energy, $m$=mass, $c$=speed of light, $p$=momentum. Is ...
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3answers
242 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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4answers
278 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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4answers
860 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
1k 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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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 ...