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.

learn more… | top users | synonyms (1)

1
vote
4answers
162 views

Newtonian physics vs Special relativity - what is the most “relative”?

This might be a question purely of words and the meaning of them but isn't Newtonian physics more "relative" than Einstein's Special relativity? Newtonian physics predicts that laws of momentum & ...
1
vote
2answers
54 views

Are high redshift masses corrected for relativistic mass dilation? They would appear more massive right?

A distant quasar would be less massive in its frame of reference than our observations would suggest. Are such highly red-shifted objects corrected for relativistic mass dilation?
1
vote
2answers
1k views

Charge to mass ratio inversely proportional to curved path radius?

In a cloud or bubble chamber, charged particles follow circular paths. I learned that charge to mass ratio of the particles is inversely proportional to the radius of the path. Thus, a particle ...
1
vote
1answer
315 views

Maxwell's equations as the particular case of massive vector field equation

There was a discussion (please look to the comments on my answer) about getting Maxwell's equations for free spin-1 field by using massive spin-1 representation's equations. I'll start from the ...
1
vote
2answers
237 views

Do particles gain mass only at energy levels found during the big bang?

I am trying to make sure my understanding is correct. At energies and temperatures found during the big bang (or at CERN recently), the Higgs mechanism comes into effect. When it does, there is a ...
1
vote
2answers
65 views

Interpretation of the mass of the field

Before QFT I had never thought if a field should or should not have any mass. Now it turns out that either case is possible. It might be naive to think this way, but I picture the mass of the field in ...
1
vote
3answers
93 views

What is the physical meaning of reduced mass?

If we stick two block masses by a string and pass it over a pully and let the blocks free then mathematically we can obtain that the whole weight on the pully is more if the blocks are kept at rest, ...
1
vote
1answer
36 views

Lorentz Invariants and Time dilation/Distance contraction?

If distances contract in direction of motion and time dilates at high speeds, why are the rest mass $m_0$ and proper time $t_0$ called "invariant" under Lorentz transformations. Since depending on ...
1
vote
1answer
88 views

A question about the Dirac mass and Majorana mass

I am sorry if my question seems to be naive. For the free Dirac field, the Lagrangian is $$\mathcal{L}=\bar{\psi}(i\gamma^{\mu}\partial_{\mu}-m_D)\psi$$ or expressed in the Weyl spinor, the mass term ...
1
vote
2answers
189 views

At What Point Does Mass Cease to Matter?

I know very little about physics so I naturally have a lot of simple minded questions. Assuming I am piloting a rocket and want to obtain the fastest speed possible. At what point does mass more ...
1
vote
5answers
2k views

Is it possible for an object to have mass but zero volume?

Can there exist a particle/object in the universe having mass but no volume? Is it possible that mass can exist without volume and density? We think we know that matter is anything having mass and ...
1
vote
1answer
144 views

Why cannot massless particles carry charges? [duplicate]

How to show that massless particles do not carry charges from QFT's point of view?
1
vote
1answer
79 views

Real-world evidence that non-massive entities (or even: antiparticles), and their behaviors, are sources of gravity?

The theory of general relativity tells us that non-massive entities, and their behaviors, are possible sources of gravity. Mass isn't needed, the theory says. What's the real-world evidence that non-...
1
vote
2answers
303 views

What is the fastest speed that a massive object can travel at? [duplicate]

What is the fastest speed (in miles per hour) that a massive object can travel at? I have heard that an object can travel at the speed of light, but I've also heard that massive objects cannot travel ...
1
vote
2answers
147 views

Understanding variable mass equation for mass ablation/ejection

The "Variable-mass system" entry in Wikipedia, under the "Mass ablation/ejection" title, shows: $$p_2 = (m+dm)(v+dv) + u(-dm)$$ The parameter $p_2$ is for the momentum at $t+dt$, meaning $p_2 = p(t+dt)...
1
vote
1answer
83 views

Can we define the effective mass or the moving mass of a photon?

I know that the rest mass of a photon is zero. but the photon can be bent by gravity (which can also be explained by the curvature of space-time due to the effect of mass), this implies that it must ...
1
vote
1answer
107 views

Confused about gravitational potential energy [duplicate]

So learning the concept of gravitational potential energy, my professor says that when lifting an object without any acceleration, the force we exert on the object to lift it is the same as the force ...
1
vote
1answer
58 views

Mass of small fluctuation around vacuum

For a potential $V$, how do we define the mass of a small fluctuation around its vacuum? For example I have the potential $$ V_\mathrm{eff}(\phi) = \frac{1}{2} \left(\frac{\rho}{M^2} - \mu^2\right) \...
1
vote
1answer
123 views

Calculating Gravitational Attraction Involving Massless Objects

Using the formula $F=G\frac{m_1m_2}{d^2}$ where $m_1$and $m_2$ are the masses of two objects, $G$ is the gravitational constant, and $d$ is the distance between the objects, it is possible to ...
1
vote
1answer
821 views

Question about teeter totters or see saws

I have a basic enough question. Assume that one has one of those ideal see saws, i.e. the teeter-totter pivots on point source, the balance is of uniform mass etc. Now assume that one places an ...
1
vote
1answer
727 views

Why does Lorentz factor not hold for relativistic mass when we apply it to photons? [duplicate]

We know that the photon itself is massless particle $m_0=0$. But we also know, that the mass of the objects does increase with their energy. And we know that under certain circumstances (gravity, ...
1
vote
2answers
637 views

Is light affected by gravity? Why?

I would like to know if light is affected by gravity, also, I would like to know what is the correct definition of gravity: "A force that attracts bodies with mass" or "a force that attracts bodies ...
1
vote
1answer
704 views

Does mass concentration affect the torque induced by a force?

If you had two bodies with the same weight but one having mass concentrated more in the center, while the other had most mass concentrated on the outside, but both had the same center of mass and ...
1
vote
1answer
617 views

What is the definition of density as a function?

(Before I start, I don't know which tag is suitable for this post. Please retag my post if it bothers you.) Let's say there is a string on $[0,1]$ with a mass given by $m(x)$. ($m(x)$ means the mass ...
1
vote
1answer
698 views

What gives matter Gravitational Mass? [duplicate]

Possible Duplicate: Does the equivalence between inertial and gravitational mass imply anything about the Higgs mechanism? In Higgs mechanism, Higgs field, which likes syrup, slows down ...
1
vote
1answer
6k views

Calculate mass of air in a tyre from pressure

How can one calculate the mass of air inside a tyre, given a particular tyre size; a pressure, in $kPa = \frac{1000kg}{m\cdot s^2}$; and assuming room temperature, and normal air composition? I can't ...
1
vote
2answers
330 views

Lepton masses in the Standard Model

Some simple questions regarding leptonic masses in the Standard Model (SM): Why there is not an explicit mass term in addition to the effective mass term that arises from the Yukawa terms after ...
1
vote
1answer
279 views

Why not accurate masses of elementary particles?

In the standard model of particle accuracy in calculating mass is very low. And you can not predict the upper limit of Higgs particle mass accurately. Why not accurate masses of elementary particles?
1
vote
1answer
61 views

Is it contradictory with any theory or experimental result to have a negative gravitational force mass?

I am aware that there are many similar questions here about this in this site, but most answers concentrate on negative inertial and gravitational energy. My question is more specific. QM together ...
1
vote
1answer
100 views

Spinning a string with a mass on the end. What makes the mass rotate parallel to the ground? [closed]

Say you use your hand to rotate a string with a mass attached to the end. The string will first become taunt and then the mass and string will move upwards until they are spinning parallel to the ...
1
vote
1answer
109 views

Does massive particle really move at speed of light? [closed]

According to this answer I understood that particles with mass also move at speed of light but interaction with higgs field make this movement zigzag. So average speed is below speed of light. Is ...
1
vote
4answers
132 views

Where does the energy lost due to light emission come from?

If an object lose energy when it emits light, does that energy come from the mass of the object? Examples: Does a flashlight lose mass when it's turned on? Does a regular object (like a pencil or a ...
1
vote
2answers
39 views

Balancing Utensils: Center of Mass

If you have a cork piece on top of a nail, it is extremely hard to keep it stable, and the slightest action will make the cork fall off. However, when you balance it on top of a nail but put forks ...
1
vote
1answer
93 views

Spin of a gauge field

I was wondering what is the simplest way to understand the reduction of the Wigner's little group from $SO(d-1)$ to $SO(d-2)$ when one considers massive and massless fields respectively (in a $d$ ...
1
vote
1answer
46 views

What is the property which flows as described by the stress energy tensor in GR?

I found the following definitions: The stress–energy tensor (sometimes stress–energy–momentum tensor or energy–momentum tensor) is a tensor quantity in physics that describes the density and flux of ...
1
vote
1answer
97 views

Reason for not using Higgs mechanism to solve mass gap problem

I am curious as to precisely why one can't introduce masses for gluons in Yang-Mills by a Higgs-type mechanism as in electroweak theory. Is it because then one would end up with an unwanted massless ...
1
vote
1answer
211 views

In which experiments the charge to mass ratio of proton was determined?

Are there experiments where the charge to mass ratio for protons have been determined in the same way as in Thompson’s experiments (where he determined the charge to mass ratio of electron) but with ...
1
vote
1answer
72 views

Why can center of mass be used in calculating gravity?

Why can gravitational forces be based on the center of mass. Due to the fact that gravity is related to the square of the distance should not the gravitational sum of every particle exceed the force ...
1
vote
1answer
218 views

Gravity amplifier

Just a hypothetical question. Is it possible to increase or amplify gravitational interactions between two or more bodies ( without changing the mass)? Will changing the graviton count(theoretically,...
1
vote
1answer
718 views

How is the fall time for a parachute affected by the mass of the load?

Why do parachutes with a heavier load fall faster than a parachute with a lighter load?
1
vote
1answer
55 views

How fast does gravitational information travel? [duplicate]

Imagine two objects with equal mass in empty space attracting each other. One of these objects moves tangentially with a very high speed (lets say 0.9c). (p1 = (0, 0) p2 = (1, 0) v1 = (0, 0) v2 = (0, ...
1
vote
1answer
48 views

Elements of particle mass

From what I can tell, it seems that particles have two kinds of mass, the mass inherent in a fundamental particle itself, or for composite particles, additional mass associated with the Higgs field. ...
1
vote
1answer
106 views

Kettlebell squats center of mass

I should, first of all, state that I have very limited knowledge of physics but as a fitness enthusiast the following question has puzzled me for a while. When I do squats on the gym holding a ...
1
vote
2answers
645 views

How to increase flow rate? [closed]

I am coming up with ideas of how to increase grain (corn, soybeans etc,) flow in a tube. My first idea is to have spiral ribs inside of the tube to create a vortex effect that will allow the grain to ...
1
vote
2answers
216 views

Does mass curve space?

Just to be sure, according to the theory of General Relativity, my understanding is that mass curves space-time. My question is, can mass also curve space?
1
vote
1answer
105 views

Is Helicity an intrinsic property of massive Neutrinos?

Hyperphysics states that, unlike an electron, the helicity of a neutrino is invariant because we cannot change to a reference frame where it is different: This and subsequent experiments have ...
1
vote
2answers
72 views

Mass of NGC 1097 Galaxy

I've been looking all over the internet for this and can't seem to find a reference. Can anyone refer me to a paper citing the mass of NGC 1097 based on luminosity?
1
vote
1answer
372 views

Does rotation increase mass?

If an object is rotated on its axis near the speed of light would its mass increase? Normally if the object was moving (in relationship to the Earth for example) I would agree that its mass would ...
1
vote
2answers
845 views

Is space-time a property of mass?

Imagine looking at a quasar millions of light years away. From your perspective, a photon emitted by the quasar has spent millions of years travelling through space, and its trajectory has been ...
1
vote
1answer
88 views

Measuring mass by acceleration due to electromagnetic forces in free fall

My question is a simple one (I think): How precise will the results be if you attempt to measure the mass of a macroscopic object by measuring it's acceleration when a constant electromagnetic force ...