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.
23
votes
8answers
13k views
If photons have no mass, how can they have momentum?
As an explanation of why a large gravitational field (such as a black hole) can bend light, I have heard that light has momentum. This is given as a solution to the problem of only massive objects ...
16
votes
7answers
10k views
How can a photon have no mass and still travel at the speed of light?
I've read a number of the helpful Q&As on photons that mention the mass/mass-less issue. Do I understand correctly that the idea of mass-less (a rest mass of 0) may be just a convention to make ...
42
votes
9answers
7k views
Don't heavier objects actually fall faster because they exert their own gravity?
The common understanding is that, setting air resistance aside, all objects dropped to Earth fall at the same rate. This is often demonstrated through the thought experiment of cutting a large object ...
2
votes
5answers
2k views
Why can't photons have a mass
Why can't photons have a mass? Could you explain this to me in a short and mathematical way?
8
votes
2answers
706 views
Does $E = mc^2$ apply to photons?
Photons are massless, but if $m = 0$ and $E = mc^2$ then $E = 0c^2 = 0$. This would say that photons have no energy, which is not true.
However, given the formula $E = ℎf$, a photon does have energy ...
7
votes
9answers
6k views
Why does the mass of an object increase when its speed approaches that of light?
I'm reading Nano: The Essentials by T. Pradeep and I came upon this statement in the section explaining the basics of scanning electron microscopy.
However, the equation breaks down when the ...
9
votes
2answers
609 views
Does a photon exert a gravitational pull?
I know a photon has zero rest mass, but it does have plenty of energy. Since energy and mass are equivalent does this mean that a photon (or more practically, a light beam) exerts a gravitational pull ...
26
votes
7answers
3k views
Is a hard drive heavier when it is full?
Browsing Quora, I saw the following question with contradicting answers.
For the highest voted answer:
The bits are represented by certain orientations of magnetic fields
which shouldn't have ...
7
votes
2answers
1k views
Why do we need Higgs field to re-explain mass, but not charge?
We already had definition of mass based on gravitational interactions since before Higgs. It's similar to charge which is defined based on electromagnetic interactions of particles.
Why did Higgs ...
8
votes
3answers
3k views
What's the difference between the five masses: inertial mass, gravitational mass, rest mass, invariant mass and relativistic mass?
I have learned in my physics classes about five different types of masses and I am confused about the differences between them.
What's the difference between the five masses:
inertial mass,
...
3
votes
4answers
348 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?
32
votes
7answers
2k views
Why do we have an elementary charge but no elementary mass?
Why do we have an elementary charge $e$ in physics but no elementary mass? Is an elementary mass ruled out by experiment or is an elementary mass forbidden by some theoretical reason?
19
votes
5answers
2k views
Do photons gain mass when they travel through glass?
Please correct me if I'm wrong, but I believe that photons slow down when travelling through glass. Does this mean they gain mass? Otherwise, what happens to extra kinetic energy?
I understand now ...
12
votes
3answers
1k views
If the universe were compressed into a super massive black hole, how big would it be?
I understand only a little of general relativity, but that's why I'm here! :)
Consider the hypothetical situation of some extra-terrestrial intelligence pushing all the mass in the universe, every ...
5
votes
3answers
243 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 ...
5
votes
2answers
689 views
The contribution to mass from the dynamical breaking of chiral symmetry
The claim is often made that the discovery of the Higgs boson will give us information about the origin of mass. However, the bare masses of the up and down quarks are only around 5 MeV, quite a bit ...
3
votes
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?
1
vote
1answer
379 views
If photons are deflected by a strong gravitational field, then how come photons do not have mass? [duplicate]
Possible Duplicate:
Explain how (or if) a box full of photons would weigh more due to massless photons
It has been proved and showed through experiments that light can be bent by the Sun or ...
4
votes
4answers
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?
1
vote
1answer
99 views
Is light affect by gravity? Why?
I would like to know if light is affected by gravity, also, I would like to know what is the more correct for the definition of gravity: A force that attracts bodies with mass or force that attracts ...
0
votes
1answer
167 views
Expression for the (relativistic) mass of the photon [closed]
I started learning a bit ahead from an old physics book, and they were discussing the photoelectric effect and after that Planck's hypotheses and energy quantas.
The book said that the mass of a ...
48
votes
14answers
70k views
How Does Mass Leave the Body When you Lose Weight?
When your body burns calories and you lose weight, obviously mass is leaving your body. In what form does it leave? In other words, what is the physical process by which the body loses weight when ...
16
votes
7answers
2k views
Is mass quantized?
I learned today in class that photons and light are quantized. I also remember that electric charge is quantized as well. I was thinking about these implications, and I was wondering if mass was ...
4
votes
1answer
149 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. ...
3
votes
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 ...
5
votes
3answers
1k views
What defines the mass of elementary particle?
The electron is particle.
The mass of electron is $9.10938215(45)\times 10^{−31}\, {\rm kg}$.
But why is the mass exactly what it is?
What in physics defines the mass of elementary particle?
11
votes
3answers
771 views
Decay of massless particles
We don't normally consider the possibility that massless particles could undergo radioactive decay. There are elementary arguments that make it sound implausible. (A bunch of the following is ...
6
votes
3answers
509 views
Special Relativity and $E = mc^2$
I read somewhere that $E=mc^2$ shows that if something was to travel faster than the speed of light then they would have infinite mass and would have used infinite energy.
How does the equation show ...
3
votes
4answers
585 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
...
2
votes
2answers
544 views
How could something have negative mass?
With all the theories on how Neutrinos apparently broke the light barrier, there was one theory someone told me of how neutrinos might have less than zero mass, but she didn't explain how this was ...
2
votes
2answers
1k views
Mass of particle near light speed in a medium
I am trying to get a common understanding from these two previous questions:
Why does the mass of an object increase when its speed approaches that of light?
What happens if light/particles exceeded ...
0
votes
3answers
982 views
How is light affected by gravity?
Light is clearly affected by gravity, just think about a black hole, but light supposedly has no mass and gravity only affects objects with mass.
On the other hand, if light does have mass then ...
6
votes
3answers
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 ...
3
votes
2answers
386 views
How Can We Measure The Mass Of Particle?
As we know, the mass of well known particles are below.
$m_{n}\approx0.0000000000000000000000000016749286[kg]$
$m_{p}\approx0.0000000000000000000000000016726231[kg]$
...
2
votes
1answer
473 views
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?
2
votes
2answers
336 views
Mass in terms of energy
Given the relationships between mass and energy in relativity, and given that particles with mass can be created given energy over the threshold energy, and vice-versa, can we say that mass is simply ...
1
vote
4answers
587 views
Does matter with negative mass exist?
Or does it exist mathematically?
Is it really inconsistent with a common-sense, mathematics or known physical laws?
As far as I understand, if it exists, it must be far away from the "positive" ...
0
votes
1answer
240 views
Mass points of a Mass-spring model
Let's say I have a mass spring model like the one in the picture below:
So, there are 3 parts of the spring joined together in an equilateral triangular manner. Each of the joints has a mass of ...
0
votes
1answer
68 views
How much meteoric/space dust does the moon accumulate daily?
Just what the title states.
Any body, as it travels through space, probably sweeps meteoric/general dust from the vicinity into itself. How much (in tons/kilograms) dust does the moon accumulate ...
5
votes
3answers
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?
$$\sum_{m=1}^{\infty } \frac{1}{10^{26}(m^2+1)_{2m}}=$$
...
4
votes
2answers
148 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, ...
2
votes
4answers
364 views
Do we say that phonon has effective mass through its dispersion relation?
The effective mass is proportional to the second derivative of the dispersion relation d2k/dE2.
Do we say that phonon have effective mass through it ? Spin wave have.
8
votes
1answer
155 views
How the inverse square law in electrodynamics is related to photon mass?
I have read somewhere that one of the tests of the inverse square law is to assume nonzero mass for photon and then, by finding a maximum limit for it , determine a maximum possible error in ...
7
votes
3answers
468 views
What is the exact gravitational force between two masses including relativistic effects?
I was wondering if there is a closed-form formula for the force between two masses $m_1$ and $m_2$ if relativistic effects are included. My understanding is that the classic formula $G \frac{m_1 ...
5
votes
3answers
374 views
What is the mass of a wave?
The slide called "QUANTA" here says that "One Quantum has a definite mass" and the picture shows a wave. So, What is meant by the mass of a wave?
8
votes
4answers
2k views
Why don’t photons interact with the Higgs field?
Why don’t photons interact with the Higgs field and hence remain massless?
4
votes
3answers
117 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 ...
4
votes
2answers
250 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 ...
3
votes
2answers
91 views
Gravitational distortion of an object's diameter, at a distance,
Does the curvature of space-time cause objects to look smaller than they really are? What is the relationship between the optical distortion and the mass of the objects?
3
votes
4answers
556 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 ...
