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)

4
votes
2answers
3k views

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, ...
4
votes
3answers
18k views

Why do we use kilograms instead of newtons to measure weight in everyday life?

What was the reason to use kilograms to measure weight (e.g. body weight, market vegetables etc.) instead of using newtons?
4
votes
4answers
477 views

Why should mass be attractive in nature?

Why does a mass attract all the masses around it? Why should't it repel or just stay calm? Why should it be like that?
4
votes
1answer
666 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 ...
4
votes
3answers
2k views

Why does the Standard Model predict Neutrinos are massless?

Why are neutrinos massless in the Standard Model? Is it connected with experimental fact that neutrinos always have only one direction of projection of spin on motion direction?
4
votes
5answers
12k 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? ...
4
votes
4answers
3k views

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?
4
votes
1answer
432 views

What would happen if a negative mass crossed the event horizon of a black hole?

If negative mass really existed and somehow a very fast traveling negative mass object reached near the black hole's event horizon. What would happen when it crosses the event horizon? According to ...
4
votes
3answers
365 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. ...
4
votes
3answers
10k 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 ...
4
votes
3answers
2k 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 ...
4
votes
3answers
759 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 ...
4
votes
2answers
493 views

If a photon has no mass, how can it be attracted by the Sun?

I read that the photon doesn't have mass, but my teacher says that the photon has mass because the sun can attract it (like in the experiments to prove the theory of relativity). I think that there ...
4
votes
4answers
188 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 ...
4
votes
4answers
346 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 ...
4
votes
1answer
672 views

Does string theory pose a photon mass problem?

A few weeks ago, I started reading books on string theory. One thing that really seemed confusing or contradictory was that string theory explains that the energy of a superstring gives mass to the ...
4
votes
3answers
11k views

Orbital speed for a circular orbit?

I wanted to look up the formula for orbital speed for a circular orbit on Wikipedia, and I found 2 formulas: All bounded orbits where the gravity of a central body dominates are elliptical in ...
4
votes
1answer
291 views

Photon mass and life time

In this article, the author tried to explain that, Einstein's theory may not valid because he says "photon can decay because it may have minute amount of mass". I'm totally in a conundrum state that ...
4
votes
1answer
284 views

Imaginary masses

While watching this video, at around 5:00, the man mentions a certain type of particle having imaginary mass. He also says that these kind of particles can go faster then light. But how it is possible ...
4
votes
4answers
2k 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 ...
4
votes
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?
4
votes
3answers
2k 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 ...
4
votes
2answers
982 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 ...
4
votes
3answers
2k 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 ...
4
votes
1answer
230 views

How much mass is typically ejected from a supernova?

How much mass is released from a supernova of a 15 solar-mass star? 20? 25? What is the relation between star mass and mass ejected?
4
votes
2answers
1k views

When you breath in a helium balloon, do you lose weight?

We all know the trick of breathing in a helium balloon to get a funny squeaky voice! When you do this, would it be correct to say you lose weight? On the one hand, the helium should make you more ...
4
votes
1answer
849 views

Have negative pressures any physical meaning?

Some cubic thermodynamical equations of state predict negative pressures, have negative pressures any physical meaning? Could they be related to negative mass?
4
votes
2answers
708 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 ...
4
votes
1answer
12k views

Terminal velocity of two equally shaped/sized objects with different masses?

I've tried doing research on this and there are some similar questions. However, they have slightly different scenarios and to make sure I understand things perfectly, I wanted to word it into my ...
4
votes
2answers
253 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, ...
4
votes
1answer
278 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. ...
4
votes
2answers
1k views

How Can We Measure The Mass Of Particle?

As we know, the mass of well known particles are below. $m_{n}\approx0.0000000000000000000000000016749286[kg]$ $m_{p}\approx0.0000000000000000000000000016726231[kg]$ ...
4
votes
3answers
2k views

Active gravitational mass of the electron

In PSE here electrons are added to a sphere and gravitational modifications are expected. My question is: Is there any experiment that show that a negatively charged object is source of a stronger ...
4
votes
1answer
62 views

In GR what is a “source-frame mass”?

In the recent LIGO paper, "GW150914: First results from the search for binary black hole coalescence with Advanced LIGO, (LIGO Scientific Collaboration and Virgo Collaboration)", they refer to the ...
4
votes
2answers
213 views

How can we get the mass of an uncharged proton?

How can we get the mass of an uncharged proton, i.e. how varies the mass of the charged proton if i remove the electric charge? For the isotopic spin theory neutron and proton have the same mass and ...
4
votes
1answer
423 views

Why is Planck mass much larger than the smallest mass that we actually know about?

The three fundamental constants $h$, $c$ and $G$ are manipulated and rearranged in different ways to get the Planck time, Planck mass etc. The Planck time is said to be the smallest time possible and ...
4
votes
2answers
23k views

Does a scale measure weight or mass? [closed]

What does a measuring scale measure: mass or weight? I mean, when we stand on a weighing scale the reading we get is in $\mathrm{kg}$'s. What does this mean?
4
votes
1answer
442 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. ...
4
votes
2answers
339 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 ...
4
votes
2answers
960 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 ...
4
votes
4answers
2k 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 ...
4
votes
2answers
502 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 ...
4
votes
3answers
111 views

Must we test whether e.g. $A=B$ and $A=C$ implies $B=C$ by experiment?

Chaper 10, conservation of momentum in "The Feynman Lectures on Physics" in the chapter entitled, the authors write that Suppose we know from the foregoing experiment that two pieces of matter, ...
4
votes
1answer
457 views

If virtual particles have negative mass why do they contribute positive mass to atoms?

According to Lawrence Krauss, atoms containing in our body consists of merely 10% (if I remember correctly) of our total mass. The rest come from virtual particles popping in and out of existence from ...
4
votes
1answer
289 views

What is the density and energy of a photon?

As I understand, photons are considered mass-less, which is a necessary condition for moving at the speed of light. However, does that mean their density is 0, as they will occupy some volume. If ...
4
votes
2answers
907 views

Where is Strong Equivalence Principle stronger than Weak Equivalence Principle

In my note, the two equivalence principles are stated as follows Weak Equivalence Principle: Gravitational and inertial masses are equal. Strong Equivalence Principle: There is no observable ...
4
votes
1answer
103 views

Commercial large scale production of graphene

I am a third year undergraduate Physics student, and for my solid state physics course I am asked to give a short (10 minute) qualitative presentation on the current standings of graphene production, ...
4
votes
2answers
1k views

Where does the mass term come from in the Proca Lagrangian?

There are many good books describing how to construct the Lagrangian for an electromagnetic field in a medium. $$ \mathcal{L}~=~-\frac{1}{16\pi}F^{\mu\nu}F_{\mu\nu}-\frac{1}{c}j^{\nu}A_{\nu} $$ ...
4
votes
1answer
90 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 ...
4
votes
1answer
528 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 ...