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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83 views
Why the kilogram is not defined? [duplicate]
Possible Duplicate:
Why do we still not have an exact definition for a kilogram?
I was thinking about SI units. I found the following definition for the base units:
Meter: distance ...
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2answers
217 views
Center of mass of a car
This might be little of the track but my question is more on possibility of application of principle of center of mass.
The probability of a vehicle overturning depends more on the level of center of ...
4
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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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0answers
32 views
Could the quantity mass in the whole galaxies decrease to zero if all particle in the galaxies convert into subatomic particle? [closed]
Could the quantity mass in the whole galaxies decrease to zero if all particle in the galaxies convert into subatomic particle?
How does your statement work?
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0answers
122 views
Neutrino mass with Dirac and Majorana
Why both Dirac mass and Majorana mass terms are needed to explain the mass of a neutrino?
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3answers
112 views
Does Earth's rotation change at a constant rate?
Follow-up to
Is Earth's orbit altered by recoil from take-off/launch/recovery of aero/space vehicles? and
How much meteoric/space dust does the moon accumulate daily?
Is the length of the day ...
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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 ...
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1answer
89 views
Why is the lightness of particles remarkable?
Why is the lightness of particles unexpected?
http://motls.blogspot.com/2012/09/experimenters-susy-frustrations-and.html
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2answers
423 views
Free fall of two spheres made of same materials, different masses, with air resistance
Two people falling with the same parachute will gain different speeds if their masses are different. The upward air drag will needed to be bigger for a heavier person, since gravitational force is ...
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1answer
569 views
Does the mass of a battery's change when charged/discharged?
... and if so, how much? Is it possible to detect it, or is it beyond any measurement? I'd say there are two possible scenarios (depending on the battery type) and both seem interesting:
The battery ...
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1answer
53 views
Non-conversion of mass & energy?
This article is certainly an interesting alternative perspective, but is it factual or does it contain fallacies?
http://www.circlon-theory.com/HTML/EmcFallacies.html
Are mass and energy not ...
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3answers
607 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 ...
5
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2answers
162 views
Why would a particle in an extra dimension appear not as one particle, but a set of particles?
I was reading an article in this months issue of Physics World magazine on the three main theories of extra dimensions and stumbled across something I didn't quite understand when the author began ...
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2answers
2k views
Why do objects with different masses fall at the same rate? [duplicate]
Possible Duplicate:
Confused about the role of mass
Today we were in our Literature class talking about the Renaissance and the Enlightement and our teacher also said that scientific ...
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1answer
184 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 ...
7
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2answers
935 views
'Density' of a proton
I was doing some exercises the other day, when I came across this question in my book:
A proton weighs about 1.66 x 10-24 g and has a diameter of
about 10-15 m. What is its density in g/cm3?
...
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2answers
131 views
The physics behind The Great Flood [closed]
The book of Genesis floats (pardon the pun) some interesting numbers when discussing the Great Flood. For example, it rained for 40 days and 40 nights, and at the end of that time, the entire planet ...
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3answers
207 views
Formation of black holes
If stars start with a finite density and light can escape from them, how can they be compacted to form a mass with infinite density which light cannot escape? The black hole will have the same mass as ...
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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 ...
12
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3answers
3k views
How do we determine the mass of a black hole?
Since by definition we cannot observe black holes directly, how do astronomers determine the mass of a black hole?
What observational techniques are there that would allow us to determine a black ...
4
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3answers
255 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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1answer
116 views
How do the energy eigenvalues of rotational degrees of freedom in statistical mechanics come about?
I want to understand the hierarchy different degrees of freedom of a mechanical system. Specifically, I want to understand which subsystems equibrilate faster and why. This question comes up:
Why ...
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3answers
117 views
How to recognize broken candies from whole ones [closed]
Let's say I have a bag full of sugar candy. Some will be whole, some will be dent, some will be broken (in part, or half, etc).
Let's say I have a device with an input box where I empty the bag, and ...
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2answers
245 views
Why do photons add mass to a black hole?
Why do photons add mass to a black hole?
When photons are taken irreversibly into a black hole does the mass of the BH increase?
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3answers
977 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
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3answers
417 views
How are the masses of unstable elementary particles measured?
I am interested in knowing how (Q1) the particle's masses are experimentally determined from accelerator observations.
What kind of particles? They must be as far as we know elementary and unstable ...
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2answers
162 views
Why does the (relativistic) mass change & why?
I studied that when an object moves with a velocity comparable to the velocity of light the (relativistic) mass changes...but I am really eager to know how does this alteration take place....If anyone ...
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3answers
148 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
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 ...
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1answer
238 views
Why are all observable gauge theories not vector-like?
Why are all observable gauge theories not vector-like?
Will this imply that the electron and/or fermions do not have mass?
How is this issue resolved?
Background:
The Standard Model is a ...
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2answers
205 views
Does the potential energy related to a particle determines its rest mass?
Would it be possible to determine the rest mass of a particle by computing the potential energy related to the presence (existence) of the particle, if this potential energy could be determined ...
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0answers
37 views
What gives photons their energy? [duplicate]
Possible Duplicate:
Does $E = mc^2$ apply to photons?
I've been to a presentation by a CERN scientist, and he briefly talked about photons. It was stated that photons have different energy ...
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1answer
59 views
Is mass of the parent star is equal to the mass of the born blackhole
I want to know whether mass of the black hole which has born from a star is similar to its parent star or not. whether the born black hole will have high or low mass comparing to its parent star. ...
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1answer
619 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 ...
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2answers
130 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 ...
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1answer
117 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 ...
3
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2answers
413 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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2answers
2k views
Does an Increase of Force affect the Speed of an object if the acceleration stays constant?
If I had a mass of $100\:\rm{kg}$ accelerating due to gravity, using $F=ma$:
$F = 100\:\rm{kg} \times 9.8\:\rm{m/s^2}$
$F = 980 \:\rm N$...
If I increased the mass to 200kg, the force would be 1960 ...
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5answers
977 views
Why Gravity attracts all objects with the same speed?
Why Gravity attracts all objects with the same speed? Is this question was solved? What is the exact answer?
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1answer
458 views
What is the difference between 'running' and 'current' quark mass?
When looking at the PDG, there is a difference between the 'running' and the 'current' quark masses.
Does anyone know which is the difference between these two?
2
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1answer
187 views
What is meant by the rest energy of non-composite particle?
When talking about the rest energy of a composite particle such as a proton, part of the rest energy is accounted for by the internal kinetic energy of its constituent quarks. But what is physically ...
5
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3answers
462 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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vote
1answer
92 views
Are there any well-known theories successfully unifying the inertial and gravitational mass?
From what little I know of general relativity, the equality of inertial and gravitational mass is an axiom of the theory. I suspect that this precludes GR from unifying them in the same sense as ...
3
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2answers
227 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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3answers
473 views
Relation between Newtons and Kilograms
Work is expressed as W=F*d, where the F is in Newton, d is in meters and result ...
16
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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 ...
2
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1answer
583 views
Transforming a sound wave into a literal light wave. Is it possible?
Literally transforming sound into an actual light wave seems almost impossible. But transforming the sound wave into a light wave while containing a single mass? I know that sound can contain a mass ...
1
vote
3answers
468 views
Why does a semiconductor hole have a mass?
I have read that holes in semiconductor are nothing but vacancies created by electrons. But how can this vacancy i.e. hole has a mass?
2
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1answer
471 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?
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1answer
153 views
How to calculate Rest Mass practically with Standard Model?
With relativistic physics, we can apply force to see resistance against acceleration. It'd give us relativistic mass and we have well established formula to get to the Rest Mass as long as we know the ...
