Do you think light has mass? I do. If you don't you're an idiot.
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does light have relative mass is what I was getting at and if you don't think it has mass, then you are an idiot.
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Do you think light has mass? I do. If you don't you're an idiot.
edit
does light have relative mass is what I was getting at and if you don't think it has mass, then you are an idiot.
/edit
http://math.ucr.edu/home/baez/physic...ight_mass.html
http://image.gsfc.nasa.gov/poetry/ask/a10594.html
http://www.earthsky.com/2003/es030802.html
http://www.nsf.gov/nstw_questions/phys/quest084.htm
http://imagine.gsfc.nasa.gov/docs/as...rs/961102.html
People who make general and simple statements when not presenting facts or argument are "misguided" cough .
<---- an idiot
Me --> Idiot with degree in physics . . . .
<-------- advanced idiot with labotomy
O kI guess I will join with the greatest scientific minds of our age as an idiot and say that light has no mass.
I told you, clintonsucks, but don't listen to me.... :rolleyes:
Actually I think light does have Mass. clintonsucks is a jerk for phrasing his question in such a way that it would cause anger amongst fellow geeks. Light has mass because it is a particle wave. It follows both the actions of a wave and a particle therefore it could have mass. But it is also assumable that it does; either way measuring the mass of light would be difficult if not impossible. Thats just my opinion, so don't flame me.
There is a reproduceable experment that shows light does have mass. You must have a very sensitive scale, a transparent near vacume enclosure, and a very strong light source.
I read an artical on this in 'Scientific American' and seen the experiment reproduced on some TV show (perhaps 'Discovery' or 'PBS' (sorry, I don't remember exactly where)
The scale will show that light striking the scale will cause it to show a weight, and when the light is removed, the weight goes away.
Now then, do I join with the rest of the scientific world, and most of hte respondents here, or do I go with someone who considers those who don't agree with them to be idiots?
Tough one there.
moxnix - the first link that RoadClosed posted suggested a reason why this experiement would appear to have mass - because it has momentum without mass, and can therefore exert a pressure on a scale ( if I understood the article right ).
Does anyone want to support the idea? I would be interested in arguments in favour, that did not relate to my inteligence level.
moxnix: light dose have enery(or is energy) and as Schrodinger stated it has momentum, so while it is on the scale it registers. Mush like you can get a sound wave to register on a scale to show weight even though it dosn't have any mass. Light isn't a partical - wave its a partical and a wave (or neither) at the same time.
More hereQuote:
Light, mass, gravity and momentum.
The photon has no mass: The argument goes " light has energy and momentum, it responds to gravity, therefore it has mass" Not true. Light does have energy and momentum but these don't imply mass. In fact what they lead to is relativistic mass.
RaodClosed's first link does give proof that light does not have mass, but may appear to due to it's momentum. Besides, a photon is a massless particle if we are to beieve our friend Einstein's general theory of relativity. You still lose, clintonsucks!
Yes the theory of relativity would fall to pieces if light has mass. It would be incapable of reaching it's own measured constant. In addition light does not have an acceleration factor. If it did, it would take time to excellerate because mass takes time to excellerate. Light does not do this.
<------ still an idiot.
//edited later... in case no one notices the original posted topic was modified instead of a new post being added to change the flow of thinking.
Does an electron have mass? Then? Why a fight? Doesn't solve anything.
Here we go again....... For a min. am going with the scientific belief, if gas where to have no matter (which it does) and the sun where made up from it, would you still stick next to your theory?Quote:
Yes the theory of relativity would fall to pieces if light has mass. It would be incapable of reaching it's own measured constant. In addition light does not have an acceleration factor. If it did, it would take time to excellerate because mass takes time to excellerate because mass takes time to excellerate. Light does not do this.
You said something about, that the sun doesn't move or nonetheless have motion? The galaxy is always growing and moving...
PS: Will add more, in a sec., am working on something important!
:confused: Huh!?!?!Quote:
Originally posted here by d00dz Attackin
Does an electron have mass? Then? Why a fight? Doesn't solve anything.
Here we go again....... For a min. am going with the scientific belief, if gas where to have no matter (which it does) and the sun where made up from it, would you still stick next to your theory?
You said something about, that the sun doesn't move or nonetheless have motion? The galaxy is always growing and moving...
Imma be an idiot too. A photon has no mass. Does a photon have relativistic mass ¿. . . of course, but where getting into a semantic argument about the word 'mass', b/c relativistic mass would just be a measure of energy. So no, no mass to a photon, but what about a tachyon, heh?? :D
err, ugghh, is'nt light energy? I don't think energy has mass.
but then again, i'm a network admin, not a physics guru.
Thanks that's kind of what i meant but I didn't know how to phrase it.Quote:
Originally posted here by bballad
moxnix: light dose have enery(or is energy) and as Schrodinger stated it has momentum, so while it is on the scale it registers. Mush like you can get a sound wave to register on a scale to show weight even though it dosn't have any mass. Light isn't a partical - wave its a partical and a wave (or neither) at the same time.
d00dz Attackin said:
I'm not sure if I am understanding correctly, but the sun is made up of hydrogen, a gas, not photons which only make up the light that it emits. Just like a lightbulb is made up of glass and tugsten, but still emits light, made of photons which are massless.Quote:
if gas where to have no matter (which it does) and the sun where made up from it, would you still stick next to your theory?
doodz, I am not sure where your going with the electron gas analogy. They both have mass and aren't related to light. Electrons are atomic particles with weight and gas could be anything: water, hydrogen, farts... etc.
Light is Energy and that is entirely where the thinking comes from that light has to have mass. After all no one disputes that E in the equation equals mass, just look at E=MC, it says it right there! So people went, "Hmm light has to have mass because the theory of special relativity says so! Energy EQUALS Mass, times C. In early discovery some thought it did have mass and those experiments are where the term "Relativistic Mass" as known today come from. It's old thinking that has since been disproved. Because it was once associated with the possibility of physical mass on a photon. The experiment with light producing a "weight" on a scale is the result of momentum. It does not change the physical properties of light and does not give it mass. The term is misleading.
"Relativistic Mass" does not equal "Mass” They are two extremely different things and do not relate to one another. It's like saying the reflection in the mirror IS you, and the reflection has your mass and physical properties. It IS an argument in semantics.
Also some seem to want to dispute the theory of Special Relativity. Good luck, I hope you do because it means we can shape the universe and space time to our bidding and toss everything out the window. It does not relate to anything else except light. The C in E=MC^2 is the light constant speed in a vacuum as measured and accepted. It’s not a belief or a religion. Sure it’s an uncontested theory, but the ramifications of its failure are astounding. As stated we humans would be able to warp time and space to our will.
//edit the term "unconstested theory" is misleading. I meant to say the theory hasn't been broken. It's been contested heavily by leagues of scientists trying to find holes in it and disprove it. The theory of special relativity is also much more than just the subjects posted here. It rocks.
You're almost entirely correct, but I think you meant to say the general theory of relativity. I google'd it, and I found this page:
http://csep10.phys.utk.edu/astr162/l...y/gravity.html
I could be wrong, but because gravity does affect light (black holes, etc.) there is a force at work there so the general theory would apply.
Actually E=mc^2 is slightly outdated, it never accounted for -mass, so it should be E=(- or +)mc^2
c= the speed of light. fyi they have brought it's speed to 0, I belive SCIAM.com had a detailed article on it... not sure... but I think so.
You have to remember that when searching on the web to check your sources, some may be outdated or "billy bobs super cool home page", normaly howstuffworks.com is a good place to check things out.
Drakain Zeil,
I checked howstuffworks and I didn't see anything on negative mass. Are you sure that it exists? Scaim.com didn't turn up anything either. If you could give a URL, I'd be very appreciative.
I should clarify for those interested. Einstein wrote a papers back in the early 1900s and consolidated them in 1920 and called it Relativity: The Special and General Theory .
I may have crossed the line a bit but the SPECIAL theory describes the motion of particles in relation to the speed of light. The reference of momentum and energy is the Special Theory. Later it was expanded to add gravitation and how it effects the shape of space and the flow of time, that is the general theory. It says space and time or not linear and are intertwined and expanded greatly upon by Steven Hawking in A brief History In Time at a later date.
I was saying that if we could overcome the limitation posed by strict boundaries in the universe, as applied to light speed and our inability to accelerate mass to C, we could reshape time and in reshaping time you are also reshaping space because gravitation would change.
The fact the negative mass could exist doesn't mean much to the Special Theory. We already know there are mass less particles that can go the speed of light. One is a photon and IS light. Even if I entertain the idea that negative mass exists, of which I am not convinced it does; who cares? The theory still applies. If you can accelerate a particle with 0 mass to C then certainly something that weighs less than nothing can reach C and beyond.
It's curious that the mathematical computations supplied by Einstein resulted in anomalies: Black Holes and Gravitational Waves. Some still believe they do not exist and they are purely mathematical mistakes of the original equations used. I say Steven's work is quite evident that a singularity exists. It's even more curious that Einstein himself, thought they were mathematical mistakes and he didn't live to see current observations of blacks holes and the singularities they contain.
That makes much more sense. Obviously you have done more research than me on the topic. Einstein should have put a warning on that paper, "May cause severe headaches!". ;)
I don't know if I put more research into it, only while others had Rock stars and sports stars has childhood heros: mine are as follows in order.... Carl Sagan, Steven Hawking, Albert Einstein, and all the great minds of the classic civilisations. Of course, Bono, Roger Waters, Johnny Bench and others are up there too, alnong with all the great brewmasters of the world. :D
Hey road closed check out "The future of time" its a collection of essays dilivered by hawkings and others at UC Berkly for their head physacist's birthday. I would also sugest "The Universe in a nut Shell" for any of you just getting interested in space-time, its a book by Hawkings that gives a bref overview of the current happings in theorectical physics.
Thanks got the recomendations. Also, the "Brief History in Time" is hard to read. I had to go out and get a math book to comprehend some items. BUT, we (non mathematically gifted) are saved. A couple of years ago, the illustrated "dumbed" down version was released. It's amazing and is called "The Illustrated, brief history in Time"
Oh I forgot someone on my list of top 3, now 4. Issac Asimov. Sure he wrote tones of science fiction, many dealing with the social issues of "what if" robots were made human like. But he also worte essays and books about basic physics that are sort of "physics for dummies" where things are explained with down to earth models.
Good stuff.
The nutshell and future book are much kinder to those of us how had to take liniar algabra twice (defeq killed me.) so don't let the math in history of time scare ypu.
I got the "Future of Space Time" from the library at lunch. Good ****.
From what I understand, mass is how much someting weighs at rest, so one argument can be that you can never take a weight of light because it is always moving at light speed. Another argument is and object with a given weight will have more "weight " when it is set into motion, if this is true, then if light had a weight at rest then its weight while moving at the speed of light would be damn near infinite.
Im not too sure how to explain the scale experiment from page one ot this thread, I have never witnessed it. But maybe it was the heat from the emmiting light source that caused the scale to give a reading?
Well lets clear up your missunderstanding then, weight is a mesure of the force that gravety exerts on a mass. Mass is the amount of matter in an object. Two vastly difrent things, if you went to the moon you would weigh less but your mass wouldn't change. Hope that helps.Quote:
Correct, you said it better than I did, but that is how I understand it. Weight of an object is normally considered by taking this measurement at rest.
weight is a just a mesure of force exerted on an objcet, usualy the scal reads the force of gravety on a mass. In the light/vacume experiment it mesured the force created by packets of light energy (photons) hitting the scale, difrent type of force but still a force so it registers.
Great point volcanic:
It would be hard to measure weight of light because it has no mass.... and thus cannot have weight. Here is my understanding:
Mass is measured by the amount of matter something contains and then balancing that to known matter as compared to unkown matter . Weight is measured on a scale. You can't weigh a planet, or a black hole. You can just compare it's mass to space or other objects and base that on something bballad said.
Weight a measurement of the pull of gravity on something. Mass does not change when an object is moved from point A to B, weight on the otherhand does change. Also the more energy you add to an object in order to excellerate it, the more it weighs.
Your statement... "then if light had a weight at rest then its weight while moving at the speed of light would be damn near infinite." is true. If it had weight. Since you can't have weight without mass, I think you just added one more argument to the fact that light has no physical mass.
The light on the scale experiement was a test, as everything is tested, to see what the hell light is. It was first believed that because a beam of light measured something that is had mass. The was later found to be not entirely correct and the term "relative mass" was coinded to describe was is really the effects of propulsion of the photons and as an inverse to it's actual physical mass or "Invarient Mass."
So mass is measured by balancing and unkown matter with a known matter and weight is measured on a scale. Outside of Earth, in physics terms the unit of measure for mass is the KiloGram and the unit of weight as it's core effect by gravitational pull is the Newton . The meassurement of mass get's even deeper when comparing the different equations and methods used.
So at zero velocity invarient mass is equal to relativistic mass. I agree with that but the invarient mass of light is Zero. There fore light at rest will not have mass. There are some arguable experiments that almost touch on a way for light to have mass but not quite. Here is one from a posted link earlier:
Quote:
If we now return to the question "Does light have mass?" this can be taken to mean different things if the light is moving freely or trapped in a container. The definition of the invariant mass of an object is m = sqrt{E2/c4 - p2/c2}. By this definition a beam of light, is massless like the photons it is composed of. However, if light is trapped in a box with perfect mirrors so the photons are continually reflected back and forth in the box, then the total momentum is zero in the boxes frame of reference but the energy is not. Therefore the light adds a small contribution to the mass of the box. This could be measured - in principle at least - either by an increase in inertia when the box is slowly accelerated or by an increase in its gravitational pull. You might say that the light in the box has mass but it would be more correct to say that the light contributes to the total mass of the box of light. You should not use this to justify the statement that light has mass in general.