What is mass, and how does speed increase it?

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The same would hold true for a black hole, that the definition of a black hole is nothing, even light escapes from it implies that, while not detcected or understood Photons do have mass, if they didn't they would escape and a black hole would not be black.</DIV></p><p>Not quite true.&nbsp; Photons have momentum and energy, but do not have mass.&nbsp; At least, they are predicted to have no rest mass.&nbsp; There have been continuing experiments that keep dropping the upper limit of the minimum mass that we can measure.&nbsp; I believe it is somewhere around 10^-50 grams.&nbsp; Every time photons have been "weighed", they always fall below what our threshhold for measurements are.&nbsp;</p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That would then imply that the gravity of a black hole exerts enough force to accelerate objects, or photons to a speed in excess of the established speed of light, pulling them in and not letting them out.</DIV></p><p>First, black holes don't 'exert' a force.&nbsp; They affect the curvature of spacetime around them.&nbsp; Photons (or any particle) follow this curvature.&nbsp; The particles are following what is referred to as a geodesic... a straight line in curved space.&nbsp; The event horizon of black hole is the region of spacetime where all geodesic paths fall towards the singularity.&nbsp; Particles are not accelerated to speeds beyond the speed of light when they hit the event horizon.&nbsp; In particlular with supermassive black holes, a rocket ship might not even recognize it crossed the event horizon... at least until it tried to change it trajectory outward. </p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[scottb50]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> First, black holes don't 'exert' a force.&nbsp; They affect the curvature of spacetime around them.&nbsp; Photons (or any particle) follow this curvature.&nbsp; The particles are following what is referred to as a geodesic... a straight line in curved space.&nbsp; The event horizon of black hole is the region of spacetime where all geodesic paths fall towards the singularity.&nbsp; Particles are not accelerated to speeds beyond the speed of light when they hit the event horizon.&nbsp; In particlular with supermassive black holes, a rocket ship might not even recognize it crossed the event horizon... at least until it tried to change it trajectory outward. &nbsp; <br /> Posted by derekmcd</DIV></p><p>I think the curvature of spacetime is a mistaken theory that tries to explain what happens when simple Gravity accelerates matter faster then light. It is an explanation for a distorted view of the event, not the event itself. For it to work you have to assume the physics of Gravity change at the speed of light and becomes something entirely different.&nbsp;</p><p>A rocket being affected by the gravity of a black hole would react the same way it would if it was put in an orbit around the Sun. The falacy of aiming Nuclear waste at the Sun is it would never hit the Sun, it would go into an orbit around it. The same would hold true with a black hole, the rocket would miss the black hole and enter an orbit. Taken further the same physics that is used to gain momentum by close encounters with planets would operate exactly the same with stars or black holes.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[origin]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think the curvature of spacetime is a mistaken theory that tries to explain what happens when simple Gravity accelerates matter faster then light.</DIV></p><p>Matter cannot go faster than light.</p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;A rocket being affected by the gravity of a black hole would react the same way it would if it was put in an orbit around the Sun. The falacy of aiming Nuclear waste at the Sun is it would never hit the Sun, it would go into an orbit around it. The same would hold true with a black hole, the rocket would miss the black hole and enter an orbit.&nbsp; <br />Posted by scottb50</DIV></p><p>If a rocket was 'aimed' at the sun it would most definitely hit the sun.&nbsp; If the rocket was aimed near the sun it would either hit the sun, go into an oribit around the sun, or fly by the sun (changing its original trajectory), depending on the intial velocity of the rocket and how near the sun the rocket was at closest approach.</p> <div class="Discussion_UserSignature"> </div>

 

[billslugg]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>How does increased speed increase volume or&nbsp;density, or does it, and what of gravity?Posted by xmo1</DIV></p><p>The mass increases because of the energy that has been added. Energy has mass.</p> <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[lildreamer]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This is actually the second time I've investigated this. The clue was on wikipedia of all places.http://en.wikipedia.org/wiki/InertiaThere is gravitational mass and inertial mass. So my question is about inertial mass, and it is apparent to me that the equation means that as a particle's speed approaches c that the force required to accelerate the particle approaches infinity. This would require larger magnets regardless of the choice of either a&nbsp;linear or circular path.The question might be asked as why does this happen, and the answer would probably be that there is no explanation. It just does. My guess.I wonder, with tongue in cheek, if an&nbsp;effect of elasticity of a particle, or some other property of the particle itself, or of other nearby particles, could push the speed enough to cause a matter/energy transformation.I also wonder if there might be variable thresholds of that barrier, the SOL, for differing conditions or particles. Could be that the barrier is reached at a much lower or higher speed for some conditions or particles. <br />Posted by xmo1</DIV><br /><br />another link you might want to venture to is </p><p>http://galileoandeinstein.physics.virginia.edu/lectures/mass_increase.html</p><p>it might help your understanding - <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" /></p> <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not really sure what your questions are, but here's a brief, yet descriptive write-up of the LHC magnets.&nbsp; <br /> Posted by derekmcd</DIV></p><p>I just noticed I never provided the link.</p><p>http://www.hep.ucl.ac.uk/undergrad-projects/3rdyear/PPguide/cool.htm</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think the curvature of spacetime is a mistaken theory that tries to explain what happens when simple Gravity accelerates matter faster then light. It is an explanation for a distorted view of the event, not the event itself. For it to work you have to assume the physics of Gravity change at the speed of light and becomes something entirely different.&nbsp;A rocket being affected by the gravity of a black hole would react the same way it would if it was put in an orbit around the Sun. The falacy of aiming Nuclear waste at the Sun is it would never hit the Sun, it would go into an orbit around it. The same would hold true with a black hole, the rocket would miss the black hole and enter an orbit. Taken further the same physics that is used to gain momentum by close encounters with planets would operate exactly the same with stars or black holes.&nbsp; <br /> Posted by scottb50</DIV></p><p>Good luck contesting General Relativity.&nbsp; It has passed every experiment thrown at it.&nbsp; Where you get the idea that "simple gravity accelerates matter faster then light" is beyond me.&nbsp; There are no theories that make this statement.&nbsp; I also don't understand where you get the idea that nuclear waste, rocket ship, etc would never hit the object they are aimed at.&nbsp; We see comets hitting the sun rather often.&nbsp; Go check out a few impact craters... some pretty clear evidence that things don't just fall into an orbit.&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[scottb50]

<p>

Matter cannot go faster than light... </p><p>At one point exceeding the speed of sound was impossible.</p><p>If a rocket was 'aimed' at the sun it would most definitely hit the sun....</p><p>Not entirely true. Just aiming it at the Sun is one thing, giving it enough energy to overcome the urge to go into orbit is another thing. If this was the case there would not be any Comets left, they would have long ago fallen into the Sun. Only if the acceleration was enough would it actually fall into the Sun, figuring the effects of the Sun's atmosphere, for lack of a better term, an object would slow as it approached and be captured into an orbit.</p><p>&nbsp; If the rocket was aimed near the sun it would either hit the sun, go into an oribit around the sun, or fly by the sun (changing its original trajectory), depending on the intial velocity of the rocket and how near the sun the rocket was at closest approach...</p><p>Exactly my point. Why do the laws of physics change when you are dealing with a black hole as opposed to a simple star?</p><p>For lack of a better analogy the Dopplar Effect explains the same phenomena with sound. As an object passes the perception is it changes momentum, the reality is it doesn't, it is your perception of the event. The same would hold true with light. Space does not bend the object goes faster and gets there sooner. Theory says it is like putting a bowling ball on a rubber sheet, the rubber sheet is distorted and the object gets from point A to point B quicker then it would get there if it was traveling a straight path. If it is getting there faster because it is exceeding the speed of light doesn't fit with established thinking. Nothing can excedd the speed of light, period, so it must have another answer. </p> <div class="Discussion_UserSignature"> </div>

 

[schmack]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I'm not sure where you get the idea that the particles must be bigger.&nbsp; But let me use your maglev train to better illustrate the difference between mass and weight.&nbsp; Assume the train is here on Earth and let's also put it in a vacuum tunnel so there's no wind resistance.&nbsp; To elevate the train I must produce a force exactly equal to the force produced be the Earth's gravity, but in the opposite (up) direction.&nbsp; The train is now floating.&nbsp; If I had exactly the same train in the same tunnel on the same track but on the Moon instead of the Earth the lifting force needed would be less because the Moon's gravity is less.&nbsp; This is an example of weight.Now let me push on the train (somehow) to make it move down the tracks.&nbsp; If I push on the train with a constant force it will accelerate, increasing it's speed every second so long as I keep applying the push.&nbsp; Interestingly the pushing force works exactly the same on the Moon as on the Earth.&nbsp; Push equally hard on the Moon as on the Earth and the train will accelerate equally on both tracks.&nbsp; That's because&nbsp;the train's&nbsp;mass is the same in both places even though the train's&nbsp;weight is less on the Moon.&nbsp; While mass is related to the numbers and type of particles making up the train, weight is a force acting on that mass.&nbsp; Reducing the number of particles that make up the train reduces it's mass and also it's weight.&nbsp; If you could somehow spread the same number of particles across a larger volume (= less density) you'd still have the same mass and same weight but a longer, taller, wider train. Note that in all of the above I'm keeping the train speeds to be "low", much less than the Speed of Light (C). <br />Posted by Mee_n_Mac</DIV></p><p>&nbsp;</p><p>Thanks for your posts like this one Mee_n_Mac. It's descriptions like this that make it easier for the likes of even me to understand the "Hard stuff". Cheers. <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" /><br /></p> <div class="Discussion_UserSignature"> <p><font size="4" color="#ff0000"><font size="2">Assumption is the mother of all stuff ups</font> </font></p><p><font size="4" color="#ff0000">Gimme some Schmack Schmack!</font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not increasing the number or types of particles, how is mass increased by approaching the speed of light? What is the physical manifestation? Is it simply the resistance to a force&nbsp;attempting to change the path of&nbsp;the momentum? Why are larger magnets required if density, weight, or volume are not changed? I'm thinking that density, atomic weight of the particles including the sub atomic particles, and volume are the attributes of mass. I've asked a question or two, but still do not see direct answers to what I've asked. Excuse the complaining for the moment please.Cross posting is frowned upon ... so I hesitate to post the same question in the physics forum. Maybe a moderator would be so kind as to move it there. <br />Posted by xmo1</DIV></p><p>The increase of mass with speed is a result of the Lorentz transformation of special relativity.&nbsp; It is a logical consequence of two postulates:&nbsp; 1)&nbsp; the laws of physics are the same in all inertial reference frames and 2) the speed of light is constant in all inertial reference frames.</p><p>You can see the derivation of the Lorentz transformation in any good book on special relativity.&nbsp; I highly recommend Introduction to Special Relativity by Wolfgang Rindler.&nbsp; Or you can look at the Wiki article http://en.wikipedia.org/wiki/Special_relativity<br /></p> <div class="Discussion_UserSignature"> </div>

 

[Saiph]

<p>Hmm...speed of light, increased mass and it's affects on density...</p><p>&nbsp;</p><p>I want to say density does increase from the observers frame of reference...(length contraction reduces observed volume..)</p><p>&nbsp;</p><p>So...does a relativistic boat sink?&nbsp; Assuming the water doesn't obliterate it of course <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-tongue-out.gif" border="0" alt="Tongue out" title="Tongue out" /> </p> <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[Mee_n_Mac]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>So I guess most people would&nbsp;wonder what economic gain&nbsp;will&nbsp;be realized from the Higgs experiments. <br />Posted by <strong>xmo1</strong></DIV><br /><br />Probably nothing you could directly point to and say "See there". But the above is basic science research, who knows what develops because we come to&nbsp;understand how the world operates just a bit better.&nbsp; Let me speculate in a big way here (simply because it's fun to do so) ....&nbsp; If mass is the result of an interaction with an external Higgs field, might we find a way to reduce or completely block this field from affecting matter ?&nbsp; The flip side of mass is inertia and so imagine the effect on space flight and propulsion&nbsp;if inertia could be reduced to 1% of normal.</p><p>&nbsp;</p><p>As for relativistic ships ... assuming the hull holds and the radiation doesn't kill you, I guess a displacement type hull would sit lower in the water.&nbsp; (and so much for&nbsp;&nbsp;<font size="2"><font face="Arial">1.34 * (LWL)^1/2</font></font> <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-wink.gif" border="0" alt="Wink" title="Wink" />)</p> <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not quite true.&nbsp; Photons have momentum and energy, but do not have mass.&nbsp; At least, they are predicted to have no rest mass.&nbsp; There have been continuing experiments that keep dropping the upper limit of the minimum mass that we can measure.&nbsp; I believe it is somewhere around 10^-50 grams.&nbsp; Every time photons have been "weighed", they always fall below what our threshhold for measurements are.&nbsp;First, black holes don't 'exert' a force.&nbsp; They affect the curvature of spacetime around them.&nbsp; Photons (or any particle) follow this curvature.&nbsp; The particles are following what is referred to as a geodesic... a straight line in curved space.&nbsp; The event horizon of black hole is the region of spacetime where all geodesic paths fall towards the singularity.&nbsp; Particles are not accelerated to speeds beyond the speed of light when they hit the event horizon.&nbsp; In particlular with supermassive black holes, a rocket ship might not even recognize it crossed the event horizon... at least until it tried to change it trajectory outward. &nbsp; <br />Posted by derekmcd</DIV></p><p>Whether you refer to gravity as a force or not is a matter of taste.&nbsp; It is not really wrong to do so, and the gravity of a black hole is the same as gravity of anything else, just more intense near the source.</p><p>A rocket crossing the event horizon of a supermassive black hole would start to notice tidal forces pretty quickly as it progressed along the geodesics towards the singularity.&nbsp; In fact it and everything in it would be stretched out and pulled apart -- rather like being on a midevil rack with hydraulic power.&nbsp; You would probably notice that, for a short period of time. <br /></p> <div class="Discussion_UserSignature"> </div>

 

[xmo1]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The mass increases because of the energy that has been added. Energy has mass. <br />Posted by billslugg</DIV></p><p>Energy has mass?</p><p>http://en.wikipedia.org/wiki/Inertia#Inertial_mass</p><p>http://en.wikipedia.org/wiki/Photon</p><p>http://en.wikipedia.org/wiki/Electric_charge</p><p>http://en.wikipedia.org/wiki/Power_(physics)</p><p>http://en.wikipedia.org/wiki/Energy</p><p>During a 1961 lecture<sup class="reference">[7]</sup> for undergraduate students at the California Institute of Technology, Richard Feynman, a celebrated physics teacher and Nobel Laureate, said this about the concept of energy:</p><table border="0" class="cquote" style="margin:auto;border-collapse:collapse;background-color:transparent;border-style:none"><tbody><tr><td width="20" valign="top" style="font-weight:bold;font-size:35px;color:#b2b7f2;font-family:'TimesNewRoman',serif;text-align:left;padding:10px">&ldquo;

 

[xmo1]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The increase of mass with speed is a result of the Lorentz transformation of special relativity.&nbsp; It is a logical consequence of two postulates:&nbsp; 1)&nbsp; the laws of physics are the same in all inertial reference frames and 2) the speed of light is constant in all inertial reference frames.You can see the derivation of the Lorentz transformation in any good book on special relativity.&nbsp; I highly recommend Introduction to Special Relativity by Wolfgang Rindler.&nbsp; Or you can look at the Wiki article http://en.wikipedia.org/wiki/Special_relativity <br />Posted by DrRocket</DIV><br /><br />Thank you so much.</p><p>I just posted in Physics (Matter/Energy Transformation), having an image in my mind that may be preventing my understanding of special relativity. I'll get Rindler's book, and hopefully if someone answers my questions then all the better.</p> <div class="Discussion_UserSignature"> <p>DenniSys.com</p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Energy has mass?http://en.wikipedia.org/wiki/Inertia#Inertial_masshttp://en.wikipedia.org/wiki/Photonhttp://en.wikipedia.org/wiki/Electric_chargehttp://en.wikipedia.org/wiki/Power_(physics)http://en.wikipedia.org/wiki/EnergyDuring a 1961 lecture[7] for undergraduate students at the California Institute of Technology, Richard Feynman, a celebrated physics teacher and Nobel Laureate, said this about the concept of energy:&ldquo;There is a fact, or if you wish, a law, governing natural phenomena that are known to date. There is no known exception to this law; it is exact, so far we know. The law is called conservation of energy; it states that there is a certain quantity, which we call energy, that does not change in manifold changes which nature undergoes. That is a most abstract idea, because it is a mathematical principle; it says that there is a numerical quantity, which does not change when something happens. It is not a description of a mechanism, or anything concrete; it is just a strange fact that we can calculate some number, and when we finish watching nature go through her tricks and calculate the number again, it is the same.&rdquo;&mdash;The Feynman Lectures on Physics[7]So if I push off (from rest) a hydrogen atom what happens? My understanding is that the force imparted to the atom is added, as inertia, to it&nbsp;through the increase in&nbsp;the atom's&nbsp;momentum. It does not add to the gravitational mass of the atom, but&nbsp;on the other hand gravitational and inertial masses are equal.I would say at this point, that the new inertial mass of the atom has increased in energy because it will now take an equal force to bring it back to rest.I've added the URL's because they have helped me&nbsp;understand the concepts being discussed.I'm still not out of the woods with this. So I'm going to post another question. <br />Posted by xmo1</DIV></p><p>Ihaven't looked through you links but this is what is going on.</p><p>Mass and energy are the same thing -- and gravitational mass and inertial mass are also the same thing.</p><p>The mass and energy of a body are dependent on the reference frame of the observer.&nbsp; </p><p>If a body is moving, relative to an observer, then in that observer's frame of reference the body has a mass greater than the rest mass, and the change is described by the Lorentz transformation.&nbsp; That mass affects inertia, and it affects gravity.&nbsp; Mass is mass. It is also energy.&nbsp; The kinetic energy of the moving body can be calculated from Einstein's equation for the equivalence of mass and energy.&nbsp; In fact the total energy is E=mc^2 where m is the total mass as determined using the Lorentz transformation and the kinetic energy is (m - m0)c^2 where m0 is the rest mass.</p><p>When you apply a force to a hydrogen atom, or anything else, and cause it to move it is not the force that contributes to the energy, but rather the energy.&nbsp; Energy is the force times the distance over which it is applied.&nbsp; That appears as energy of the body, calculated according to the above formula and the increase in energy is the kinetic energy.&nbsp; It is not the mass that has increased in energy but rather the body that has increased in energy and that increase in energy is reflected by the increase of mass (remember that in relativity mass and energy are the same thing).<br /></p> <div class="Discussion_UserSignature"> </div>

 

[i_think]

<p><font size="1">Matter/energy/information can't exceed the speed of light.&nbsp; Matter is composed of a group of&nbsp;elementary particles&nbsp;operating as a cohesive unit, as opposed to various radomn particles&nbsp;moving through space independantly.&nbsp;&nbsp;This organization of particles into matter&nbsp;requires the exchange of information between particles, and&nbsp;this exchange of information is limited by&nbsp;c.&nbsp; Of course&nbsp;matter can't exceed c&nbsp;because&nbsp;at c the elementary particles can no longer exchange information&nbsp;with each&nbsp;other as required to operate as a unit.&nbsp; </font><font size="1">With a unit of matter at rest, the&nbsp;information being exchanged between&nbsp;the&nbsp;elementary particles can&nbsp;travel at c, however as the unit approaches c the relative speed of information exchange is reduced&nbsp;by the speed of the unit.&nbsp; Time is the rate of information exchange,&nbsp;the information is energy, and&nbsp;mass is the processing of energy/information.&nbsp; </font></p><p>&nbsp;</p><p>&nbsp;&nbsp;<br /></p>

 

[vandivx]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> ... Without changing the volume or density, accelerating stuff that has mass to near C speeds will increase it's apparent mass. This <font color="#993300">fast moving stuff will now be harder to change it's path</font> <font color="#800000">or speed it up or slow it down than it would be if it were sitting still.&nbsp; That's why</font> <font color="#993300">you need very strong magnetic feilds in something like the LHC which has to <font color="#ff0000">redirect the path</font> of fast moving protons.</font>&nbsp; </p><p>Imagine a single proton&nbsp;...&nbsp; With a single particle concepts like density and volume now don't matter.&nbsp;...&nbsp; Now <font color="#993300">accelerate that single particle to 0.999C</font>.&nbsp; It's still the same particle but it'll <font color="#993300">now if you want to change it's <font color="#ff0000">path</font> you'll have to use a much large force to do it that you would if it were sitting still.</font>&nbsp;Why this is true is not obvious to me but it's been proven experimentally a number of times. <br />Posted by Mee_n_Mac</DIV><br /><br />you seem to believe that the relativistic mass increase acts in the same way as the&nbsp;rest mass, that is, you seem to think that the mass increase is isotropic - same in all directions,&nbsp;like if you kick a foot ball along the playing field or crosswise, it puts up the same resistance against your&nbsp;foot.</p><p>But relativistic mass increase&nbsp;acts with increased inertia&nbsp;only in the direction of the&nbsp;motion of the particle. As far as&nbsp;changing its&nbsp;path goes (its direction of motion), the mass&nbsp;(its 'crossways' mass so to speak) is the rest mass.</p><p>Reason why the magnets have to be so powerfull in LHC is because heavy particles get deflected in magnetic field much less at given velocity than the&nbsp;light ones. Where electron makes nicely curved path in magnetic field, a&nbsp;proton hardly curves under the same conditions and it is not because of relativistic mass increase at all. At speeds nearing speed of light,&nbsp;protons must be hard to change their direction of&nbsp;motion never mind the relativistic mass increase.&nbsp;Of course, not being an experimentalist, I don't know if they aren't using those magnets nowadays also to accelerate the particles along the direction of motion&nbsp;in which case it would not be&nbsp;as I say. I mean there still wouldn't be crosways mass increase but the magnets would have to be very big as they are indeed.</p><p>With the relativistic mass increase only in the direction of motion,&nbsp;it is the same as when you simulate gravitational field by pushing for example a small&nbsp;globe - say&nbsp;a foot in diameter with little figures of people placed&nbsp;on it and you give it&nbsp;9.8 m/s/s acceleration&nbsp;and those figures that find themselves on the fore part of the globe are pressed down as if they were on real Earth... point is, you can't accelerate the globe (while keeping its size constant)&nbsp;so that all&nbsp;the&nbsp;figures on all parts of it and at the&nbsp;same time&nbsp;are pressed down by that artificial gravitation at 1g. All motionally simulated gravitation is only unidirectional and so it is with the&nbsp;relativistic mass increase. After all, acceleration is also a velocity, albeit changing one but&nbsp;that is inessential. </p><p>We can 'play' with mass, increasing it&nbsp;by giving it relativistic speed but that kind of mass is not the same in all respects as the rest mass, same as with using acceleration to generate artificial&nbsp;gravitation is not in all respects the same as real gravitation.</p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>you seem to believe that the relativistic mass increase acts in the same way as the&nbsp;rest mass, that is, you seem to think that the mass increase is isotropic - same in all directions,&nbsp;like if you kick a foot ball along the playing field or crosswise, it puts up the same resistance against your&nbsp;foot.But relativistic mass increase&nbsp;acts with increased inertia&nbsp;only in the direction of the&nbsp;motion of the particle. As far as&nbsp;changing its&nbsp;path goes (its direction of motion), the mass&nbsp;(its 'crossways' mass so to speak) is the rest mass.Reason why the magnets have to be so powerfull in LHC is because heavy particles get deflected in magnetic field much less at given velocity than the&nbsp;light ones. Where electron makes nicely curved path in magnetic field, a&nbsp;proton hardly curves under the same conditions and it is not because of relativistic mass increase at all. At speeds nearing speed of light,&nbsp;protons must be hard to change their direction of&nbsp;motion never mind the relativistic mass increase.&nbsp;Of course, not being an experimentalist, I don't know if they aren't using those magnets nowadays also to accelerate the particles along the direction of motion&nbsp;in which case it would not be&nbsp;as I say. I mean there still wouldn't be crosways mass increase but the magnets would have to be very big as they are indeed.With the relativistic mass increase only in the direction of motion,&nbsp;it is the same as when you simulate gravitational field by pushing for example a small&nbsp;globe - say&nbsp;a foot in diameter with little figures of people placed&nbsp;on it and you give it&nbsp;9.8 m/s/s acceleration&nbsp;and those figures that find themselves on the fore part of the globe are pressed down as if they were on real Earth... point is, you can't accelerate the globe (while keeping its size constant)&nbsp;so that all&nbsp;the&nbsp;figures on all parts of it and at the&nbsp;same time&nbsp;are pressed down by that artificial gravitation at 1g. All motionally simulated gravitation is only unidirectional and so it is with the&nbsp;relativistic mass increase. After all, acceleration is also a velocity, albeit changing one but&nbsp;that is inessential. We can 'play' with mass, increasing it&nbsp;by giving it relativistic speed but that kind of mass is not the same in all respects as the rest mass, same as with using acceleration to generate artificial&nbsp;gravitation is not in all respects the same as real gravitation. <br />Posted by vandivx</DIV></p><p>You seem to be confusing, within the context of special relativity,&nbsp;mass with rest mass, and also accepting the common F = ma in place of the correct F = dp/dt.&nbsp; If you try to cling to F = ma then you get into trouble that requires re-thinkin the idea of mass so that it is not a simple scalar (which is of necessity isotropic).</p><p>But if you correctly formulate Newton's second law, as Newton stated it F = dp/dt with incorporates provisions for non-constant mass then the notion of relativistic mass (which increases with speed) works perfectly and mass remains a scalar and therefore isotropic.&nbsp; It has no variation with direction.&nbsp;</p><p>http://en.wikipedia.org/wiki/Mass_in_special_relativity</p><p>If you are making your statements within the context of general relativity, rather than just special relativity, then you are quite simply over-reaching.&nbsp; The concept of mass in general relativity becomes a bit complicated, to say the least.</p><p>http://en.wikipedia.org/wiki/Mass_in_general_relativity</p><p>In either case you are basically wrong.<br /></p> <div class="Discussion_UserSignature"> </div>

 

[vandivx]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You seem to be confusing, within the context of special relativity,&nbsp;mass with rest mass, and also accepting the common F = ma in place of the correct F = dp/dt.&nbsp; If you try to cling to F = ma then you get into trouble that requires re-thinkin the idea of mass so that it is not a simple scalar (which is of necessity isotropic).But if you correctly formulate Newton's second law, as Newton stated it F = dp/dt with incorporates provisions for non-constant mass then the notion of relativistic mass (which increases with speed) works perfectly and mass remains a scalar and therefore isotropic.&nbsp; It has no variation with direction.&nbsp;http://en.wikipedia.org/wiki/Mass_in_special_relativity</p><p>If you are making your statements within the context of general relativity, rather than just special relativity, then you are quite simply over-reaching.&nbsp; The concept of mass in general relativity becomes a bit complicated, to say the least.http://en.wikipedia.org/wiki/Mass_in_general_relativityIn either case you are basically wrong. <br />Posted by DrRocket</DIV></p><p>"F = ma in place of the correct F = dp/dt" I must say that I am quite&nbsp;familiar with this argument and don't accept it, same as many in the physics field out there. This is no small dispute and I suppose we both know it. That's also&nbsp;why it took you no time to bring it up.</p><p>Why don't we ask the accelerator people whether they have to battle relativistic mass in steering the particle beams around. Offhand, I'd wagger that if they had to overcome in deflecting the relativistic particles all their increased mass - then&nbsp;curved path&nbsp;accelerators&nbsp;would not be feasible.&nbsp;</p><p>In short, I don't believe that&nbsp;'mass is mass', IMHO it all depends, there is mass and mass.</p><p><br /><br />as for the second part, this whole thread topic is about special relativistic mass increase&nbsp;</p><p>&nbsp;</p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>In either case you are basically wrong. <br />Posted by DrRocket</DIV></p><p>that is typical line&nbsp;of those on the defensive</p> <div class="Discussion_UserSignature"> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>"F = ma in place of the correct F = dp/dt" I must say that I am quite&nbsp;familiar with this argument and don't accept it, same as many in the physics field out there. This is no small dispute and I suppose we both know it. That's also&nbsp;why it took you no time to bring it up.Why don't we ask the accelerator people whether they have to battle relativistic mass in steering the particle beams around. Offhand, I'd wagger that if they had to overcome in deflecting the relativistic particles all their increased mass - then&nbsp;curved path&nbsp;accelerators&nbsp;would not be feasible.&nbsp;In short, I don't believe that&nbsp;'mass is mass', IMHO it all depends, there is mass and mass.as for the second part, this whole thread topic is about special relativistic mass increase&nbsp;&nbsp;that is typical line&nbsp;of those on the defensive <br />Posted by vandivx</DIV></p><p>I agree that you do not accept <strong>F</strong> = d<strong>p</strong>/dt, but that is most certainly not true of "many in the physics field out there."&nbsp; You may be quite familiar with the concept, but you clearly do not understand it and there is no argument.&nbsp; It is simply Newton's second law, and it applies in special relativity as well as in classical mechanics.&nbsp; In special relativity it shows up directly as&nbsp;<strong>F</strong> = d<strong>p</strong>/dt, when you consider 3-force and in a basically equivalent form in the 4-force formulation.</p><p>&nbsp;<strong>F</strong> = d<strong>p</strong>/dt is in fact Newton's second law as originally formulated by Newton and it is Newton's second as found in all standard physics texts on classical mechanics.&nbsp; The standard text for first-year graduate students is <em>Classical Mechanics </em>by Herbert Goldstein.&nbsp; On page 1, Chapter 1 you will find Newton's second law of motion clearly written, as equation (1-1) F = d<strong>p</strong>/dt.&nbsp; That is pretty clear and equally fundamental.</p><p>That equation also holds in special relativity as I stated, and as you can find in section 35 of <em>Introduction to Special Relativity </em>by&nbsp;Wolfgang Rindler. &nbsp; There is no controversy, except in your mind.&nbsp; And physicists do not care what you believe.</p><p>Who is on the defensive ? And what are you talking about ?</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[Mee_n_Mac]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> As far as&nbsp;changing its&nbsp;path goes (its direction of motion), the mass&nbsp;(its 'crossways' mass so to speak) is the rest mass. Posted by <strong>vandivx</strong></DIV><br /><br />I hear ya but what's your response to the deflection equation given here ...</p><p class="heading"><strong>Magnetic deflectors<br /></strong>In the small deflection angle <em>&theta;</em> limit, tan <em>&theta;</em> <img class="symbol" src="http://www.kayelaby.npl.co.uk/images/approx.gif" alt="" height="9" /> <em>&theta;</em>, a magnetic deflector of length <em>l</em> in metres, and field strength <em>B</em>, in Tesla, will produce a deflection</p><table border="0" cellspacing="0" cellpadding="2"><tbody><tr><td rowspan="2"><p align="right"><em>&theta;</em>(rad) =&nbsp; </p>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I hear ya but what your response to the deflection equation given here ...Magnetic deflectorsIn the small deflection angle &theta; limit, tan &theta; &theta;, a magnetic deflector of length l in metres, and field strength B, in Tesla, will produce a deflection&theta;(rad) =&nbsp; qeBl&nbsp;&nbsp;300qBl&nbsp;&nbsp;(Eo in MeV)p(&gamma;2 &minus; 1)1/2Eoor, in the non-relativistic approximation,&theta;(rad)&nbsp;qBl&nbsp;&nbsp;&nbsp;(Ek in MeV, m0, in a.u.)0.144(Ekm0)1/2Using the particle's rest energy Eo, the kinetic energy Ek and the Lorentz factor &gamma; &equiv; 1 + Ek/Er the comments in Chap 2.3.3 at this linkhttp://ocw.mit.edu/NR/rdonlyres/09EF537D-6E64-49EB-B0D1-91B72CE0665D/0/chap2.pdfEDIT : Yikes it appears the equations, specifically the divisor sign, didn't paste so good.&nbsp;Perhaps best to go to the URL.&nbsp; Sorry 'bout that. <br />Posted by Mee_n_Mac</DIV></p><p>Out of curiousity, which MIT course does this come from ?&nbsp; I was not able to back the URL through the opens course lists and figure out to which specific course this (rather good) chapter applies.&nbsp; It appears to be a good electrodynamics text, on line.&nbsp; </p> <div class="Discussion_UserSignature"> </div>

 

[Mee_n_Mac]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Out of curiousity, which MIT course does this come from ?&nbsp; I was not able to back the URL through the opens course lists and figure out to which specific course this (rather good) chapter applies.&nbsp; It appears to be a good electrodynamics text, on line.&nbsp; <br />Posted by <strong>DrRocket</strong></DIV><br /></p><p>Sure, now you ask.&nbsp;<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-wink.gif" border="0" alt="Wink" title="Wink" />&nbsp; It came up via a Google search.&nbsp; I went to MIT's OpenCourseWare siteto try to find the corresponding course.&nbsp; I couldn't find it but it's got to be there somewhere.&nbsp; Lot's of good info there otherwise though ....&nbsp;&nbsp; Now you've got me curious, I'll have to look again when I have some free time.</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>

 

[vandivx]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I hear ya but what's your response to the deflection equation given here ..</p><p>....</p><p>Or the comments in Chap 2.3.3 at this linkhttp://ocw.mit.edu/NR/rdonlyres/09EF537D-6E64-49EB-B0D1-91B72CE0665D/0/chap2.pdf </p><p>Posted by Mee_n_Mac</DIV></p><p>I'd rather stick to discussing&nbsp;special relativity and uncharged masses, I realize now that in particle&nbsp;accelerators with electromagnetics involved in it, things are different but will look at it and give it some thinking this weekend.&nbsp;After five minutes looking at it (have to do other things at the moment), I am not sure if that actually fully makes your point or mine, all I can see is that I wasn't at minimum quite correct about particle accelerators. </p><p>&nbsp;But what chiefly interests me is uncharged mass in special relativistic situations. There I would say I am still open to change my mind but I would need to see some convincing physical argumentation, the F=dp/dt vs F=ma looks to me as not really resolving the issue at hand. All it does is do away with the&nbsp;rest mass at the root&nbsp;and I really don't have problem going with the momentum 'm*v composite' equation.</p><p>&nbsp;----------</p><p>thank you for argumenting in civilized way, that is&nbsp;without making personal slighting comments</p><p>I think I should make that into my signature</p> <div class="Discussion_UserSignature"> </div>