RE: For the physicists in the house. (Full Version)

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MrRodgers -> RE: For the physicists in the house. (1/1/2013 9:47:18 AM)


quote:

ORIGINAL: Aswad

quote:

ORIGINAL: InnerExtrovert

Hey, I know! Let's get out some weighted nipple clamps, burner, and the Cavendish Torsion Balance and do an experiment.


quote:

If you're offering up your own nipples, I'm game. If you want to singe mine, I'm not. [:D]


'I knew a girl from Kansas City, she served whiskey...right out of her titties.'

quote:

Now, as for the equivalence, I was under the impression that a moving object has an effective mass that is porportional to the speed of its movement. If that is incorrect, I would appreciate a correction. If it's actually correct, I fail to see how this wouldn't also be the case for the thermal motion within the object, and would also appreciate being shown how that isn't so (random movements leading to a net zero contribution?).


IWYW,
— Aswad.

Don't tell that to the nuclear crowd. Or... maybe we should.





ARIES83 -> RE: For the physicists in the house. (1/1/2013 9:51:35 AM)

This is from Wiki,

Raising the temperature of an object (increasing its heat energy) increases its mass. For example, consider the world's primary mass standard for the kilogram, made of platinum/iridium. If its temperature is allowed to change by 1°C, its mass will change by 1.5 picograms.
----------------





Aswad -> RE: For the physicists in the house. (1/1/2013 9:59:22 AM)

quote:

ORIGINAL: Hillwilliam

As gravity only affects massive objects, a photon must have mass.


Actually, a photon only has inertial mass, as I recall, not "ordinary mass".

In a flat spacetime, a geodesic is a straight line. The relativistic view is that a photon simply moves along a geodesic. Essentially, that it's not the photon that is influenced by gravitation, but rather the spacetime through which the photon moves that is influenced. In the curved spacetime near a massive body, a geodesic is no longer a straight line.

quote:

Maybe I mistunderstand you but the thermal energy of an object in my definition is the heat contained in that object. heat is an artifact of atomic/molecular vibration.


The speed of that vibration, specifically.

IWYW,
— Aswad.



Musicmystery -> RE: For the physicists in the house. (1/1/2013 10:25:52 AM)


quote:

ORIGINAL: Aswad

quote:

ORIGINAL: Musicmystery

So getting hot and getting heavy are the same?


Hot implies temperature, which is porportional to heat, but not the same as heat.

Apart from that, such seems to be the case, to my ignorance.

It was a joke; both phrases are idioms for a passionate encounter.



Muttling -> RE: For the physicists in the house. (1/1/2013 10:37:32 AM)


quote:

ORIGINAL: ARIES83

This is from Wiki,

Raising the temperature of an object (increasing its heat energy) increases its mass. For example, consider the world's primary mass standard for the kilogram, made of platinum/iridium. If its temperature is allowed to change by 1°C, its mass will change by 1.5 picograms.
----------------






This is incorrect. Raising the temperature of an object increases the volume of the object (except in the case of ice when it's melted into water), but it has absolute NO effect on the mass of the object.



ARIES83 -> RE: For the physicists in the house. (1/1/2013 10:43:37 AM)

Thanks for that Aswad, good explanation, a lot
better that trying to visualize relativistic mass.[:D]

While your at it can you do a similar version for
time dilation?

-Aries

PS, I just cut pasted it muttling, it's in
"practical examples".
Wiki

Here's another one
-Wiki
Another example is hydroelectric generation. The electrical energy produced by Grand Coulee Dam's turbines every 3.7 hours represents one gram of mass. This mass passes to the electrical devices (such as lights in cities) which are powered by the generators, where it appears as a gram of heat and light.[23] Turbine designers look at their equations in terms of pressure, torque, and RPM. However,
Einstein's equations show that all energy has mass, and thus the electrical energy produced by a dam's generators, and the heat and light which result from it, all retain their mass, which is equivalent to the energy. The potential energy—and equivalent mass—represented by the waters of the Columbia River as it descends to the Pacific Ocean would be converted to heat due to viscous friction and the turbulence of white water rapids and waterfalls were it not for the dam and its generators. This heat would remain as mass on site at the water, were it not for the equipment which converted some of this potential and kinetic energy into electrical energy, which can be moved from place to place (taking mass with it)



Muttling -> RE: For the physicists in the house. (1/1/2013 10:45:10 AM)


quote:

ORIGINAL: Aswad

Is, by mass-energy equivalence, the thermal energy of an object part of its effective gravitational mass?


No. There is no mass-energy equivalence unless you're referring to nuclear reactions in which case E=mC^2 applies.

Thermal energy has no impact on gravitational mass. Gravitational mass is the mass of an object which is effected by a gravitational field of another object as well as itself and it generally total mass. The other type of mass is inertial mass which can differ from total mass in an object that is spinning. (Basically, the mass towards the outer part of the object has far more inertia than the mass towards the center of rotation as the outer parts of the object are moving much faster than the inner parts.)


Or, phrased differently, does the gravitation of an object depend in part on its heat?

Nope.



MrRodgers -> RE: For the physicists in the house. (1/1/2013 11:13:46 AM)


quote:

ORIGINAL: ARIES83

This is from Wiki,

Raising the temperature of an object (increasing its heat energy) increases its mass. For example, consider the world's primary mass standard for the kilogram, made of platinum/iridium. If its temperature is allowed to change by 1°C, its mass will change by 1.5 picograms.
----------------

'Heat energy' is like saying water wetness. Heat...IS energy. Heating a mass expands the mass because the atoms are active and experience a greater separation.

Unlike gases or liquids, solid materials tend to keep their shape when undergoing thermal expansion.

The effect of heat has only a small fractional effect on gravity, at least of solids.



kdsub -> RE: For the physicists in the house. (1/1/2013 11:57:48 AM)

I would think it would depend on how the heat was applied and how much. Otherwise at a certain temperature certain elements will react with each other forming in some instances different compounds and in the process either gain or loose mass as they gain or lose energy.

Otherwise if you took a pure element contained in a pure vacuum contained in an impervious precisely weighed container that could be precisely weighed at absolute zero and then again at say 1,000,000 degrees the weight of the element in my view would not change. Only when chemical reactions between more than one element will there be conversion to energy.

Most likely wrong of course…lol

Butch



Aswad -> RE: For the physicists in the house. (1/1/2013 12:21:28 PM)

quote:

ORIGINAL: Musicmystery

It was a joke; both phrases are idioms for a passionate encounter.


Mea culpa.

I wasn't familiar with the latter of the two as an idiom.

Thanks for expanding my vocabulary. [:)]

IWYW,
— Aswad.



Aswad -> RE: For the physicists in the house. (1/1/2013 12:47:54 PM)

quote:

ORIGINAL: ARIES83

Thanks for that Aswad, good explanation, a lot better that trying to visualize relativistic mass.[:D]


Thanks for the compliment. You're welcome, of course.

quote:

While your at it can you do a similar version for time dilation?


The distance travelled along a curved path between two points is longer than the distance travelled along the straight path between the same two points. When the local gravitation is weak, you're moving in a straighter line through time than would be the case if the local gravitation were strong, because gravity introduces curvature in the spacetime. Local time, the time you experience, is analogous to the actual distance travelled.

You can verify this yourself with a pair of very precise clocks and a vacation on a high mountain. Such has been done as a family outing by one clock enthusiast, although granted he's pretty "into" timekeeping, being one of the few people around to privately own a hydrogen maser frequency standard. I'm not sure, but I think a rubidium frequency standard might be accurate enough, and those can be had for maybe fifty bucks on eBay for a unit with enough time left on it.

IWYW,
— Aswad.



Aswad -> RE: For the physicists in the house. (1/1/2013 3:59:17 PM)

quote:

ORIGINAL: Muttling

The other type of mass is inertial mass which can differ from total mass in an object that is spinning.


And, if I'm understanding you correctly, gravitation doesn't depend on inertial mass / momentum?

IWYW,
— Aswad.



mnottertail -> RE: For the physicists in the house. (1/2/2013 6:05:48 AM)

well, ya it does.  the old bucket full of water on a rope and swing it around you trick. 

general theory and special theory, gravitation and speed respectively, cute huh?  G=g + S=s. 




vincentML -> RE: For the physicists in the house. (1/2/2013 11:22:34 AM)

quote:

ORIGINAL: ARIES83

This is from Wiki,

Raising the temperature of an object (increasing its heat energy) increases its mass. For example, consider the world's primary mass standard for the kilogram, made of platinum/iridium. If its temperature is allowed to change by 1°C, its mass will change by 1.5 picograms.
----------------

That seems counterintuitive. As an object loses heat its molecules slow. Intermolecular attractions increase and the object becomes more dense. (think of testicles on a cold day) Since mass is not converted to energy by ordinary physical means the same amount of mass remains. The energy lost was kinetic energy not material conversion. Neu?

ETA: What Hillwilliam said :)

ETA: Another thought experiment. The standard kilogram of mass is stored in a vault in France (Wiki) and was patterned after the mass of one deciliter of water at 4C (the greatest density of water) So the volume of the cylinder should be taken into consideration. When heated the molecules of platinum/iridium will move away from each other slightly so there will be less molecules within the deciliter volume, hence a decrease in mass. Check me on this. I may have really screwed it up. . . .lol!



mnottertail -> RE: For the physicists in the house. (1/2/2013 11:53:22 AM)

but you confuse (a mole of weight) with atomic mass, agreeing that they are sort of closely related, but when being punctillious....

Where did the heat go?  It was dissapated and reclaimed by the atoms surrounding it.

Like in the spring here, heat comes in the ground and fog arises (think of the atomic explosion of capturing all those btus in a bottle) and the fall, the heat leaves the ground and fog arises.....  

Don't focus on the fog and say they are equivalent events here, the physics question is you put in cold and it comes out cold, and you put in hot, it comes out hot.....

HOW DO IT KNOW?

And, how many million megatons of heat are decending upon our earth from the sun at any given instant?   How much does the light weigh that we see around us on our earth?



vincentML -> RE: For the physicists in the house. (1/2/2013 12:06:22 PM)

quote:

Where did the heat go? It was dissapated and reclaimed by the atoms surrounding it.

If it was disappated and the temperature of the object reduced then kinetic energy warmed molecules surrounding the object, say air molecules for simplicity, and the air molecules vibrated faster. How do we know? The air temp has been raised. The energy is transfered from kinetic to radiant to kinetic at the expense of the object molecules and to the enrichment of the air molecules.



mnottertail -> RE: For the physicists in the house. (1/2/2013 12:11:39 PM)

It has, and with that energy went mass.   excited atoms (photons if you will) have got to throw it off somewhere.

And we know that to be the case, turn on your gas stove and look from eye level at above the flame, the air shimmies in excitation, and we all know that the air above that flame will burn your ass the worst of it, even more so that sticking it into the flame itself.

Lotta shock and awe stuff there at the cusp. 



MercTech -> RE: For the physicists in the house. (1/2/2013 1:11:16 PM)

The crux is whether you are talking an open system or a closed one...
But, the caveat is that the increase is so infinitesimal that one would be very very hard pressed to measure it.

i.e. The burning of a ton of coal causes a mass to energy reaction and reduces the mass of the combustion products by a few pico-grams. C+O2 => CO2 + Energy... and the energy released is in the mass differential between one mole of carbon plus two moles of oxygen and the mass of one mole of carbon dioxide... E=mC**2

Bottom line, it would but not noticeably so.



vincentML -> RE: For the physicists in the house. (1/2/2013 1:12:03 PM)

quote:

It has, and with that energy went mass. excited atoms (photons if you will) have got to throw it off somewhere.

You have a point. Radiant energy exiting as photons would represent a loss of mass . . . but Lawd! It would be infinitesimal.



mnottertail -> RE: For the physicists in the house. (1/2/2013 1:46:02 PM)

Yeah, that is true.   Think of the fog again, each interaction is infintesimal, but taken together you got more than any built to this date atomic bomb.

But look at the girls we go out with, nowhere near the approaching of light speed, and nowhere near the heat of the core of the sun, with masses that are perhaps less than infintesimal when considering photons that are running maybe 60-80% celerity when excited by our pedestrian stoves.   A blast of hot air, I guess is bigtime for the earthly geometer driving the old chevy slova from 0-60 in 5 minutes. 

Now out there in the otherworld............



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