Thought Experiment.... "In a Closed System, what would be heavier"?

[Times Roman]

Assumptions.

Two closed containers (air/water tight) each with the EXACT same amount of water.

Container 1:
Is Frozen with the water inside

Container 2:
Is heated to boil the water inside

At the precise moment, whether the container was just frozen or boiled, it is weighed.

Please tell me, which one is heavier? And Please explain to me why you say that.

Have fun!

---Roman

[Euroholic]

Same?

[Times Roman]

Same?

wrong. and btw, everything weighs the same before the experiment

[Euroholic]

Its #1 then

[Times Roman]

Its #1 then

and why is that?

[Euroholic]

If its boiling its losing water

[Times Roman]

If its boiling its losing water

which is why I said "closed system".

I also said "air/water tight" which means nothing gets in and nothing gets out.....

try again?

[Euroholic]

I give up

[Times Roman]

anyone else?

[kronik420]

1. Ice is heavier than water?

[almostgone]

Hmmm.....a stickler.....closed system = pressure vessel= higher boiling temp for H2O....freezing in a pressure vessel with no head space = damaged container......
Am I reading too much into it?????

[almostgone]

Same container construction...materials, weldments, etc?




I still don't know...

[lovbyts]

The hot water is actually heavier. Accoring to Einstein Energy has mass. E=mc2 Therefore when you add energy to something it actually gets heavier. Therefore Hot water is actually heavier than cold or frozen water.

[almostgone]

But a closed system allows no transfer of energy or matter so wouldn't they weigh the same given the same volumes?

[almostgone]

In thermodynamics, it would be an isolated system.....correct?

[lovbyts]

But a closed system allows no transfer of energy or matter so wouldn't they weigh the same given the same volumes?

No transfer of energy? Heat causes the molecules to move quicker, freezing slows them down. That's energy.

[almostgone]

But the definition of a closed system is that it doesn't allow the transfer of energy...if I recall correctly.....
That's why I threw in the thermodynamics disclaimer...at that point it becomes an isolated system....


My head hurts....lol

[clarky.]

Oh thats a good one TM

[Zodiac82]

which is "heavier"...would be number one...even though they weigh the same ice would appear heavier bcuz its more dense...kind of like a piece of plywood or somethin..if its 200 lbs it would be easier to pick up than the same 200 pound plywood that's been made into a condensed cube....I think lol

[Zodiac82]

somehow I knew this was a TR thread before I opened it lol

[trikydik]

Sorry - they still weigh the same.

The mass of the water does not change when you heat it up or freeze it. All you have done is change it from one state of matter to another.
The heating of water will excite the individual molecules causing them to move around more. In fact, depending on how much water is in the vessel, it may not even boil.

For Einstein's equation to mean anything on the macroscopic scale, like your thought experiment - you would need pressures equal to a healthy stellar core. Then you would begin to loose mass due to the conversion to energy and the breakdown of the nuclear force through fusion. As a paperclip sized object breaking down would be about 18-20 kT, your water vessel would be in the megatons.

But back to your experiment - simply heating the water does not change how much it weighs in a given vessel. In your experiment you would use Plank's version of this equation M = (E0 + pV0)/c2 where p is the pressure and V the volume, in order to express the relation between mass, its "latent energy", and thermodynamic energy within the body.

["Maximus"]

Sorry - they still weigh the same.

The mass of the water does not change when you heat it up or freeze it. All you have done is change it from one state of matter to another.
The heating of water will excite the individual molecules causing them to move around more. In fact, depending on how much water is in the vessel, it may not even boil.

For Einstein's equation to mean anything on the macroscopic scale, like your thought experiment - you would need pressures equal to a healthy stellar core. Then you would begin to loose mass due to the conversion to energy and the breakdown of the nuclear force through fusion. As a paperclip sized object breaking down would be about 18-20 kT, your water vessel would be in the megatons.

But back to your experiment - simply heating the water does not change how much it weighs in a given vessel. In your experiment you would use Plank's version of this equation M = (E0 + pV0)/c2 where p is the pressure and V the volume, in order to express the relation between mass, its "latent energy", and thermodynamic energy within the body.

I would say: yes, no, and "maybe".. by conventional physics, both weigh the same, by Particle physics up thrust of actual weight and the weight due to their matter state is significant different.

I can't pull all the formulas right now but this got me going so early in the morning.. had to be TR!

[tarmyg]

Closed system means the First Law of Thermodynamics apply IMO.

~T

[bartman314]

if they are sealed prior to heating or cooling, then they weigh the same because each has the same mass of water and air.

if they are sealed at the moment of weighing (which would allow the air to equilibrate with to the undisplaced volume of water/ice in the container), then the hot container weighs more because the density of ice is lower than the density of water. ice expands more as a result of freezing than water expands as a result of thermal expansion, which results in a smaller volume for air in the cold container.

[DeniZen]

doesn't make sense. If it's a closed system, how can it be heated or frozen externally?

[trikydik]

doesn't make sense in another way. If I freeze 1 pound of water, it is still 1 pound of water. Freezing it changes it density yes, but that does not change its weight. If I melt one pound of lead, it is still 1 pound of lead.

The only time relativistic effects of density come into play is when you crush something so small that its gravity increases such as in a singularity. However, you would need to crush 100 gallons of water to the size of a single molecule for that to happen. So increase in weight due to increase in density is out for the thought experiment as we are not crushing the tank of water only heating and cooling it.

[noon]

Hmm.
- If the research proves true, that would bolster the validity of a thought experiment suggesting a cat can be both alive and dead at the same time.

[trikydik]

Hmm.
- If the research proves true, that would bolster the validity of a thought experiment suggesting a cat can be both alive and dead at the same time.

Schrodinger's cat - you cannot know if it is alive or dead unless you look at it....not quite the same thing here but OK...

[trikydik]

It’s a little known fact that Albert Einstein’s famous work on special relativity was spurred by a thought experiment he conducted when he was only 16 years old. In his book Autobiographical Notes, Einstein recalls how he once daydreamed about chasing a beam of light as it traveled through space. He reasoned that if he were able to move next to it at the speed of light, he should be able to observe the light frozen in space as “an electromagnetic field at rest though spatially oscillating.” For Einstein, this thought experiment proved that for his imaginary observer “everything would have to happen according to the same laws as for an observer who, relative to the Earth, was at rest.”

[DrewZ]

Reading this thread I feel like I'm watching an episode of The Big Bang Theory.

Only there's one thing missing.....


Ahhhhhhh, there thats better.
Carry on!

[Euroholic]

Reading this thread I feel like I'm watching an episode of The Big Bang Theory.

Only there's one thing missing.....


Ahhhhhhh, there thats better.
Carry on!

She looks like my sister. Ugly

[trikydik]

Reading this thread I feel like I'm watching an episode of The Big Bang Theory.

Only there's one thing missing.....


Ahhhhhhh, there thats better.
Carry on!

Her ass is so very spankable and kissable...