Calling Science, Physics/Chemistry, Sci-Fi buffs - Page 2

Bobby Jim · #16 Jun 7, '12, 11:36 pm

If you can convert the solid to a gas, then liquify it at high pressure and transport it by pipeline. Much more efficient than trucks. If you can get past the environmental regulations to get your pipeline built!

Bobby Jim · #17 Jun 7, '12, 11:54 pm

Quote:

Originally Posted by Rolltide

Instead of transporting gases like nitrogen, they pressurize them, forcing them into a liquid state (which also makes them super cold). They can then transport much larger volmes in a standard tanker truck.

Forgive the digression, but it's not exactly true, that pressurizing gases into liquids makes them cold. It's kind of the opposite actually - if you compress a gas "adiabatically" (i.e. very quickly, so there is no heat flow) it'll get hot. If you want the gas to liquify at reasonable pressure, you have to cool it. Some gases at least, you can theoretically have in liquid or solid form at room temperature, if you have a strong enough container, because the pressure would need to be very high. Now for nitrogen, for example, room temperature is well above the critical point so you can't "liquify" it at room temperature. But a familiar example is carbon dioxide. Your fire extinguisher is filled with liquid CO2, in equilibrium with CO2 gas at high pressure. Maybe it was cold when it was manufactured, but after it sits in your garage for 3 years, it is in thermal equilibrium with your garage. As soon as you open the valve and spray the CO2 out, it rapidly depressurizes. Then it gets very cold (this is the "adiabatic expansion"). Same principle works in your air conditioner and refrigerator by the way, just with fluids that go from liquid to gas at more reasonable temperatures and pressures.

didymus · #18 Jun 8, '12, 3:09 am

Quote:

Originally Posted by GEddie

Until you have atomic transmutation.

Speaking of efficiency, aren't ships better still? Or are we limited to cross-continental movement?

ICXC NIKA

Yes, I was thinking only of ground-based transport -- the OP did start off asking about trucks.

As for transmutation I'd assume the energy requirements would be too huge to ever make it economically feasible.

Hokomai · #19 Jun 8, '12, 3:31 am

Quote:

Originally Posted by MarcoPolo

I believe there is memory metal of some kind that can revert to its original shape, but that doesn't transcend states of matter.

It is like God. Believing does not make it so.

jbarbaretta · #20 Jun 8, '12, 5:56 am

Quote:

Originally Posted by MarcoPolo

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Thanks all for the answers. Layp3rs0n, thanks for the outside of the box thinking - that may be useful.
That link says this: "The Mythbusters theorized that the air being displaced by the birds’ wings and the helicopter rotors was pressing down the box, which is why there was no change in the overall weight."

Okay, that I do not understand. If I am on a scale in a closed bathroom and I jump, the scale spins back to 0 until I land on it again. I'm not pushing air down on it just because I jumped. Nor was there any change in my mass.

That actually isn't a perfect comparison, since what you are talking about is closer to hot air in a balloon rather then flying ducks. There is no coefficient of lift (induced or dynamic) involved in a hot air balloon rising. You would in fact be creating a very light truck (assuming you're gaseous cargo is less dense than the air outside the truck). Great gas mileage, but still - no usable cargo at the other end.

didymus · #21 Jun 8, '12, 6:33 am

Re: the birds in the truck, I've resisted temptation as long as I can.

1.) looking to MythBuster for real science is is a huge mistake.

2.) as for the birds in the truck; "weight" = gravitational force acting on mass, in this case the mass of the truck + the mass of the birds. Those numbers and their sum remain the same no mater what the birds are doing.

3.) Imagine you have a truck holding a box of Mylar balloons (flat). You fill the balloons with He, put them in the truck and throw the box back in for good measure. The balloons are all up against the ceiling even though you've added a couple micrograms of He to the total load.

4.) as for hanging from monkey bars on a scale; again the mass = you plus the bars. Doing chin-ups or hanging from one hand instead of two won't change the total. But, if you let go you're subtracting yourself, however briefly from the bars-you system.

I'm sure I've included some flagrant error for everyone to pounce on.

**GEddie** · #22 Jun 8, '12, 6:51 am

Quote:

Originally Posted by didymus

Re: the birds in the truck, I've resisted temptation as long as I can.

1.) looking to MythBuster for real science is is a huge mistake.

2.) as for the birds in the truck; "weight" = gravitational force acting on mass, in this case the mass of the truck + the mass of the birds. Those numbers and their sum remain the same no mater what the birds are doing.

3.) Imagine you have a truck holding a box of Mylar balloons (flat). You fill the balloons with He, put them in the truck and throw the box back in for good measure. The balloons are all up against the ceiling even though you've added a couple micrograms of He to the total load.

4.) as for hanging from monkey bars on a scale; again the mass = you plus the bars. Doing chin-ups or hanging from one hand instead of two won't change the total. But, if you let go you're subtracting yourself, however briefly from the bars-you system.

I'm sure I've included some flagrant error for everyone to pounce on.

It's all good except #3:

Although you have added some He to the system, you have also subtracted an equal volume of air, which is why the balloons float. The net weight has thereby decreased slightly.

Air is also displaced when a solid body such as a bird or human being is put in. But in those cases, the weight is far greater than that of the air.

ICXC NIKA

MarcoPolo · #23 Jun 8, '12, 7:10 am

Ok, so let me steer this in a slightly different direction. Forget whether the gas increases or decreases weight/mass. What in the bounds of science/pseudo-science could convert a solid, such as a brick or a rabbit, into a gas, and then back again?

MarcoPolo · #24 Jun 8, '12, 7:13 am

Quote:

Originally Posted by GEddie

It will zero while you are falling. When your feet touch, there will be again be a large increase in weight, which reduces to normal body as the springs relax.

Nice graphics btw. I should really learn to post pix.

ICXC NIKA

Thank you.

Okay, so in theory, if a solid became a gas for the duration of a transport, would it at least not cause less wear on the tires?

jbarbaretta · #25 Jun 8, '12, 7:30 am

Quote:

Originally Posted by MarcoPolo

Ok, so let me steer this in a slightly different direction. Forget whether the gas increases or decreases weight/mass. What in the bounds of science/pseudo-science could convert a solid, such as a brick or a rabbit, into a gas, and then back again?

to gas = add energy (i.e. heat)

to solid = remove energy

but you won't be happy with what you get back....
you start out with a cute bunny...
you get back a non-living glob of stuff (stuff being a scientific term for various molecules made out of the various molecules that went into the process, but not necessarily the same molecules that went into it. A simple example. Lets say you ship a product with a preservative (Sodium Nitrite) in it (NaNO2). After heating and cooling you are likely to get back NaNO3 (Sodium Nitrate) and the extra oxygen would then not be available for whatever molecule it originally came from. So, maybe instead of some water (H2O) also in the product, you just get some Hydrogen ions floating around. Not what you started with.

You would need to map every molecule and be able to re-create it in the proper sequence.
Wouldn't it be easier at that point to just buy the raw materials at the destination and build it from scratch?

MarcoPolo · #26 Jun 8, '12, 8:23 am

Quote:

Originally Posted by jbarbaretta

You would need to map every molecule and be able to re-create it in the proper sequence.

We're talking sci-fi here, so that's no problem.

**GEddie** · #27 Jun 8, '12, 9:24 am

Quote:

Originally Posted by MarcoPolo

Thank you.

Okay, so in theory, if a solid became a gas for the duration of a transport, would it at least not cause less wear on the tires?

Is this a heavier, or lighter than air gas?

If the first (like carbon dioxide) then no; if the second (like helium) then yes, but remember, the metal tank adds a huge amount of weight.

ICXC NIKA

MarcoPolo · #28 Jun 8, '12, 10:28 am

Quote:

Originally Posted by GEddie

Is this a heavier, or lighter than air gas?

If the first (like carbon dioxide) then no; if the second (like helium) then yes, but remember, the metal tank adds a huge amount of weight.

ICXC NIKA

There is no tank in my postulation.

Just a floating cloud. What if it was converted to a cloud? Like water vapor and kind of floated around in the cabin?

Also, what do you think about this question:
Ok, so let me steer this in a slightly different direction. Forget whether the gas increases or decreases weight/mass. What in the bounds of science/pseudo-science could convert a solid, such as a brick or a rabbit, into a gas, and then back again?

roselily · #29 Jun 9, '12, 1:08 am

Quote:

Originally Posted by hihiip201

I guess you can say that. when a person is in the air, the moment he is no longer touching the scale he is subjected to gravity and gravity alone(neglecting air drag) so he's not "pushing on the weight" anymore. therefore the the scale doesn't have a force acting on it - hence shows no weight.

But when a bird flying in a tank however it's a little different, if the bird flew to the tip of the box and let themselves subject to gravitation force alone, the scale should show a decrease in weight just like in the case when the person is subjected to gravity alone when in the air.

But FLYING in the air is a different thing, when you are flying, the most naive way (i hope im using the right word) to put it is that when the bird is flying it is essentially pushing down the air(or increasing the pressure under it's wings). hence Newton's 3rd law tells us that the air will push the bird upward (we call that lift) to encounter gravity, allowing the bird to maintain altitude.consequently, the air now has a net momentum downward that is cause by the bird's wings, and that momentum is accounted for the "loss" of bird's weight on the scale, which is why the scale doesn't show a change in weight when birds are flying in the box.

That's the way you can think of it if I take the bird and the fluid as different systems.

Thanks!

I thought something else when I just not read all about it, I thought that all birds on truck had no significent weight compare the big truck. Now see all the birds weight together still too light to weight compare to big truck, so that they stand on the truck or flying up is same for the truck.

Quote:

Originally Posted by MarcoPolo

There is no tank in my postulation.

Just a floating cloud. What if it was converted to a cloud? Like water vapor and kind of floated around in the cabin?

Also, what do you think about this question:
Ok, so let me steer this in a slightly different direction. Forget whether the gas increases or decreases weight/mass. What in the bounds of science/pseudo-science could convert a solid, such as a brick or a rabbit, into a gas, and then back again?

O Marco, Christ Himself could convert a rabbit to gas, then back again. Christ Himself died on the cross, and rise to heaven, the glory of his resurrection. If body died then went to heaven, is soul looks like gas but only could not see through human eyes? then, God can change soul to eternal body.

What is it, body or soul? or both?

2Corinthians 12
2 I know a person in Christ who fourteen years ago was caught up to the third heaven—whether in the body or out of the body I do not know; God knows.3And I know that such a person—whether in the body or out of the body I do not know; God knows—4was caught up into Paradise and heard things that are not to be told, that no mortal is permitted to repeat.

didymus · #30 Jun 9, '12, 3:34 am

Quote:

Originally Posted by MarcoPolo

We're talking sci-fi here, so that's no problem.

Totally the wrong attitude. I expect an author to show some respect for my intelligence even when writing about the impossible (like FTL travel).

Look at Larry Niven -- he did a takedown of the transporter system in Star Trek then used "transfer booths" (pretty much the same as transporters) explaining how all these objections were overcome.

I still don't understand why the focus on trucks BUT the problem remains; matter in whatever form has mass. The only way to reduce it weight would be a gravity reducer/polariser/whatever. But if you had such a thing you'd be moving asteroids into Earth orbit for mining, not worrying about 18-wheelers.