Recent content by Christofer Br

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    B Irreversible expansion of gas against gas

    Actually I have a problem with calculating the final pressure when the initial volumes aren't equal; I end up with: (Cv/R)*[P*V_20+P*V_10-(V_10*P_10-V_20*P_20)]=0 when P=10, P_10=100, P_20=1, V_20=1 I calculate V_10 (initial volume of the gas doing the work) as 1/10 When I plug in the numbers...
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    B Irreversible expansion of gas against gas

    Thank you, this is very useful (and clear so far).
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    B Irreversible expansion of gas against gas

    Of course I am interested!
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    B Irreversible expansion of gas against gas

    Let's say I have a liter of gas at pressure of 4 atm and T=900K. I use it to move perfect massless frictionless and insulative piston to compress a liter of 1 atm, T=300K gas. When the pressure on both sides is equal and the piston stops moving, will the temperature on both sides of the piston...
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    I Can a fusion reaction propagate in a cappilary?

    Can fusion reaction propagate inside a (very thick walled) cappilary if fusion has been initiated at one end? In this situation it seems like all the energy would have nowhere to go but into heating and pressurizing the fuel, providing conditions for further reaction. I imagine this is a...
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    Is Specific impulse indicative of performance as a gun propellant?

    Black powder has specific impulse of around 80s, while rocket candy has up to 130s of specific impulse. Does that mean I could replace the propellant in a BP cartridge with 80/130 of the weight in rocket candy and obtain the same performance in an idealized gun? (as in without considering...
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    B Are massless particles truly massless?

    So what it boils down to is gravity acts on both energy and mass, but they're not the same thing, there's no "duality" there? Does energy resist acceleration in the same sense that mass resists acceleration (F=m*a)?
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    B Are massless particles truly massless?

    Most of the mass of matter comes from energy of strong force interactions between quarks. However the quarks still have intrinsic mass. Other particles have no intrinsic mass but still have energy. So according to mass-energy equivalence, these particles should still have effectively mass, to my...
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    Wood/Glass/Metal Can I use sodium silicate waterglass to cast a glass object?

    Waterglass is sodium silicate dissolved in water that upon drying forms soda glass. Could it therefore be used to cast a glass object like a slab or will it not form nicely?
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    I Detect Negative Mass Matter: Experiments in Solar System

    How could we detect negative mass matter? The only proposal I've ever heard of is that we could detect there's a cutoff frequency in the gravitational waves we receive, due to attenuation of those lower frequency waves by negative matter. Are there more experiments that could be conducted...
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    B Could steam be expanded through a nozzle to get 0°C gas?

    Obviously expanding the gas cools it down. I'm interested if you could boil water and then expand the high pressure steam to cool it down to 0°C. Or are there subtler thermodynamics that would prevent this?
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    I Is there a mechanism for creation of negative energy density

    Excuse me for bad wording in the title, but there is only so much you can do with the character limit. So, has there ever been a proposal for a mechanism through which negative energy density could be created? Or the only possibility considered so far was that it would have been created in the...
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    Is this the simplest optical cloak possible?

    https://www.researchgate.net/publication/273269952_A_Simple_Unidirectional_Optical_Invisibility_Cloak_Made_of_Water Why did the authors of this cloak not choose a system with only three refractions for each light ray, so that the cloaked area would be a parallelogram? Is this impossible, or...
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    How is the 2nd law of thermodynamics obeyed in this system?

    Imagine there is an radiation concentrator (winston cone) surrounded with extremely many layers of foil for radiation insulation, except at the smaller opening. Every part of the setup is initially in thermal equilibrium with the surroundings. The amount of thermal radiation flowing through the...
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    Is there refraction upon frustrated total internal reflection

    You meant the transmitted wave at the end, right? For clarity, I was asking if the ray transmitted through the gap is "bent" (refracted) in relation to the ray in the first medium if there's a difference in refractive index between the two higher index media
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