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Re: IRC

Posted: Wed May 10, 2017 9:52 pm
by Dinosawer
Grumblesaur wrote:
Dinosawer wrote:You could, and someone did before, but you don't visit irc enough to maintain it, so it'd probably just end up being down all the time, like the previous one.
I would just run it on an EC2 instance in a bash script that restarts it if it hits an error. Problem solved.
Well, the previous one didn't crash, it just stopped working. :ghost:
Then again, you're probably a much better programmer than who made that thing

Re: IRC

Posted: Thu May 11, 2017 8:05 pm
by Detritus

Code: Select all

[18:54:36] <Hema> Break a fortune cookie for Detviet
[18:54:40] <Taiya> The fortune cookie says: Not intended for children 5 and under.
[18:54:43] <Detviet> xD
[18:54:47] <Silver> xD
[18:54:56] <Hema> XD
[18:55:10] <Talvieno> xD
[18:55:33] <Zorathos> XD

Re: IRC

Posted: Fri May 12, 2017 12:34 am
by JanB1
Detritus wrote:

Code: Select all

[18:54:36] <Hema> Break a fortune cookie for Detviet
[18:54:40] <Taiya> The fortune cookie says: Not intended for children 5 and under.
[18:54:43] <Detviet> xD
[18:54:47] <Silver> xD
[18:54:56] <Hema> XD
[18:55:10] <Talvieno> xD
[18:55:33] <Zorathos> XD
Welp. Poor Det. Not allowed to have a fortune cookie. :ghost:

But Hema was on a real run yesterday. He went nuts in the chat, broke a fortune cookie for everybody and wrote all kinds of crazy stuff in all caps. :mrgreen:

Re: IRC

Posted: Fri May 12, 2017 9:23 am
by Detritus
JanB1 wrote:
Detritus wrote:

Code: Select all

[18:54:36] <Hema> Break a fortune cookie for Detviet
[18:54:40] <Taiya> The fortune cookie says: Not intended for children 5 and under.
[18:54:43] <Detviet> xD
[18:54:47] <Silver> xD
[18:54:56] <Hema> XD
[18:55:10] <Talvieno> xD
[18:55:33] <Zorathos> XD
Welp. Poor Det. Not allowed to have a fortune cookie. :ghost:

But Hema was on a real run yesterday. He went nuts in the chat, broke a fortune cookie for everybody and wrote all kinds of crazy stuff in all caps. :mrgreen:
He was high on cookie. :3

Re: IRC

Posted: Sat May 13, 2017 5:12 pm
by Triggerhappy

Code: Select all

Trigger> hmmmm is there no way to convert all that heat into some form of power?
* Cornflakes is now known as Thermodynamics
<Thermodynamics> nope

Re: IRC

Posted: Sun May 14, 2017 1:51 am
by Black--Snow
Triggerhappy wrote:

Code: Select all

Trigger> hmmmm is there no way to convert all that heat into some form of power?
* Cornflakes is now known as Thermodynamics
<Thermodynamics> nope
>Heat to energy

What is.... A reactor & Turbine?
What is.... A coal power plant?
What is.... A Nuclear reactor?

Hmmmm

Re: IRC

Posted: Sun May 14, 2017 3:23 am
by 0111narwhalz
Black--Snow wrote:
Triggerhappy wrote:

Code: Select all

Trigger> hmmmm is there no way to convert all that heat into some form of power?
* Cornflakes is now known as Thermodynamics
<Thermodynamics> nope
>Heat to energy

What is.... A reactor & Turbine?
What is.... A coal power plant?
What is.... A Nuclear reactor?

Hmmmm
No, that's a heat gradient. Heat flows downhill, and it is this flow which we call power. If you just have a bunch of heat, it won't flow anywhere. You need a place for it to go.
Also, it's a lot easier to deal with pressure gradients than heat gradients. Most heat engines just convert heat gradients into pressure gradients. Exchanger+turbine, Stirling cycle, internal combustion; they all take heat gradients and turn them into pressure gradients. The pressure gradients are turned into velocity gradients, then into charge gradients, as per whatever is of greatest utility. Then the charge gradients flow to appliances which turn them into velocity or heat or other gradients. Along the way, a certain amount of flow is wasted to heat, particularly during the gradient conversions. Sometimes this heat produces useful gradients on its own, but these are always weaker than the loss.

Re: IRC

Posted: Sun May 14, 2017 3:29 am
by JanB1
Black--Snow wrote:
Triggerhappy wrote:

Code: Select all

Trigger> hmmmm is there no way to convert all that heat into some form of power?
* Cornflakes is now known as Thermodynamics
<Thermodynamics> nope
>Heat to energy

What is.... A reactor & Turbine?
What is.... A coal power plant?
What is.... A Nuclear reactor?

Hmmmm
You don't turn heat into energy DIRECTLY in these. That's only possible with thermoelements (heat->a tiny little bit of energy). In power plants, you turn heat into steam (pressure) and then into momentum and then into power. Tha's why they aren't really effective with a coefficient of about 35% for a nuclear power plant. You have so much dissipation.

Re: IRC

Posted: Sun May 14, 2017 5:42 am
by Cornflakes_91
Black--Snow wrote:
Triggerhappy wrote:

Code: Select all

Trigger> hmmmm is there no way to convert all that heat into some form of power?
* Cornflakes is now known as Thermodynamics
<Thermodynamics> nope
>Heat to energy

What is.... A reactor & Turbine?
What is.... A coal power plant?
What is.... A Nuclear reactor?

Hmmmm
the question was "can i turn all the waste heat of my spaceship into power to get rid of giant radiators"

and the answer is more or less "No" :P

Re: IRC

Posted: Mon May 15, 2017 11:29 am
by Scytale
Cornflakes_91 wrote:
the question was "can i turn all the waste heat of my spaceship into power to get rid of giant radiators"

and the answer is more or less "No" :P
^this

Also you guys, a terminology thing, if anyone cares: "heat content" can be misleading. Often we talk about heat moving into or out of a system, and useful work being done on or by a system; things that exist in the system as a volume are usually referred to as internal energy in closed systems or enthalpy in open systems. But this understanding of heat is violated by ideas like "heat content of the ocean", which is probably better understood as "quantity of heat that has been input into the ocean". It's a subtle distinction but worth keeping in mind!

Re: IRC

Posted: Mon May 15, 2017 1:57 pm
by JanB1
Scytale wrote: Also you guys, a terminology thing, if anyone cares: "heat content" can be misleading. Often we talk about heat moving into or out of a system, and useful work being done on or by a system; things that exist in the system as a volume are usually referred to as internal energy in closed systems or enthalpy in open systems. But this understanding of heat is violated by ideas like "heat content of the ocean", which is probably better understood as "quantity of heat that has been input into the ocean". It's a subtle distinction but worth keeping in mind!
Don't write this so small, this is important and a good point! :thumbup:

Re: IRC

Posted: Mon May 15, 2017 3:41 pm
by Scytale
JanB1 wrote:
Scytale wrote: Also you guys, a terminology thing, if anyone cares: "heat content" can be misleading. Often we talk about heat moving into or out of a system, and useful work being done on or by a system; things that exist in the system as a volume are usually referred to as internal energy in closed systems or enthalpy in open systems. But this understanding of heat is violated by ideas like "heat content of the ocean", which is probably better understood as "quantity of heat that has been input into the ocean". It's a subtle distinction but worth keeping in mind!
Don't write this so small, this is important and a good point! :thumbup:
I didn't want to be an offtopic dick!

But I'll continue anyway :P heat and work "happen" at system boundaries - they are not thermodynamic properties of a system. They do not define the state of a thermodynamic system: this is done in general by temperature, density, pressure, entropy content, internal energy etc. When we talk about converting "heat to useful energy" this means transferring heat into a system boundary, something happens within that system in a process, and work is exerted by that system through its boundary. In this sense, the role of the heat is to induce a change in the properties of the system that allow us to extract work from it.

Example: coal-burning power plant. Coal is burnt (in what we call ideally a high-temperature reservoir), transferring heat into a working fluid, e.g. water. The effect of this heat transfer is to increase the temperature and (most notably) enthalpy and some other properties of the water. The water turns to steam, more-or-less, and is then put through a turbine or set of turbines in an 'expansion' process (so called because its pressure drops as this is done), in which its enthalpy is reduced by the turbine action. In this process the fluid does work on the turbine, which is 'spun up' by the action of the fluid: this is the useful energy which eventually comes through your power supply. The working fluid as it comes out of the turbine has a low enthalpy and temperature, and it is put through an evaporator to shed further energy that could not be harvested by the turbine. This excess energy leaves the fluid as heat. More work is then put into the fluid for various reasons, to bring it to a condition where heat can be dumped into it again by the burning of coal, increasing its enthalpy and temperature, and the process repeats.

Re: IRC

Posted: Tue May 16, 2017 12:44 am
by JanB1
"heat and work "happen" at system boundaries"

What are the boundaries of a system for you? How do you define these boundaries?

Re: IRC

Posted: Tue May 16, 2017 12:47 am
by Dinosawer
A boundary is the line between places with different macroscopic parameters (i.e. different temperature, pressure, density etc)

Re: IRC

Posted: Tue May 16, 2017 12:50 am
by Cornflakes_91
Well, one can place the boundaries in their math arbitarily, but only at physically meaningful boundaries something actually happens