this post was submitted on 18 Dec 2023
77 points (89.7% liked)

Science Memes

10950 readers
2114 users here now

Welcome to c/science_memes @ Mander.xyz!

A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.

Rules

  1. Don't throw mud. Behave like an intellectual and remember the human.
  2. Keep it rooted (on topic).
  3. No spam.
  4. Infographics welcome, get schooled.

This is a science community. We use the Dawkins definition of meme.

Research Committee

Other Mander Communities

Science and Research

Biology and Life Sciences

Physical Sciences

Humanities and Social Sciences

Practical and Applied Sciences

Memes

Miscellaneous

founded 2 years ago
MODERATORS
[email protected]
[email protected]
[email protected]
77
I've invented a 100% efficient combustion engine (aussie.zone)
submitted 10 months ago by [email protected] to c/[email protected]
27 comments fedilink hide all child comments
 

I use it to heat my house.

top 27 comments
sorted by: hot top controversial new old
[–] [email protected] 22 points 10 months ago

Ive been testing combustion engines made of wood but keep getting more energy out than I put in...

[–] [email protected] 13 points 10 months ago

Lisa, in this meme we obey the laws of thermodynamics!

[–] [email protected] 10 points 10 months ago (3 children)

Sorry, I’m a bit dumb for this one.

Could someone please explain?

[–] [email protected] 49 points 10 months ago (2 children)

There's no such thing as a 100% efficient "engine". But in this case, since the waste heat is put to use (heating the house), OP thinks there's a loophole.

But, house would also need to be soundproof. Any noise leaking to the outside is lost energy.

[–] [email protected] 24 points 10 months ago* (last edited 10 months ago) (1 children)

Ah, but that’s by design: it also acts as a soothing white noise machine.

Then you might point out the exhaust and all it’s associated wastes, but that’s by design: it produces a heady and aromatic product for recreational huffing.

Then you might point out the vibrations, but that’s by design: the engine also provides invigorating massages to relax taut muscles.

[–] [email protected] 13 points 10 months ago

You. Come sell my book

[–] [email protected] 5 points 10 months ago (1 children)

Let's allow a rounding error for 99.51% shall we?

[–] [email protected] 9 points 10 months ago

Don't tell anyone, but I actually only used 1 significant figure, so anything above 50% will do.

I'm also using the version of significant figures where I work backwards from the answer, otherwise I'd need 95% or higher and that's too difficult.

[–] [email protected] 30 points 10 months ago (1 children)

Most engines are less than 30% efficient at producing movement. The majority of the energy is lost as heat.

Thermodynamics tells us that pretty much all energy ends up as heat. In a closed system, any device that uses energy is 100% efficient at making heat. A 1000W computer will make exactly as much heat as a 1000W heater.

A 100% efficient engine can only exist if the desired output is heat, thus making it a pretty useless engine. Also, in a closed system, the exhaust cannot leave.

[–] [email protected] 10 points 10 months ago (3 children)

A 1000W computer will make exactly as much heat as a 1000W heater.

All space heaters should be coin miners (or some other borderline useless energy wasting tech, like AI training). Change my mind.

[–] [email protected] 6 points 10 months ago

We have enough of a chip shortage, tyvm

[–] [email protected] 3 points 10 months ago

If you want to be philanthropic, there are programs you can run that use your computer's idle time to process data for cancer research and such.

[–] [email protected] 2 points 10 months ago

You can sign up for research crunching.

[–] [email protected] 9 points 10 months ago (1 children)

Furnace.

[–] [email protected] 3 points 10 months ago (1 children)

But even a furnace/fireplace is subject to incomplete combustion, where some portion of the wood is transformed into byproducts that rob some of the energy of the fire. There's actually a big difference in the amount of energy you can get out of a fire, depending on the type of stove that's used.
That's some of what NGOs have tried to do for developing countries - find cheap and easily produceabke stove designs that can reduce the amount of wood needed and improve air quality in the home.

[–] [email protected] 2 points 10 months ago

Yes he is incorrect. NG furnace is 95% efficient iirc.

[–] [email protected] 8 points 10 months ago (1 children)

I'm more impressed by that fact that if either runs perfectly silent or that your house has perfect sound insulation

[–] [email protected] 28 points 10 months ago* (last edited 10 months ago) (1 children)

I have a spherical frictionless house in a vacuum.

[–] [email protected] 23 points 10 months ago (1 children)

In this economy?

[–] [email protected] 2 points 10 months ago

At these prices?

[–] [email protected] 8 points 10 months ago

Wait till you hear about reverse cyxling air conditioning it exceeds 100% efficiency.

[–] [email protected] 7 points 10 months ago (1 children)

this is true only if you dont vent the exhaust outside making the air inside quite fun to breathe

[–] [email protected] 1 points 10 months ago (2 children)

He burns h2

[–] [email protected] 1 points 10 months ago

He doesn't burn very well.

[–] [email protected] 1 points 10 months ago

so a heater and a humidifier all in one, now just have to make sure that it doesnt eat all the oxygen or make it rain inside

[–] [email protected] 2 points 10 months ago* (last edited 10 months ago)

Fyi I think they're around 95%.

[–] [email protected] 2 points 10 months ago

It's only 100% efficient if you're also letting all the exhaust into the house too...