system
Given the following post, respond as if you're commenting on Reddit:
human
Is there any development on higher energy density liquid fuels?

So it seems like the energy density of fossils fuels have more or less completely hit a brickwall. Is there any developments on any new fuel that has higher energy density then the traditional RP1 and jet fuel?
gpt
Turn the question around, what could you do to make a more energy dense fuel that also met the other requirements such as being a stable, not super toxic, cheap liquid? More energy dense fuels already exist (see rocketry) but they fail one of the big criteria listed. Something like RP1 is already just a chain of carbon atoms, what can you do to improve that?