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There is a physical limit to the efficiency of a heat engine though. If your powertrain is 25% efficient, you can double it to 50%. But if it's 50%, you cannot double it to 100% unless the engine is operating at a temperature of absolute zero. You're going to reach a point- and current model cars are probably just about there- where the engine is operating about as efficiently as the laws of physics permit, and then you're not going to make further progress. Just google "Carnot cycle" and you can learn more.



>- and current model cars are probably just about there-

Very true, in order to get more progress, one would have to develop systems that are sufficiently different and more efficient at some level which may be odds with how we currently allocate resources.


Such as series hybrids and electric cars. (Dropping complex transmission for batteries, but using a more efficient engine.)

At some point though friction against road and minimum weight for safety and comfort come into play, and once you optimize these you end up with a train. :)

It's the same problem electronics face right now, when they really butt into quantum physics and consequently have huge yield issues - and you can scale horizontally (more transistors) only for subset of problems.


Neither of which are physical limitations, just limitations on our understanding of physics and our ability to apply them to issues of the day. We are always in the process of trying to determine what the limits of physics actually are (modulo a given societies acceptance level of such experimentation and mechanisms to explore such).


We actually know the limits of information density from bottom, that puts a bottom floor on electronics unless someone really figures out new physics. Likewise we know bottom floor for efficiency during transit in atmosphere under same condition.

Breaking both in any major way would require or beget actual teleportation. (Which unlike electricity or moving in atmosphere has not been seen in nature.)

There does exist a series of absolute limits on Earth, such as capacity for growing food limited on sunlight, water and availability of specific minerals. Inserting more planets adds to that limit with a transportation losses... Unknown exactly but bottom floor is easy to figure out for spaceflight and mining (unless teleportation).

You can even limit maximum size of "life speed" cone around Earth which would be the maximum distance we can get things from during lifetime of any person. (Unless immortality or teleportation or high multiplier FTL.)


Such limits are derived from our current understanding, of which one would have probably given a completely different answers 150 years ago based on our understanding then.

>Breaking both in any major way would require or beget actual teleportation. (Which unlike electricity or moving in atmosphere has not been seen in nature.)

Well maybe we haven't seen them because we didn't know how to look… recently declassified FLIR from US navy reporting archives suggest things that we haven't typically seen in nature in the past, can be seen.

>There does exist a series of absolute limits on Earth, such as capacity for growing food limited on sunlight, water and availability of specific minerals.

True, but what is the purpose of any of these things, and do we currently pursue the most efficient ways of doing such for those ends in a way that we cannot think about it anymore?


Correct, the are multiple ways to extend each of the limits, even one based on food, however mathematical limits on complexity exist and are really hard to surpass. On the upside, we're really far from them. Smart matter is not quite in our grasp.

Once we figured out information-theoretic entropy we got tools to set bottom limits on everything. I'm not entirely sure when, but Kolmogorov was quite some time ago. The math is in good company of Shannon and Fischer.

Remember that reducing costs by not doing something has risks. Existential risks in fact. (E.g. reliance on a single source of energy without fallback.)


Kolmogorov was about 90 years ago. Shannon, similar. Neither of their accomplishments will limit future accomplishments and understanding (except those bound slavishly to such frameworks [as good as they may be today in certain applications])

>Existential risks in fact. (E.g. reliance on a single source of energy without fallback.)

Existential risks for oil companies investors or CSP investors?


Now, not to be rude but if you think we are going to break the laws of thermodynamics or other physics then you literally believe in supernatural forces. As in magic.


If you think meta materials violate laws of thermodynamics, impossible to exist "naturally" in the universe and our understanding of the physical laws that govern the universe are static throughout time, then I have a bridge to sell you.




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