For Questions That Don't Merit Their Own Thread

[JoeSchmuckatelli]

30 minutes ago, farmerben said:

Diesel fuel has 44 times more energy/kg compared to lithium ion batteries.  That is 4400% better.  

 

*correction its not that much better because the conversion of thermal power to shaft power is around 40%, whereas electric battery combos are closer to 90% 

Oh yeah - trust me I was also thinking about ways to capture the heat and convert to electricity... But it's the same problem = adding weight + inefficiency. 

[magnemoe]

8 hours ago, farmerben said:

Taking the motion of a shaft into electricity and then back into a shaft involves losses.  What percentage is lost I'm not sure but 10% is quite significant.  It makes the most sense if you stagger the inputs and outputs in time.  A hybrid that stops and starts frequently and has good batteries is ideal.  If you need to motor continuously for many hours than basic diesel powered shaft is going to be more efficient than hybrid.

Now  diesel electric locomotives have no batteries but guess the zero rpm torque and many driving wheels makes this preferable. 
Else hybrids are nice you getting the best of both worlds. 

Fun fact the US made steam turbine electrical battleships, the problem was that they had issues with geared turbines so using generators and motors worked. It had the benefit of not needing an long drive shaft and that you could route power easy. Say you lost the left propeller and the right engine, just have the left engine drive the right propeller. Downside was losses and the fun of high power electricity and sea water if you took damage. 

[magnemoe]

14 hours ago, razark said:

https://en.wikipedia.org/wiki/List_of_oldest_extant_buildings

Looking at some very sad looking pyramids 

Stuff who get buried survive much better unless its massive and / or build of huge stones.
One thing who would survive for up to billions of years would be mines, yes they will be filled with mud who become stone but that its an old mine would be pretty obvious. More fun thick steel structures like the stuff holding up the roof and railroad track would fossilize easy compared to bones as it take much longer to break down. 
And it should be iron here, instead we find this weird stuff. Also stuff like ceramics don't break down more than stone if buried. Silurian hypnosis debunked. Yes they could be stone age, people find stone tools all the time, mostly arrowheads as they was semi disposable. 

 

[farmerben]

Edenborough, Scotland is built mostly of granite blocks over a foot thick.  I'll bet on it as the city that changes the least in the next 1000 years.