Marx revisited

[TrueStory]

My theory about the evolution of the human society is a little bit similar to Marx's theory. Marx distinguished the epochs of the human society based on the form of exploitation. I think it is more relevant to distinguish the evolution of the human society based on the forms of energy used. These are the epochs based on the newly discovered energy forms:

0. -                            2 million BC - 100,000 BC
1. Fire                         100,000 BC - 10,000 BC
2. Animals                      10,000 BC - 3,000 BC
3. Slaves                       3,000 BC - Jesus
4. -                            Jesus - 1000
5. Peasants, Laborers, Slaves
   Wind- and Hydro power        1000 - 1865
6. Fossil fuels: coal,
   petrol, natural gas          1865 - 1945
7. Atomic Energy                1945 - today

Notes:
1. The energy resulted from Fire today we call energy from biomass (it's a good one, because it's renewable :))
2. Domesticating of animals began at the end of the Ice Age (the first animal domesticated was the reindeer). After melting of the Ice the wheel has been discovered.
3. The discovery of the slavery is as important like the discovery of the fire and the discovery of the wheel.
The EROEI (Energy Returned on Energy Invested) in case of slaves is not very good, but since slaves possess intelligence, a combination of Slaves + Animals + Fire is a pretty good Energy resource - antic civilizations in Egypt, Greece and Rome were based on this Energy.
4. Then Jesus came. He said "Let's love each other!". It's OK, when masters love each other or slaves love each other, but when masters love slaves and liberate them, then problems arise: more free people who wants to use energy, and less slaves who provide energy. This is why Romans hated so much Christians, and not because of a different God - and this was the end of the Roman empire.
Then several hundred of years come, with only basic energy from Fire and Animals, enough only for surviving. This was the Dark Age, when nothing noticeable happened.
5. Human society discovered once again the master-slave combination, but this time slaves were called peasants and later-on laborers.
Windmills and watermills have been constructed, but the most efficient was using the wind power for sailing. No wonder the most successful nations were those which could use this new type of energy: in the beginning the Vikings and Normans, and later on Great Britain, France and Spain.
6. Theoretically the Fossil Fuel Age begins in 1760, when James Watt discovered the steam engine, but this is valid only for Great Britain.
Practically 1865 - the end of US Civil War signaled the new age worldwide. The US civil war was an "Energy War". The Southern States thought only slavery can assure the Energy needs for their society and Northern states thought farmers + laborers + fossil fuels will be more then enough.
7. First "atomic reactor" has been built in 1942, but this was top secret. The atomic energy has been presented to the world in the form of a very powerful bomb in 1945, then it was used to construct even more powerful bombs - therefore most of the people can't accept a society based on atomic energy.


Conclusion:
By 2050 the oil and natural gas resources will be depleted and if no new Energy resource is discovered than in 2050 human society will be based on coal or atomic energy or slavery - or a combination of these.