1. Energy, Heat, & Entropy

2. Development of the Steam Engine Concepts of Heat and Energy Laws of Thermodynamics Meteors and Energy – Types of Meteors – Consequences of Meteor Strikes

3. Definitions Energy = ability to do work (expressed in Joules) Work (also expressed in Joules) = Force (in Newtons) X Distance (Meters) Power (Watts) = Joules per second Kinetic Energy = ½ (kg x v 2 ) = ½ (kg x h x g) Potential Energy = (kg x v 2 ); (kg x c 2 )

4. James Watt Inventor and natural philosopher Member of the Lunar Society Made improvements to the original Newcomen Steam engine by adding a condensing chamber UK (b. Scotland): 1736-1819

5. Watt-Boulton Steam Engine of 1784 B steam valve C steam chamber E exhaust steam valve N cold water pump P piston Q regulator/governor T steam input flap controlled by regulator

6. Nicolas Leonard Sadi Carnot When a system goes through different energetic states and returns to its original state, a thermodynamic cycle has occurred. While a cycle occurs, work can be done There must be an absolute low temperature France: 1796-1832

7. Concepts of Heat Considered an element in Aristotelian and Alchemical systems Even Lavoisier (founder of modern chemistry) considered it an element Motion of atoms (Boyle) Heat is a form of energy (Count Rumford)

8. Robert Boyle and Boyle’s Law Image from NASA UK (b. Ireland): 1627-1691

9. Benjamin Thompson, Count Rumford Born in Massachusetts Property in Concord (formerly called Rumford), NH Royalist during the revolution (worked on force of gunpowder) Moved to London and then to Bavaria American Colonies, UK, Bavaria, & France: 1753-1814

10. no mass change after heat transfer work boring cannons could boil water (it was thought that chopping up matter released caloric, but Rumford pointed out that more work equals more heat, whereas caloric would be finite in amount) cannons firing blanks get hotter than cannons firing cannonballs Published in 1798 by Royal Society

11. James Prescott Joule Nature of heat – Heat and mechanical energy – Heat and electrical energy Formulation of the 1 st Law of Thermodynamics: Conservation of energy England: 1818-1889

12. Joule’s Apparatus

13. Rudolph Clausius Built on Carnot’s engine to develop a theory of heat that became the laws of thermodynamics On the Mechanical Theory of Heat (1850). A statement of the second Law of thermodynamics Prussia (now Koszalin, Poland) 1822-1888

14. William Thompson, Lord Kelvin Clearly defined 1 st and 2 nd laws of thermodynamics Determined -273.15C is absolute zero Absolute temperature scale defined in degrees Kelvin Knighted for his role in laying transatlantic cable Used thermodynamics to determine the age of the earth United Kingdom (b. Ireland): 1824-1907

15. Laws of Thermodynamics 1.Energy is conserved in a closed system, but it can be transferred from one form to another. For example heat and work are types of energy transfer. 2.Entropy – a closed system tends toward thermodynamic equilibrium 3.Entropy of a closed system approaches a constant as the temperature approaches absolute zero. That is, the entropy of a crystal at absolute zero is zero.

16. Forms of Energy Kinetic Chemical Electric Magnetic Electromagnetic radiation Nuclear Ionization Elastic Sound Gravitational Intrinsic (E=mc 2 ) Thermal

17. Entropy and Time Carnot engine

18. Heat Transfer

19. Meteor airbursts Aftermath of the Tunguska event (19 years after the airburst on 30 June 1908) Chelyabinsk meteor Feb 15, 2013

20. Meteor Strikes Types of meteorites – Chondrites – Iron-nickel – Others are fragments of planets and the moon

21. Mechanism of the Meteor Strike

22. Meteor Crater Winslow Arizona Diameter 1-1.25 km

23. Stony asteroids that impact sedimentary rock and create a crater Impactor diameter Kinetic energyKinetic energy at atmospheric entry Impact energy Crater diameter Average frequency 100 m (330 ft)mft47 MtMt3.8 Mt1.2 km (0.75 mi)kmmi5200 years 130 m (430 ft)103 Mt31 Mt2 km (1.2 mi)11000 years 150 m (490 ft)159 Mt71.5 Mt2.4 km (1.5 mi)16000 years 200 m (660 ft)376 Mt261 Mt3 km (1.9 mi)36000 years 250 m (820 ft)734 Mt598 Mt3.8 km (2.4 mi)59000 years 300 m (980 ft)1270 Mt1110 Mt4.6 km (2.9 mi)73000 years 400 m (1,300 ft) 3010 Mt2800 Mt6 km (3.7 mi)100000 years 700 m (2,300 ft) 16100 Mt15700 Mt10 km (6.2 mi)190000 years 1,000 m (3,300 ft) 47000 Mt46300 Mt13.6 km (8.5 mi)440000 years

24. Crater Copernicus Diameter 93 Km

25. Chicxulub Impactor KT-Asteroid Strike 65 mya Crater diameter 180 km