1. Plane
   Train
2. Car
   Spaceship

The ACS-64 is a new locomotive that features these traction motors. Its name stands for Amtrak Cities Sprinter, and it helps bring the ageing Amtrak fleet up to date. These motors are particularly smart because they are electric, and also because they use regenerative power to save and re-use 15% of their energy, which increases efficiency.

1. Jet and rocket
   Internal combustion and rocket
2. Ramjet and scramjet
   Any non-rocket engine, and rocket

Rockets carry their fuel and oxygen with them, hence they only have an exhaust, instead of an intake. Other engines need air to make their fuel work, so they need an intake for air, as well as an exhaust.

1. Air
   Jet
2. Fuel
   Piston

A ramjet works by "ramming" air into the system to create a much higher-pressure combustion than would otherwise be possible, hence far more thrust. The idea came to French inventor Rene Lorin in 1908, though a ramjet was not built for some decades after.

1. Oil
   Air
2. Steam
   Lubricant

Regular internal combustion engines combust a mix of fuel and air. Turbo engines push a little extra air into the cyclinder to move pistons down with more force, which increases the oomph of the engine.

1. Rotational force
   Direct force
2. Direct force that produces rotation
   Another word for horsepower

Torque is when you apply force in a straight line but it produces a rotational effect. For example, when you open a door, you apply force to the handle end of the door but you get rotation at the hinge side. Engines do the same thing to the crankshaft, thus driving the wheels to rotate.

1. Nothing
   It's rotary.
2. It was the first enclosed engine.
   It was the first liquid fuel engine.

A Wankel engine has a rotary instead of a piston motion. This is much more efficient but presents lots of issues in actually making it work. Wankel engines were invented in the 1950s but generally didn't find a lot of commercial uses until the last 20 years.

1. A crankshaft
   A piston
2. A cylinder
   The first steam engine

Heron's model was just a toy where you heated up water which drove a sphere to spin and thus cause a little pair of fins to twiddle. However, it used all the principles of the Industrial Revolution. It's likely a copy of the plans burned in the Great Library of Alexandria.

1. A machine that drives a vehicle or pump
   A machine that converts energy into motion
2. A machine that converts heat into motion
   A machine that produces power

Engines are machines that convert energy into motion. For example, a steam engine burns a fuel source like coal to generate heat, which turns water into steam, which drives pistons. These are connected to a pump or axles, where the energy becomes motion.

1. Christiaan Huygens
   Ismail Al-Jazari
2. James Watt
   George Stephenson

Ismail al-Jazari invented the crankshaft in 1206. As we see with Heron of Alexandria, there were a lot of opportunities back in older times for the Industrial Revolution to start earlier, but unfortunately society wasn't connected or rich enough to make it happen. That means even brilliant minds like al-Jazari didn't get to flourish as much as they should have.

1. Thomas Mead
   Thomas Newcomon
2. Christiaan Huygens
   George Brayton

Huygens built this engine in the 1600s but could only get it to move one stroke at a time. An engine only provides value if it goes up and down continuously, which other thinkers were able to crack using Huygens' work - meaning he was yet another brilliant mind trapped before his time.

1. All engines are motors but not all motors are engines.
   All motors are engines, but only some engines are motors.
2. Some motors are engines, and some engines are motors.
   All motors are engines, and all engines are motors.

Motors and engines both use power to supply movement. Motors specifically have to supply movement to a machine, so not all engines are motors, but some are. Motors run on electricity or combustion, while engines only run on combustion, so not all motors are engines, but not all. Thus electric cars arguably have a motor but no engine.

1. Coal
   Coke
2. Wood
   Crude oil

Coke is what happens when you heat coal without any air. This removes impurities and provides a nice energy-dense fuel that has all the upsides of coal but few of the downsides.

1. Gasoline
   Natural gas
2. Steam
   Farts

Natural gas is mostly methane, which contains a lot of energy and is a fine source of power (carbon emissions that endanger the planet notwithstanding!). It's the "gas" that is in early gas engines, instead of gasoline or petroleum.

1. Literally just burning, as applied to fuels
   Rapid chemical combination of a substance with oxygen
2. Blowing up
   Making motion

Combustion is like burning except that the latter produces flames - that is, heat and light. Combustion likewise creates energy and is a kind of burning, but a more specific kind involving oxidation - and hopefully, motion instead of flames.

1. Set spray carburetor
   Spark plug
2. Ignition coil
   All of the above

Butler's work was key to the production of early cars, which had more components in them than you'd think. Foremost among the users of his ideas was a certain Gottlieb Daimler, who you may have heard of!

1. A vehicle powered by a steam engine
   A vehicle powered by a gas engine
2. A vehicle powered by an engine
   A vehicle with an engine providing power

It had a gas engine, and so that's how it was described. Of course, it was in German, but the translation above is pretty solid. Patents are an essential part of the invention process as they enable monetization of ideas, which means investment and research.

1. Turbine
   Propeller
2. Turbo
   Jet

Turbines were the dream goal of a lot of inventors in the 1800s, but they always used more energy than they put out. Norwegian Ægidius Elling build the first turbine that put out a net plus, and now of course, that principle is key to wind technology, which is due to overtake natural gas as the second-cheapest form of energy (solar is cheapest). Technology really does change quickly when the investment is there!

1. 1,000 lbs or less
   500 lbs or less
2. 200 lbs or less
   100 lbs or less

The Wright Brothers didn't build all their own stuff, though they did build a lot of it. They were a rare combination of mechanical genius and daredevil insanity.

1. Start moving
   Turn on the ramjet
2. Stop moving
   Turn off any other engine while moving

Ramjets only work when the outside air is going very fast. That means vehicles that use a ramjet need a conventional jet engine to get up to speed before turning on the ramjet.

1. 1832
   1932
2. 1994
   1981

You couldn't buy a Prius until the 1990s, but the electric car is actually older than cars that drive on liquid fuel! It was invented by Robert Anderson, an oddball who put a little electric motor and a battery on a carriage and drove it up a hill. Electric cars were king until lack of electrical infrastructure, Henry Ford and rising mass production made the fuel-powered cars cheaper.

1. Super cool ramjet
   Supersonic combustion ramjet
2. Superspeed coaxial ramjet
   Supersonic coolant ramjet

If you fly a ramjet-powered plane really fast, it gets more and more efficient until Mach 5, when it starts to get less efficient due to having to slow down the air that it takes in before combusting it. Enter scramjet, which doesn't have to do this, and can thus go super-duper fast. Scramjet can fly about 7,000 mph!

1. Old people old cars
   Outside-piston on-cyclinder
2. Opposed-piston opposed-cylinder
   Other-piston other-cylinder

OPOC is a modern engine based on an old idea. As the electric car supplants the internal combustion engine, other new layouts and ideas are springing up, and OPOC is one of them.

1. Desktop computer
   Subway train
2. Range extender on an electric car
   Coffee maker

Since you're a forward-looking person who hates paying for fuel and maintenance, you've probably got an electric car already. OK, maybe not, but you're probably going to have one soon, because internal combustion engines are being banned in a lot of countries and EVs are already cheaper. One of the fun elements in your EV might be the rotary engine in the range extender.

1. Railways
   Pumping water out of mines
2. Hoisting large weights on construction sites
   Opening locks on canals

The Industrial Revolution started with coal as much as anything, and if you want to have a safe(ish) mine to work in, pumping out the water is a must. The ability to partially automate this by using an engine instead of hand or animal power was a huge factor in the coal-fueled revolution taking off.

1. Ion thruster
   Booster engine
2. Scramjet
   Regular rocket

An ion thruster sounds like something out of Star Trek, but it's real! NASA has one in development that could get humanity to Mars in under two months.

1. Crankshaft
   Gasoline
2. Piston
   A self-rotating spit

Taqi al-Din is one of the giants of the Islamic Golden Age whose name ought to be as familiar as James Watt. He was a Newtonian figure who kept inventing things that nobody else in his time could comprehend. He became rich and famous as a result, but alas, not outside his own time.

1. Watt
   Ohm
2. Wisp
   Volt

A wisp is not a unit of energy. Watts, volts and ohms respectively measure power, speed of current and resistance of a wire. Thus you need to be able to calculate all of them to make your engine go. They're all named for pioneers of relevant technology.

1. Diesel
   Gasoline
2. Petroleum
   Naphtha

There's a handy mnemonic to remember the order of distillation in crude oil: grand-parents never knock down friendly little boys. That is, gasoline, petroleum, naphtha, kerosene, diesel, fuel oil, lubricant oil, and bitumen!

1. One burns fuel continuoulsy to generate heat to turn to motion; the other creates lots of tiny explosions by mixing air and fuel then igniting them, which is combustion.
   One burns the fuel inside the engine and the other burns it outside.
2. Steam is much less efficient because it gets jammed more.
   One is fueled by coal, the other by gas.

The difference is that steam engines need a continuous source of heat but combustion engines don't. That's why steam takes a while to get going by building a "head of steam" while the other just needs ignition.

1. 1200
   746
2. 1832
   66

For some reason, James Watt decided to make horsepower a super annoying amount of energy for people who'd prefer to calculate with round numbers. He was brilliant, sure, but he didn't care how much misery he inflicted on generations of school students.

1. V
   Vehicle
2. Vent
   Volt

The cylinders in a V8 or V6 etc are lined up in two sets of three or four. These are typically set at an angle from one another, which means they create a V shape. So the V is just describing what's right there!

1. Gottlieb Daimler
   Nikolaus Otto
2. Wilhelm Maybach
   Karl Benz

Daimler and Maybach both worked for Otto, who sued them for stealing his work, even though he later got in trouble for stealing patents himself. Benz was a contemporary and competitor of the other three.

1. Concorde
   Boeing 747
2. McDonnell-Douglas MD-80
   Airbus A380

Concorde was a supersonic passenger jet that sadly doesn't fly anymore, as the economics of it were too challenging. However, it was a technological marvel and the ideas used to produce it are currently being used to generate a new generation of lighter, more affordable supersonic commercial airliners that you should expect soon, coming to a sky near you!

1. 2
   200
2. 2000
   117

There are two moving parts in the Tesla motor. Both are involved in making the drive train go. This is one reason that electric vehicles are so quiet and also practically maintenance-free; they have about 1% (that's just one, not a typo!) of the total moving parts of a traditional car.

1. It reflects the sound waves back so they cancel themselves out.
   It makes the sound waves go upward so you can't hear them from the ground nearby.
2. It makes the sound waves go through a tube that makes them smaller.
   It stops the engine wobbling so much, which reduces the sound at source.

If you bounce soundwaves into each other so the peaks and troughs line up just so, they cancel out. It's a matter of designing your muffler so the angles are just right.