What is Relativity by Jeffrey Bennett

 This is an excellent intuitive treatment.  The speed of light is constant. So if Al, moving with respect to you, shines a light up to a mirror in his spaceship the distance the light travels for him is just up and down. Because Al is moving away, you see the light following a longer path. Since the speed of light in constant Al's clock must record a smaller time that your clock where light travels a greater distance to make distance /time constant.

Simultaneity is relative for events that do not occur in the same place. If you are equidistant from two lights and they flash you will see each light at the same time but someone who is moving toward one of the lights will see it first.

Spacetime, with three space and one time dimension provides an accurate representation. By analogy we can measure dimensions of a three-dimensional book using different two-dimensional views from photos that give different lengths and widths. Your frame of reference is different. There is an invariant spacetime distance.

Gods of Money -- Wall Street and the Death of the American Century by F. William Engdahl

      This book is "a history of power, more precisely, of the colossal abuse of power in the hands of a tiny elite who have constituted themselves as the 'Gods of Money'". Slavery requires the care of the laborers while capitalists control labor . The Federal Reserve Act allows private banks to control the issuance of money.. The dollar is the reserve currency and the US military has been dominant.

      Lincoln wanted money to be issued solely by the government. With his greenback he avoided paying high interest to London or New York bankers. John Wilkes Booth was a mercenary working for British bankers. J.P. Morgan and John D. Rockefeller concentrated the wealth and control of American industry into their own hands. After the Civil War both silver and gold backed money but the New York bankers wanted no competition from silver. Around 1900 about 60 ultra-rich families controlled American industry and banking. They put up a third-party candidate in the 1912 presidential election so Woodrow Wilson would win and approve the Federal Reserve Bank.

      Britain need World War I to challenge the growing German strength. The Germans were building a railroad to Mesopotamia and building up their navy to challenge Britain's dominance. Britain was declining and the US power elite felt they could dominate. The US entered the war to protect the bankers' financial interests. They made a lot of money. The cause of the great depression was "the misconceived attempt by the House of Morgan and the Wall Street banking establishment to replace the city of London with New York as the heart of world finance."

     The elite US power shared synthetic rubber and gas technology with the Nazis to make sure Britain wouldn't keep thei former dominance. Hitler let the British retreat from Dunkirk to encourage them to settle so they could fight a one-front war with Russia. Churchill didn't support the German anti-Hitler opposition because Britian didn't want a strong Germany sensibly ruled.

     The US encouraged the war in Korea to recover from a recession and build the military-industrial complex. For that they needed a strong German industry so NATO changed its policy toward Germany.

     "Shortly before he was assassinated , JFK issed United States Note, interest free and independent of the Federal Reserve. ... The Notes were immediately recalled by his successor."

     There is much more in this book. With globalization interests of the financial elite no longer align with those of the American people.