Shortly after the Space Race began, an early objective was to get a person into Earth orbit as soon as possible, therefore the simplest spacecraft that could be launched by existing rockets was favored. The US Air Force's Man in Space Soonest program considered many manned spacecraft designs, ranging from rocket planes like the X-15, to small ballistic space capsules. By 1958, the space plane concepts were eliminated in favor of the ballistic capsule.
When NASA was created that same year, the Air Force program was transferred to it and renamed Project Mercury. The first seven astronauts were selected among candidates from the Navy, Air Force and Marine test pilot programs. On May 5, 1961, astronaut Alan Shepard became the first American in space aboard Freedom 7, launched by a Redstone booster on a 15-minute ballistic (suborbital) flight. John Glenn became the first American to be launched into orbit by an Atlas launch vehicle on February 20, 1962, aboard Friendship 7. Glenn completed three orbits, after which three more orbital flights were made, culminating in L. Gordon Cooper's 22-orbit flight Faith 7, May 15–16, 1963.
The Soviet Union (USSR) competed with its own single-pilot spacecraft, Vostok. They sent the first man in space, by launching cosmonaut Yuri Gagarin into a single Earth orbit aboard Vostok 1 in April 1961, one month before Shepard's flight. In August 1962, they achieved an almost four-day record flight with Andriyan Nikolayev aboard Vostok 3, and also conducted a concurrent Vostok 4 mission carrying Pavel Popovich.

 Main article: Project Mercury

The X-15 was an NACA experimental rocket-powered hypersonic research aircraft, developed in conjunction with the US Air Force and Navy. The design featured a slender fuselage with fairings along the side containing fuel and early computerized control systems. Requests for proposal were issued on December 30, 1954, for the airframe, and February 4, 1955, for the rocket engine. The airframe contract was awarded to North American Aviation in November 1955, and the XLR30 engine contract was awarded to Reaction Motors in 1956, and three planes were built. The X-15 was drop-launched from the wing of one of two NASA Boeing B-52 Stratofortresses, NB52A tail number 52-003, and NB52B, tail number 52-008 (known as the Balls 8). Release took place at an altitude of about 45,000 feet (14 km) and a speed of about 500 miles per hour (805 km/h).
Twelve pilots were selected for the program from the Air Force, Navy, and NACA (later NASA). A total of 199 flights were made between 1959 and 1968, resulting in the official world record for the highest speed ever reached by a manned powered aircraft (current as of 2014), and a maximum speed of Mach 6.72, 4,519 miles per hour (7,273 km/h).The altitude record for X-15 was 354,200 feet (107.96 km). Eight of the pilots were awarded Air Force astronaut wings for flying above 260,000 feet (80 km), and two flights by Joseph A. Walker exceeded 100 kilometers (330,000 ft), qualifying as spaceflight according to the International Aeronautical Federation. The X-15 program employed mechanical techniques used in the later manned spaceflight programs, including reaction control system jets for controlling the orientation of a spacecraft, space suits, and horizon definition for navigation. The reentry and landing data collected were valuable to NASA for designing the Space Shuttle.

Main article: North American X-15(Wikipedia)

Theory of Relativity (Simply Explained)

                                 Large Hardon Collidor

ATLAS	A Toroidal LHC Apparatus
CMS	Compact Muon Solenoid
LHCb	LHC-beauty
ALICE	A Large Ion Collider Experiment
TOTEM	Total Cross Section, Elastic Scattering and Diffraction Dissociation
LHCf	LHC-forward
MoEDAL	Monopole and Exotics Detector At the LHC

LHC is the world's largest and most powerful particle collidor.