The Baltic Way or Baltic Chain (also Chain of Freedom Estonian: Balti kett, Latvian: Baltijas cels, Lithuanian: Baltijos kelias, Russian: ) was a peaceful political demonstration on August 23, 1989. An estimated 2 million people joined hands to form a human chain extending 600 kilometres (370 mi) across Estonia, Latvia and Lithuania, which had been forcibly reincorporated into the Soviet Union in 1944. The colossal demonstration marked the 50th anniversary of the MolotovRibbentrop Pact that divided Eastern Europe into spheres of influence and led to the occupation of the Baltic states in 1940.
How many people were involved in the Baltic Chain?
estimated 2 million

The mosaics of St. Peter's often show lively Baroque compositions based on designs or canvases from like Ciro Ferri, Guido Reni, Domenichino, Carlo Maratta, and many others. Raphael is represented by a mosaic replica of this last painting, the Transfiguration. Many different artists contributed to the 17th- and 18th-century mosaics in St. Peter's, including Giovanni Battista Calandra, Fabio Cristofari (died 1689), and Pietro Paolo Cristofari (died 1743). Works of the Fabbrica were often used as papal gifts.
The mosaics of St.Peter's are often based on what?
designs or canvases

By the late 1990s, blue LEDs became widely available. They have an active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN, called cladding layers. By varying the relative In/Ga fraction in the InGaN quantum wells, the light emission can in theory be varied from violet to amber. Aluminium gallium nitride (AlGaN) of varying Al/Ga fraction can be used to manufacture the cladding and quantum well layers for ultraviolet LEDs, but these devices have not yet reached the level of efficiency and technological maturity of InGaN/GaN blue/green devices. If un-alloyed GaN is used in this case to form the active quantum well layers, the device will emit near-ultraviolet light with a peak wavelength centred around 365 nm. Green LEDs manufactured from the InGaN/GaN system are far more efficient and brighter than green LEDs produced with non-nitride material systems, but practical devices still exhibit efficiency too low for high-brightness applications.[citation needed]
What are cladding layers?
active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN