But the lumps are distributed unevenly. In other words, the universe is anisotropic. But scientists find it difficult to explain how matter in the early universe began clumping together to make those lumps. Yet there wasn't enough time for the gravity of all those newborn galaxies to grab onto each other and cause them to form many of the superclusters.
Technicians attach the parachute and explosive device to the balloon.
Big Bang theory says that all matter, energy, and even space and time were born in a single instant of cosmic creation, probably about 12 billion to 15 billion years ago. Hydrogen atoms formed, and the universe became transparent. But the glow of the opaque fireball is still visible, because as astronomers look deeper into the universe, they're looking farther back in time. The expansion of the universe has stretched the light from the fireball and lowered its equivalent temperature, so it now appears at a temperature of about 2.7 degrees Kelvin. It forms a faint glow across the entire sky, which is detectable only by microwave instruments.