What is the most complex thing in the Universe? Most results from internet searches say it is the human brain.
There is no question the brain is very complex. It weighs only three pounds yet contains 100 billion specialized cells called neurons. Connected to each neuron are about 10,000 “wires” that are used to communicate with other neurons. The number of wired connections in the entire brain is about one quadrillion (1,000,000,000,000,000), and if all the wires were placed end-to-end, they would extend for 100,000 miles. The 100 billion neurons with this massive web of wired connections gives a person the ability to think, remember, reason, love, hate, and a host of other functions.
The human brain is mind-boggling complex, but is it the MOST complex thing in the Universe? Absolutely not! At best, it is only a distant second to DNA.
DNA contains the instructions to automatically build an entire human being, including the brain. Certainly, the instructions for building the brain are more complex than the brain itself! And in addition to the brain, DNA contains instructions to build a heart, eyes, kidneys, lungs, etc. It also has instructions to heal cuts and bruises, to cure many diseases, and to duplicate itself !
Human DNA is the size of a microscopic dot yet contains six billion chemical letters. The letters are in an order that is so complex that it puts to shame anything ever written by man. The microscopic dot that we call DNA is by far the most complex thing we know of in the physical Universe.