Ten scientific experiments that changed the world (I)

In 2007, according to science experiments the National Science Foundation, the United States spent about $368 billion on research and development. Almost 18% of that huge pie went to fund basic research, another 22% to applied research, research aimed at solving practical problems.

Surely with this type of investment Science will continue its path to complete knowledge, but in this article we will consider the ten most sublime experiments.

They are organized according to the main disciplines of Science: biology, chemistry, physics and psychology, extending to more than 200 years of research.

In some cases, two closely related experiments have been linked, not to cover more but to demonstrate that science is a team effort.1. Darwin’s flowers

Most of us know the work Charles Darwin did aboard HMS Beagle on his famous voyage to South America. He made some of his most important observations in the Galapagos Islands, where he was able to classify several subspecies of finch perfectly adapted to the feeding of the island on which they lived. But few people know about Darwin’s experiments after his return to England, which focused on orchids.

Darwin studied several species of native orchids, realizing that the complex shapes of orchids were adaptations that allowed flowers to attract certain insects, which would then carry pollen to other nearby flowers.

Each insect was perfectly designed to pollinate a single type of orchid, just like the beaks of Galapagos finches. Darwin used the data he collected on orchids and their pollinating insects to bolster his theory of natural selection.

He argued that cross-pollination produced orchids better able to survive than orchids that reproduced by self-pollination, a form that reduces genetic diversity and, ultimately, the survival of the species. And so, three years after he first described natural selection in “The Origin of Species,” he was able to reinforce the framework of modern evolution with his flower experiments.2. DNA decoding

James Watson and Francis Crick took credit for finding the mystery of DNA, but that discovery depended largely on the work of others, such as Alfred Hershey and Martha Chase, who in 1952 conducted an experiment in which they identified DNA as the molecule responsible for heredity.

Later, Rosalind Franklin focused on deciphering its molecular structure using a technique based on X-ray diffraction, (the famous photo of Franklin’s DNA shows an X-shaped pattern).

He was also able to determine the width of the propeller. The suggested width of two strands makes up the molecule, leading to the double helix shape we all know today.3. The first vaccine

Until its global eradication in the 20th century, smallpox represented a serious health problem. In the 18th century, the disease caused by the Variola virus killed one-tenth of children born in Sweden and France.

Edward Jenner, a British physician, set out to study smallpox to develop a viable treatment. In 1796, he observed that milk collectors occasionally acquired a kind of “cowpox” by continued contact with these animals, and then were safe from becoming ill with common smallpox.

Working on this inoculation case, Jenner took cowpox from farmer Sarah Nelmes. He inserted this fluid via injection into the arm of an eight-year-old boy, James Phipps. The little boy showed symptoms of cowpox infection. Forty-eight days later, Jenner exposes the boy to smallpox, only to prove that the boy was immune and sure enough this time he didn’t show any symptoms or signs of illness.

Today, scientists know that the cowpox virus and the human virus are so similar that the body’s immune system cannot distinguish them. In other words, antibodies produced to fight the cow virus attack and kill smallpox viruses as if they were the same.