Many major scientific breakthroughs in humanity stem from the purest curiosity about the unknown. The fundamental research that was once considered 'useless' ultimately profoundly changed the world. From thermophilic bacteria in hot springs to the genetic sequences of archaea, from the whitening of petals to lead isotopes in meteorites... Seven basic studies have given rise to achievements such as polymerase chain reaction (PCR), gene editing, RNA interference, magnetic resonance imaging (MRI), liquid crystal display, weight loss drugs, and global ban on lead gasoline decades later. They prove that what truly drives human progress is the exploration and persistence of the unknown in science. Thermophilic bacterial enzymes make life replication possible. In the summer of 1966, Hudson Fritz, a graduate student at Indiana University in the United States, cultured a bacterium that could survive in high temperatures from a nearly boiling mushroom spring while taking samples in Yellowstone National Park, and remained active and growing in environments above 70 ℃. Three years later, he and his mentor officially described and named this thermophilic bacterium - the aquatic thermophilic bacteria. In 1976, scientists isolated an enzyme called Taq DNA polymerase from this bacterium that could work stably at 80 ℃. In 1983, American biochemist Cary Mullis used this type of heat-resistant enzyme to invent PCR technology, allowing scientists to amplify extremely small amounts of DNA into millions of copies in a short period of time. It is this technology that makes DNA testing, disease diagnosis, and criminal investigation and identification a reality. From the detection of COVID-19 to forensic DNA fingerprinting, human interpretation of the code of life can be traced back to the spoonful of water samples taken from hot springs. Spin resonance experiments open a new chapter in medical imaging. MRI is now one of the most important imaging methods in hospitals, capable of generating high-resolution images of the human body without invasiveness. Its foundation, however, stems from physicists' fundamental research on the "spin" properties of atomic nuclei. In the 1930s, American physicist Isidore Rabi and others discovered that atomic nuclei exhibit energy level differences in a magnetic field due to different spin directions, and can absorb electromagnetic waves of specific frequencies, which is the phenomenon of nuclear magnetic resonance. At first, this study was only used for analyzing molecular structures in chemical laboratories. In the 1970s, American chemist Paul Lauterbach and British physicist Peter Mansfield extended the principle of magnetic resonance imaging to live tissue imaging, giving birth to MRI technology. They were awarded the 2003 Nobel Prize in Physiology or Medicine for their contributions. Today, MRI not only reveals small changes in the heart and tumors, but also develops functional magnetic resonance imaging (fMRI) to track brain activity, opening up new avenues for neuroscience. This exploration, originating from fundamental physics, ultimately changed the way modern medical diagnosis is conducted. The discovery of liquid crystals began with a carrot. In 1888, Austrian botanist Friedrich Reinitzer extracted a compound called "cholesterol ester" from carrot roots, and one of the crystals called "benzoic acid cholesterol ester" exhibited peculiar phenomena. Ordinary crystals lose both their solid state and color when heated, while this type of crystal loses its solid state at 145 ℃ and its blue color at 178 ℃. Renize sent the sample to German physicist Otto Riemann. Lehman discovered through a microscope that this substance can flow and has the optical properties of a crystal, which is a completely new state between liquid and solid. He conducted systematic research and named it liquid crystal. At first, this discovery was considered 'useless'. It was not until the 1950s that American engineers re studied the optical properties of liquid crystals and manufactured the first liquid crystal display screen in 1968 that liquid crystal technology truly changed the world. Nowadays, LCD displays are almost ubiquitous, from televisions and laptops to smartphones and tablets. The microbial defense mechanism has led to the development of gene editing tool CRISPR (clustered regularly spaced short palindromic repeat sequences), which is a precise tool for genome editing and opens up new avenues for disease treatment. Its discovery can be traced back to 1989. At that time, Spanish microbiologist Francisco Mochica discovered a series of regularly repeated short sequences in the genome, interspersed with phage DNA fragments, while studying the "Mediterranean salt rich bacteria". He speculated that this is an immune mechanism of microorganisms: bacteria can preserve the genetic information of viruses in order to recognize and destroy invaders when reinfected. Later, scientists confirmed that these sequences and their related proteins together form the CRISPR system, which can achieve defense by cutting DNA. In 2012, French microbiologist Emmanuel Charpentier and American biochemist Jennifer Dodner modified it into programmable "gene scissors" that can accurately edit DNA. Thus, CRISPR technology was born, opening a new chapter in fields such as disease treatment and gene breeding. The lizard hormone has become a brand new weight loss drug. Now the weight loss and diabetes drugs, such as smeglutide, are popular all over the world. There is also unexpected biological inspiration behind them. Its key clue actually comes from the only venomous lizard on American soil - the Gila lizard. In 1992, scientists isolated a molecule called "Exopeptide-4" from its venom, which is very similar to the human gut hormone glucagon like peptide-1 (GLP-1). GLP-1 can stimulate insulin secretion and suppress appetite, but its lifespan in the body is extremely short. Exogenous peptide-4 can activate GLP-1 receptors for a long time and exert stable effects. In 2008, Canadian medical scientist Daniel Drucker led a phase III clinical trial based on this molecule, with a drug called "exenatide". The results showed that it not only improved the blood sugar control of diabetes patients, but also significantly reduced their weight. This discovery has spurred a series of GLP-1 receptor agonist drugs and sparked a global weight loss craze. Flower color mutation reveals gene silencing mechanism. In March 2024, the US Food and Drug Administration (FDA) approved a new drug called "Fetuximab" for the treatment of hemophilia. It belongs to a novel drug family that utilizes RNA interference (RNAi) mechanism. The birth of RNAi drugs took 30 years, starting with a chance plant experiment. In 1990, American scientist Richard Jorgensen wanted to make the color of the dwarf morning glory darker, so he added the same pigment gene to it. The petals not only did not darken, but also turned white. This abnormal phenomenon has puzzled scientists for many years. In 1998, American biomedical scientists Andrew Farr and Craig Melo revealed its molecular mechanism: double stranded RNA can trigger a series of reactions that degrade messenger RNA (mRNA), thereby preventing protein synthesis, which is RNA interference (RNAi). Both of them were awarded the Nobel Prize in Physiology or Medicine in 2006 for this. From then on, a new class of gene silencing drugs was born. Measuring the age of the Earth unexpectedly purified the air. In the 1950s, geochemist Claire Patterson attempted to determine the age of the Earth. He used the radioactive decay of uranium and thorium to calculate the proportion of lead isotopes in meteorites, but was repeatedly disturbed by lead pollution in the air. To eliminate errors, he built the world's first "ultra clean laboratory" at the California Institute of Technology. Ultimately, Patterson accurately determined the composition of the meteorite and estimated that the Earth is approximately 4.55 billion years old. However, this study also made him realize that the lead content in modern air is much higher than natural levels, mainly from leaded gasoline. In 1963, he co published a paper with geochemist Mitsunobu Tatsumoto, pointing out that even the most remote oceans had been contaminated with lead, and early ocean samples had much lower lead levels. This discovery sparked intense conflict with the lead industry, but ultimately led to the implementation of a global ban on lead gasoline policies. (New Society)