Since ages, scientific and technological advances have influenced and shaped the world around us. From simple household appliances to space exploration and complex medical procedures, technology has revolutionized every aspect of our living. However, in the craze for 'venturing past the limits', and coming up with 'technology indistinguishable from magic', certain researchers opted for unethical routes of hideous experimentation, which are highly frowned upon, even today. Given below is an account of a few experiments considered to be the scariest experiments of the scientific world. What is more bone-chilling than the experimental procedures, is the use of innocent lives as experimental subjects. In the early 1800s, an Italian physicist named Giovanni Aldini traveled all over Europe, demonstrating his ability to use electricity and have dead bodies jerk around and dance. His most widely known demonstration was the one in January 1803, when he electrified the body of an executed murderer named George Forster. Luigi Galvani was an Italian physician and physicist, who pioneered in studying the effects of electricity on animal tissue. He suggested the existence of animal electricity that flowed from the brain to the muscles, and thus controlled their movements. His experiments in 1781 demonstrated electricity-induced muscle twitching in the limbs of dead frogs. It was on these observations that his nephew Giovanni Aldini published and demonstrated using several animals as well as human corpses. He attached wires to the mouth and ear which led to twitching of facial muscles. In one instance he attached a wire to the ear and probed another one into the rectum resulting in rapid jerking of the arms, and kicking of the legs. This freaky public demonstration of the electrification of George Forster made headlines and managed to scare an observer to death. Although, we might think creatures like two-headed dogs exist only in fiction or legends, that was not the case in Dr. Vladimir's lab in Russia. He was well-known for his pioneering studies in organ transplants, but infamous for his two-headed dogs. The doctor and his team carefully severed the head (and even forepaws in some cases) of a smaller dog or puppy and stitched it onto the torso of a larger dog. The first surgery took about 12 hours, with over 20 such surgeries the duration had reduced to about three and half hours. The resultant dogs survived and could drink and eat from both the mouths. However, the dogs died due to rejection and the maximum survival recorded was of 29 days. In addition to this, Dr. Vladimir's lab had more interesting animals like dogs with two hearts, dogs with mechanical cardiac-assist devices, etc. Nevertheless, he was the first to perform heart transplant, lung transplants, heart-lung transplants, bypass surgeries, and many more. He devised innovative surgical techniques, many of which are a part of routine surgical procedures today. Being so, he is regarded as one of the greatest experimental surgeons of the 20^th century. In a remote location in Pingfang, Manchukuo, was located a laboratory called Unit 731 or the 'den of cannibals', which was headed by Lieutenant General Shirō Ishii. Established in 1935 - 36 during World War II and Second Sino-Japanese War, it was the site for the study of chemical and biological weapons. Ghastly human experiments were studied under a special project called Maruta, and the victims were referred to as logs. These human subjects for experimentation were prisoners of war, and mostly included Chinese prisoners. The grisly experiments that occurred here included infecting the prisoners with bacteria that caused anthrax, cholera, tuberculosis, etc. These infected individuals were then subjected to vivisection (live dissections without administration of anesthesia), in order to study the effect and progression of the diseases. The live dissections were "justified" under the premise that death alters the physiology, and may not be the precise representation of the diseased condition. Other alleged activities here included hanging individuals upside down until they died, spinning them in a centrifuge, burying prisoners alive, injecting air into their veins, and even thawing and amputating limbs, in order to study the effect of frostbite. The above mentioned atrocities are mostly known through interviews of prisoners and surgeons. These have been supplemented with excavations that revealed mass graves. Media reports indicate that all the experimental data was surrendered to USA, in lieu of which, the Japanese government was granted immunity against these crimes. Although, a class action suit was filed against the Japanese government, it was considered baseless due to lack of substantial records and documentary evidence. Nevertheless, this 'den of cannibals' remains infamous as one of the largest and most inhuman biological warfare programs. This psychological experiment performed in the basement of the psychology building at Stanford University in California, clearly demonstrated that evil behavior can be induced into good people. The experiment consisted of a set of 24 students, of which, half were assigned the role of prisoners, and the rest were supposed to be their guards. The basement of the building served as the mock prison. Although it seems a rather normal experiment, the results were beyond anybody's predictions and the experiment halted in mere six days. The volunteer students were arrested from their homes with the help of local Palo Alto police officers, and subjected to procedures like mug shots and fingerprint recording, similar to that followed for real criminals. They were then brought to the mock prison, their belongings were confiscated, they were provided prisoner uniforms, were assigned a unique ID which served as their identity, and their feet were chained. Similarly, the guards were instructed and provided with khaki uniforms and wooden batons. However, they were instructed not to harm the prisoners physically. The first day was a quiet and boring one, however, on the second day, the students appeared to have taken their roles much too seriously. The powerlessness and loss of individuality of prisoners, coupled with the power accrual in the hands of the guards, had changed the way they interacted with each other. Despite the warnings from the research staff, the guards started physical and mental torture. The prisoners reacted by banging beds onto the doors of their cells. The guards became increasingly cruel and most of them exhibited sadistic tendencies. Nighttime was the worst time for prisoners and the best for guards, since horrible punishments were given during that time. Solitary confinement, humiliation, forcing the prisoners to clean toilet bowls, stripping their clothes, putting bags on their heads, etc., were a few of them. The Nazi concentration camps and the torments therein are well-documented and known. During the World War II, as much as 20,000 prison camps and subcamps were set up by Nazi Germany, which inflicted terror amongst war prisoners, Jews as well as the civilians. The reason for this terror were the medical atrocities performed by Nazi physicians and surgeons, especially those by Dr. Josef Mengele, who is also referred to as the 'Angel of Death'. Interested in the science of heredity, Mengele isolated twins and used them as guinea pigs for his "research". In one experiment, the twins were stitched together in order to get conjoined twins. The pair soon died due to infection at surgical site and gangrene. Others included killing 14 pairs of twins and dissecting them to study anatomical similarities and differences. He injected dyes into the eyeballs of children to see if the color of eyeball changes. Other procedure included limb amputations and vivisections. This 'Angel of Death' experimented on thousands of children, including about 1500 pairs of twins. Other gruesome experimentation at the concentration camps included vivisection of pregnant women, deliberate bacterial and viral infections, removal of organs and nerves without anesthesia and transplanting them into other victims, forced sterilization, artificial insemination, and many more. In an attempt to learn about head injury, one prisoner was strapped to a chair with a mechanical hammer above him that delivered head-blows after regular intervals. A neuroscientist at the Laurentian University in Canada, Dr. Michael Persinger, along with a Korean scientist Stanley Koren, developed a helmet that could alter the electromagnetic fields of brain. Although named as God helmet, it was designed to test the brain function in relation to parapsychological and spiritual experiences. Participants were made to wear the helmet and sit in an acoustic chamber, isolated from all radiation except the earth's magnetic field. Their eyes were closed and a goggle with tissues stuffed on the inside were placed on their eyes. In such isolated darkness and altered brain waves, the individuals felt the presence of other being(s) around them. Their experiences include the visions of bright light, a sensation that they were moving around, demonic beings, as well as out-of-body experiences. Around 80% of the individuals reported of feeling the presence of someone around them; whereas 1% of them mentioned that they felt the presence of God. According to Persinger, the human sense of self is due to a combination of neural activities of the left and right hemispheres; and a disruption in their coordination leads to the sense of two different selves. The electrodes present on the helmet then delivered carefully-controlled electromagnetic radiation, that altered the fields of temporal lobes of the brain. However, it has been argued that the experiment was not a double-blind study, and the participants knew beforehand how the helmet will affect them. Being so, their experiences may be due to this knowledge and not the helmet. Nevertheless, the experiment sure scared the bejesus out of some participants. Project MKUltra was a human research program conducted by the Scientific Intelligence Division of the US CIA. Officially initiated in 1953, this program used US and Canadian citizens to study mind control and employed several techniques to manipulate their minds. For two decades, CIA conducted about 149 projects through 185 non-governmental researchers at 44 universities, 12 hospitals, prisons, and pharmaceutical companies. Although, the main agent of focus was LSD (Lysergic acid diethylamide), other methods included administration of hallucinogens, hypnosis, physical abuse, and isolation. The subjects for these studies were not limited to voluntary participants but also included several unsuspecting civilians. The illicit activities include drugging of victims by prostitutes, spraying unspecified gas (probably containing LSD) in the streets and subways of New York, administration of drugs that induce amnesia, brain washing experiments, etc. It all began in January 1942, when a surgeon and inventor from Pennsylvania wrote a letter to President Roosevelt providing him with a proposal for a surprise attack on Japan. The element of surprise was supposed to be bats with incendiary material tied to their tails along-with built-in-timers. A series of tests were conducted, and bat carriers were developed that contained about 1040 hibernating bats. These carriers were fired from airplanes and released at an appropriate altitude. The bats would reach the cracks and crevices as well as other unreachable places of the Japanese buildings and hide there. Owing to built-in timers, explosions would take place over a vast area. However, during experimentation, some bats got accidentally released at Carlsbad Army Airfield Auxiliary Air Base. They hid under the fuel tank and later exploded inflicting major damage. The project was then transferred to the US Navy, where further experimentation took place. These bat bombs could give rise to about 625 to 4,748 fires, as compared to 167 to 400 fires given by regular bombs. Nevertheless, the project was discontinued in 1944 due to its slow progress and comparatively rapid progress in the development of atomic bombs. Officially termed 'Tuskegee Study of Untreated Syphilis in the Negro Male', this experiment began in 1932, with intention to study the effects and progression of untreated syphilis. Syphilis is a sexually transmitted disease that occurs due to a bacterium called Treponema pallidum. Back then, there was no established treatment regimen, and the medical care often focused on symptomatic treatments. The "study" involved a set of 600 African-American men - 399 suffering from syphilis and 201 normal. These men were offered free meals, medical exams, and treatment for minor ailments, thus enticing them into the study. They were informed that they were being treated for 'bad blood', which was the local term for a several ailments including fatigue, anemia, syphilis, and many more. They were unaware of their disease, and with no treatment and precautions, the number of infected members increased. In spite of penicillin treatment being approved as a standard therapy for syphilis in the late 1940s, this study continued till 1972 (for a period of 25 years). Several men had died and the infection spread to the wives and children of many. It was only in July 1972 that the study was exposed, making it to the headlines of reputed newspapers. An ad hoc advisory panel investigated the case, and a suit was filed on behalf of the participants and their families. The suit ended with the US government paying a compensation of more than $9 million, and the Tuskegee Health Benefit Program (THBP) was established to provide medical benefits, burial services, and many other free services. A theologian, philosopher, and alchemist, Johann Konrad Dippel is well-known today for discovering the dye called Prussian blue, but is also infamous for his experiments with animal and human cadavers, and especially for his alleged soul transplant attempts. What is even more spooky about this man is the fact that he was born at Castle Frankenstein. Like all alchemists of that era, Dippel too was in search of the 'elixir of life', but put forth controversial ideas and views that were beyond the normal conventions of that time. In this pursuit, he studied and dissected several animal cadavers, boiled and distilled bones and flesh, and concocted an oil called Dippel's oil. In addition to this, it was said that he attempted soul transplants on human corpses and was even accused of grave robbery. These experiments were based on his claim that souls can be transferred from one body to another by using a funnel. Later on, the knowledge of these attempts lead the townspeople to drive him out of town. Although soul transplant experiments were common among alchemists, there is no direct evidence for the same. It has been argued that these were nothing but rumors and has no documentation. Nevertheless, his series of experiments with flesh and bones led to the discovery of the important dye Prussian blue, which has many applications in the paint industry as well as in pathology and medicine. Experiments like these are viewed with terror, since they were a sharp blow in the face of humanity, and demonstrated the horrors that can take place in the name of science. Although, it is equally true that most of these experiments have made extremely notable contributions to our knowledge about human anatomy and physiology as well as surgical procedures, they still remain unjustified and will always be frowned upon.