Category Science

Every astronaut who leaves a spacecraft has to wear a specially designed spacesuit. It is called an Extra-Vehicular Activity (EVA) suit and acts like a miniature spaceship. Layers of material protect the astronaut from the Sun’s rays, as well as tiny particles of space dust that travel at hundreds of thousands of kilometres per hour. The suit provides everything that an astronaut needs to survive in space for short periods of time, including oxygen to breathe and water to drink. It also provides heating and cooling, communication devices and toilet facilities.

Astronauts must wear spacesuits whenever they leave a spacecraft and are exposed to the environment of space. In space, there is no air to breath and no air pressure. Space is extremely cold and filled with dangerous radiation. Without protection, an astronaut would quickly die in space. Spacesuits are specially designed to protect astronauts from the cold, radiation and low pressure in space. They also provide air to breathe. Wearing a spacesuit allows an astronaut to survive and work in space.

Spacesuits help astronauts in several ways. Spacewalking astronauts face a wide variety of temperatures. In Earth orbit, conditions can be as cold as minus 250 degrees Fahrenheit. In the sunlight, they can be as hot as 250 degrees. A spacesuit protects astronauts from those extreme temperatures.

Spacesuits supply astronauts with oxygen to breathe while they are in the vacuum of space. The suits contain water to drink during spacewalks. They protect astronauts from being injured from impacts of small bits of space dust. Space dust may not sound very dangerous, but when even a tiny object is moving many times faster than a bullet, it can cause injury. Spacesuits also protect astronauts from radiation in space. The suits even have visors to protect astronauts’ eyes from the bright sunlight.

A spacesuit is much more than a set of clothes astronauts wear on spacewalks. A fully equipped spacesuit is really a one-person spacecraft. The formal name for the spacesuit used on the space shuttle and International Space Station is the Extravehicular Mobility Unit, or EMU. “Extravehicular” means outside of the vehicle or spacecraft. “Mobility” means that the astronaut can move around in the suit. The spacesuit protects the astronaut from the dangers of being outside in space.

Nuclear reactions are the result of the strong nuclear force, which binds together the particles that form atoms. During a nuclear explosion, this powerful force is released, expelling vast amounts of energy.

A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, though to date all fusion-based weapons have used a fission device to initiate fusion, and a pure fusion weapon remains a hypothetical device.

Atmospheric nuclear explosions are associated with mushroom clouds, although mushroom clouds can occur with large chemical explosions. It is possible to have an air-burst nuclear explosion without those clouds. Nuclear explosions produce radiation and radioactive debris.

The effects of a nuclear explosion on its immediate vicinity are typically much more destructive and multifaceted than those caused by conventional explosives. In most cases, the energy released from a nuclear weapon detonated within the lower atmosphere.

Depending on the design of the weapon and the location in which it is detonated, the energy distributed to any one of these categories may be significantly higher or lower. The blast effect is created by the coupling of immense amounts of energy, spanning the electromagnetic spectrum, with the surroundings. The environment of the explosion (e.g. submarine, ground burst, air burst or exo-atmospheric) determines how much energy is distributed to the blast and how much to radiation. In general, surrounding a bomb with denser media, such as water, absorbs more energy and creates more powerful shockwaves while at the same time limiting the area of its effect. When a nuclear weapon is surrounded only by air, lethal blast and thermal effects proportionally scale much more rapidly than lethal radiation effects as explosive yield increases. The physical-damage mechanisms of a nuclear weapon (blast and thermal radiation) are identical to those of conventional explosives, but the energy produced by a nuclear explosion is usually millions of times more powerful per unit mass and temperatures may briefly reach the tens of millions of degrees.

Energy from a nuclear explosion is initially released in several forms of penetrating radiation. When there is a surrounding material such as air, rock, or water, this radiation interacts with and rapidly heats the material to an equilibrium temperature (i.e. so that the matter is at the same temperature as the fuel powering the explosion). This causes vaporization of the surrounding material, resulting in its rapid expansion. Kinetic energy created by this expansion contributes to the formation of a shockwaves. When a nuclear detonation occurs in air near sea level, much of the released energy interacts with the atmosphere and creates a shockwave which expands spherically from the center. Intense thermal radiation at the hypocenter forms a nuclear fireball which, if the burst is low enough, is often associated with a mushroom cloud. In a high-altitude burst, where the density of the atmosphere is low, more energy is released as ionizing gamma radiation and X-rays than as an atmosphere-displacing shockwave.

From Earth, space can seem calm and quiet, but in actual fact it is deadly. If humans ventured into space without the protection of a spacesuit they would die almost instantly. The lack of oxygen would mean suffocation. But before this, the lack of pressure would cause gases in the blood to separate as if it were boiling. With no protection from the Sun’s harmful ultraviolet radiation, the astronaut would be burned to death.

What happens to your body in space? NASA’s Human Research Program has been unfolding answers for over a decade. Space is a dangerous, unfriendly place. Isolated from family and friends, exposed to radiation that could increase your lifetime risk for cancer, a diet high in freeze-dried food, required daily exercise to keep your muscles and bones from deteriorating, a carefully scripted high-tempo work schedule, and confinement with three co-workers picked to travel with you by your boss.

But what, exactly, happens to your body in space, and what are the risks? Are risks the same for six months on the space station versus three years on a Mars mission? No. There are several risks NASA is researching for a Mars mission. The risks are grouped into five categories related to the stresses they place on the space traveler: Gravity fields, isolation/confinement, hostile/closed environments, space radiation, and distance from Earth.

Scott Kelly was the first American to spend nearly one year in space aboard the International space Station, twice the normal time. Science takes time, and researchers are eagerly analyzing results of the mission to see how much more the body changes after a year in space. One year is a stepping stone to a three-year journey to Mars, and Scott’s data will help researchers determine whether the solutions they’ve been developing will be suitable for such long, onerous journeys.

Together, the four forces can explain everything that happens in the Universe. Many scientists are now working to prove that they are all separate parts of the same universal force that once existed at the birth of the Universe.

A theory of everything (TOE or ToE), final theory, ultimate theory, or master theory is a hypothetical single, all-encompassing, coherent theoretical framework of physics that fully explains and links together all physical aspects of the universe. Finding a TOE is one of the major unsolved problems in physics. Over the past few centuries, two theoretical frameworks have been developed that, together, most closely resemble a TOE. These two theories upon which all modern physics rests are general relativity (GR) and quantum field theory (QFT). GR is a theoretical framework that only focuses on gravity for understanding the universe in regions of both large scale and high mass: stars, galaxies, clusters of galaxies, etc. On the other hand, QFT is a theoretical framework that only focuses on three non-gravitational forces for understanding the universe in regions of both small scale and low mass: sub-atomic particles, atoms, molecules, etc. QFT successfully implemented the Standard Model that describes the three non-gravitational forces – strong nuclear, weak nuclear, and electromagnetic force — as well as all observed elementary particles.

Physicists have experimentally confirmed virtually every prediction made by GR and QFT when in their appropriate domains of applicability. Nevertheless, GR and QFT are mutually incompatible – they cannot both be right. Since the usual domains of applicability of GR and QFT are so different, most situations require that only one of the two theories be used. As it turns out, this incompatibility between GR and QFT is only an issue in regions of extremely small scale – the Planck scale – such as those that exist within a black hole or during the beginning stages of the universe (i.e., the moment immediately following the Big Bang). To resolve the incompatibility, a theoretical framework revealing a deeper underlying reality, unifying gravity with the other three interactions, must be discovered to harmoniously integrate the realms of GR and QFT into a seamless whole: the TOE is a single theory that, in principle, is capable of describing all phenomena in the universe.

In pursuit of this goal, quantum gravity has become one area of active research. One example is string theory, which evolved into a candidate for the TOE, but not without drawbacks (most notably, its lack of currently testable predictions) and controversy. String theory posits that at the beginning of the universe (up to 10?43 seconds after the Big Bang), the four fundamental forces were once a single fundamental force. According to string theory, every particle in the universe, at its most microscopic level (Planck length), consists of varying combinations of vibrating strings (or strands) with preferred patterns of vibration. String theory further claims that it is through these specific oscillatory patterns of strings that a particle of unique mass and force charge is created (that is to say, the electron is a type of string that vibrates one way, while the up quark is a type of string vibrating another way, and so forth).

Gravity is one of only four forces that govern every event in the entire Universe. Gravity binds together the Universe, while electromagnetic force is responsible for light and electricity. A strong nuclear force holds together basic particles, and a weak nuclear force causes the decay of unstable atoms. These four forces may have been united during the Big Bang, emitted as one superforce bound by extremely high temperatures. As temperatures began to cool, the superforce was gradually broken down into four separate forces. All four forces are linked with special particles that act in the same way as couriers, transferring the force from one place to another. Electromagnetism and gravitation can work over large distances, but the two nuclear forces only operate on an atomic level.

In physics, the fundamental interactions, also known as fundamental forces, are the interactions that do not appear to be reducible to more basic interactions. There are four fundamental interactions known to exist: the gravitational and electromagnetic interactions, which produce significant long-range forces whose effects can be seen directly in everyday life and the strong and weak interactions, which produce forces at minuscule, subatomic distances and govern nuclear interactions. Some scientists hypothesize that a fifth force might exist, but these hypotheses remain speculative.

Each of the known fundamental interactions can be described mathematically as a field. The gravitational force is attributed to the curvature of space-time, described by Einstein’s general theory of relativity. The other three are discrete quantum fields, and their interactions are mediated by elementary particles described by the Standard Model of particle physics.

Within the Standard Model, the strong interaction is carried by a particle called the gluon, and is responsible for quarks binding together to form hadrons, such as protons and neutrons. As a residual effect, it creates the nuclear force that binds the latter particles to form atomic nuclei. The weak interaction is carried by particles called W and Z bosons, and also acts on the nucleus of atoms, mediating radioactive decay. The electromagnetic force, carried by the photon, creates electric and magnetic fields, which are responsible for the attraction between orbital electrons and atomic nuclei which holds atoms together, as well as chemical bonding and electromagnetic waves, including visible light, and forms the basis for electrical technology. Although the electromagnetic force is far stronger than gravity, it tends to cancel itself out within large objects, so over large distances (on the scale of planets and galaxies), gravity tends to be the dominant force.

Many theoretical physicists believe these fundamental forces to be related and to become unified into a single force at very high energies on a minuscule scale, the Planck scale, but particle accelerators cannot produce the enormous energies required to experimentally probe this. Devising a common theoretical framework that would explain the relation between the forces in a single theory is perhaps the greatest goal of today’s theoretical physicists. The weak and electromagnetic forces have already been unified with the electroweak theory of Sheldon Glashow, Abdus Salam, and Steven Weinberg for which they received the 1979 Nobel Prize in physics. Progress is currently being made in uniting the electroweak and strong fields within what is called a Grand Unified Theory (GUT). A bigger challenge is to find a way to quantize the gravitational field, resulting in a theory of quantum gravity (QG) which would unite gravity in a common theoretical framework with the other three forces. Some theories, notably string theory, seek both QG and GUT within one framework, unifying all four fundamental interactions along with mass generation within a theory of everything.

Space science has led to many amazing developments in technology. Scientists have studied combustion in microgravity in order to design more efficient jet engines. We have all benefited from technology that was designed for use in space. Microchips found in digital watches, computers and mobile phones were first developed so that lots of equipment could fit into a small spacecraft. Many household items have come about because of space technology, including air-tight cans and tin foil. Technologies such as solar power and keyhole surgery have also advanced largely due to the space programme.

The study of space has taken ideas that began outside our corner of the universe and adapted them to benefit our own planet Earth in amazing ways. Here are some out of this world space exploration technologies and innovations that came from studying space but have changed our lives here on Earth. These contributions from space may have had out-of-this-world origins, but they ended up advancing technology right here on our own planet.

Digital photography technology was developed at NASA’s Jet Propulsion Laboratory in the 1960s as a way to capture images from long range telescopes. In the 1990s, the technology was miniaturized to enable spacecraft to carry it on board, which led to the ability to make cameras on smartphones inexpensively. The first wireless headsets were created so Neil Armstrong and other astronauts could communicate with NASA from the moon, and technology has continued to evolve into today’s Bluetooth technology and other wireless communication devices.

This easy-to-use device for taking someone’s temperature in seconds started out as a way for space scientists to determine the temperature of distant planets and stars using infrared technology. Now, it enables medical professionals and parents to easily take the temperature of patients, their kids, or anyone in need of medical evaluation. Originally developed by NASA to use aboard spacecraft, the technology for purifying water supplies is now commonly used in water treatment plants. It keeps contaminants and pollutants from getting into Earth’s water distribution systems and causing widespread disease outbreaks.

Solar energy was responsible for two-thirds of the new energy capacity generated worldwide in 2017. Solar energy technology came from space scientists who wanted to find ways to generate energy in space without using fossil fuels, which are heavy to carry and eventually run out. Space scientists developed temper memory foam to make space capsule seats more comfortable for long flights. However, it is now used in mattresses, pillows, shoes, and prosthetic limbs to provide comfort and cushioning for those with chronic pain or who spend long hours on their feet. Equipment used to track the heart rates of astronauts while they were in space or walking on the moon was modified to provide a way to track athletes’ and exercisers’ heart rates and make sure they are within healthy limits.

Current technology, which can be used on tumors resistant to other methods, was developed by NASA to grow food in space and perform other tasks. NASA asked Black & Decker to create Dustbusters in 1979 as a handheld device to suck up moon rocks and dust to be studied. The company then applied the technology to portable vacuum cleaners and a new era of cleaning tools was born.

The type of insulation used in most newly built homes today was developed as a way to protect its equipment and systems from extreme temperatures in space. The first portable computers were developed for use during space travel and were later adapted for commercial use by manufacturers. Now, they are the majority of the home computer market.