Artificial gravity is collection of systems planned to mimic the gravity of a planet so that people in space can do work comfortably. With the help of artificial gravity, people experience the same conditions as on the surface of the Earth and it even lessens the problems related with the extended periods of weightlessness, plus loss of muscle tone. The formation of artificial gravity is considered advantageous for in-space fluid management, long-term space travel or habitation, ease of mobility, and to keep away from the undesirable long-term health effects of weightlessness.
Photo courtesy: galaxywire.net
Artificial gravity is the change (increase or decrease) of visible gravity (g-force) through artificial means. Artificial gravity can be practically obtained either by using a “long-range centrifuge” in which a huge spacecraft rotates constantly or a “short-range centrifuge” in which an individual is attached to a spinning formation for alternating periods. In any set-up, the spinning motion produces an acceleration field that mimics the upshots of gravity on the body of individual. Artificial gravity has long been observed as the most efficient technique to thwart deconditioning of space travelers. Artificial gravity is exclusive since it goes to the depth of the problem, unlike other methods that are intended to counter the deconditioning of individual physiological systems. Artificial gravity can be gained with the use of a number of various forces, mainly the centrifugal force and linear acceleration (fictitious forces).
One of the major barriers to space travel includes the requirement for artificial gravity. People who spend so much time in low gravity or free fall surroundings could develop severe musculoskeletal problems, which is extremely unwanted. Low gravity can be very frustrating too, since objects have to be carefully secured for safety.
Albert Einstein showed that Gravity and Acceleration are equivalent – both of them are connected with a force that’s comparative to the mass of the object. The effect is the identical whether you are standing on the surface of the Earth or in a spaceship, continuously accelerating at 1g. As you are able to accelerate perpetually without attaining the speed of light, you could produce gravity for as long as you require it, provided you can travel in a straight line and have sufficient energy to keep accelerating. There is also other way to create gravity, i.e. centripetal force, spinning a craft about a central axis; however this generates Coriolis Effect, and makes moving things travel in curved paths. Though, you can reimburse for these effects, and spinning can be a practical alternate for acceleration.
Different ways to generate Artificial Gravity in space
Technically, rotation generates the same effect as gravity since it creates a force called the centrifugal force, same as gravity creates a force. By adjusting definite parameters of a space station like the radius and rotation rate, you can produce a force on the outside walls that is alike the force of gravity. You can really produce artificial gravity by rotating a space station. For moving into a circular path, a “centripetal force” is essential to drive you into the circle. As per Newton’s first law, an object will stay in motion at a stable speed in a straight line when there is not any external net force. A force is necessary for changing that constant-velocity motion. In order to move in a circular path, the force should always be perpendicular to the motion. For instance – it is the force of gravity that acts as a centripetal force which drags an orbiting satellite into its circular path. To produce artificial gravity, you have to adjust the rotation rate of your space station so that a = g (the acceleration because of gravity on Earth). According to the reviews of people rotating with the habitat, artificial gravity by rotation acts in a few ways similarly to normal gravity although has 2 effects: Centrifugal force and Coriolis effect. Out of these two effects, the centrifugal is easier to explain, and the more broadly understood.
- Centrifugal force:
- It is an outward force caused by an object being prepared to chase a curved path rather than a straight line, as stated by the Law of Inertia. In fact, this pseudo-force emerges in rotating reference frames that delivers a rotational ‘gravity’ which pushes away from the axis of rotation. Artificial gravity levels differ proportionately with the distance from the centre of rotation – the amount of gravity felt at one’s head would be notably diverse from the amount felt at one’s feet with a small radius of rotation. As a result, it can make movement and changing body position uncomfortable. Slower rotations or bigger rotational radii may lessen or eradicate this problem.
- Coriolis effect:
- It just acts on moving objects, and causes their path to curve. This force works at right angles to the motion & the rotation axis, and has a tendency to curve the motion in the contrary logic to the habitat’s spin. For instance – if an astronaut inside rotating artificial gravity surroundings moves parallel to the path of rotation, they will momentarily feel an increase or decrease in weight.
It’s a fact that all objects, which have mass, use a gravitational pull on other objects, however unless the mass is very outsized (similar to the earth) it has slight effect. To create artificial gravity, install an ultra-high density mass in a spacecraft so that it can produce its own gravitational field and drag everything inside the spacecraft towards it. A very huge amount of mass is needed to generate even a small gravitational field. For instance – a quite large asteroid could make several thousandths of a g. One could visualize that by attaching a propulsion system of some type to this asteroid, it may loosely qualify as a space ship. The downside is that gravity at such a low level is not probable to have any practical value. Moreover, the mass would apparently require moving with the spacecraft; if the spacecraft is to be accelerated drastically, then this would significantly raise fuel consumption. As per the principal of mass, the practical way to apply artificial gravity is to find as of yet uncovered materials with very high densities such that large mass is there in a low volume.
Devices for simulating alterations in gravity vary from centrifuges to vomit comets, however simple magnetism may deliver the most versatile technique. Magnetism would mimic (using diamagnetism) low gravity circumstances in the space. To cause a repulsive effect, big magnets with strong magnetic fields would be used. Safety for use with humans is uncertain with such powerful magnetic fields. As well, it would entail evading any ferromagnetic or paramagnetic materials near the powerful magnetic field necessary for diamagnetism to be apparent. Facilities using diamagnetism might prove efficient for laboratories simulating low gravity circumstances here on Earth.
Linear acceleration is also one way by which artificial gravity can be obtained in a spacecraft. By accelerating the spacecraft constantly in a straight line, objects inside the spacecraft are forced in the contrary direction of that of the applied acceleration. This phenomenon is being experienced by astronauts usually throughout orbital adjustments of the space shuttle and other orbital spacecraft whilst the thrusters are ablaze. The outcome is intermittent impulsive artificial gravity forces imposed on the astronauts, that is similar to the acceleration level attained by the thrusters or automobile engines. Please note that the period of this artificial gravity is just a few seconds and it is very short to be measured as a prospective counter measure.
With buoyancy for space simulations, an estimate to 0 gravity could be formed and note that the approximation is imperfect. The inertial and viscosity properties of a suspension fluid with a realistic density like water generate superior drag on the body than created by either air or vacuum. Moreover, an individual’s sense of which way is “up” (equilibrioception) is not tricked because the fluid in the inner ear will yet settle in the “down” way. In some circumstances the method is nevertheless helpful and practical. For instance – a big pool is being used by NASA to train astronauts for extra-vehicular activity.
In science fiction, artificial gravity or paragravity or cancellation of gravity is occasionally there in spacecraft that are not rotating also not accelerating. Besides actual mass or acceleration, currently there is no confirmed method that could create gravity. Since many years, there have been several claims of such type of device. Since the early 1990s, a Russian engineer – Eugene Podkletnov has claimed to have prepared such a device that consists of a spinning superconductor generating an influential gravitomagnetic field, although there have been no confirmation or negative results from third parties. Later in the year 2006, a research group supported by ESA claimed to have produced identical device that verified positive results for the creation of gravitomagnetism, but it formed just 100 millionths of a g.