(Phys.org)—Ideal invisibility cloaks like those in Harry Potter may be physically impossible, a new study shows. The researchers demonstrate that even the best invisibility cloaks can hide an object from only some observers, ...
(Phys.org)—Physicists have found that invisibility cloaks that can achieve perfect invisibility when not in motion will become visible when moving at speeds of around thousands of meters per second. This is because invisibility ...
(Phys.org)—Typically when two magnets are brought close together, they either attract or repel each other due to interactions between their magnetic fields. In a new study, researchers have designed a 3D magnetic invisibility ...
(Phys.org)—Physicists have built a nanowire cage that blocks one or more wavelengths of light from either entering or escaping, yet allows liquids and gases to pass through the small gaps between the nanowires. The "optical ...
Metamaterials – engineered materials with properties not found in nature – have led to an astounding range of optical, acoustic, thermodynamic, two-dimensional solid mechanics, and other types of invisibility cloaks that ...
Invisibility cloaks can make objects invisible not just to light in the visible part of the spectrum, but to many other physical excitations. These include acoustic waves, matter waves, heat flux, and infrared or ultraviolet ...
(Phys.org) —When Harry Potter walks around with a visible head but an invisible body, the performance seems strongly rooted in fantasy. But in a new study, scientists have designed and fabricated an invisibility cloak that ...
(Phys.org)—Researchers have created a dc invisibility cloak made of a metamaterial that not only shields an object almost perfectly, but at 1-cm thick is also the thinnest cloak ever constructed, reaching the ultimate limit ...
(Phys.org)—A general property of magnetic fields is that they decay with the distance from their magnetic source. But in a new study, physicists have shown that surrounding a magnetic source with a magnetic shell can enhance ...
(PhysOrg.com) -- While most people know of DNA as the building blocks of life, these large molecules also have potential applications in areas such as biosensing, nanoparticle assembly, and building supramolecular structures. ...
Invisibility is the state of an object that cannot be seen. An object in this state is said to be invisible (literally, "not visible"). The term is usually used as a fantasy/science fiction term, where objects are literally made unseeable by magical or technological means; however, its effects can also be seen in the real world, particularly in physics and perceptional psychology.
Since objects can be seen by light in the visible spectrum from a source reflecting off their surfaces and hitting the viewer's eye, the most natural form of invisibility (whether real or fictional) is an object that neither reflects nor absorbs light (that is, it allows light to pass through it). In nature, this is known as transparency, and is seen in many naturally occurring materials (although no naturally occurring material is 100% transparent).
Visibility also depends on the eyes of the observer and/or the instruments used. Thus an object can be classified as "invisible to" a person, animal, instrument, etc. In the research of sensorial perception invisibility has been shown to happen in cycles.
Invisibility is often considered the supreme form of camouflage, as it doesn't show any kind of vital, visual, nor any of the frequencies of the electromagnetic spectrum such as radio, infrared, ultra violet, etc.
This text uses material from Wikipedia, licensed under CC BY-SA
