“Mass tells space-time how to curve, and space-time tells mass how to move,” pioneering American physicist John Wheeler (1911-2008) once said. Wheeler was commenting on a result by Albert Einstein. General Theory of Relativity (1915), describing how space-time can bend like the flexible fabric of a springboard when a heavy object is placed on it. According General relativity, The gravitational force can be explained by a massive object causing warp in the space around it, and this warping of space-time can result in strange shapes distorted in a way that has been compared to a “funhouse” mirror. “In a carnival. In October 2019, astronomers released an image of the Hubble Space Telescope (HST) revealing a galaxy dubbed the “Sunburst Bow” which has been splintered into a bizarre and lovely kaleidoscopic illusion of a dozen images created by a massive foreground cluster of galaxies located 4.6 billion light-years away. This image beautifully demonstrates Einstein’s prediction that the gravity of massive objects in space should bend the light that travels, thus causing some very strange distortions.
Imagine a child’s trampoline. A little girl picks up a bowling ball and places it on the flexible fabric of the trampoline. Next, her brother takes a handful of marbles and throws them near where the bowling ball rests on the cloth. The marbles travel around the dimple created in the trampoline fabric by the heavy bowling ball. If the bowling ball is removed, the marbles travel along straight paths. The mass of the heavy bowling ball created a deformation, a curvature, in the trampoline fabric that “told” the marbles how to move. The trampoline fabric is Spacetime.
Einstein’s view of the warping of space-time originated in 1919 from observations of a solar eclipse where the bending of space (the trampoline cloth) of the Sun (the bowling ball) could be measured. An additional prediction was that the deformation would create a gravitational-lensing which, in addition to distortion, would increase the apparent size and brightness of a distant object, behaving like a magnifying glass, much to the delight of astronomers who find such distortions valuable when observing distant objects in the Universe.
Mother Nature’s magnifying glass
The term gravitational lensing itself refers to the path that traveling light has taken when it has been diverted. This happens when the mass of an object in the foreground distorts the light coming from a farther object in the background. The light does not have to be visible light. It can be any form of electromagnetic radiation. Due to the effects of gravitational lensing, light beams that normally would not have been observable are distorted in such a way that their paths wander toward the observer. However, light can also be distorted so that its beams travel far of the observer.
There are three different ways to gravitational lensing: strong lensing, weak lensing, and microlenses The differences between the three types depend on the position of the background object that sends its light beams into space, the foreground object that serves as lens deforming that light, and the position of the observer. Also, the shape and mass of the foreground lens itself plays an important role. This foreground object is what determines how much light from the background object will be bent, as well as the path this light will take through space-time.
The Universe we see today shines brightly with the furious and fabulous fireworks of billions and billions of stars. The scintillating stellar inhabitants of the Universe populate the billions of galaxies that inhabit the relatively small expanse of Space-time we call the visible gold observable Universe. Observers are unable to see what may exist beyond the cosmological horizon (edge) of the visible Universe. This is because the light emitted by the bright objects that inhabit these unimaginably remote regions has not had sufficient time to reach us since the birth of the Universe by the Big Bang nearly 14 billion years ago. The expansion of the Universe and the finite speed of light have made such a journey impossible.
The speed of light sets a kind of universal speed limit: no known signal can travel faster than light in a vacuum. We cannot see what may exist beyond the cosmological horizon, and the greatest of all mysteries, the unanswered secret of our very existence, may lie in those very remote realms far beyond our visibility. When we look deep into Space, we look back in Time. The more distant a luminous object is in space, the longer it has taken its stream of light to reach us. It is impossible to locate an object in Space, without also locating it in Time (space time). The three spatial dimensions that characterize our familiar world are up and down, front and back, and side to side. Time is the fourth dimension.
gravitational lensing can dramatically magnify remote sources in the ancient Universe, Yeah there is a sufficiently massive object lurking in the foreground that is situated between the background source and the prying eyes of curious observers.
It was not until 1979 that the first gravitational-lensing it was confirmed. An otherwise dark galaxy served as lens and divided and magnified the light from a remote control quasar situated far behind in a duo of images. gravitational lens Observations today are often used to discover new exoplanets stars orbiting beyond our Sun. Astronomers zoom in on very remote galaxies and then map the distribution of what is otherwise transparent and invisible. dark matter.
dark matter it is believed to be an exotic form of matter made up of non-atomic particles, which do not interact with light, which is why it is invisible. It is believed to be the most abundant form of matter in the Universe, far more abundant than the “ordinary” atomic matter that makes up our familiar world. Because dark matter it is transparent, it does not interact with visible objects except through the force of gravity, its existence has not been directly verified. It is thought to play the important role of the gravitational “glue” that holds galaxies together, and its gravitational effects on objects that can be observed indicate that it probably lurks like a ghost in the Cosmos.
glasses in the sky
gravitational lens reveals that the foreground cluster of galaxies magnifies the sunbeam arc It is so extremely massive that its powerful gravity warps the fabric of space-time, bending and magnifying the light emitted by it. sunbeam arc located far behind him. This distortion effect also creates multiple images of the same galaxy.
Tea sunbeam arc It is located almost 11 billion light years from our planet, and has been with lens in multiple images by the massive cluster of foreground galaxies that lie between the sunbeam arc and the earth Tea glasses The phenomenon created at least a dozen images of this distant background galaxy, spread over a quartet of major arcs. Three of these arches can be seen at the top right of the HST image, while a counterbow is located at the bottom left. However, the counter-arc is partially obscured by a very bright foreground star in our Milky Way.
HST uses these gravitational magnifying glasses in space-time to study objects that would otherwise be too dim, too distant, and too small for even very sensitive instruments to detect. Tea sunbeam arceven though he is one of the brightest of gravitational lens galaxies, is no exception. without the foreground lens magnifying and distorting its distant light, it would be too faint for astronomers to detect.
Tea lens Images created from the sunbeam arc they are between 10 and 30 times brighter than this background galaxy would be without the effects of gravitational glasses. scaling enabled HST to look at structures as small as 520 light-years across that would otherwise be too tiny to see without Mother Nature’s gift of a lens. The structures resemble star birth regions in nearby galaxies in the local Universe. This helped astronomers to carry out a detailed study of the remote galaxy and its environment.
HST observations reveal that the sunbeam arc it is very similar to galaxies that existed much earlier in the history of the Universe, perhaps as little as 150 million years after the Big Bang.