Horizons2019-05-22T14:57:17-05:00

Horizons

Alice laughed. “There is no use trying,” said Alice; “one can’t believe impossible things.”

“I dare say you haven’t had much practice,” said the Queen. “When I was your age, I always did it for half an hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”

 

Here we will present a concepts that interest us. 

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“This new concept is, potentially, as drastic an enlargement of our cosmic perspective as the shift from pre-Copernican ideas to the realization that the Earth is orbiting a typical star on the edge of the Milky Way.” – Sir Martin Rees, 1998, current Astronomer Royal of Britain

There are stars with enough mass to collapse on themselves, forming what have been theorized as black holes. It is thought that within these black holes there is a point called “singularity” at which all physical laws may cease to exist. At this point the curvature of space-time becomes infinitely large, and modern science can no longer predict what will happen. Einstein’s theory of relativity cannot determine what effect singularity will have on an object, forming an uncertainty in our universe. It is from this uncertain state that many theories have arisen surrounding singularity. It has been theorized that beyond singularity exist tunnels – shortcuts – to other ends of the universe. These “wormholes” could be a solution to interstellar travel, which currently is limited by relativity. However, many complications surround this possible theory. Most notable is the fact that the gravitational force of a black hole would crush any possible interstellar spacecraft, which is something that will have to be worked out. While this theory about singularity is questionable at best and will probably be left to science fiction, there is another theory about the center of a black hole that has been gaining more acceptance from respected physicists and astronomers, and describes a whole new view about our known universe.

At the point of singularity it is agreed that it is impossible to predict physical behavior. This could mean that beyond this point of singularity there may be an entirely new set of physical laws. It is quite possible that after singularity, there may be an absence of such basic forces as gravity, electromagnetism, and the strong and weak nuclear forces. If this were to happen, or if just one of these forces did not exist or was changed, then technically it would not be a part of this universe. Our universe is defined as the observable (if not explainable) aspects of the cosmos that involve the galaxies, stars, planets, and life that we know. Should a basic component of our physical laws be changed, none of what we know would exist. According to Before the Beginning, by Sir Martin Rees, “If nuclear forces were slightly weaker, no chemical elements other than hydrogen would be stable and there would be no nuclear energy to power stars. But, if the nuclear forces were slightly stronger than they actually are relative to electric forces, two protons could stick together so readily that ordinary hydrogen would not exist, and stars would evolve quite differently.” (Rees 232) This demonstrates the small chance that it took for things to actually turn out like they did, and implies that it may be difficult for things to ever duplicate themselves should this idea of a “Multiverse” be more than just a theory.

The Multiverse theory for the universe has been a recently accepted theory that describes the continuous formation of universes through the collapse of giant stars and the formation of black holes. With each of these black holes there is a new point of singularity and a new possible universe. As Rees describes it, “Our universe may be just one element – one atom, as it were – in an infinite ensemble: a cosmic archipelago. Each universe starts with its own big bang, acquires a distinctive imprint (and its individual physical laws) as it cools, and traces out its own cosmic cycle. The big bang that triggered our entire universe is, in this grander perspective, an infinitesimal part of an elaborate structure that extends far beyond the range of any telescopes.” (Rees 3) This puts our place in the Multiverse into a small spectrum. While the size of the earth in relation to the sun is minuscule, the size of the sun, the solar system, the galaxy, and even the universe, could pale in comparison to this proposed Multiverse. It would be a shift in thinking that may help explain our big bang theory and possibly give light to the idea of parallel universes.

While the idea of a parallel universe may sound farfetched, a recent book from an Oxford physicist named David Deutsch entitled, “The Fabric of Reality: The Science of Parallel Universes – And Its Implications” describes the possibilities of tapping in on parallel universes. He proposes that through a parallel universe one computer would be able to find an identical counterpart computer from the other universe, and collaborate with it to increase knowledge of the other universe. This involves the collaboration of many theories that have yet to have much proof. However, it is another arm of the Multiverse theory that has become more accepted in recent years that could possibly yield positive benefits for society.

The Multiverse theory itself, regardless of parallel universes, has many implications. Most notable is the unique, complex process from which our own universe was born, and how easily it could have been different. It may imply that, out of the possibly thousands, millions, or billions of universes, ours was special enough to develop life, which, in itself is special. Maybe life in another universe has a different meaning, but we know that our universe, at the very least is special in that it houses our kind of life. If just one physical law were slightly different, then there would be nobody to appreciate the beauty that we can see on an everyday basis. This brings up one ultimate question. If every universe began from another universe, where did it all begin? Recent physicists imply that there is no room for a creator under the current model of thinking. However, with such a complex system of laws, principles, and forces that allowed life to exist, one must give to the possibility of a creator behind it all.

Source: astronomy.pomona.edu

The warps in space that make Einstein’s perfect cosmic accident

Picture a glimmering arc of light, the artifact of a lens made of warped space-time instead of glass. Einstein thought there was “no hope” of observing these bizarre cosmic illusions, predicted by his theory of general relativity – but we’ve been collecting so-called “Einstein rings” since 1987.

An Einstein ring is not a place to visit but a trick of perspective. Two distant galaxies have to line up just so, or we won’t see it. At its most perfect, it’s a big, unbroken circle: beautiful and scientifically valuable in equal measure.

A complete Einstein ring is one of the universe’s most accurate bathroom scales – the circle it draws around a galaxy lets us add up the mass of everything inside. This means they can help solve mysteries as diverse as dark matter and the ancient universe.

We know of only a few dozen arcs that approach a full circle, though. So it seems fair to ask: of the Einstein rings we’ve found hidden in the sky so far, is there one that rules them all?

A ring is born
Here’s the ideal scenario. We need a light source: a distant galaxy that is bright all over, not just at its core or in a knot of newly formed stars. We need a lens: another galaxy, a heavy one, which can be far away from the source but must sit directly in front of it along our line of sight.

As general relativity predicts, space sags around the mass of the lens galaxy, making light from the source bend on its way to us. As a result, the lens appears surrounded by multiple images of the background light source.

It’s common to see four distinct images of the source, as if at compass points around the lens, which is called an Einstein cross. In 2015, researchers using the Hubble Space Telescope even saw the same supernova four separate times through this configuration. Partial arcs of light around galaxy clusters are also somewhat common.

But for a true ring, we need the images to blend into each other, completely encircling the lens galaxy.

The more complete the ring, the more accurately astronomers can weigh all the mass enclosed inside the circle. That helps constrain theories of galaxy formation and dark matter. And by definition, an Einstein ring magnifies a faraway background galaxy, so it also helps us study the ancient universe.

“It satisfies that amateur astronomer drive to discover cool-looking things,” says Adam Bolton at the National Optical Astronomy Observatory in Tucson, Arizona. “But they’re cool-looking things that also have this unique and powerful quantitative utility.”

The contenders
Many of the most picturesque contenders have been found by mining the Sloan Digital Sky Survey, which was Bolton’s strategy to identify eight new ones – some verging on complete – in 2005.

There have also been lucky finds this year. In June, Margherita Bettinelli at the Instituto de Astrofísica de Canarias in Spain spotted a ring spanning 300 degrees during an unrelated project.

But in my opinion, the fairest of them all is the Cosmic Horseshoe found in the Sloan survey in 2007: light from an ancient blue galaxy draped 300 degrees around a red galaxy 10 times heavier than the Milky Way.

Other rings are more complete, but the Cosmic Horseshoe benefits from its large size – plus the fact that it has been imaged by the Hubble Space Telescope’s most powerful camera.

That will do until future telescopes reveal even more beautiful rings further out in deep space, where the shadows lie.

Source: newscientist.com