Movie: Julian Melchiorri on the first synthetic biological leaf. The "first man-made biological leaf" could enable humans to colonise space Dezeen and MINI Frontiers: RCA graduate Julian Melchiorri says the synthetic biological leaf he developed, which absorbs water and carbon dioxide to produce oxygen just like a plant, could enable long-distance space travel. "Plants don't grow in zero gravity," explains Melchiorri. "NASA is researching different ways to produce oxygen for long-distance space journeys to let us live in space.
This material could allow us t0 explore space much further than we can now. " Melchiorri's Silk Leaf project, which he developed as part of the Royal College of Art's Innovation Design Engineering course in collaboration with Tufts University silk lab, consists of chloroplasts suspended in a matrix made out of silk protein.
"The material is extracted directly from the fibres of silk," Melchiorri explains. Like the leaves of a plant, all Melchiorri's Silk Leaf needs to produce oxygen is light and a small amount of water. Cosmic String Time Travel. Cosmic Strings are a hypothetical 1-dimensional (spatially) topological defect in the fabric of spacetime left over from the formation of the universe. Interaction could create fields of closed time-like curves permitting backwards time travel. Some scientists have suggested using "cosmic strings" to construct a time machine. By maneuvering two cosmic strings close together – or possibly just one string plus a black hole – it is theoretically possible to create a whole array of "closed time-like curves.
" Your best bet is to fire two infinitely long cosmic strings past each other at very high speeds, then fly your ship around them in a carefully calculated figure eight. In theory, you would be able to emerge anywhere, anytime! At the moment, these are purely theoretical objects that might possibly be left over from the creation of the universe in the Big Bang. A cosmic string is a 1-dimensional (spatially) topological defect in various fields. Observational evidence.
Phase Transitions. Towards the very early universe... As we move backwards in time towards the moment of creation, prior to one hundredth of a second, the universe becomes hotter and denser until matter actually changes its phase, that, is it changes its form and properties. An everyday analogue familiar to all is simply water. With increasing temperature we see a succession of phase transitions for water in which its properties change dramatically: the solid phase - ice - melts to the liquid phase - water - and then eventually boils to the gaseous phase - steam.
You should notice that steam is `more symmetric' than water, which is in turn more symmetric than ice (Can you see why? You can find an explanation below...) As we shall see in the next few pages, phase transitions may have had profound implications on the evolution of our Universe and its contents. Unification G -> H -> ... -> SU(3) x SU(2) x U(1) -> SU(3) x U(1). Phase transitions First order phase transitions proceed by bubble nucleation. Brian Greene: Making sense of string theory. 'Huge' Physics Finding Supports Big Bang Theory. Scientists announced today (March 17) that they had found the first direct evidence of the dramatic expansion that created the known universe, known as cosmic inflation, or the "bang" in the Big Bang. This dramatic expansion is thought to have occurred in the first instants of existence, nearly 14 billion years ago, causing the universe to expand beyond the reach of the most powerful telescopes.
In 1979, a physicist named Alan Guth came up with the theory of cosmic inflation, and theorized that such an event would create ripples in space-time called gravitational waves. But their existence remained hypothetical. Today, a team of researchers said that they had detected these gravitational waves, using a telescope near the South Pole. "This is huge," Marc Kamionkowski, a researcher at Johns Hopkins University who was not involved in the discovery but who predicted how these gravitational wave imprints could be found, told Scientific American. Confused, Dr. Life in the Universe - Stephen Hawking. Life in the Universe This lecture is the intellectual property of Professor S.W.Hawking. You may not reproduce, edit, translate, distribute, publish or host this document in any way with out the permission of Professor Hawking.Note that there may be incorrect spellings, punctuation and/or grammar in this document.
This is to allow correct pronunciation and timing by a speech synthesiser. In this talk, I would like to speculate a little, on the development of life in the universe, and in particular, the development of intelligent life. I shall take this to include the human race, even though much of its behaviour through out history, has been pretty stupid, and not calculated to aid the survival of the species. Two questions I shall discuss are, 'What is the probability of life existing else where in the universe?
' and, 'How may life develop in the future? ' Physics. Advanced Physics. Gravitational Cosmology. Concepts. Astronomy. Gravitational singularity. A gravitational singularity or spacetime singularity is a location where the quantities that are used to measure the gravitational field become infinite in a way that does not depend on the coordinate system. These quantities are the scalar invariant curvatures of spacetime, which includes a measure of the density of matter. The two most important types of spacetime singularities are curvature singularities and conical singularities.[2] Singularities can also be divided according to whether they are covered by an event horizon or not (naked singularities).[3] According to general relativity, the initial state of the universe, at the beginning of the Big Bang, was a singularity.
Interpretation[edit] Many theories in physics have mathematical singularities of one kind or another. Equations for these physical theories predict that the ball of mass of some quantity becomes infinite or increases without limit. Types[edit] Curvature[edit] , which is diffeomorphism invariant, is infinite. Black hole. A black hole is defined as a region of spacetime from which gravity prevents anything, including light, from escaping.[1] The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole.[2] Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return. The hole is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.[3][4] Quantum field theory in curved spacetime predicts that event horizons emit radiation like a black body with a finite temperature.
This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater. Objects whose gravity fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. History General relativity. Meteors, Comets & Asteroids. Active galactic nucleus. Models of the active nucleus[edit] Accretion disc[edit] In the standard model of AGN, cold material close to a black hole forms an accretion disc. Dissipative processes in the accretion disc transport matter inwards and angular momentum outwards, while causing the accretion disc to heat up. The expected spectrum of an accretion disc peaks in the optical-ultraviolet waveband; in addition, a corona of hot material forms above the accretion disc and can inverse-Compton scatter photons up to X-ray energies. The radiation from the accretion disc excites cold atomic material close to the black hole and this in turn radiates at particular emission lines.
A large fraction of the AGN's radiation may be obscured by interstellar gas and dust close to the accretion disc, but (in a steady-state situation) this will be re-radiated at some other waveband, most likely the infrared. Relativistic jets[edit] Radiatively inefficient AGN[edit] Observational characteristics[edit] Types of active galaxy[edit] Quasars: Definition & Facts About Brightest Objects in the Universe. Shining so brightly that they eclipse the ancient galaxies that contain them, quasars are distant objects powered by black holes a billion times as massive as our sun. These powerful dynamos have fascinated astronomers since their discovery half a century ago.
In the 1930s, Karl Jansky, a physicist with Bell Telephone Laboratories, discovered that the static interference on transatlantic phone lines was coming from the Milky Way. By the 1950s, astronomers were using radio telescopes to probe the heavens, and pairing their signals with visible examinations of the heavens. This artist's concept illustrates a quasar, or feeding black hole, similar to APM 08279+5255, where astronomers discovered huge amounts of water vapor. Gas and dust likely form a torus around the central black hole, with clouds of charged gas above and below.Credit: NASA/ESA However, some of the smaller point-source objects didn't have a match.
Light-speed jets Most quasars have been found billions of light-years away. Active Galaxies and Quasars - Introduction. Active galaxies are galaxies which have a small core of emission embedded in an otherwise typical galaxy. This core may be highly variable and very bright compared to the rest of the galaxy. Models of active galaxies concentrate on the possibility of a supermassive black hole which lies at the center of the galaxy. The dense central galaxy provides material which accretes onto the black hole releasing a large amount of gravitational energy.
Part of the energy in this hot plasma is emitted as x-rays and gamma rays. For "normal" galaxies, we can think of the total energy they emit as the sum of the emission from each of the stars found in the galaxy. For the "active" galaxies, this is not true. There are several types of active galaxies: Seyferts, quasars, and blazars. Active galaxies are intensely studied at all wavelengths. A diagram of an active galaxy, showing the primary components. Seyfert Galaxies An artists concept of an active galactic nucleus Quasars Blazars. Miralda-Escude. Jordi Miralda-Escudé Quasars are the most luminous objects known in our universe, and they are found in the centers of galaxies. Some quasars are as bright as 100 or 1000 times our galaxy the Milky Way, and this enormous amount of light is coming from a region so small that it appears point-like, in the center of the host galaxy, even with the most powerful telescopes we have. Some quasars are seen to emit a powerful jet of particles, often seen in the radio or X-ray wavelengths.
An example of what a distant quasar may look like when viewed with the Hubble Space Telescope and the Chandra X-ray Observatory is found in these images of PKS 1127-145 , one of these quasars that is so bright that you can't even see the galaxy around it because it is outshined by the light of the quasar. The first quasars were discovered in 1963, and shortly after their discovery astrophysicists theorized that they were perhaps being caused by very massive black holes. J. Einstein for Everyone. Einstein for Everyone Nullarbor Press 2007revisions 2008, 2010, 2011, 2012, 2013 Copyright 2007, 2008, 2010, 2011, 2012, 2013 John D. Norton Published by Nullarbor Press, 500 Fifth Avenue, Pittsburgh, Pennsylvania 15260 with offices in Liberty Ave., Pittsburgh, Pennsylvania, 15222 All Rights Reserved John D.
An advanced sequel is planned in this series:Einstein for Almost Everyone 2 4 6 8 9 7 5 3 1 ePrinted in the United States of America no trees were harmed web*bookTM This book is a continuing work in progress. January 1, 2015. Preface For over a decade I have taught an introductory, undergraduate class, "Einstein for Everyone," at the University of Pittsburgh to anyone interested enough to walk through door. With each new offering of the course, I had the chance to find out what content worked and which of my ever so clever pedagogical inventions were failures. At the same time, my lecture notes have evolved.
This text owes a lot to many. I i i. String Theory.