Charlie's Diary: The High Frontier, Redux (I am currently suffering from a bad cold, and it's screwing with my ability to think straight. So rather than risk damaging my real work in progress, I decided to tidy up some thoughts I've been kicking around for a while, and bolt together this essay. Which will, I hope, begin to highlight the problems I face in trying to write believable science fiction about space colonization.) I write SF for a living. Possibly because of this, folks seem to think I ought to be an enthusiastic proponent of space exploration and space colonization. Space exploration? I'm going to take it as read that the idea of space colonization isn't unfamiliar; domed cities on Mars, orbiting cylindrical space habitats a la J. And I don't want to spend much time talking about the unspoken ideological underpinnings of the urge to space colonization, other than to point out that they're there, that the case for space colonization isn't usually presented as an economic enterprise so much as a quasi-religious one.
Physics 20b: Introduction to Cosmology - Spring 2010 - Download free content from UC Irvine Slide 1 of 50 (Sci-fi I like, Fictional Futures, Goldsmiths) Matt Ward runs the MA in Design – Critical Theory and Practice at Goldsmiths College, London. As part of their Fictional Futures project (about the design of “imagined, science fiction inspired, future artefacts”—read the original brief for more), Matt asked Jack and I, as Schulze & Webb, to run a teaching day. We led the students through a number of drawing exercises, talks and discussions on stories, belief and the aesthetics of artefacts in science fiction, and finally a look at their work. As part of all of this, I took some time to discuss my own favourite concepts from science fiction. There’s no argument or narrative arc to what I show—just a bunch of pictures and quotations. I spoke without notes, so I’ll attempt to reconstruct some of what I rambled about in the notes here. I want to reiterate: This presentation isn’t about telling.
Relativity Tutorial Galilean Relativity Relativity can be described using space-time diagrams. Contrary to popular opinion, Einstein did not invent relativity. Galileo preceded him. Aristotle had proposed that moving objects (on the Earth) had a natural tendency to slow down and stop. Note the curved worldline above. Now it is still moving in its final state. Straight worldlines (unaccelerated particles) remain straight in this process. But Galilean transformations do not preserve velocity. Special Relativity But 200 years after Newton the theory of electromagnetism was developed into Maxwell's equations. Because the speed of light is special, space-time diagrams are often drawn in units of seconds and light-seconds, or years and light-years, so a unit slope [45 degree angle] corresponds to the speed of light. The left-hand section of the figure shows the Galilean transformation into the frame of reference of the moving observer. What is the evidence for the invariance of the speed of light? Radar
Mysterious New 'Dark Flow' Discovered in Space As if the mysteries of dark matter and dark energy weren't vexing enough, another baffling cosmic puzzle has been discovered. Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. Astronomers are calling the phenomenon "dark flow." The stuff that's pulling this matter must be outside the observable universe, researchers conclude. When scientists talk about the observable universe, they don't just mean as far out as the eye, or even the most powerful telescope, can see. Mysterious motions Scientists discovered the flow by studying some of the largest structures in the cosmos: giant clusters of galaxies. The X-rays scatter photons in the CMB, shifting its temperature in an effect known as the kinematic Sunyaev-Zel'dovich (SZ) effect. Inflationary bubble In these regions, space-time might be very different, and likely doesn? Surprising find
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Light cone In general relativity, the future light cone is the boundary of the causal future of a point and the past light cone is the boundary of its causal past. [Wikipedia] From the moment of my birth, light [that I could have influenced] has been expanding around the Earth and light [which could influence me, from an increasing distance of origin] reaching it -- this ever-growing sphere of potential causality is my light cone. Today... (Data taken from the utterly excellent An Atlas of the Universe, which has maps from the solar system out to the the Local Group and beyond.
Quantum Entanglement and Information First published Mon Aug 13, 2001; substantive revision Thu Aug 26, 2010 Quantum entanglement is a physical resource, like energy, associated with the peculiar nonclassical correlations that are possible between separated quantum systems. Entanglement can be measured, transformed, and purified. A pair of quantum systems in an entangled state can be used as a quantum information channel to perform computational and cryptographic tasks that are impossible for classical systems. The general study of the information-processing capabilities of quantum systems is the subject of quantum information theory. 1. In 1935 and 1936, Schrödinger published a two-part article in the Proceedings of the Cambridge Philosophical Society in which he discussed and extended a remarkable argument by Einstein, Podolsky, and Rosen. It should not be supposed that Einstein's definition of a complete theory included the requirement that it be deterministic. He added (Schrödinger, 1935; p. 555): 2. 3. 4.
Stellarium Astronomy Software Nuclear Weapons - basic technology concepts [UNC] A few words about nuclear weapons technology.. Fission weapons Nuclear weapons exploit two principle physical, or more specifically nuclear, properties of certain substances: fission and fusion. Fission is possible in a number of heavy elements, but in weapons it is principally confined to what is termed slow neutron fission in just two particular isotopes: 235U and 239Pu. These are termed fissile, and are the source of energy in atomic weapons. An explosive chain reaction can be started with relatively slight energy input (so-called slow neutrons) in such material. An actual 239Pu ingot, alloyed with gallium for improved physical properties Isotopes are 'varieties' of an element which differ only in their number of neutrons. Typical appearance of a thermonuclear weapon detonation -- from many miles away. *Special techniques were required to record the fleeting moments of a weapon's initial detonation.
Daylight Hours Explorer Shows the hours of daylight received during the year for an observer at a given latitude. This is an important factor contributing to the seasons. Running this animation on your computer... right-click to download daylighthoursexplorer.swf and daylighthoursexplorer.html to the same directory open the html file in a browser to run the animation Linking to this animation... copy and paste the code below into your webpage or blog: Putting this animation on your website... upload daylighthoursexplorer.swf to the same directory as your webpage copy and paste the following code into your webpage:
Quantum Physics made simple