NASA details looming Mars rover landing, '7 Minutes of Terror' | Cutting Edge. In just 41 days, on August 5, NASA's Mars Science Laboratory rover will touch down on the Red Planet, and this will be no ordinary landing. In fact, NASA has dubbed the descent "Seven Minutes of Terror. " "When people look at it, it looks crazy," senior EDL engineer at the Jet Propulsion Laboratory Adam Steltzner said in a new video by NASA on the rover landing. "It is the result of reasoned engineering thought, but it still looks crazy. " The recently released video (see below) outlines exactly how crazy the feat of landing the rover actually is. Named Curiosity, the rover must tear through Mars' atmosphere, which takes up to seven minutes. However, transmitting a signal to Earth of its progress takes 14 minutes because of the distance between the planets. "When we first get word that we've touched the top of atmosphere the vehicle has been alive or dead for at least seven minutes," Steltzner said.
The rover is the size of a small car and weighs 1,982 pounds. Physics. [English translation follows.] Je voulais prendre la résolution de me coucher tôt, mais j'ai tout de même voulu rester voir l'éclipse, hier soir. Je ne l'ai pas regretté, parce qu'elle était très belle et très visible : la Lune était très haute dans le ciel puisqu'elle se produisait vers 1h du matin heure solaire (soit 2h heure légale d'hiver à Paris) et puisqu'on n'est plus si loin du solstice (de sorte que l'écliptique est haut dans le ciel la nuit), et par ailleurs la météo était très favorable (vers 2h du matin il n'y avait pas un nuage à proximité de la Lune). Au début j'étais un peu déçu : un observateur inattentif aurait pu croire à un croissant de Lune (la partie cachée ne se voyait pas du tout, sans doute masquée par la partie non encore éclipsée et par la luminosité résiduelle du ciel à Paris).
On entend parfois des légendes selon lesquelles telle ou telle civilisation ancienne (les Égyptiens, les Mayas, que sais-je encore ?) Arrivait à « prédire les éclipses ». Écliptique saros. Kerr black holes images and videos. This page presents a number of videos and still images of Kerr black holes which were computed using a program I wrote. For the impatient, jump straight to the videos; or read on for the explanations, including a (hopefully accessible) course on black holes. Contents Introduction black hole in general is a region of space from which nothing, not even light, can escape the gravitational pull (or, to put things in a different way, clearer though perhaps not quite accurate, space-time itself is “falling” inward faster than the speed of light, so one would need to go faster than light merely to stand still something which is impossible for a material object). See further below for much more detailed explanations, and/or see the Wikipedia article on the subject for a start.
Event horizon These features (although largely theoretical, and presumably absent in real black holes), along with the catchy name wormhole, have made the black hole a popular theme in popular imagination or science-fiction. The Laws of Thermodynamics: Three Basic Principles Govern Thermal Physics, Heat, & Work. Origin of Thermodynamics Early in the industrial revolution, engineers tried to improve the efficiency of heat engines, which are any engines using some form of heat to do useful work.
Fundamental research into general principles governing the efficiency of heat engines led to the branch of physics known as thermodynamics. Thermodynamics is the study of heat and thermal energy. There are three laws of thermodynamics and a more basic zeroth law. Zeroth Law of Thermodynamics When two objects or systems are in thermal equilibrium with each other, the heat energy flowing from the first object to the second is the same as that flowing from the second object to the first.
The zeroth law simply states that if two objects, objects a and b, are both in thermal equilibrium with object c, then objects a and b are in thermal equilibrium with each other. First Law of Thermodynamics The first law of thermodynamics is the law of conservation of energy applied to work and heat engines. Irreverent Summary. 1) You Can't Win. (2) You Can't Break Even. (3) You Can't Even Quit The Game. You Can’t Win. You Can’t Break Even. You Can’t Leave the Game « The Inverse Square Blog.
Colors and Colorimetry. Physical and biological color Note: All images on this page are drawn in the sRGB colors space, which is something of a standard (if arguably a poor one). If your monitor does sRGB (many of them do), please put it in that mode for the descriptions to be accurate; if your browser and system are intelligent, however, and know about your monitor's colorimetry, you may not have to do this—in fact, the opposite may be the case, you may ruin things by using the wrong correction. There's a (very poor) experimental test you can run at the bottom of this page.
What is light? Light is the region of the electromagnetic spectrum which the unaided human eye can perceive. An elementary light stimulus is an arbitrary mixture of the pure lights of the spectrum. A light (a spectrum) is said to be monochromatic when it consists of radiation of a single wavelength: thus, it is the most discrete spectrum possible. What is color? Rods , while the other is called cones The color The three kinds of cones brightness or . Lux.