Science blog

The heat waves of the future will be even hotter. Global warming is affecting the weather. The trend is pointing toward even warmer heat waves in the future. Kevin Trenberth, climate analysis branch chief for Atmospheric Research in Boulder, Colorado, says that heat waves and global warming “are very strongly” connected. He confirmed that studies in the last five years have shown that climate changes are most dangerous during high temperatures, droughts and flooding. Currently, persistent high pressure systems in the upper atmosphere prevent cooler air from reaching the West Coast. California is experiencing heat waves daily. The nights are generally warmer and the days have become drier. While heat waves always occur, Trenberth said that global warming is pushing it up another notch. Ken Kunkel, director, stated that the computer models show that soon we’ll get many more and they will become increasingly hotter. In the past twenty-five years, evenings in the summer have gotten warmer. The studies have shown that European heat waves have increased in frequency since 1880. They will continue to increase. In the United States, California seems to be hit hardest. The temperature in Death Valley last week reached one hundred twenty – six degrees. The United States is experiencing higher temperatures in general and a study done between 1999 and 2003 showed nine hundred heat related deaths. This year there have been one hundred thirty two in central California already. It is important to recognize that we are becoming more vulnerable to the heat and temperature. It is important that each of us gets at least three hours a day of cooling to avoid serious problems. Encourage your elderly friends and neighbors to be alert to the problem. If each of us looks out for our neighbors, there will be less heat related deaths.

The transmission of images obsessed inventors as early as 1875 when George Carey of Boston proposed his cumbersome system. Only five years later, the principle of scanning a picture, line by line and frame by frame - still used in modern television sets - was proposed simultaneously in the USA (by W.E. Sawyer) and in France (by Maurice Leblanc). The first complete television system - using the newly discovered properties of selenium - was patented in Germany in 1884, by Paul Nipkow. Boris Rosing of Russia actually transmitted images in 1907. The idea to incorporated cathode -ray tubes was proposed in 1911 by a Scottish engineer, Campbell Swinton. Another Scot, John Logie Baird, beat American inventor C.F. Jenkins to the mark by giving the first public demonstration of - a dim and badly flickering - television in 1926 in Soho, London. Britain commenced experimental broadcasting almost immediately thereafter. Irish actress Peggy O'Neil was the first to be interviewed on TV in April 1930. The Japanese televised an elementary school baseball match in September 1931. Nazi Germany started its own broadcasting service in 1935 and offered coverage of the 1936 Olympics. By November 1936, the BBC was broadcasting daily from Alexandra Palace in London to all of 100 TV sets in the kingdom. At the beginning there were many competing standards on both sides of the Atlantic. Baird's technological solutions were trounced by Isaac Shoenberg and his team, set up in 1931 by Electric and Musical Industries (EMI). RCA refined its own system, as did the Dutch Philips. Not until 1951 were the standards for public broadcasting set in the USA and in Europe. But the Americans were the ones to grasp the commercial implications of television. Bulova Clock paid $9 to WNBT of New York for the first 20-seconds TV spot, broadcast during a game between the Brooklyn Dodgers and the Philadelphia Phillies in July 1941. Soap operas followed in February 1947 (DuMont TV's A Woman to Remember) and the first TV news helicopter was launched by KTLA Channel 5 in Los Angeles on 4 July 1958. The first patent for color television was issued in Germany in 1904. Vladimir Kosma Zworykin, the Russia-born American innovator, came up with a complete color system in 1925. Baird himself demonstrated color TV transmission in 1928. Various researchers at Bell Laboratories perfected color television in the late 1920s. Georges Valenso of France patented a series of breakthrough technologies in 1938. But color TV became widespread only in the 1960s.

By Albert Einstein The basal principle, which was the pivot of all our previous considerations, was the special principle of relativity, i.e. the principle of the physical relativity of all uniform motion. Let as once more analyze its meaning carefully. It was at all times clear that, from the point of view of the idea it conveys to us, every motion must be considered only as a relative motion. Returning to the illustration we have frequently used of the embankment and the railway carriage, we can express the fact of the motion here taking place in the following two forms, both of which are equally justifiable : (a) The carriage is in motion relative to the embankment, (b) The embankment is in motion relative to the carriage. In (a) the embankment, in (b) the carriage, serves as the body of reference in our statement of the motion taking place. If it is simply a question of detecting or of describing the motion involved, it is in principle immaterial to what reference-body we refer the motion. As already mentioned, this is self-evident, but it must not be confused with the much more comprehensive statement called "the principle of relativity," which we have taken as the basis of our investigations. The principle we have made use of not only maintains that we may equally well choose the carriage or the embankment as our reference-body for the description of any event (for this, too, is self-evident). Our principle rather asserts what follows : If we formulate the general laws of nature as they are obtained from experience, by making use of (a) the embankment as reference-body, (b) the railway carriage as reference-body, then these general laws of nature (e.g. the laws of mechanics or the law of the propagation of light in vacuo) have exactly the same form in both cases. This can also be expressed as follows : For the physical description of natural processes, neither of the reference bodies K, K1 is unique (lit. " specially marked out ") as compared with the other. Unlike the first, this latter statement need not of necessity hold a priori; it is not contained in the conceptions of " motion" and " reference-body " and derivable from them; only experience can decide as to its correctness or incorrectness. Up to the present, however, we have by no means maintained the equivalence of all bodies of reference K in connection with the formulation of natural laws. Our course was more on the following lines. In the first place, we started out from the assumption that there exists a reference-body K, whose condition of motion is such that the Galilean law holds with respect to it : A particle left to itself and sufficiently far removed from all other particles moves uniformly in a straight line. With reference to K (Galilean reference-body) the laws of nature were to be as simple as possible. But in addition to K, all bodies of reference K1 should be given preference in this sense, and they should be exactly equivalent to K for the formulation of natural laws, provided that they are in a state of uniform rectilinear and non-rotary motion with respect to K ; all these bodies of reference are to be regarded as Galilean reference-bodies. The validity of the principle of relativity was assumed only for these reference-bodies, but not for others (e.g. those possessing motion of a different kind). In this sense we speak of the special principle of relativity, or special theory of relativity. In contrast to this we wish to understand by the "general principle of relativity" the following statement : All bodies of reference K, K1, etc., are equivalent for the description of natural phenomena (formulation of the general laws of nature), whatever may be their state of motion. But before proceeding farther, it ought to be pointed out that this formulation must be replaced later by a more abstract one, for reasons which will become evident at a later stage. Since the introduction of the special principle of relativity has been justified, every intellect which strives after generalization must feel the temptation to venture the step towards the general principle of relativity. But a simple and apparently quite reliable consideration seems to suggest that, for the present at any rate, there is little hope of success in such an attempt; Let us imagine ourselves transferred to our old friend the railway carriage, which is traveling at a uniform rate. As long as it is moving uniformly, the occupant of the carriage is not sensible of its motion, and it is for this reason that he can without reluctance interpret the facts of the case as indicating that the carriage is at rest, but the embankment in motion. Moreover, according to the special principle of relativity, this interpretation is quite justified also from a physical point of view. If the motion of the carriage is now changed into a non-uniform motion, as for instance by a powerful application of the brakes, then the occupant of the carriage experiences a correspondingly powerful jerk forwards. The retarded motion is manifested in the mechanical behavior of bodies relative to the person in the railway carriage. The mechanical behavior is different from that of the case previously considered, and for this reason it would appear to be impossible that the same mechanical laws hold relatively to the non-uniformly moving carriage, as hold with reference to the carriage when at rest or in uniform motion. At all events it is clear that the Galilean law does not hold with respect to the non-uniformly moving carriage. Because of this, we feel compelled at the present juncture to grant a kind of absolute physical reality to non-uniform motion, in opposition to the general principle of relativity. But in what follows we shall soon see that this conclusion cannot be maintained. To read more, go to http://www.EffortlessPhysicsLessons.com/relativity/ Stephan Bourget, physicist Effortless Physics Lessons http://www.EffortlessPhysicsLessons.com

In the quantum vacuum there are many transient acceleration vectors of mean magnitude a randomly oriented. If the vacuum is viewed from an accelerated frame, the vectors going with the frame appear diminished, and the vectors going against the frame appear enhanced, resulting in a net polarization of the vacuum. If the frame's acceleration g is small, the effect is linear, and if the vacuum is filled with vectors the coefficient of the polarization will be unity. The standard exponential term for suppressing high-energy fluctuations must also be applied. Hence the vacuum polarization is g exp (g/a). The terms of the exponent when multiplied by the dipole moment have the dimensions of energy. The rest frame of the galaxy, for example, is accelerated with respect to local inertial frames that fall into the center. In this rest frame the vacuum appears polarized and enhances the galaxy's gravitational field g. So we have g= -GM/r2 + g exp (g/a) where g is understood to be negative. For g much greater than a, the exponential is negligible and Newton's law results. But for g less than a, the exponential can be expanded to 1 + g/a and we get g2 = aGM/r2 This is precisely the formula found empirically by Milgrom to explain the motion of stars and galaxies in the weak-field region, except the law of gravity is altered, not the law of motion (Scientific American, August 2002). He finds that a is about one Angstrom per second squared, which is near the "surface gravity" of an electron, the field of a one-kilogram mass at one meter, or the field of a galaxy in its outer parts. Also, the square of a is not far from the value of the cosmological constant, in units where c=1. In this model, a may be viewed as the saturated field strength of the quantum vacuum. The observations can be adequately explained by assuming a plausible amount of ordinary matter M and using the correct quantum law of gravity. There is no need for dark matter. As space accelerates away from us, the resulting apparent polarization would enhance the acceleration, and indeed might cause the acceleration, once the process has begun, due perhaps to some disturbance long ago. If space is collapsing in some remote region, the same process would enhance the collapse. So the cosmos may consist of interspersed regions of expansion and collapse. When expansion becomes extreme, a big bang would result as virtual particles are ripped out of the vacuum. A collapsing region would produce a big crunch, where matter is crushed back into the vacuum. The whole process is presumably infinite and eternal.