Saturday, January 30, 2010

Jan. 29 - Universe has less time left than thought‏

Dear Friends,

http://www.cosmosmagazine.com/node/3263/full

Be Well.

David

Universe has less time left than thought

Friday, 29 January 2010

by Meghan Bergamin

Cosmos Online

Supermassive black holes are increasing the overall amount of entropy in the universe - and lessening the amount of time the universe has left.

Credit: Wikimedia

SYDNEY: The amount of entropy, or disorder, in the observable universe is 30 times higher than previous estimates, report Australian astronomers, suggesting the universe may not have as much time left as previously thought.

Supermassive black holes, dark matter and stars are some of the contributors to the overall entropy of the universe, which is a measure of the irreversible processes occurring throughout.

Previous estimations of the total entropy of the universe were limited by insufficient measurements of supermassive black holes, as well as uncertainty about the entropy of dark matter, according to a study to be published in the Astrophysical Journal.

New advances on an old problem

The concept of entropy, which has existed in physics for almost 200 years, is central to the second law of thermodynamics and relates to the tendency of order in the universe to progressively turn to disorder.

Entropy is an important contributor to our understanding of both cosmology and biology. Life, along with every other chemical or physical process, cannot occur without producing entropy.

Everything from gravitational clustering, to supernovae, to the biological processes in our own bodies are contributors to the entropy budget of the universe; a budget which has been found to be 30 times larger than previously suspected, according to research by astrophysicists Chas Egan and Charles Lineweaver, from the Australian National University in Canberra.

“The work of Egan and Lineweaver is a significant advance in tallying the known sources of entropy in the universe,” says Adelaide based astrophysicist Roger Clay.

Gas tank of the universe running low

All particles in the universe emit energy as radiation, which results in entropy being produced. The amount of radiation emitted by a particle usually correlates to the temperature – high radiation produces high temperatures.

Entropy results from radiation as well as gravitation emissions, so calculating the amount of entropy in the entire observable universe involves identifying the major radiation and gravitation producing objects and their approximate number and size. Once this is known, entropy can be estimated by converting the known temperature of particles into units of energy.

Lineweaver describes the universe as a giant engine; the more efficient the engine, the lower the total entropy produced. His findings show that engine of our universe has a lot less gas left in the tank than we thought.

“It’s like driving along, thinking you have half a tank of gas, but when you get out and check it with a dipstick, you find you only have about a third of a tank.”

Supermassive black holes biggest entropy contributors

Using recent measurements of Stephen Hawking's supermassive black hole mass function, Egan and Lineweaver were able to produce a more accurate quantification of entropy.

Their calculations revealed that supermassive black holes, such as the one at the centre of the Milky Way, were the biggest contributors to the universe’s entropy in its entirety.

The approximate entropy of dark matter was also included for the first time. Dark matter emits no radiation, but can be detected by its gravitational effects on visible matter.

As it produces no radiation, dark matter does not produce a large amount of entropy when compared with visible matter, but it is still considered an important inclusion in the overall total, as there are large quantities of dark matter in the universe.

“In recent times, some of the most famous names in theoretical astrophysics and cosmology have been associated with trying to understand the entropy of the universe and its most esoteric members, the black holes and the dark matter,” says Clay.

Previous estimates of the amount of entropy in the observable universe place it at around 10¹⁰²k - 10¹⁰³kk represents the Boltzmann constant (a number which relates energy to temperature). Lineweaver says this is an underestimate by a factor of 30. joules per degree Celsius, where k represents the Boltzmann constant (a number which relates energy to temperature). Lineweaver says this is an underestimate by a factor of 30.

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MUFON

How to Digitally Record/Video a UFO sighting:

Como registar digitalmente ou gravar um vídeo de um avistamento de um UFO:

Stabilize the camera on a tripod. If there is no tripod, then set it on top of a stable, flat surface. If that is not possible lean against a wall to stabilize your body and prevent the camera from filming in a shaky, unsteady manner.

Estabilize a camera com um tripé. Se não tiver um tripé, então coloque-a em cima de uma superfície estável. Se não for possível, então encoste-se a uma parede para estabilizar o corpo e evitar que a camera registe de maneira tremida e instável.

Provide visual reference points for comparison. This includes the horizon, treetops, lampposts, houses, and geographical landmarks (i.e., Horsetooth Reservoir, Mt. Adams, etc.) Provide this in the video whenever is appropriate and doesn’t detract from what your focus is, the UFO.

Forneça pontos visuais de referência para comparação. Isso inclui o horizonte, cimo das árvores, postes de iluminação, pontos de referência geográficos (como o Reservatório de Horsetooth, Mone Adams, etc) Forneça esses pontos no vídeo sempre que for apropriado e não se distraia do que é o seu foco, o UFO/a Nave.

Narrate your videotape. Provide details of the date, time, location, and direction (N,S,E,W) you are looking in. Provide your observations on the weather, including approximate temperature, windspeed, any visible cloud cover or noticeable weather anomalies or events. Narrate on the shape, size, color, movements, approximate altitude of the UFO, etc and what it appears to be doing. Also include any unusual physical, psychological or emotional sensations you might have. Narrate any visual reference points on camera so they correlate with what the viewer will see, and thereby will be better able to understand.

Faça a narração do vídeo. Forneça pormenores sobre a data, hora, local e direcção (Norte, Sul, Este, Oeste) que está a observar. Faça observações sobre as condições atmosféricas, incluindo a temperatura aproximada, velocidade do vento, quantidade de nuvens, anomalias ou acontecimentos meteorológicos evidentes. Descreva a forma, o tamanho, a cor, os movimentos, a altitude aproximada onde se encontra o UFO/nave, etc e o que aparenta estar a fazer. Inclua também quaisquer aspectos pouco habituais de sensações físicas, psicológicas ou emocionais que possa ter. Faça a narração de todos os pontos de referência visual que o espectador irá ver e que, deste modo, será capaz de compreender melhor.

Be persistent and consistent. Return to the scene to videotape and record at this same location. If you have been successful once, the UFO sightings may be occurring in this region regularly, perhaps for specific reasons unknown, and you may be successful again. You may also wish to return to the same location at a different time of day (daylight hours) for better orientation and reference. Film just a minute or two under “normal” circumstances for comparison. Write down what you remember immediately after. As soon as you are done recording the experience/event, immediately write down your impressions, memories, thoughts, emotions, etc. so it is on the record in writing. If there were other witnesses, have them independently record their own impressions, thoughts, etc. Include in this exercise any drawings, sketches, or diagrams. Make sure you date and sign your documentation.

Seja persistente e não contraditório. Volte ao local da cena e registe o mesmo local. Se foi bem sucedido uma vez, pode ser que nessa região ocorram avistamentos de UFOs/naves com regularidade, talvez por razões específicas desconhecidas, e talvez possa ser novamente bem sucedido. Pode também desejar voltar ao mesmo lugar a horas diferentes do dia (durante as horas de luz)para ter uma orientação e referência melhor. Filme apenas um ,inuto ou dois em circunstâncias “normais” para ter um termo de comparação. Escreva tudo o que viu imediatamente após o acontecimento. Logo após ter feito o registo da experiência/acontecimento, escreva imediatamente as impressões, memórias, pensamentos, emoções, etc para que fiquem registadas por escrito. Se houver outras testemunhas, peça-lhes para registar independentemente as suas próprias impressões, pensamentos, etc. Inclua quaisquer desenhos, esbolos, diagramas. Certifique-se que data e assina o seu documento/testemunho.

Always be prepared. Have a digital camera or better yet a video camera with you, charged and ready to go, at all times. Make sure you know how to use your camera (and your cell phone video/photo camera) quickly and properly. These events can occur suddenly, unexpectedly, and often quite randomly, so you will need to be prepared.

Esteja sempre preparado, Tenha sempre uma camera digital, melhor ainda, uma camera vídeo consigo, carregada e pronta a usar sempre que necessário. Certifique-se que sabe como lidar com a sua camera (ou com o seu celular/camera fotográfica) rápida e adequadamente. Esses acontecimentos podem acontecer súbita e inesperadamente e, por vezes, acidentalmente, por isso, necessita estar preparado.

Look up. Be prepared. Report. Share.

Olhe para cima, Esteja preparado, Relate, Partilhe.

MUFON.COM