Science and Exploration

[dreadgeek]

So since I mentioned dark energy I thought I would go ahead and talk about this subject as well. There's another problem in cosmology and it is this: the expansion of the Universe isn't slowing down. To understand why this is a problem it's necessary to go back to the very beginning: the Big Bang. So according to the prevailing model, at one point the whole of the Universe was contained in a space about the size of what is called the Planck length (10^-43 or 1 with 43 zeroes in front of it) which is the smallest anything existing can be said to be. For reasons that may forever be beyond our understanding this fantastically small object suddenly became *much* larger. This is the Big Bang. In the first few moments of the Universe spacetime grew hugely. Things settled down after a while, the balance of matter-antimatter tipped in favor of matter and it started to get cold enough for atoms to start to form. After the rapid inflation expansion started to slow down a bit and matter started clumping together to form stars and galaxies and all the rest of the things observable in the Universe.

Now, here's where things get interesting. Gravity is *always* attractive and is caused by the warping of spacetime by the presence of mass. The consequence of this is that what we should see is that over time, the expansion of the Universe should slow down and then, possibly, reverse coming together in a Big Crunch (or as Douglas Adams put it in Restaurant at the End of the Universe, a gnab gib). The problem is that we aren't observing this. In fact, not only has the expansion continued but it is still accelerating. This cries out for explanation.

That explanation is dark energy. *Some* form of energy, that we lack the means to detect at present levels of technology, is pushing the Universe apart. We don't know precisely what it is but there is a damn lot of the stuff whatever it is. This more or less seals the fate of the universe. Eventually what will happen is that all of the galaxies will be so far apart from one another that they will be too faint to see.

How do we know that the galaxies are all rushing away from one another? (on the whole, the Milky Way is going to eventually collide with the Andromeda galaxy because the greater mass of our galaxy is pulling the Andromeda galaxy toward us) We know because of what is called red shift. This is simply the familiar Doppler effect applied to light. When a siren is approaching you the pitch increases and as it speeds away from you the pitch decreases. The same thing happens to light (although we can't detect it because the distances light travels here on Earth can never be far enough to see any kind of shifting) but at the astronomical level stars or galaxies moving away from us have their light shifted toward the red part of the spectrum. The more red shift the farther away you are from the observed object.

Cheers
Aj

[Jean_TX]

Scientists are further investigating a phenomenon called 'dark lightning' : "Dark lightning that is almost invisible within clouds may regularly blast airline passengers with large numbers of gamma rays, scientists find." Although it sounds ominous, the effects on the body may not be dangerous. The full article can be read at http://www.livescience.com/28594-dar...assengers.html

[Corkey]

http://news.yahoo.com/ancient-creatu...183441713.html

Australopithecus sediba, human and apelike creature.

[KCBUTCH]

HAD TO SHARE LOVE THIS

[puddin']

http://www.npr.org/blogs/krulwich/20...towel-on-earth



(solly, don't know how to embed)

[Hollylane]

Earth's core far hotter than thought



New measurements suggest the Earth's inner core is far hotter than prior experiments suggested, putting it at 6,000C - as hot as the Sun's surface.

[Tommi]

Soft Drink Consumption Tied To Increased Type 2 Diabetes Risk. Bloomberg News (4/25, Torsoli) reports, “Just one soft drink consumed daily can raise the risk of diabetes by 22 percent,” according to a study published April 24 in Diabetologia. The study found that “a mere 12 ounces serving size of sugar-sweetened soft drink a day may increase the chance of developing type 2 diabetes, the most common form of the disease.”

Reuters (4/25, Kelland) reports that researchers analyzed data from some 350,000 individuals in the UK, Denmark, Spain, Sweden, Italy, the Netherlands, France, and Germany who had provided information on the amount of naturally and artificially sweetened soft drinks consumed on a daily basis.

MyHealthNewsDaily (4/25, Rettner) reports, “In the study, people who drank a 12-ounce sugar-sweetened soda daily were 18 percent more likely to develop type 2 diabetes over a 16-year period compared with those who did not consume soda.” In addition, “people who drank two sodas daily were 18 percent more likely to have a stroke than those who drank one; those who drank three sodas daily saw the same risk increase compared with those who drank two, and so on.” Notably, “the results held even after the researchers took into account risk factors for type 2 diabetes, such as age and physical activity levels, body mass index (BMI) and the total daily calorie intake.”

MedPage Today (4/25, Petrochko) points out, “Compared with those who consumed lower levels of sugary soft drinks, high-level consumers were more likely to be male, physically active, less educated, smokers, and have a higher waist circumference,” whereas “juice and nectar high consumers were mostly younger, female, physically active, former smokers, and better educated than those with lower juice and nectar consumption.” Even though “soft drink consumption was linked with diabetes incidence, there was no association between diabetes and consumption of juices and nectars.”