A group of European astronomers has discovered an ancient planetary system that is likely to be a survivor from one of the earliest cosmic eras, 13 billion years ago. The system consists of the star HIP 11952 and two planets, which have orbital periods of 290 and 7 days, respectively. Whereas planets usually form within clouds that include heavier chemical elements, the star HIP 11952 contains very little other than hydrogen and helium. The system promises to shed light on planet formation in the early universe – under conditions quite different from those of later planetary systems, such as our own.
In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.
Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two.
Now University of Washington researchers, using evidence from fossilized raindrop impressions from 2.7 billion years ago to deduce atmospheric pressure at the time, have demonstrated that an abundance of greenhouse gases most likely caused the warm temperatures.
Their work, which has implications for the search for life on other planets, is published March 28 in Nature.
BOSS (the Baryon Oscillation Spectroscopic Survey) has just announced the most accurate measurement yet of the distribution of galaxies between five and six billion years ago. This was the key pivot moment at which the expansion of the universe stopped slowing down due to gravity and started to accelerate instead, due to a mysterious force dubbed “dark energy.”
The nature of this “dark energy” is one of the big mysteries in cosmology today, and scientists need precise measurements of the expansion history of the universe to unravel this mystery — BOSS provides this kind of data.
Somebody has created a video condensing the history of the Earth
This video was done for educational purposes, as it was made for a geology project. All rights and credit belong to National Geographic and the Pixes.
Time scale is roughly 18.4 my per second.
Sorry for the choppy audio, I’m a Geo major not an audio engineer.
NASA has released two videos. One takes viewers through the moon’s evolutionary history, and reveals how it came to appear the way it does today.
The other gives viewers a guided tour of prominent locations on the moon’s surface, compiled by the spacecraft’s observations of the moon.
The researchers found that in the first 1.5 billion years or so of the Earth’s history, the average net rate at which new continental crust formed remained high, at about 0.7 cubic miles (3 cubic kilometers) annually, enough to establish about 65 percent of the present-day volume of the crust by 3 billion years ago. However, after that, average net new crust growth slowed greatly to about a third of its prior rate as the proportion of crust that formed after being recycled through the mantle rose sharply.
Megavirus chilensis is a giant virus isolated off the coast of Chile in 2010. It probably contains enough genes to encode over 1000 proteins, more than most bacteria. It seems to have originated either from a eukaryotic cell or from its near-ancestor, by losing the ability to reproduce.
Archeological evidence points to the sudden appearance of strikingly modern behaviour in humans around 50,000 years ago in the form of sophisticated tools and art like painting, sculpture and engravings. A possible reason for this could be the development of a fully modern human language, the proto-language that eventually gave rise to all the current languages. What can we conclude about the nature of this language?
Consider the word order of a sentence such as “the man killed the bear”. The man is the subject (S), killed is the verb (V) and the bear is the object (O) so the ordering of the sentence is SVO (subject, verb, and object).
Nobel-prize winning physicist Murray Gell-Mann from the Santa Fe Institute and linguist Merritt Ruhlen from Stanford University have analysed the distribution of word-orders in a sample of 2,135 languages, classified into seven major families. They conclude that five of them were originally SOV, one must have been either SOV or SVO, and another was SVO.
This strongly favours the proto-language being SOV (so the sentence would have been: the man the bear killed). The existing SOV languages, such as Danish, have apparently not changed their structure since their origin. Most modern languages have, however, adopted the possibly more logical SVO word order.
The origin and evolution of word order. The full text costs.
This on-line game lets you free a mammoth from the ice, create fire and invent the wheel, all with a time limit. Needless to say I was too slow to achieve anything!
Seriously though, I’m sure that games are a great way to learn and would love to have time to develop a history of the universe game, but I know I never will.
Completing Time Crystal is about as much as I can ever hope to do, but it could easily form the kernel of a game.
Reuters reports that the French government is likely to renew its ban on GM maize despite its highest court ordering the ban illegal. The government claims that MON810 is a risk to the environment. Monsanto, which manufactures the seed, will withdraw the seed from the French market despite its claim that it is perfectly safe.