Energy drinks - Good or bad for you?

Energy drinks are becoming more and more popular worldwide, for instance 1.5 billion cans of Red Bull were sold in the United States in 2004. This is because many young people, especially students consume these energy drinks in order to increase their concentration during long study through the night. But are these popular energy drinks good or bad for you?

These energy drinks are made up of caffeine and sugar, and according to scientists they have negative impact on human body because they don't hydrate the body efficiently simply because they have too much sugar in it. And caffeine on the other hand doesn't always improve physical performance, especially in large quantities when it can even significantly increase the risks of fatigue and dehydration.

Consumption of Vodka Red Bull could lead to all sorts of trouble since it gives you the feeling you're not drunk though you very much are drunk.

And not only these as several different studies showed how strong doses of caffeine can increase hypertension, cause heart palpitations, provoke irritability and anxiety as well as cause headaches and insomnia. So it is definitely not wise to consume more than two cans a day.

However many young people consume lot more than two cans a day, and what is even worse almost 50 % of young people in US between 18-24 have admitted that they consume these energy drinks mixed with alcohol, and especially popular are Vodkas Red Bull. Consumption of Vodkas Red Bull is dangerous because it cancels the warning signs that the person is actually drunk. In many cases when someone consumes too much alcohol, their head spins and they feel tired but energy drinks cancel this effect so person thinks it is sober but in fact it is very much drunk. This can of course lead to all sorts of troubles.

Earth's outer core consists of which materials?

Despite an impressive technological advances scientists still know very little about Earth's interior. It is a bit odd that we seem to be gathering knowledge about distant planet and far galaxies while at the same time we know so little about our own planet.

Scientists at the University of Calgary hope to put more light on the interior of our planet, specifically the outer core, and their latest findings have been published in the May edition of the journal Physics of the Earth and Planetary Interiors.

They have gathered valuable data by observing distant earthquakes, and according to them these earthquakes can provide valuable clues about Earth's outer core. One of the lead scientists, professor Dave Eaton, said that Earth's outer core is composed of molten iron, nickel and other as-yet unknown lighter elements such as silicon, sulfur, carbon or oxygen.

Earth'c core is located almost 3,000 km below the surface (2,891 km), and in order to determine of which materials does the earth's core consists scientists measured the seismic wave speed (speed of sound) at the top of Earth's core.

This method isn't exactly novelty but scientists from the University of Calgary used brand new digital processing approach, which helped them analyze faint signals, produced by 44 earthquakes, and with it they were able to measure the sound speed at the top of Earth's core with unprecedented accuracy.

The results of this study should be of great help to research efforts at laboratories where core composition is studied by simulating extreme pressure and temperature conditions that exist in the Earth's core.

What event caused the end of the last ice age?

Scientists are still anything but certain in what event led to the end of the last ice age that resulted in warmer climate and the birth of human civilization. From the geological point of view we know that ice sheets in the northern hemisphere began to collapse and warming spread quickly to the south. Most scientists support the theory that the event that led to warming was an orbital shift that caused more sunlight to fall across Earth's northern half.

The latest interesting scientific report that tries to put more light into the event(s) that ended the last ice age comes from the team of scientists from the Columbia University. They believe that not one event, but actually entire chain of events caused the end of the last ice age.

According to their theory the events began with the melting of the large northern hemisphere ice sheets that happened 20,000 years ago. The melting ice sheets reconfigured the planet's wind belts, pushing warm air and seawater south, and pulling carbon dioxide from the deep ocean into the atmosphere, allowing the planet to heat even further.

Our planet regularly goes into an ice age every 100,000 years or so, and this is caused by the shifts in Earth's orientation toward the sun. At the peak of the last ice age that happened around 20,000 years ago, Earth's orbit shifted. This event lead to more summer sunlight began falling on the northern hemisphere, melting those massive ice sheets and sending icebergs and fresh water into the North Atlantic Ocean.

The report also says that freshening of the North Atlantic triggered a series of cold spells in Greenland and northern Europe by shutting down the Gulf Stream current, which usually carries warm water north from the equator. Sea ice spread across the North Atlantic, bringing bitter cold winters to Europe and profoundly reshaping the planet's wind belts. And with the North Atlantic covered in ice, the tropical trade winds shifted south, bringing dry spells across much of Asia and rain to normally arid regions of Brazil. The displaced winds moved not only rain further south, but hot air and warm seawater, heating up the southern hemisphere.

The report also states that ice core records show that between 18,000 and 11,000 years ago atmospheric carbon dioxide levels rose from 185 parts per million to 265 parts per million. (Current levels are 393 parts per million, after the heavy industrial expansion across the globe). The infusion of carbon dioxide came just as the planet's orientation was shifting, and summer sunlight to the northern hemisphere was declining, at about 11,000 years ago. The scientists have also concluded that the boost in carbon dioxide may have even prevented Earth from falling into another ice age.

This is one way to answer the question why does the Earth, when it appears so firmly in the claws of an ice age, start to warm? Most scientists agree that carbon dioxide played the crucial role in warming of the planet but up to this point scientists didn't have sound explanations in explaining the early warming in the southern hemisphere, where glaciers in Patagonia and New Zealand were melting before carbon dioxide levels rose significantly.

There were some scientists that supported a theory that a change in ocean currents, triggered by the freshening of the North Atlantic, caused this early warming. But computer models using ocean circulation to explain the rapid warming in the south have been unable to recreate the large temperature jumps seen in the paleoclimate record. Now, with the evidence for shifting southern hemisphere westerlies, the rapid warming looks to be finally explained.

Huge stars in space - The biggest one yet

Today's astronomy news are all about scientists detecting the most massive star of all time, and they have named it R136a1, not very original name if I may add.

If you thought that our Sun is enormous you better think again because this star has a mass about 265 times that of our own Sun, and to make things even more interesting scientists believed that at the time when this star was born its mass was even bigger, at about 320 times that of the Sun's mass.

The biggest star in the universe - Our Sun looks so small compared to this massive star.

Professor Paul Crowther from UK's Sheffield University said that "if it (this star) replaced the Sun in our Solar System, it would outshine our Sun by as much as the Sun currently outshines the full Moon.

This star as many stars before them, and even more after them will one day explode as supernova to seed the Universe with heavy elements.

It is also very interesting to add that astronomers also detected several stars with surface temperatures over 40,000 degrees - more than seven times hotter than our Sun.

Scientists are also convinced that no planet can exist in orbit around such huge stars. Professor Crowther explained this on very funny way by saying that "planets take longer to form than these stars take to live and die, and even if there were planets, there would be no astronomers on them because the night sky would be almost as bright as the day in these clusters".

Previously observed huge stars had been seen to get as big as 150 times the mass of our Sun but these latest findings will no doubt raise interesting questions about upper limits of size these colossal stars have.

Many scientists support the theory that stars must have some physical barrier of their growth because their growth should come to a moment where the pressure from all the radiation emitted by a stellar behemoth pushes back against any further infall of gas and dust.

Most astronomers will agree that very early Universe has lots of these massive stars, and when these colossal stars blew apart, their cataclysmic demise was so violent they may not have left behind a remnant core of material as is often the case following a supernova; or even a black hole which is another common consequence, too. Instead, they simply have dumped all their contents back into space, dispersing heavy elements like iron equivalent to the mass of 10 of our Suns.