maandag 27 juni 2011

Astronomers find evidence for a strange new planetary system

An artist’s impression of the binary UZ For and planet
( -- A team of astronomers, including Dr Gavin Ramsay of the Armagh Observatory, has found evidence that suggests the existence of an extraordinary planetary system. Two giant planets appear to be revolving at some distance around a compact, interacting stellar binary known as UZ For, which comprises two small stars orbiting very closely one about the other.

If confirmed, this would be an example of a very strange new , given the nature of the stellar pair. The two stars, one a white dwarf and the other a red dwarf, are each smaller than our Sun and are orbiting in such close proximity that they take only a couple of hours to complete one revolution. The stellar pair would actually fit comfortably inside our Sun! By chance, the system is oriented in such a way that the stars pass in front of one another every orbit as seen from Earth, producing mutual eclipses that allow the properties of the system to be very well determined.
But the researchers noticed that the eclipses were not occurring precisely on time. Instead, they were sometimes too early and sometimes too late. This led them to suggest the presence of two , whose gravitational tugs would cause the orbits of the stars to "wobble" in space and so slightly change the measured time between eclipses. According to their calculations, the masses of the two planets would have to be at least eight and six times that of Jupiter, and they would have to take respectively five and sixteen years to orbit the two central stars. The system is too far away for these planets to be directly imaged.
The interacting system, which is called UZ For because of its location in the southern constellation of Fornax, produces an extremely inhospitable environment for planets. Due to their close proximity, the gravity of the more massive, but much more compact white dwarf star is constantly "stealing" material from the surface of the red dwarf in a continuous stream. This stream of material collides with the surface of the white dwarf, where it is heated to millions of degrees Kelvin, flooding the entire planetary system with enormous amounts of deadly X-rays.
The discovery was made using new observations from the Southern African Large Telescope (SALT) together with archival data spanning 27 years gathered from multiple observatories and Earth-orbiting satellites. The Armagh Observatory has access to SALT through its membership of the UK SALT Consortium. Astronomy at Armagh is supported by core funding from the Northern Ireland Department of Culture, Arts and Leisure.

More information: The research has been accepted for publication in the journal Monthly Notices of the Royal Astronomical Society, under the title "Possible detection of two giant extrasolar planets orbiting the eclipsing polar UZ Fornacis". The authors are: Steve Potter, Encarni Romero Colmenero (South African Astronomical Observatory), Gavin Ramsay (Armagh Observatory) and a number of others. A pre-print can be seen here.
Provided by Armagh Observatory

zondag 19 juni 2011

Could we survive the trip to another planet?

There is third obstacle we would have to surmount if humans like us were to colonize another planet even after we’d found it.  That’s the problem of getting there in the first place.  To put this in perspective, it was a mere four centuries ago that Europeans began sailing across the Atlantic to what we now call the Americas.  It was a perilous journey that thousands did not survive.  Many ships were lost at sea, and illness killed many more on the journey.  Nor was survival assured once they hit land.  Even though it was already inhabited by earlier arrivals, many newly founded colonies died out, killed by starvation and disease. 
How much more challenging would be a trek to another planet?  How much more treacherous surviving once the space ship touched down?
First of all the trip itself.  We don’t know how far the nearest habitable planet we might find is, but the best candidate so far is more than 20 light years away.  A light year is the distance light travels in a year which is 186,282 miles a second.  Multiplied by 60 is the distance in a minute, multiplied by 60 again is the distance in an hour;  multiplied by 24 is the distance in a day;  and multiplying that by 365 is the distance in miles light travels in a year.  That’s 5,874,589,152,000 miles.
The fastest astronauts have ever travelled so far is 7 miles a second.  That means it would take more than 26 thousand years for us to travel the distance of a light year.  The good news is that optimistic scientists think we could eventually multiply the speed of human space travel by 100, so that it would take only 260 years to travel the distance of a light year.
The bad news is that the nearest scientists think an inhabitable planet might be is 10 light years away, and the nearest planet scientists have at this point actually found that might be potentially inhabitable is 20 light years away.  So optimistically, we would have to assume that it would take between 2,600 and 5,000 years for us to reach the nearest inhabitable planet.
So the trip itself poses gigantic obstacles.
First, we would need volunteers to go into space where they would spend the rest of their lives, with no expectation that they or any of their offspring for thousands of years would reach land.  Space stations that we set up along the way might help break up the journey, but it would also slow it down.  And space stations themselves as permanent support stops are not yet feasible.
Second, we would have to solve the problems associated with the fact that humans have evolved to live in a world with certain levels of gravity and pressure.  Without it, our bones tend to disintegrate.  So far, we haven’t any idea of how the human body would cope with living from birth to death in an atmosphere without gravity.  The question of whether new human life could be conceived and nurtured successfully in a space ship is an obvious one that would need to be solved.  So would questions of disease, and the inevitable friction that would develop when a small group of people are living permanently in a cramped space – not even able to get out for a walk.
Of greatest concern would be one of genetic diversity.  Would the original humans take along a large gene pool so that the pioneers would not eventually become a small incestuous group highly vulnerable to disease?
Then, of course, we would have to build a space ship that could fuel itself for 5,000 years and provide food for its passengers.
When I think about it, I think it might be easier to save this planet.  Because the problems don’t stop with getting to a new planet.  What is your opinion?

donderdag 16 juni 2011

Eclipse of 15 June 2011

Did you get a chance to see it?

Global Visibility of the Total Eclipse of the Moon on 2011 June 15
The global visibility of this lunar eclipse is shown in the diagram to the left. A higher quality version of this global plot can be downloaded in pdf format by clicking on this image.
An explanation of this diagram can be found here.

Eclipse Trivia

This lunar eclipse can be seen in its entirety from western China, India, Pakistan, Kazakhstan, Arabia and the eastern half of Africa. Fortunately, about half of the eclipse is visible from parts of the United Kingdom. For most UK observers, the Moon rises close to mid-eclipse when the Moon is already totally eclipsed. However, for observers in Scotland and north-west Ireland, north of a line from Fraserburgh to Londonderry, the Moon will rise after totality has ended and only the partial and penumbral phases of the latter stages of the eclipse will be visible.
As the Moon is close to the southerly limit of its declination range at the time of the eclipse, it will not rise very high in the sky during the night of June 15th/16th. Moonrise in the United Kingdom ranges from 21:09 BST (British Summer Time) in the Channel Islands through to 22:23 BST in the Shetland Islands. As mid-eclipse takes place at 21:12.6 BST and the end of totality at 22:03.0 BST, observers in the southernmost parts of the United Kingdom can expect to see no more than 54 of the 101 minutes of totality, decreasing the further north you travel. Much of the eclipse will take place in the south-eastern part of the sky at an altitude of less than 5° so a clear view of this horizon is vital.
During totality, the Moon is illuminated only by light that has been refracted through the upper part of the Earth's atmosphere, hence the coppery-red colour of the eclipsed Moon. Depending on the amount of obscuring material in the upper atmosphere, the Moon can be quite dark during totality to the point where even identifying the Moon can be difficult. It will be interesting to see if the low altitude of this eclipse combined with the ash from the eruption of the Grimsvötn volcano in Iceland will make the eclipse much redder than usual.
In terms of the duration of totality, this eclipse is the fifth longest this century, the longest being that of July 27th, 2018 at nearly 104 minutes. It is interesting to note that the circumstances of the July 27th 2018 eclipse are a close match to those of the June 15th 2011 eclipse.

Eclipses in 2011

Junuary 4th (Solar: Partial)
June 1th (Solar: Partial)
June 15th (Total)
July 1th (Solar: Partial)
November 25th (Solar: Partial)
December 10th (Total)

For those of that missed the June 15th 2011 eclipse you will get a second chance at December 10th.
And you that did see it.. let me know what you think of it?

dinsdag 14 juni 2011

Update: Who build the Egyptian Pyramids? Men or Aliens?

To make up your mind better here is a good documentary from Discovery Channel about Pyramids.

What do you think now? Still Men's work or....

Who build the Egyptian Pyramids? Men or Aliens?

I can remember standing in the desert near Cairo and gazing across the Sphinx to the Great Pyramid of Giza, one of the most impressive structures on Earth, and counting myself extremely fortunate to be there. The pyramid carries some impressive statistics. It stands 450 feet tall (137mtrs) and consists of two million blocks of stone, weighing from the most common at 2.5 tons up to 50 tons. The weight of the pyramid is six million tons. The four corners are almost perfect right angles and align almost exactly to the four points of the compass. The sides slope at a perfect 52 degrees, or would do had not the smoothly polished limestone finishing blocks been removed and used in building works in Cairo. It is one one of the original Seven Wonders of the World. Impressive though the statistics are, they do not reveal the true magnificence of this wonderful construction. I have to admit that upon entering the pyramid and climbing up the narrow cramped access shaft to the upper burial chamber, which was surprisingly cool, I experienced an eerie feeling of stepping back into history, and a strong feeling of trespassing.
To have seen this pyramid when perfectly smooth and dazzlingly white in the desert sun must have been an incredible sight.
So impressive are the pyramids that it has caused many to wonder how they could possibly have been built some 4500 years ago. Some even go as far as to suggest that it is not possible for these structures to have been made by the labours of men, but were instead made by aliens.
Who built the pyramids, aliens or men?
The case for the Aliens:
The pyramids are so accurately aligned with the points of the compass that only aliens could have achieved this all those thousands of years ago. The angle of the slope of the sides is so precise only aliens could achieve this. The blocks are so heavy and the pyramid so tall only aliens could achieve this. In the period 2500 BC man did not have the tools or knowledge necessary to build the pyramids, so only aliens could have done it. How the aliens built the pyramids is not known, but they would have employed the use of advanced construction equipment.
The case for men:
Never underestimate the ingenuity of man. We are today so used to using machinery to carry out virtually all our major construction work that we sometimes forget that machinery, in terms of historical events, is a very new development, its only been around a couple of hundred years or so. Mankind managed very well without it for many thousands of years. We have long forgotten the techniques that were used in the building of the pyramids, but this doesn't mean that we are unable to work out how it was done.
In order to try and establish who built the pyramids we have to examine the evidence that we have. We have only the pyramids themselves, the excavation sites where the blocks were quarried from, and historical accounts.
The evidence:
Lets start with the excavation site. If like me, you have been there, you will know that it looks pretty much like any other quarry you might see today, except there is obviously no machinery. At the quarry face there are blocks cut into the rock but not yet cut away. There are rough hewn blocks scattered around ready for transporting and on-site finishing. The entire quarry shows obvious signs of systematic development of cutting blocks out from the face and transporting them from site. The rough hewn free standing blocks show the scars of repeated chisel blows where they were chiseled out of the rock face. There is nothing in the manner of these blocks that is anything other than old fashioned quarry work using a mallet and chisel. Nowhere is there any sign of advanced technology having been employed, just the opposite. The blocks were hewn out of the rock-face by manual labour, the signs are unmistakable. The chisels used were made of copper, the hardest metal then available, but even they were only good for about 100 blows before blunting, even though limestone is relatively soft and easy to work compared to hard rock such as granite. As the chisels were blunted they were exchanged for re-sharpened ones, and the process was repeated with a team of blacksmiths constantly re-sharpening and tempering the chisels.
How were the blocks transported to the pyramids? By man power. The vast majority of the blocks weighed in the region of 2.5 tons and were transported on wooden sledges. They could of course have chosen any size for the blocks, but this must have been the optimum size, any bigger would probably have slowed them down. A team of men with ropes could drag the sledge across the clay floor, and this could be eased with a little water tipped in front of the runners helping the sledge to slide easier. It is estimated that it may have taken 10 years just to build the ramp from the quarry to the pyramids. In this manner all the blocks could be transported to the site of the pyramid without presenting any insurmountable challenges. So far no alien technology required, it could all be done by well organised teams of men, and a great deal of manual labour. During the time of the annual flooding of the Nile the stone blocks could have been floated to the site of the pyramids on rafts, making the task a lot easier.
The work force was was not one of slaves , the Egyptians didn't need slaves. The Nile supplied a very fertile land where farming was relatively easy and food abundant. This civilisation had time on its hands, no wonder they were such great mathematicians, astronomers and architects. The work force was primarily made up of farmers, recruited nationwide for a period ranging from a few months to a few years, and they served their time for their king, much like serving National Service today in the armed forces. A total of 20,000 to 30,000 workers would have been needed for the task, ranging from unskilled hauliers, semi-skilled quarry men, skilled quarry men, masons who finished the blocks, men who placed the blocks, officials and caterers. A village was purpose built to house them all and they were well fed and cared for in return for their work. The remains of the village can still be seen today.
Now for making the pyramids themselves. About 2,550 B.C., King Khufu, the second pharaoh of the fourth dynasty, commissioned the building of his tomb at Giza. Some Egyptologists believe it took somewhere in the region of 80 years to construct the pyramid. Having man-hauled the blocks to the site of the pyramid the obvious problem now is how to stack them up. There are a number of ways this may have been achieved, all of which require a ramp, or a system of ramps, as the only method available to the ancient Egyptians was man-power, and they had that in abundance.
The actual method of ramps used is not known with any certainty, but it most likely started with a single ramp by which means the blocks could be hauled into position. The blocks were laid down in layers, each successive layer being a little smaller in area than the one below it to give the pyramid its shape. As the blocks are layed onto a level surface, the same height as the ramp, no lifting was required, only hauling of the sledges. Removing the blocks from the sledge may have involved no more than dragging the block off the sledge. The entire pyramid could have been built using this simple system without a single block actually having to be lifted off the ground! No alien technology required. Very smart people these Egyptians.
As each successive layer was laid the ramp would need be heightened, and lengthened so as not to be too steep. Eventually this method would reach a limit where the size and construction of the ramp would be nearly as complex as the pyramid. The easiest way around this problem is to curve the ramp around the pyramid as the pyramid increased in height.
Finally, all that remained was the placing of the top stone, followed by the placing and fitting of the smooth white blocks. As the facing stones were placed so the ramp could be removed as they worked their way back down. The pyramid required a certain amount of interior design and construction for the burial chambers, and this was no easy task. The blocks that protected the burial chamber were 50 ton blocks of granite. Even with the huge teams of men at their disposal and a system of ropes and overseers guiding them, it would have been a difficult and dangerous task. There are still marks visible on the blocks and in the interior of the pyramid that were used to guide the blocks into position. Difficult yes, impossible no.
It was men that built the pyramids, make no mistake. Do not underestimate the intelligence of the ancient Egyptians or the trained manpower that was at their disposal. It was a colossal effort of team work taking 80 years to complete.
How did they align the corners of the pyramid so accurately with the four points of the compass? This was the easy part. It just takes a curved wall facing more or less North as judged by the stars. Select a rising star on the Eastern horizon and mark a line on the top of the wall pointing to it. Mark another line on the wall when it is low on the Western horizon. Take the line straight down the wall , using a plumb line, and then extend it along the ground until it meets the other line. Bisect this angle and you now have a line pointing exactly due North.
There are any number of very simple methods that can then be employed to construct a right angle that will then align with the other points of the compass. After that its just a question of placing markers in the ground for the four corners of the pyramid. As I said, that part is easy, it does not require alien technology, just a little brain power.
How did they achieve such a perfect 52 degree angle of slope? Because they were clever! They were masters of angles, a skill they had acquired in part through astronomy, and also through a good knowledge of mathematics. Each mason that worked on finishing the outer blocks had a template with an angle of 52 degrees that he used to cut his block to fit. After that it was careful alignment of block to block as they placed them carefully on the inner blocks. It was literally done step by step.
Mystery solved, that's how it was done. Maybe not using that exact method, but something very like it. There is absolutely no need to suggest that it couldn't be done by man power, and certainly there is no need to go to the ridiculous lengths of suggesting it was done with the help of aliens. That idea is pure nonsense.
Why were the pyramids built? They were tombs for the king. The Egyptians had long observed a point in the sky around which all the stars appeared to rotate (the north celestial pole, today marked by the close proximity of the Pole Star) and believed the area to be an immortal place. The alignment of the pyramid to the compass points was to align it with the 'immortal place' in the sky, and the shape was believed to represent the rays of the Sun. The pyramid was in fact a device designed to transport the king to the immortal place so that he may live forever, as would all the workers that assisted in its construction.
N.B. The theory of how the pyramids were actually built is not my own pet theory, but one considered by experts in the field as to be the most likely. It is a known fact how the stones were carved out of the quarry. Graffiti inside the pyramid reveals that teams were used in competition with one another, with the best performers receiving 'bonuses' of extra beer or days off. The workers village is a known fact. The ramp from the quarry to the pyramid is a known fact. That the huge work force was recruited is a known historical fact. The labour force required and the time it would have taken has been very carefully calculated. The type of ramps used is open to question, but all are agreed that ramps were used, there is no other way it could have been done. And it was done - by men!

zaterdag 11 juni 2011

What if aliens do exist?

Okay, I believe aliens exist. Whether they are actually smart or not is undecided, as they could have been created just 5 minutes ago. With the universe as big as it is, it's impossible to discredit the fact that there could have been other "big bangs" somewhere out there that created planets with water. But could scientists and astronauts searching for planets with other life forms bring an end to our planet? If there are indeed these beings of "superior intelligence" then why search for them? Wouldn't it be better to leave things alone for our own benefit and security?

Saturn's many moons

Saturn's many moons have shaped its beautiful rings. And now we have an amazing collection of close up photos courtesy of the Cassini Spacecraft. What do you think? Check the vid!