Space Time Wrap : Bending Space And Time

Space and Time Warps are a commonplace. They are used for rapid journeys around the galaxy, or for travel through time. But today's science fiction, is often tomorrow's science fact. So what are the chances for space and time warps.

The idea that space and time can be curved, or warped, is fairly recent. For more than two thousand years, the axioms of Euc

lidean geometry, were considered to be self evident. As those of you that were forced to learn Euclidean geometry at school may remember, one of the consequences of these axioms is, that the angles of a triangle, add up to a hundred and 80 degrees.

However, in the last century, people began to realize that other forms of geometry were possible, in which the angles of a triangle, need not add up to a hundred and 80 degrees. Consider, for example, the surface of the Earth. The nearest thing to a straight line on the surface of the Earth, is what is called, a great circle. These are the shortest paths between two points, so they are the roots that air lines use. Consider now the triangle on the surface of the Earth, made up of the equator, the line of 0 degrees longitude through London, and the line of 90 degrees longtitude east, through Bangladesh. The two lines of longitude, meet the equator at a right angle, 90 degrees. The two lines of longitude also meet each other at the north pole, at a right angle, or 90 degrees. Thus one has a triangle with three right angles. The angles of this triangle add up to two hundred and seventy degrees. This is greater than the hundred and eighty degrees, for a triangle on a flat surface. If one drew a triangle on a saddle shaped surface, one would find that the angles added up to less than a hundred and eighty degrees. The surface of the Earth, is what is called a two dimensional space. That is, you can move on the surface of the Earth, in two directions at right angles to each other: you can move north south, or east west. But of course, there is a third direction at right angles to these two, and that is up or down. That is to say, the surface of the Earth exists in three-dimensional space. The three dimensional space is flat. That is to say, it obeys Euclidean geometry. The angles of a triangle, add up to a hundred and eighty degrees. However, one could imagine a race of two dimensional creatures, who could move about on the surface of the Earth, but who couldn't experience the third direction, of up or down. They wouldn't know about the flat three-dimensional space, in which the surface of the Earth lives. For them, space would be curved, and geometry would be non-Euclidean.

It would be very difficult to design a living being that could exist in only two dimensions.

Food that the creature couldn't digest would have to be spat out the same way it came in. If there were a passage right the way through, like we have, the poor animal would fall apart.

So three dimensions, seems to be the minimum for life. But just as one can think of two dimensional beings living on the surface of the Earth, so one could imagine that the three dimensional space in which we live, was the surface of a sphere, in another dimension that we don't see. If the sphere were very large, space would be nearly flat, and Euclidean geometry would be a very good approximation over small distances. But we would notice that Euclidean geometry broke down, over large distances. As an illustration of this, imagine a team of painters, adding paint to the surface of a large ball. As the thickness of the paint layer increased, the surface area would go up. If the ball were in a flat three-dimensional space, one could go on adding paint indefinitely, and the ball would get bigger and bigger. However, if the three-dimensional space, were really the surface of a sphere in another dimension, its volume would be large but finite. As one added more layers of paint, the ball would eventually fill half the space. After that, the painters would find that they were trapped in a region of ever decreasing size, and almost the whole of space, was occupied by the ball, and its layers of paint. So they would know that they were living in a curved space, and not a flat one.
This example shows that one can not deduce the geometry of the world from first principles, as the ancient Greeks thought. Instead, one has to measure the space we live in, and find out its geometry by experiment. However, although a way to describe curved spaces, was developed by the German, George Friedrich Riemann, in 1854, it remained just a piece of mathematics for sixty years. It could describe curved spaces that existed in the abstract, but there seemed no reason why the physical space we lived in, should be curved. This came only in 1915, when Einstein put forward the General Theory of Relativity.

General Relativity was a major intellectual revolution that has transformed the way we think about the universe. It is a theory not only of curved space, but of curved or warped time as well. Einstein had realized in 1905, that space and time, are intimately connected with each other. One can describe the location of an event by four numbers. Three numbers describe the position of the event. They could be miles north and east of Oxford circus, and height above sea level. On a larger scale, they could be galactic latitude and longitude, and distance from the center of the galaxy. The fourth number, is the time of the event. Thus one can think of space and time together, as a four-dimensional entity, called space-time. Each point of space-time is labeled by four numbers, that specify its position in space, and in time. Combining space and time into space-time in this way would be rather trivial, if one could disentangle them in a unique way. That is to say, if there was a unique way of defining the time and position of each event. However, in a remarkable paper written in 1905, when he was a clerk in the Swiss patent office, Einstein showed that the time and position at which one thought an event occurred, depended on how one was moving. This meant that time and space, were inextricably bound up with each other. The times that different observers would assign to events would agree if the observers were not moving relative to each other. But they would disagree more, the faster their relative speed. So one can ask, how fast does one need to go, in order that the time for one observer, should go backwards relative to the time of another observer. The answer is given in the following Limerick.

There was a young lady of Wight,
Who traveled much faster than light,
She departed one day,
In a relative way,
And arrived on the previous night.

So all we need for time travel, is a space ship that will go faster than light. Unfortunately, in the same paper, Einstein showed that the rocket power needed to accelerate a space ship, got greater and greater, the nearer it got to the speed of light. So it would take an infinite amount of power, to accelerate past the speed of light.

Einstein's paper of 1905 seemed to rule out time travel into the past. It also indicated that space travel to other stars, was going to be a very slow and tedious business. If one couldn't go faster than light, the round trip to the nearest star, would take at least eight years, and to the center of the galaxy, at least eighty thousand years. If the space ship went very near the speed of light, it might seem to the people on board, that the trip to the galactic center had taken only a few years. But that wouldn't be much consolation, if everyone you had known was dead and forgotten thousands of years ago, when you got back. That wouldn't be much good for space Westerns. So writers of science fiction, had to look for ways to get round this difficulty.

In his 1915 paper, Einstein showed that the effects of gravity could be described, by supposing that space-time was warped or distorted, by the matter and energy in it. We can actually observe this warping of space-time, produced by the mass of the Sun, in the slight bending of light or radio waves, passing close to the Sun. This causes the apparent position of the star or radio source, to shift slightly, when the Sun is between the Earth and the source. The shift is very small, about a thousandth of a degree, equivalent to a movement of an inch, at a distance of a mile. Nevertheless, it can be measured with great accuracy, and it agrees with the predictions of General Relativity. We have experimental evidence, that space and time are warped. The amount of warping in our neighbourhood, is very small, because all the gravitational fields in the solar system, are weak. However, we know that very strong fields can occur, for example in the Big Bang, or in black holes. So, can space and time be warped enough, to meet the demands from science fiction, for things like hyper space drives, wormholes, or time travel. At first sight, all these seem possible. For example, in 1948, Kurt Goedel found a solution of the field equations of General Relativity, which represents a universe in which all the matter was rotating. In this universe, it would be possible to go off in a space ship, and come back before you set out. Goedel was at the Institute of Advanced Study, in Princeton, where Einstein also spent his last years. He was more famous for proving you couldn't prove everything that is true, even in such an apparently simple subject as arithmetic. But what he proved about General Relativity allowing time travel really upset Einstein, who had thought it wouldn't be possible.

We now know that Goedel's solution couldn't represent the universe in which we live, because it was not expanding. It also had a fairly large value for a quantity called the cosmological constant, which is generally believed to be zero. However, other apparently more reasonable solutions that allow time travel, have since been found. A particularly interesting one contains two cosmic strings, moving past each other at a speed very near to, but slightly less than, the speed of light. Cosmic strings are a remarkable idea of theoretical physics, which science fiction writers don't really seem to have caught on to. As their name suggests, they are like string, in that they have length, but a tiny cross section. Actually, they are more like rubber bands, because they are under enormous tension, something like a hundred billion billion billion tons. A cosmic string attached to the Sun would accelerate it naught to sixty, in a thirtieth of a second.

Cosmic strings may sound far-fetched, and pure science fiction, but there are good scientific reasons to believed they could have formed in the very early universe, shortly after the Big Bang. Because they are under such great tension, one might have expected them to accelerate to almost the speed of light.
What both the Goedel universe, and the fast moving cosmic string space-time have in common, is that they start out so distorted and curved, that travel into the past, was always possible. God might have created such a warped universe, but we have no reason to think that He did. All the evidence is, that the universe started out in the Big Bang, without the kind of warping needed, to allow travel into the past. Since we can't change the way the universe began, the question of whether time travel is possible, is one of whether we can subsequently make space-time so warped, that one can go back to the past. I think this is an important subject for research, but one has to be careful not to be labeled a crank. If one made a research grant application to work on time travel, it would be dismissed immediately. No government agency could afford to be seen to be spending public money, on anything as way out as time travel. Instead, one has to use technical terms, like closed time like curves, which are code for time travel. Although this lecture is partly about time travel, I felt I had to give it the scientifically more respectable title, Space and Time warps. Yet, it is a very serious question. Since General Relativity can permit time travel, does it allow it in our universe? And if not, why not.

Closely related to time travel, is the ability to travel rapidly from one position in space, to another. As I said earlier, Einstein showed that it would take an infinite amount of rocket power, to accelerate a space ship to beyond the speed of light. So the only way to get from one side of the galaxy to the other, in a reasonable time, would seem to be if we could warp space-time so much, that we created a little tube or wormhole. This could connect the two sides of the galaxy, and act as a short cut, to get from one to the other and back while your friends were still alive. Such wormholes have been seriously suggested, as being within the capabilities of a future civilization. But if you can travel from one side of the galaxy, to the other, in a week or two, you could go back through another wormhole, and arrive back before you set out. You could even manage to travel back in time with a single wormhole, if its two ends were moving relative to each other.

One can show that to create a wormhole, one needs to warp space-time in the opposite way, to that in which normal matter warps it. Ordinary matter curves space-time back on itself, like the surface of the Earth.

However, to create a wormhole, one needs matter that warps space-time in the opposite way, like the surface of a saddle. The same is true of any other way of warping space-time to allow travel to the past, if the universe didn't begin so warped, that it allowed time travel. What one would need, would be matter with negative mass, and negative energy density, to make space-time warp in the way required.

Energy is rather like money. If you have a positive bank balance, you can distribute it in various ways. But according to the classical laws that were believed until quite recently, you weren't allowed to have an energy overdraft. So these classical laws would have ruled out us being able to warp the universe, in the way required to allow time travel. However, the classical laws were overthrown by Quantum Theory, which is the other great revolution in our picture of the universe, apart from General Relativity. Quantum Theory is more relaxed, and allows you to have an overdraft on one or two accounts. If only the banks were as accommodating. In other words, Quantum Theory allows the energy density to be negative in some places, provided it is positive in others.

The reason Quantum Theory can allow the energy density to be negative, is that it is based on the Uncertainty Principle.

This says that certain quantities, like the position and speed of a particle, can't both have well defined values. The more accurately the position of a particle is defined, the greater is the uncertainty in its speed, and vice versa. The uncertainty principle also applies to fields, like the electro-magnetic field, or the gravitational field. It implies that these fields can't be exactly zeroed, even in what we think of as empty space. For if they were exactly zero, their values would have both a well-defined position at zero, and a well-defined speed, which was also zero. This would be a violation of the uncertainty principle. Instead, the fields would have to have a certain minimum amount of fluctuations. One can interpret these so called vacuum fluctuations, as pairs of particles and anti particles, that suddenly appear together, move apart, and then come back together again, and annihilate each other. These particle anti particle pairs, are said to be virtual, because one can not measure them directly with a particle detector. However, one can observe their effects indirectly. One way of doing this, is by what is called the Casimir effect. One has two parallel metal plates, a short distance apart. The plates act like mirrors for the virtual particles and anti particles. This means that the region between the plates, is a bit like an organ pipe, and will only admit light waves of certain resonant frequencies. The result is that there are slightly fewer vacuum fluctuations, or virtual particles, between the plates, than outside them, where vacuum fluctuations can have any wavelength. The reduction in the number of virtual particles between the plates means that they don't hit the plates so often, and thus don't exert as much pressure on the plates, as the virtual particles outside. There is thus a slight force pushing the plates together. This force has been measured experimentally. So virtual particles actually exist, and produce real effects.
Because there are fewer virtual particles, or vacuum fluctuations, between the plates, they have a lower energy density, than in the region outside. But the energy density of empty space far away from the plates, must be zero. Otherwise it would warp space-time, and the universe wouldn't be nearly flat. So the energy density in the region between the plates, must be negative.

We thus have experimental evidence from the bending of light, that space-time is curved, and confirmation from the Casimir effect, that we can warp it in the negative direction. So it might seem possible, that as we advance in science and technology, we might be able to construct a wormhole, or warp space and time in some other way, so as to be able to travel into our past. If this were the case, it would raise a whole host of questions and problems. One of these is, if sometime in the future, we learn to travel in time, why hasn't someone come back from the future, to tell us how to do it.

Even if there were sound reasons for keeping us in ignorance, human nature being what it is, it is difficult to believe that someone wouldn't show off, and tell us poor benighted peasants, the secret of time travel. Of course, some people would claim that we have been visited from the future. They would say that UFO's come from the future, and that governments are engaged in a gigantic conspiracy to cover them up, and keep for themselves, the scientific knowledge that these visitors bring. All I can say is, that if governments were hiding something, they are doing a pretty poor job, of extracting useful information from the aliens. I'm pretty skeptical of conspiracy theories, believing the cock up theory is more likely. The reports of sightings of UFO's can't all be caused by extra terrestrials, because they are mutually contradictory. But once you admit that some are mistakes, or hallucinations, isn't it more probable that they all are, than that we are being visited by people from the future, or the other side of the galaxy? If they really want to colonize the Earth, or warn us of some danger, they are being pretty ineffective.
A possible way to reconcile time travel, with the fact that we don't seem to have had any visitors from the future, would be to say that it can occur only in the future. In this view, one would say space-time in our past was fixed, because we have observed it, and seen that it is not warped enough, to allow travel into the past. On the other hand, the future is open. So we might be able to warp it enough, to allow time travel. But because we can warp space-time only in the future, we wouldn't be able to travel back to the present time, or earlier.

This picture would explain why we haven't been over run by tourists from the future.

But it would still leave plenty of paradoxes. Suppose it were possible to go off in a rocket ship, and come back before you set off. What would stop you blowing up the rocket on its launch pad, or otherwise preventing you from setting out in the first place. There are other versions of this paradox, like going back, and killing your parents before you were born, but they are essentially equivalent. There seem to be two possible resolutions.

One is what I shall call, the consistent histories approach. It says that one has to find a consistent solution of the equations of physics, even if space-time is so warped, that it is possible to travel into the past. On this view, you couldn't set out on the rocket ship to travel into the past, unless you had already come back, and failed to blow up the launch pad. It is a consistent picture, but it would imply that we were completely determined: we couldn't change our minds. So much for free will. The other possibility is what I call, the alternative histories approach. It has been championed by the physicist David Deutsch, and it seems to have been what Stephen Spielberg had in mind when he filmed, Back to the Future.

In this view, in one alternative history, there would not have been any return from the future, before the rocket set off, and so no possibility of it being blown up. But when the traveler returns from the future, he enters another alternative history. In this, the human race makes a tremendous effort to build a space ship, but just before it is due to be launched, a similar space ship appears from the other side of the galaxy, and destroys it.
David Deutsch claims support for the alternative histories approach, from the sum over histories concept, introduced by the physicist, Richard Feinman, who died a few years ago. The idea is that according to Quantum Theory, the universe doesn't have just a unique single history.

Instead, the universe has every single possible history,each with its own probability. There must be a possible history in which there is a lasting peace in the Middle East, though maybe the probability is low.
In some histories space-time will be so warped, that objects like rockets will be able to travel into their pasts. But each history is complete and self contained, describing not only the curved space-time, but also the objects in it. So a rocket can not transfer to another alternative history, when it comes round again. It is still in the same history, which has to be self consistent. Thus, despite what Deutsch claims, I think the sum over histories idea, supports the consistent histories hypothesis, rather than the alternative histories idea.

It thus seems that we are stuck with the consistent histories picture. However, this need not involve problems with determinism or free will, if the probabilities are very small, for histories in which space-time is so warped, that time travel is possible over a macroscopic region. This is what I call, the Chronology Protection Conjecture: the laws of physics conspire to prevent time travel, on a macroscopic scale.

It seems that what happens, is that when space-time gets warped almost enough to allow travel into the past, virtual particles can almost become real particles, following closed trajectories. The density of the virtual particles, and their energy, become very large. This means that the probability of these histories is very low. Thus it seems there may be a Chronology Protection Agency at work, making the world safe for historians. But this subject of space and time warps is still in its infancy. According to string theory, which is our best hope of uniting General Relativity and Quantum Theory, into a Theory of Everything, space-time ought to have ten dimensions, not just the four that we experience. The idea is that six of these ten dimensions are curled up into a space so small, that we don't notice them. On the other hand, the remaining four directions are fairly flat, and are what we call space-time. If this picture is correct, it might be possible to arrange that the four flat directions got mixed up with the six highly curved or warped directions. What this would give rise to, we don't yet know. But it opens exciting possibilities.

The conclusion of this lecture is that rapid space-travel, or travel back in time, can't be ruled out, according to our present understanding. They would cause great logical problems, so let's hope there's a Chronology Protection Law, to prevent people going back, and killing our parents. But science fiction fans need not lose heart. There's hope in string theory.

How can you use black holes for time travel?

Black holes can be used to travel into the future only. So far as we know, our universe prohibits traveling into the past.

According to Einstein's theory of general relativity, and to experimental evidence here on earth assembled by Harvard physicists Pound and Rebka, in the presence of a gravitational field, an external observer would see a clock in

a strong gravitational field tick more slowly. This is analogous to the famous time dilation effect in special relativity, except that in the 'gravitational redshift' effect no motion between the observer outside the gravitational field and the clock located within the field, is required.

What this means is that if you were traveling into a strong gravitational field and sending out pulses of light every second, an observer watching these signals from a great distance would see the interval between the pulses increase from seconds to minutes and then hours as the field got stronger and stronger.

Black holes are fantastic sources of very strong gravitational fields. What a distant observer would see as your clock got closer to the so-called Event Horizon of the black hole is that the pulse interval would increase without limit from one second to one month and longer. The frequency of the light pulses would also get longer as the light lost more and more energy struggling to get out from the vicinity of the black hole. As your friend finally entered the black hole by passing across its event horizon, the last photon capable of making it to infinity is emitted at almost infinite redshift, meaning that if you originally emitted a gamma ray with an energy of 1000 billion electron volts, buy the time your friend received it far away, it would have lost enough energy to become a radio photon with an energy of 0.00001 electron volts! So, if it took your friend 1000 hours to travel from where you are to the black hole, the last photon he sent you just before entering the black hole, would arrive at your location 1000 hours from now, but when you looked at the interval between the last two pulses he sent, you would see that they are not the one second interval you started out with, but say 1 or 2 minutes or more. But here's the rub. According to your infalling friend, he/she is still sending the pulses out once each second!

In other words, one second to your friend falling into a black hole is several minutes to you and, in essence, your friend is aging more slowly than you and is traveling into the future faster than you are. If he/she could manage to put on the breaks just before crossing over the Event Horizon and escape to rejoin you, you would note that his/her clock reads a much earlier time than your clock. To your friend, only 2000 hours may have elapsed, however, YOUR clock would read perhaps 10000 hours or several weeks have elapsed depending how close to the Event Horizon your friend could get before escaping. The tidal gravitational forces are enormous near small black holes the mass of the sun, so your friend would be shredded into spaghetti within a few hundred miles of the Horizon. For supermassive black holes of several billion solar masses, however, the tidal forces near the Horizon are very small and survivable. This means you could accidently find yourself passing across this one-way barrier, and only realize your mistake when you tried to escape and found it impossible.

In principle, if you could get within a few millimeters of an Event Horizon before escaping, you could essentially time travel years or millenia into the future as measured by outside clocks. According to your clock, however, perhaps only a few hour or days actually elapsed.

Note, all of the above numbers are pretty darn approximate and are given to qualitatively show the magnitudes of the effects.

Image Source:en.wikipedia.org

NASA Mars 'Returner'

Curiosity is making amazing progress even as we dawdle on Facebook right now. Just earlier this week, it discovered sediment that mimics deposits of what an Earth stream would leave if it were there on Mars. Hopefully this is the sort of discovery that might precede discovering remnants of microbial, or even advanced life (or even currently living organisms!).

The sad thing is that those potential samples are still anywhere between 36 - 250 million miles away (depending on orbital comparisons) from Earth. A mild hindrance for us in investigating these sedimentary samples, and even any biological samples, under clean-room laboratory conditions befitting of the potential discoveries.

This can all change in the very near-future thanks to some provisional mission plans from the great minds at NASA...

NASA's Mars Program Planning Group released on Tuesday (25th September 2012) several key mechanisms that could be employed in order to bring samples of sediment, strata and even bio-matter back to Earth for analysis and study!

Out of these options laid out, NASA have decided upon one, but refuse to commit pen to the proverbial paper until the Whitehouse release their 2014 fiscal year budget request.

One such mechanism involves the use of containment tubes, sealed several times over to protect against deep-space. These are then mounted into a supersonic rocket which relays the samples to an orbiting base-station.
Much like a carrier-pigeon, this station then passes the projectile into a larger vessel, which is propelled towards Earth. Once in proximity to Earth, it will be collected by a human-manned craft and brought down to the planet for investigation.
Quite literally a shuttle relay run!

Other options involve the use of Sky-cranes, much like how Curiosity was delivered, which drop off several collection robots which continually collect and deliver specimens.

The key thoughts and considerations here are that Mars is now potentially being 'contaminated' by Earth - what is to say that bacteria wasn't present in Curiosity or the Rover? Similarly, what is to say that specimens brought back from Mars are able to be controlled through our known methods of decontamination and bio-hazard procedures in laboratories?

Would it not be a stroke of irony, if not typical human-luck, that a newly discovered bacterium from Mars wipes out our planet, simply because we are not adapted to combat it? Well, NASA may be able to use the International Space Station to study the samples within, so we may be safe...

Water on Mars: NASA scientists are 'excited'

Mars rover Curiosity found rocks on the Martian surface that are too big to be carried by wind, so researchers suppose water must have existed on Mars at one time. Over the next two years, Curiosity will continue its search for signs of ancient microbial life on Mars.

There have been previous signs that water existed on the red planet long ago, but the images released Thursday showing pebbles rounded off, likely by water, offered the most convincing evidence so far of an ancient streambed.
There was "a vigorous flow on the surface of Mars," said chief scientist John Grotzinger of the California Institute of Technology. "We're really excited about this."

RELATED: Are you scientifically literate? Take our quiz 

The discovery did not come as a complete surprise. NASA decided to plunk Curiosity down inside Gale Crater near the Martian equator because photos from space hinted that the spot possessed a watery past. The six-wheeled rover safely landed Aug. 5 after a nail-biting plunge through the Martian atmosphere. It's on a two-year, $2.5 billion mission to study whether the Martian environment could have been favorable for microbial life.
Present day Mars is a frozen desert with no hint of water on its radiation-scarred surface, but geological studies of rocks by previous missions suggest the planet was warmer and wetter once upon a time.
The latest evidence came from photos that Curiosity took revealing rounded pebbles and gravel — a sign that the rocks were transported long distances by water and smoothed out.
The size of the rocks — ranging from a sand grain to a golf ball — indicates that they could not have been carried by wind, said mission scientist Rebecca Williams of the Planetary Science Institute in Tucson, Ariz.
Though Curiosity did not use its high-tech instruments to drill into the rocks or analyze their chemical makeup, Grotzinger said scientists were sure that water played a role based on just studying the pictures.
It's unclear how long the water persisted on the surface, but it easily could have lasted "thousands to millions of years," said mission scientist Bill Dietrich of the University of California, Berkeley.
Curiosity chanced upon the dried-up streambed while driving to Glenelg, an intriguing spot where three types of terrain meet. Its ultimate destination is Mount Sharp, a mountain rising from the center of crater floor, but it was not expected to travel there until the end of the year.
Finding past water is a first step toward learning whether the environment could have supported microbes. Scientists generally agree that besides water and an energy source such as the sun, organic carbon is a necessary prerequisite for life.
While an ancient streambed holds promise as a potentially habitable environment, scientists don't think it's a good place to preserve the carbon building blocks of life. That's why the rover will continue its trek to the foothills of Mount Sharp where there's a better chance of finding organics.

Occupy Mars: History of Robotic Red Planet Missions

Every 26 months there is an opportunity to send a vehicle from Earth to the planet Mars along an efficient, low-energy trajectory. The trip can take six months or more. Probes to Mars often fail; as of July 2012, the success rate was 47 percent.
The Soviet Union was first to attempt to send unmanned space probes to Mars. Several failed, but in 1971 the lander Mars 2 became the first object from Earth to reach the surface of the Red Planet. Unfortunately Mars 2 crashed rather than landing softly. Its sister probe, Mars 3, did manage to land on Dec. 2, 1971. The Mars 3 lander transmitted data for a few seconds before falling silent.
The first truly successful Mars surface probes were the Viking 1 and 2 landers, sent from the United States, which touched down in 1976. The landers gathered soil samples for analysis using their robotic arms, and they thoroughly photographed the area surrounding their landing sites.
Another milestone was reached in 1997, when the Mars Pathfinder was landed by the United States. Pathfinder released a tiny remote-controlled rover, called Sojourner, which explored the Martian surface for nearly three months before contact was lost.
Source:www.space.com

The Theory of Special relativity and Time Travel.

Time travel is one of my favorite topics! I have posted some time travel concepts before on this very page, and I have continued to study this fascinating concept as the time have passed by.

We all travel in time. During the last year, I've moved forward one year and so have you. Another way to say that is that we travel in time at the rate of 1 hour per hour.

But the question is, can we travel in time faster or slower than "1 hour per hour"? Or can we actually travel backward in time, going back, say 2 hours per hour, or 10 or 100 years per hour?

It is mind-boggling to think about time travel. What if you went back in time and prevented your father and mother from meeting? You would prevent yourself from ever having been born! But then if you hadn't been born, you could not have gone back in time to prevent them from meeting.
Albert Einstein

The great 20th century scientist Albert Einstein developed a theory called Special Relativity. The ideas of Special Relativity are very hard to imagine because they aren't about what we experience in everyday life, but scientists have confirmed them. This theory says that space and time are really aspects of the same thing—space-time. There's a speed limit of 300,000 kilometers per second (or 186,000 miles per second) for anything that travels through space-time, and light always travels the speed limit through empty space.

Special Relativity also says that a surprising thing happens when you move through space-time, especially when your speed relative to other objects is close to the speed of light. Time goes slower for you than for the people you left behind. You won't notice this effect until you return to those stationary people.

Say you were 15 years old when you left Earth in a spacecraft traveling at about 99.5% of the speed of light (which is much faster than we can achieve now), and celebrated only five birthdays during your space voyage. When you get home at the age of 20, you would find that all your classmates were 65 years old, retired, and enjoying their grandchildren! Because time passed more slowly for you, you will have experienced only five years of life, while your classmates will have experienced a full 50 years.

Time traveler

So, if your journey began in 2003, it would have taken you only 5 years to travel to the year 2053, whereas it would have taken all of your friends 50 years. In a sense, this means you have been time traveling. This is a way of going to the future at a rate faster than 1 hour per hour.

Time travel of a sort also occurs for objects in gravitational fields. Einstein had another remarkable theory called General Relativity, which predicts that time passes more slowly for objects in gravitational fields (like here on Earth) than for objects far from such fields. So there are all kinds of space and time distortions near black holes, where the gravity can be very intense.

In the past few years, some scientists have used those distortions in space-time to think of possible ways time machines could work. Some like the idea of "worm holes," which may be shortcuts through space-time. This and other ideas are wonderfully interesting, but we don't know at this point whether they are possible for real objects. Still the ideas are based on good, solid science. In all time travel theories allowed by real science, there is no way a traveler can go back in time to before the time machine was built.

I am confident time travel into the future is possible, but we would need to develop some very advanced technology to do it. We could travel 10,000 years into the future and age only 1 year during that journey. However, such a trip would consume an extraordinary amount of energy. Time travel to the past is more difficult. We do not understand the science as well.

Actually, scientists and engineers who plan and operate some space missions must account for the time distortions that occur because of both General and Special Relativity. These effects are far too small to matter in most human terms or even over a human lifetime. However, very tiny fractions of a second do matter for the precise work necessary to fly spacecraft throughout the solar system.

Have Aliens Left The Universe?

Recently, renowned scientist Stephen Hawking stated that he too believes aliens exist: “To my mathematical brain, the numbers alone make thinking about aliens perfectly rational.”

Hawking thinks we should be cautious about interacting with aliens — that they might raid Earth’s resources, take our ores, and then move on like pirates. “I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach.”

But where are they all anyhow?

For years, NASA and others have been searching for extraterrestrial intelligence. The universe is 13.7 billion years old and contains some 10 billion trillion stars. Surely, in this lapse of suns, advanced life would have evolved if it were possible. Yet despite half a century of scanning the sky, astronomers have failed to find any evidence of life or to pick up any of the interstellar radio signals that our great antennas should be able to easily detect.

Some scientists point to the “Fermi Paradox,” noting that extraterrestrials should have had plenty of time to colonize the entire galaxy but that perhaps they’ve blown themselves up. It’s conceivable the problem is more fundamental and that the answer has to do with the evolutionary course of life itself.

Look at the plants in your backyard. What are they but a stem with roots and leaves bringing nutriments to the organism? After billions of years of evolution, it was inevitable life would acquire the ability to locomote, to hunt and see, to protect itself from competitors. Observe the ants in the woodpile — they can engage in combat just as resolutely as humans. Our guns and ICBM are merely the mandibles of a cleverer ant. The effort for self-preservation is vague and varied. But when we’ve overcome our struggles, what do we do next? Build taller and more splendid houses?

What happens after life completes its transition to perfection? Perhaps across space, more advanced intelligences have taken the next evolutionary step. Perhaps they’ve evolved beyond the three dimensions we vertebrates know. A new theory — Biocentrism — tells us that space and time aren’t physical matrices, but simply tools our mind uses to put everything together. These algorithms are the key to consciousness, and why space and time — indeed the properties of matter itself — are relative to the observer. More advanced civilizations would surely understand these algorithms well enough to create realities that we can’t even imagine, and to have expanded beyond our corporeal cage.

Like breathing, we take for granted how our mind puts everything together. I can recall a dream I had of a flying saucer landing in Times Square. It was so real it took awhile to convince myself that it was a dream (that I was actually at home in bed). I was standing in a crowd surrounded by skyscrapers when a massive spaceship appeared overhead. Everyone started running. My mind had somehow generated this spatio-temporal experience out of electrochemical information. I could feel the vibrations under my feet as the ship started to land, merging this 3D world with my inner thoughts and sensations.

Although I was in bed with my eyes closed, I was able to run and move my arms and fingers. My mind had created a fully functioning body and placed it in a virtual world (replete with clouds in the sky and the Sun) that was indistinguishable from the one I’m in right now. Life as we know it is defined by this spatial-temporal logic, which traps us in the universe of up and down. But like my dream, quantum theory confirms that the properties of particles in the “real” world are also observer-determined.

Other information systems surely exist that correspond to other physical realities, universes based on logic completely different from ours and not based on space and time as we know it. In fact, the simplest invertebrates may only experience existence in one dimension of space. Evolutionary biology suggests life has progressed from a one dimensional reality, to two dimensions to three dimensions, and there’s no scientific reason to think that the evolution of life stops there.

Advanced civilizations would certainly have changed the algorithms so that instead of being trapped in the linear dimensions we find ourselves in, their consciousness moves through the multiverse and beyond. Why would Aliens build massive ships and spend thousands of years to colonize planetary systems (most of which are probably useless and barren), when they could simply tinker with the algorithms and get whatever they want?

Life on Earth is just beginning to send its shoots upward into the heavens. We’ve even flung a piece of metal outside the solar system. Affixed to the spacecraft is a record with greetings in 60 languages. One can’t but wonder whether some civilization more advanced than ours will come upon it. Or will it just drift across the gulf of space? To me the answer is clear. But in case I’m wrong, I have a pitch fork guarding the ore in my backyard.

Why do galaxies rotate?

There are two levels I can use to explain this. First, I’ll use a more Newtonian model of the universe, as it is the simplest way of explaining it.

In a Newtonian universe the answer is pretty simple. To start with, anything that wasn’t orbiting around the super-massive black hole located in the center of the galaxy would simply fall in a straight line to the black hole. The reason why is the exact same reason why if you drop a pencil it will fall in a straight line to the Earth, which is likely the most dominant gravitational force nearby.

By contrast anything that is orbiting the black hole has what is called centrifugal force. Centrifugal force is why if you hold a weight and swing your arm in a circle the weight feels like it is pulling on your hand even when it is upside down. There is of course a very long and perfectly well reasoned explanation for why centrifugal force appears to disregard gravity, but that’s a post for another time.

To go back to galaxy, all of the objects that are orbiting the galaxy have centrifugal force. That force is constantly pushing on them in the opposite direction as the gravity of the black hole, thus allowing a stable or semi-stable orbit.

Now Isaac Newton was a brilliant man and all, but he still spent most of his life in the seventeenth century. Since we are all in the twenty-first century, things have gotten a good bit more complex. This will get kind of technical, so read at your own risk.

Albert Einstein was the first physicist to suggest that space-time could be non-uniform in density. He basically took Minkowski’s idea of space-time and added the (very important) concept of non-uniformity. What that means is that if you have on cubic meter of empty space (a complete vacuum), it is possible for half of it to be denser than the other half. This probably doesn’t make much sense. It isn’t that the other half has more “space” in it, because it is still half a cubic meter. It doesn’t have more “nothing” either, because a vacuum is a vacuum, that’s about as empty as it gets (though how empty a vacuum is highly debatable. But that is a post for another time). The best way to explain it is with the analogy of a graph. It would be like if you taped to half pages of graph paper together, where one half has four squares to an inch and the other half has five squares to an inch. You still have one sheet of graph paper, but half of it is denser.

If that didn’t make much sense to you, it only gets worse. Because using Einstein’s understanding of the universe, the objects in a galaxy don’t orbit. For that matter, the Earth also does not orbit. The reason why is simple: An orbit is a circle. According to Einstein, gravity only causes objects to travel in straight lines. Never circles or arches. This is probably contrary to everything you know about how anything from a solar system to a galaxy works. But fear not, for an explanation is ahead.

The concept of non-uniform density in space is the reason why something can look like it is traveling in a circle (like the Earth orbiting the sun) but really be traveling in a straight line.

Gravity, according to Einstein, doesn’t really pull on objects in the same way that Isaac Newton believed. Instead, the gravitational field condenses space itself. The stronger the gravity, the denser the space. Newton discovered this equation to calculate the gravitation force between two objects:

F = (G)(m1)(m2)/r^2

Where F is the gravitational force, m is the mass of the two objects in question, G is Newton’s constant, and r is the distance between the two objects. This explains why gravity has a much lesser effect over larger distances. Due to this, the closer you get to an object, the more its gravity condenses space.

Before I tie all of these concepts together I have one more thing to bring up: circles. Everybody loves them. One very important thing about circles is that the circumference of the innermost edge of the circle will always be less than the outermost edge. Now lets imagine we had a sharpie with a tip as big around as the diameter of the Earth. Now that’s a sharpie. If you use that sharpie to draw a circle, the innermost edge of that circle will be WAY smaller than the outermost edge. Therefore when the planet Earth is orbiting the sun, the innermost part of it is traveling less distance. Except for the fact that the innermost part is considerably closer to the sun, and therefore that space is denser. So it looks like it is traveling less distance, but because of how the sun is deforming and condensing space, the innermost part of the Earth and the outermost part of the Earth are traveling the same equivalent distance. Since both sides are traveling the same distance, the Earth isn’t moving in a circle at all, but instead a straight line. The illusion of circular movement is caused by our own inability to properly perceive space, but the math is pretty clear, and Relativity is fairly bulletproof.

References:

Leonard Susskind
Albert Einstein
Isaac Newton

Picture courtesy of criticalmass.uk.com

What’s the Hottest the Earth Has Ever Gotten?

Hot enough to boil oceans and vaporize rock. The highest terrestrial temperatures occurred more than four billion years ago, when a Mars-size proto-planet smashed into the Earth. (The debris from this collision formed our moon.) Within a millennium, the surface air temperature had dropped from a high of about 3,700°F down to 3,000°. Then the planet went into a period of slower cooling that lasted a few tens of millions of years. As the atmosphere thickened with heat-trapping water clouds and carbon dioxide and a shell of solid rock formed around the Earth’s core, conditions stabilized at 440°.
The warmest weather we’ve had in recent times—since mammals diverged from the tree of life—came about 55 million years ago, during a period known as the Paleocene-Eocene Thermal Maximum. In just a few thousand years, global surface temperatures increased by 5° to 10°, with parts of North America experiencing a tropical climate and spring-like average temperatures in the Arctic.
Have a burning science question you'd like to see answered in our FYI section? Email it to fyi@popsci.com.

NASA Successfully Tests its Inflatable Heat Shield in Reentry

IRVE-3 During Vacuum Testing at NASA's Langley Research Center NASA Langley/Kathy Barnstorff

NASA’s inflatable heat shield took another big step forward early this morning when its Inflatable Reentry Vehicle Experiment (IRVE-3) came screaming through the atmosphere and splashed down in the Atlantic after spending 15 minutes undergoing the intense heat and pressure of atmospheric reentry. Launched from Wallops Flight Facility in Virginia, the IRVE-3 mission further demonstrated that an inflatable heat shield can protect a space capsule as it enters the atmosphere at hypersonic speeds.
IRVE-3 consists of a series of un-inflated rings packed into a cone and wrapped in layers of heat resistant materials, creating a kind of thermal blanket around an incoming spacecraft. At 7:01 a.m. local time this morning, this package was hurled skyward aboard a Black Brant rocket to suborbital altitudes at speeds reaching 7,600 miles per hour. About six minutes in, the 680-pound aeroshell separated from the rocket at about 280 miles up.

At this point, IRVE-3 rapidly pumped nitrogen into its aeroshell, expanding it from a conical package that fit inside the Black Brant’s 22-inch-diameter nose cone into a 10-foot-diameter mushroom-like heat shield. Onboard cameras and sensors captured the entire 20-minute mission in realtime--a mission that NASA is calling an unqualified success. IRVE-3 is part of NASA’s Hypersonic Inflatable Aerodynamic Decelerator (HIAD) Project, which aims to provide the agency with a less-expensive and modular means to return space capsules--those carrying cargo from the International Space Station, for instance--to Earth safely despite the high forces and temperatures that act on them during reentry. Doing so could make travel to and from earth orbit far more economical while also providing a tested and certified platform that could be readily adapted to various spacecraft to ensure safe reentry.
[NASA]

By Linking Telescopes, Astronomers Make the Sharpest-Ever Observation of a Distant Object

Two million times sharper than human vision

Quasar 3C 279 (Artist's Impression) ESO/M. Kornmesser

By tying together the observational power of three radio telescopes, astronomers have made the sharpest observation of a distant galaxy, some two million times sharper than human vision. That’s big news in an of itself, but it’s even bigger news for astronomers pursuing next-level Very Long Baseline Interferometry (VLBI). The observation demonstrates a kind of telescopic collaboration that’s never been seen before, hinting at the future of astronomical observation.

VLBI is a means of linking telescopes together in a way that basically creates a single huge telescope as large as the distance between the telescopes (there’s a good primer on VLBI in our previous coverage of the Event Horizon Telescope, which aims to use VLBI to create a virtual telescope the size of planet Earth). Doing so requires a lot of technological backbone--atomic clocks to sync up the observations at geographically disparate telescopes, high rates of data transfer, computational capacity to process large loads of data streaming in from various sources around the globe--and this most recent observation shows just how far the astronomical community has come on this front. The galaxy 3C 279 (astronomers actually classify it as a quasar because it shines extremely brightly as material falls into its supermassive black hole) in the constellation Virgo is 5 billion light-years from Earth, yet astronomers were able to resolve details down to 1 light-year or less. The observations were made at a wavelength of 1.3 millimeters, the shortest wavelengths ever used to image at such long baselines.

VLBI in Action:  ESO/L. Calçada

And the baselines were very long. The observations connected the Atacama Pathfinder Experiment (APEX) in Chile, the Submillimeter Array in Hawaii, and the Submillimeter Telescope in Arizona, putting thousands of miles between each of the three telescopes. It marks the first time APEX has been used for VLBI observations and required the installation of new data systems and an atomic clock by the European Southern Observatory.

That’s important for a further reason. APEX shares both its geographic home and a lot of its technology with ALMA, the Atacama Large Millimeter/submillimeter Array, a huge new 66-antenna radio telescope that is still under construction and that when complete will multiply the observational potential of global VLBI by an order of magnitude. Astronomers intend to use ALMA and other telescopes around the world to image all kinds of cosmic features in unprecedented detail, including the black hole at the center of our own galaxy. That’s why the observation of 3C 279 is such a big deal: while record-setting in its own right, it’s just the beginning of what’s possible.

http://youtu.be/0dwkKzs5nn4

Astronomers Spot Ancient Spiral Galaxy From an Era When Spirals Should Not Exist

Earliest Spiral Galaxy An artist’s rendering shows galaxy BX442 and its companion dwarf galaxy, upper left. Dunlap Institute for Astronomy & Astrophysics/Joe Bergeron

Astronomers using the Hubble Space Telescope have stumbled on a rare and surprising find: A very distant spiral galaxy, swirling billions of light years away, which formed at a time when such spiral galaxies were thought to be nonexistent. Researchers say it’s an astounding discovery — partly because it raises some questions about prevailing theories of galaxy formation.
Understanding galaxy evolution is a central part of determining the early history and future fate of the universe. Astronomers want to understand the physics that trigger vast amounts of stars to clump into galaxies, and that cause those galaxies to organize into clusters. The distant relics of early galaxies has helped solidify some of these theories, but this galaxy, known as BX442, is strange.

Most ancient galaxies — meaning very far away galaxies whose light left them billions of years ago, in the early days of the universe — are clumpy, irregular globs, not beautiful symmetric spirals or ellipses. This is because they moved around too quickly, which favors the formation of blob-like structures instead. “The vast majority of old galaxies look like train wrecks,” Alice Shapley, a UCLA associate professor of physics and astronomy, and co-author of the new study, said in a statement. “Our first thought was, why is this one so different, and so beautiful?”
Shapley and colleagues spotted it while conducting a Hubble survey of about 300 very distant galaxies. Intrigued, they went to the W.M. Keck Observatory and checked it out with a special spectrograph. The instrument allowed them to look at thousands of locations in and around the galaxy, confirming that it is indeed a self-contained rotating spiral.
This was a key observation, because other putative early spirals could be a trick of the lens, and may be actually more than one galaxy merging together or something that just happened to line up from our point of view. “What we found when we took the spectral image of this galaxy is that the spiral arms do belong to this galaxy,” Shapley said. “It wasn't an illusion. We were blown away.”
Why so surprised? After all, these “grand design” spiral galaxies are common in our cosmic neighborhood — the Milky Way is one, and so is Andromeda. The answer is that earlier galaxies almost universally have different structures, making this one an anomaly. Of the 306 galaxies in the Hubble survey, each of them around the same distance away, this is the only one with a spiral structure.
It is very large and thick, which may have something to do with the spiral formation. Or it could be the result of a collision with another system, which is at the upper left in the image at the top of the page. That might explain how this galaxy formed: You just need the right recipe, and it needs to be spotted at exactly the right moment.
“Not only must a galaxy be sufficiently massive to have stabilized the formation of an extended disk, but this disk must then be perturbed by a merging satellite sufficiently massive and properly oriented to excite an observable grand-design spiral pattern,” Shapley and her co-authors write.
A paper describing the new find appears this week in Nature

The Next Generation of Mars Rovers Could Be Smaller Than Grains of Sand

Nanobots on Mars Sand-size robots that travel on the wind. Murray Robertson/Nanovisions/John Baker

NASA’s Mars rover Curiosity, scheduled to reach the red planet this Sunday, is the size of an SUV for good reason: It’s built to carry 165 pounds of scientific instruments over boulders and into gullies. But putting Hummer-size robots on other planets is not altogether practical. For one, it’s expensive. (Getting a Curiosity-weight rover to Mars takes more than a million pounds of fuel.) Large rovers are also power-hungry and limited in range. For future missions, some researchers, eager to do more science with fewer resources, have begun looking to nanobots—each one about one-one-billionth as big as Curiosity.
The first nanobots to reach Mars could arrive as a cloud of “smart dust”—sand-grain-size robots that travel like a sand storm, using the Martian wind for propulsion. An orbiting spacecraft would drop a capsule of the dust motes onto the planet. From there, they would take advantage of Mars’s low gravity (38 percent of Earth’s) to ride the thin Martian winds. John Barker, a physicist at the University of Glasgow, says that according to his computer simulations, one release of 30,000 robots could cover thousands of square miles. Each robot would contain a nanoprocessor, an antenna for communicating with neighboring motes, a sensor for collecting data and an electrode-controlled shape-shifting polymer shell. Once on the ground, the motes would decide which would change from a smooth exterior to a dimpled silhouette that creates drag to help them catch the wind and travel. The motes would use their sensors to collect data about Mars’s air currents and chemical composition and then communicate this information to the orbiter, which would relay that data back to Earth. The project might sound impossibly complex, but shape-shifting polymers already exist in the lab, and Barker has started testing the most challenging part of the concept—the communications array—with centimeter-size prototypes.

Red Rovers: Tiny walking robots could gather information about Mars and other planets.  Courtesy NASA

One engineer is working on what amounts to a nanobot Mars base, which would protect the ‘bots from cosmic radiation.For more complex and directed missions, such as digging under Mars’s surface and collecting samples, robots will have to move autonomously and under their own power. Researchers at NASA’s ANTS (Autonomous Nanotechnological Swarm) program have been developing concepts for tiny robots, called TETwalkers, capable of doing just that. Each TETwalker would be a tetrahedron of carbon-nanotube struts connected by joints. Each individual robot could move by lengthening or shortening its struts, thereby shifting its center of gravity until it tumbles in the desired direction. Together, tens of thousands of nanoscale TETwalkers could connect together to form devices such as rovers and antennas, which could travel the planet in search of signs of life and water. So far, engineers have built a two-foot-high proof-of-concept that moves in response to human commands. To shrink this prototype to nanoscale, scientists need advanced nanotubes that can both move themselves and rearrange themselves to form different kinds of materials. Program head Steve Curtis says that depending on the speed of nanotech development and funding levels, TETwalkers could land on Mars within the next 30 to 40 years.
Without shelter, any Mars-dwelling robot will eventually succumb to the planet’s intense cosmic radiation and extreme weather. To enable nanobots to carry out long-term missions, Constantinos Mavroidis, an engineer at Northeastern University, is working on a theoretical plan for what amounts to a nanobot Mars base. Mavroidis calls this miles-long spiderweb of nanotube tunnels the Networked TerraXplorer concept. An orbiter would drop the TerraXplorer, preloaded with nanobots, onto the Martian surface. Once in place, the protected nanobots could make long-term measurements of the planet’s weather and any seismic activity.

The Scale:  MedicalRF.com/Getty Images; Inset: Courtesy Victor Habbick Visions/Science Photo Library/Corbis

Although Mars is likely the first planetary destination for nanobots, scientists could eventually send them to places much more distant and extreme. Researchers at NASA’s Jet Propulsion Laboratory are developing carbon nano­tubes that can survive Venus’s 900°F surface. Others are studying ways to move nanobots through interstellar space. No matter what, in the decades ahead, some of the most stunning revelations about space could come from robots smaller than a toy car.
Courtesy:www.popsci.com

India Will Launch Probe to Mars Next Year

India's PSLV-C12 India's space program successfully launched the PSLV-C12 satellite in 2009. EPA/ISRO/HO

While we in the U.S. wait with bated breath for Mars Rover Curiosity's August 5 landing on the red planet, India's space program, the Indian Space Research Organisation, has confirmed that it plans to send an orbiter to Mars in 2013. It's one small step in a program that's been making giant leaps in recent years, including multiple satellite launch missions.
The total price tag for the project could wind up between $70 and $90 million, a source told AFP, which would go toward a 320-ton rocket carrying the orbiter. Once in place, it would study the planet's climate and geology. That would already be a pretty big success for the program, but the ISRO is trying to go even further, planning to launch a fully manned mission by 2016.
India's space program has been in place since the '60s, but it's in more recent years that its gained notoriety. In 2009, the country successfully launched seven satellites on a single rocket and it has been providing a cost efficient means of transporting satellites into space, but it was the Chandrayaan-1 lunar probe that brought the program global attention. Officials took criticism for spending on the space program, which intensified when the ISRO lunar probe lost radio contact with the probe after ten months. But Chandrayaan-1 was deemed a major success when it discovered water and a protective magnetic field on the moon.
Of course, a mission to Mars is a whole new beast, and they'll be up against a lot of rough history when it launches.
[AFP]

NASA Invests $1.1 Billion in Manned Commercial Trips to Space

SpaceX, Boeing, and Sierra Nevada chosen to take Americans into orbit

SpaceX Falcon 9 Rocket SpaceX

The dust has settled on the final round of NASA's Commercial Crew integrated Capability program project, and three winners have been given funding for the next round of American-made space taxis: Boeing, who received $460 million; SpaceX with $440 million; and the Sierra Nevada Corporation, with a paltry $212.5. The companies will use it as seed money to create commercial spacecraft that U.S. astronauts will fly aboard.
With NASA's space shuttle program shelved, it's had to compensate for all of the spacecraft it won't be making itself, instead investing in companies that have shown promise in creating commercially viable, safe spacecraft. Once those companies have created one, NASA can put their astronauts on board (maybe even alongside civilian space tourists).
In May, SpaceX made news by launching a privately built craft to the international space station. Boeing has developed a low-Earth orbit space capsule. Sierra Nevada has a somewhat similar Dream Chaser spaceplane project.
Between now and the end of May 2014, the companies will continue working on their spacecraft designs, and if they reach the milestones set by NASA, crewed missions will be underway soon after.
[NASA]

5 Alien Planets That We Could Call Home

The controversial exoplanet Gliese 581g is the best candidate to host life beyond our own solar system, according to a new ranking of potentially habitable alien worlds.
Gliese 581g shot to the top of the list — which researchers at the University of Puerto Rico at Arecibo’s Planetary Habitability Laboratory (PHL) published last week — after a new study marshaled support for its long-debated existence.
The exoplanet was discovered in September 2010, but other astronomers began casting doubt on its existence just weeks later. Now Gliese 581g’s discoverers have rebutted their critics’ charges in a new paper, and have done so effectively enough to get the PHL onboard.
Here’s a brief rundown of the PHL’s top five habitable alien planets:

1. Gliese 581g

This rocky world — if it does indeed exist — is just 20 light-years away from our solar system. It’s likely two to three times as massive as Earth and zips around its parent star, the red dwarf Gliese 581, every 30 days or so. [Gallery: The Strangest Alien Planets]
This orbit places the planet squarely in the star’s “habitable zone” — that just-right range of distances where liquid water, and perhaps life as we know it, could exist.
Gliese 581g has at least four, and possibly five, planetary neighbors. The team that spotted Gliese 581g also detected another planet, known as 581f, circling much farther away from the star. But scientists are still arguing about that world’s existence, too.

2. Gliese 667Cc

The same core team that spotted Gliese 581g discovered Gliese 667Cc in February 2011. The planet orbits a red dwarf 22 light-years away, in the constellation Scorpius (The Scorpion).
The alien world is a so-called “super Earth” that’s at least 4.5 times as massive as our planet, and it completes an orbit every 28 days. At least one other planet resides in the 667C system.
Gliese 667Cc’s parent star is part of a triple-star system, so the planet’s night sky would probably be a sight to behold.

3. Kepler-22b

NASA’s planet-hunting Kepler space telescope spotted Kepler-22b. The telescope has detected more than 2,300 potential exoplanets since its March 2009 launch. Only a small number have been confirmed so far, but the vast majority should end up being the real deal, according to researchers.
Kepler-22b, whose discovery was announced in December 2011, is a super Earth about 2.4 times as wide as our planet. If the greenhouse effect operates on Kepler-22b like it does on Earth, the alien world would have an average surface temperature of 72 degrees Fahrenheit, researchers say.
The exoplanet is about 600 light-years away, and it orbits a star very much like our own sun.

4. HD 85512b

HD 85512b is another super Earth — one that’s thought to be about 3.6 times as massive as our planet. The alien world is located about 35 light-years from us, in the direction of the constellation Vela (The Sail).
Astronomers announced the discovery of HD 85512b — and about 50 other alien planets spotted by the HARPS spectrograph on a telescope in Chile — in September 2011. The planet’s estimated average surface temperature is 77 degrees Fahrenheit.

5. Gliese 581d

This world, which is about seven times as massive as Earth, orbits a bit farther out than its planetary sibling Gliese 581g.
When 581d was first discovered in 2007, many scientists regarded it as too cold to be potentially habitable. In the years since, however, atmospheric-modeling studies have suggested that the planet may indeed be able to support life as we know it — provided a greenhouse effect warms 581d.
To determine if this is the case, researchers will likely need to directly study the planet’s atmosphere. That sort of work could be years off, since it would probably require the development of new and advanced telescopes.
Image courtesy of Flickr, NASAblueshift

Mars...

Manned mission to Mars: The state of readiness of nations and organizations that have long-term intentions to send humans to Mars.

• The US does not have a launcher capable of sending humans to Mars, although the Orion spacecraft, currentl

y under development by NASA, could ferry astronauts from the surface of Earth to join a Mars-bound expedition in Earth orbit and then back to Earth's surface once the expedition has returned from Mars.

• The European Space Agency has sent robotic probes, and has long-term plans to send humans but has not yet built a human-capable launcher. There is a proposal to convert ESA's existing Automated Transfer Vehicle (ATV) for crewed launches.

• Russia can send humans into Earth-Orbit and has extensive experience with long-term manned orbital space flight due to its space station programs. A simulation of a manned Mars mission, called Mars-500, was completed in Russia in November 2011.

• Japan has sent one robotic mission to Mars, the Nozomi (のぞみ).

• China's mission to Mars, the Yinghuo-1 space probe, was lost with Russia's sample return mission to Phobos, Fobos-Grunt.

• India plans to launch an unmanned mission to Mars.

Alcohol IN SPACE

Astronomers discovered a cloud of alcohol called The Sagittarius B2 in part of 

the Milky Way where stars are forming from gas and dust. The good news: the 

 alcohol cloud is 463 billion kilometers (about 288 miles) across. The bad news: 

the cloud is made of methyl alcohol, the undrinkable cousin of ethyl alcohol 

(drinking alcohol). 
 
This discovery challenges the old conventional view that complex organic 

molecules, like alcohol, couldn't exist in the middle of space. It's possible that 

molecules like the ones found in this cloud helped create life on Earth.

THINGS YOU MIGHT NOT HAVE KNOWN ABOUT HUBBLE

This flying cosmic telescope completes one orbit around the Earth every 96 minutes. Its speed is approximately five miles per second.

Believe it or not, but a solid gold pin is attached to the floating space observatory. Some estimates of Hubble's total cost (including construction, deployment, servicing, and continued operation) reach as high as $10 billion -- and you can chalk some of that up to a gold pin strapped to the spacecraft. Hubble's gold ornament was used to help anchor the telescope in the space shuttle's cargo bay for its April 1990 launch. 

The farthest objects Hubble has seen? Galaxies forming when the universe, which formed about 13.7 billion years ago, was about 700 million years old. With a new camera and other major upgrades planned for Hubble's final servicing mission, astronomers hope to push that clock back to about 500 million years old. *Note : I'll post the pic in next post.*

Hubble was temporarily knocked out of commission in 1999, preventing its capture of any breath-taking images for more than a month. The intermittent shutdown went into effect when four out of six of its gyroscopes failed, leaving the observatory without an accurate pointing system.

When NASA launched the Hubble Space Telescope in April 1990, they soon discovered it beamed back only blurry images. Why? It's massive 48-square-foot mirror was flawed. The telescope was restored to its intended quality by a servicing mission in 1993.

Hundreds of tools have been developed by NASA over the years for spacewalking astronauts to work on Hubble. Among the devices debuting during the final servicing call: the deceptively named Mini Power Tool. This mini power tool was specially designed to fit into tight corners.

Putting a 24,500-pound telescope into space isn't cheap, especially, when it needs the occasional repair. According to all-inclusive estimates, NASA has spent around $10 billion to build, launch, operate and service the telescope over the past 22 years.

The first color picture from Hubble, released in August 1990, was actually a hand-colored black-and-white digital photograph. Although the tints did correspond to true emissions of the ring around Supernova 1987A, Hubble actually didn't have a multi-color filter pointed at the target.

The Hubble Space Telescope has won two Space Achievement Awards from the Space Foundation for its outreach activities, in 2001 and 2010.

There is a replica of the Hubble Telescope on the courthouse lawn in Marshfield, Missouri, the hometown of namesake Edwin P. Hubble.

The telescope is now expected to function until at least 2014. Its scientific successor, the James Webb Space Telescope (JWST), is to be launched in 2018 or possibly later.

Black Hole Unleashes Extraordinarily Bright X-Ray Burst

A NASA space telescope has detected an incredible energy burst from a distant black hole, an explosion so intense that it boosted the black hole's X-ray brightness by at least 3,000 times, scientists say.

The outburst came from a black hole in the spiral galaxy M83, about 15 million light-years away from Earth. Using NASA's Chandra X-ray Observatory, astronomers found a new object, called an ultraluminous X-ray source (ULX), that emits more X-rays than most "normal" systems in which a companion star orbits around a black hole or neutron star, the researchers said.

The observations from Chandra spanned several years, and scientists noticed that the ULX in M83 increased its X-ray brightness by at least 3,000 times.

This surprisingly sudden brightening is one of the largest changes in X-rays ever seen for this type of object, according to the researchers. In fact, ultraluminous X-ray sources do not typically have periods of dormancy.

About the Image : At left is an optical view of M83. At right is a composite image showing X-ray data from Chandra in pink and optical data from the Hubble Space Telescope in blue and yellow. The ULX is located near the bottom of the composite image.