Many of the leading surveys now coming online are based in the southern hemisphere, where celestial cartographers can expect to make the greatest impact. In the north, the granddaddy of all astronomical surveys—the Sloan Digital Sky Survey in New Mexico—has reigned for more than a decade and has already carefully mapped more than one million galaxies in three dimensions, in addition to many other accomplishments.
Among the new crop of southern surveys is a project at the European Southern Observatory’s VISTA telescope in Chile, which is already carrying out a broad infrared survey to complement the more targeted Dark Energy Survey. And the SkyMapper project in Australia plans to chart the entire southern sky in optical light. The SkyMapper telescope should detect roughly one billion stars and one billion galaxies, according to Stefan Keller of the Australian National University, one of the project’s lead scientists.
But the telescope most likely to rewrite the books on the southern sky is the Large Synoptic Survey Telescope, or LSST, in Chile. When it comes online around 2022, the LSST—as currently envisioned—will feature an 8.4-meter mirror (compared to the Sloan survey’s 2.5-meter telescope) and a three-gigapixel digital camera. The mammoth telescope will image the heavens every week to capture transient phenomena such as supernovae and close passages of potentially dangerous asteroids. In the process, it will also mark the three-dimensional location of some four billion galaxies.
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Add CommentNow we need a computer program which can display it all in 3D, then virtual travel computer programs and games.
Reply | Report Abuse | Link to thisI look forward to seeing more on this.
When we observe from earth we infer from red shift that distant galaxies are accelerating away from us .we further infer that they are our past,ergo, we are their futurethere by concluding that the so-postulated big bang occurred somewhere at the middle of the distance between us two. We also observe that as we come nearer to us the red shift indicates slower rates of "expansion".As we reach very nearby distances we observe that there is little or no increase in the distances happening.From symmetry we conclude that from any other point in the universe also their observations will give them same results .There could be many possible explanations for this.But the simplest one that would mesh with the majority of other explanations is the conclusion that the universe is expanding at an accelerating pace like a balloon and all material galaxies are on the surface of the balloon. Since gravity is the effect of space time distortions this "acceleration-effects" could be ascribed to the ironing out of the creases of space-time fabric due to stretching out of the fabric of the balloon thereby freeing galaxies from the attractions of gravity that kept the galaxies together . The effect of this freeing up would be little as nearby galaxies tend to move more uniformly together even to the point of ultimate shredding of the fabric into smaller pieces later just like two nearby ink-dots may still remain close together in the pieces of a burst balloon.Universe inherently having holographic fractal properties ,ultimately the fabric of space time in which those smaller fragments of matter exists would also "expand" into quarks or whatever smallest entities it can disintegrate into to attain superficial stability as there is no deep stability existing in the universe which would merge with the ever vibrant quantum vacuum energy or the ultimate information pool of an all pervasive cosmic awareness to burst forth again owing to spontaneous random energy fluctuations of the quantum vacuum
Reply | Report Abuse | Link to thisHurrah ! we have got rid of the mysterious "dark forces" or dark "energy' or dark matter " or "dark anything" by holding on to the analogy of a balloon! The universe will ultimately become smithereens of super-strings or atto-particles or just vibrations of energies whatever and merge back with the ever vibrating vacuum energy to pop up again into foams and bubbles of multi-verses.
Dadster said "We also observe that as we come nearer to us the red shift indicates slower rates of "expansion".As we reach very nearby distances we observe that there is little or no increase in the distances happening." and ".But the simplest one that would mesh with the majority of other explanations is the conclusion that the universe is expanding at an accelerating pace"
Reply | Report Abuse | Link to thisBut since closer to the observer also means closer in time, it would seem that the best explanation is that expansion is continuing to slow.
Example: Objects 13 bly away were moving fast at the observed time, which is 13 billion years in the past.
Objects which are observed at 13 mly away are moving apart much slower, at the observed time of 13 million years in the past.
Objects in our local group do not appear to be moving apart at all in the recent observation times.
Therefore: The farther back in the past we look, the faster objects are moving apart, and conversely, the closer in the past we look, the slower they are moving.
To Dadster and Postman
Reply | Report Abuse | Link to thisBig Bang creation of Universe, age of universe and some other phenomenon of BB cosmology are all predicted phenomenon dependent upon backward extrapolation of expansion of Space. Dark energy is a devised entity to explain accelerated expansion of space Expansion of space has remained the core phenomenon behind the cosmology of past 80 years. Not even a single cubic inch of space expansion has ever been measured directly. Whatever predictions have been made about expansion of space are based upon red shift of light emitted from remote galaxies located billion of light years away. This light after traversing for billion of years thru an unknown territory spanning billion of light years enters the telescope of researcher and based upon this predictions about expansion of universe ( space?) are made. We can not fathom by any stretch of imagination distance and time in the range of billion of light years and billion years. We can not ascertain the changing conditions of universe and the status of physical laws during the past billion of years.
In view of above, what is the reliability of expansion of space predicted upon red shift only?
Further what is the meaning of expansion of space when we don not know about the nature of space in terms of its physicality ? It has become fashionable in the cosmology lexicon to use the term "fabric of space-time" but of what constituents space is composed of? There are host of unresolved issues regarding expansion of space :
i) What is that which really expands when we say space is expanding?
ii) At the time of BB, all matter and energy emerged out in one go but space is continuously emerging out. From where that additional space emerges out?
iii) Relativity theories assign nil physicality to space. Why some expansion force or dark energy, having some physicality status, should be required for expansion of an entity having NIL physicality.
I think before going into issues of increasing or decreasing expansion of space, it will be more prudent to address more basic issues about space.
Nicely put!
Reply | Report Abuse | Link to thisWell We don't have exactly that yet, but if you want to get a feel for what a program like that would be like, check out http://en.spaceengine.org/
Reply | Report Abuse | Link to thisIt's a great program using real data combined with procedural generation of everything else. Very fun!
How do they measure the distance to objects within the galaxy? Is it some sort of parallax from images taken at different times during the year? I would think that redshift would be nonexistent or negligible for these objects.
Reply | Report Abuse | Link to thisRed shift has been observed for galaxies located at distance of more than 300 mparsec i.e. approx. 1 billion light years away from earth
Reply | Report Abuse | Link to thisAs I understand, within our own galaxy red and blue shifts are detected as galactic objects are generally rotating - some moving towards us, others away from us. In addition, local motions relative to our observations, such as the orbital motions of binary stars, and stars and gasses separating in stellar nurseries also produce their own potentially detectable spectral shifts.
Reply | Report Abuse | Link to thisHowever, these large scale galactic surveys are focusing on the cosmological redshift imparted to light from distant galaxies, generally understood to be produced by the universal expansion of spacetime. While locally galaxies within clusters, for example, may be moving within the cluster, sometime towards the observer, no such local motions can produce blue shifts more significant that the inherent cosmological redshift, which overwhelmingly increases with distance. I hope this helps.
As to distance measurements, many methods must be used for different conditions - parallax is only effective for relatively proximal objects. Please see
http://en.wikipedia.org/wiki/Cosmological_distances
When the red shift was first noticed and before the Big Bang theory was fully accepted (as the only explanation for the expanding universe), Fred Hoyle proposed an alternate explanation for the expansion
Reply | Report Abuse | Link to thiscalled, 'continuous creation'. I still find this theory plausible. Hoyle proposed that hydrogen atoms were being spontaniously created througout space causing the expansion. With quantum particles popping in and out of existance why not a surplus? Why not also question dark energy as the only explanation for the observation that universal expansion is accelerating?
Fred Hoyle may have been wrong and I am probably wrong in my explanation for the accelerating expansion but I would like to know why I am wrong.
Time slows in proportion to the strength of nearby gravity fields. We even have to adjust for this effect in coordinating with our orbiting sattelites. At the instant of the Big Bang the entire mass of the universe was concentrated in a singularity, mega gravity, and time was at a near zero rate. As the matter of the universe disbursed (expanded) universal gravity also disbused and time, as an observable rate accelerated. With this in mind, time is a variable, starting at zero and accelerating to our current measure. If we are looking into the past when we look at distant objects we are also looking at rates of time slower than our present measure and the rate of expansion of the universe would appear to be accelerating when in fact it could be stable or even decelerating.
This same 'time' paradox hides itself in any equation using speed either as a constant or as a variable. A measured rate of change, in position or condition, always involves time as a denominator and is dependent on an accepted pace designation by the observer. We can compare rates but never universally quantify them. Without an observer time is meaningless and dark matter and dark energy disappear. Streatch any equation far enough and its conclusions seperate from its premises. Are we doing this? Are our equtions leading us toward answers or just fantasy science? Hopefully our latest obsevational tools will keep us on track.
"At the instant of the Big Bang the entire mass of the universe was concentrated in a singularity, mega gravity, and time was at a near zero rate"
Reply | Report Abuse | Link to thisFor the time being, please forget about BB and other theories. Please examine with an open mind -- " can the entire matter mass and energy of the universe be concentrated in a single point?"
In case of a collapsing star leading to the formation of a white dwarf, neutron star and black hole, scientists talk of Pauli Exclusion Principle and electron/neutron degeneracy pressure, but at BB point, nothing is spoken of such phenomenon.
One thing more. At BB point it is postulated that all matter and energy is concentrated at point of singularity which emerges out in one go but space is postulated to emerge out continuously and continue to expand out.
Have we any satisfactory solution to the issue : From where the continuously expanding space has been emerging out since past 13.72 billion years?
"What is that which really expands when we say space is expanding?" Are you implying that there is a "property" or "attribute" of space that is the one that actually expands while the fundamental "measure" of space remains constant?
Reply | Report Abuse | Link to thisI thought that science considers space as a fundamental property of matter, an attribute that cannot be decomposed into any other constituents. Is this scientific assumption wrong?
When we talk about "Black Holes", the question arises, What Are They and why can we only identify "Mass"?
Reply | Report Abuse | Link to thisAccording to my view of physics, the answer lies in the fact of "For every action there is an opposite reaction".
These means that we cannot visually detect them because they exist in the universe where their time goes in the opposite direction to our time. Backwards? Our yesterday is their tomorrow.
Frank Pierce