In this theory there may be lots of parallel universes floating about in the larger medium (hidden higher dimensions) from which ours sprang. And another collision could occur at any time, effectively destroying our present universe and maybe creating yet another in its place.

In string theory, the universe consists of eleven dimensions: three of space, one of time, and seven others. M theory is a variation on string theory, suggesting that surfaces, or membranes (branes for short) may serve as the basic building blocks of reality, rather than vibrating strings.

If our universe primarily depends upon a five dimensional brane, then the other six dimensions will be so tiny and rolled up as to be insignificant. Some possible branes in the 5-dimensional space could take the abstract form of parallel planes of infinite length, and offer characteristics very like those of our current universe.

If this is how existence is structured, then other universes/branes may be floating through the fifth dimension, but be undetectable since matter and light cannot move through the fifth dimension. But gravity can move through the fifth dimension, and more brane collisions are always possible.

In this scenario the fifth dimension is limited in size, and originally (prior to our universe's creation) bounded on at least two sides with three-dimensional branes. Lower dimensional branes can apparently be exchanged between the three dimensional branes, across the fifth dimension. This exchange is apparently something like swapping spit in a kiss, as at least one brane is attracted by this action, and begins slowly moving toward the other, squashing the fifth dimensional space separating the two. The moment the two boundary branes touch, the fifth dimension implodes and disappears.

But immediately after the collision the two branes bounce away from one another again, and the intervening fifth dimension is reborn. The rebound (NOT the collision) also causes the Big Bang to occur in our universe.

Another aspect of this scenario is that both the branes were absolutely flat, thereby collided along every spot of their planar area simultaneously, and therefore created the flat universe we live in today.

This uniform application of force also insured that the entire universe would be uniform in how it developed afterwards.

Slight variations in the timing of impact between different areas of the two branes would be caused by quantum effects, and create the temperature difference necessary to seed galaxy generation. One after effect of the collision would be expansion such as we detect in our universe today.

The forces which attract branes to one another would be so miniscule that it could literally take an eternity for a collision to occur between any two or more branes.

-- When Branes Collide by Ron Cowen From Science News, Vol. 160, No. 12, Sept. 22, 2001, p. 184; Science Service; sciserv.org

Note that a given brane in the ekpyrotic model theory could be just like our universe today, filled with highly developed matter and energy. Or, it could contain just empty space.

In this scenario our universe would have been pretty large already at the moment of creation, rather than expanding like an explosion from a point. But it would still have been expanding from the start, and so share much in common with older theories. It's just that no special model of universal super fast inflation would be necessary to explain how it got from a point to the size it is today.

Although huge periods of time could separate brane collision events, the cycle likely does and will repeat eventually. If our universe participated in another collision, everything in it would likely be destroyed, and a whole new and different universe be created.

Of course, one implication of that is that practically all the branes floating around the fifth dimension are likely filled with matter and energy just like ours-- at least after all this cosmic machinery has operated long enough-- and so the infinity of possible universes idea from various sci fi works finds yet another way to be true. Of course, any universe that gets to last long enough will also eventually use up all its energy, and see its matter break down, until it's become a featureless black void once again.

In this theory there may be lots of parallel universes floating about in the larger medium (hidden higher dimensions) from which ours sprang. And another collision could occur at any time, effectively destroying our present universe and maybe creating yet another in its place.

In string theory, the universe consists of eleven dimensions: three of space, one of time, and seven others. M theory is a variation on string theory, suggesting that surfaces, or membranes (branes for short) may serve as the basic building blocks of reality, rather than vibrating strings.

If our universe primarily depends upon a five dimensional brane, then the other six dimensions will be so tiny and rolled up as to be insignificant. Some possible branes in the 5-dimensional space could take the abstract form of parallel planes of infinite length, and offer characteristics very like those of our current universe.

If this is how existence is structured, then other universes/branes may be floating through the fifth dimension, but be undetectable since matter and light cannot move through the fifth dimension. But gravity can move through the fifth dimension, and more brane collisions are always possible.

In this scenario the fifth dimension is limited in size, and originally (prior to our universe's creation) bounded on at least two sides with three-dimensional branes. Lower dimensional branes can apparently be exchanged between the three dimensional branes, across the fifth dimension. This exchange is apparently something like swapping spit in a kiss, as at least one brane is attracted by this action, and begins slowly moving toward the other, squashing the fifth dimensional space separating the two. The moment the two boundary branes touch, the fifth dimension implodes and disappears.

But immediately after the collision the two branes bounce away from one another again, and the intervening fifth dimension is reborn. The rebound (NOT the collision) also causes the Big Bang to occur in our universe.

Another aspect of this scenario is that both the branes were absolutely flat, thereby collided along every spot of their planar area simultaneously, and therefore created the flat universe we live in today.

This uniform application of force also insured that the entire universe would be uniform in how it developed afterwards.

Slight variations in the timing of impact between different areas of the two branes would be caused by quantum effects, and create the temperature difference necessary to seed galaxy generation. One after effect of the collision would be expansion such as we detect in our universe today.

The forces which attract branes to one another would be so miniscule that it could literally take an eternity for a collision to occur between any two or more branes.

-- When Branes Collide by Ron Cowen From Science News, Vol. 160, No. 12, Sept. 22, 2001, p. 184; Science Service; sciserv.org

Note that a given brane in the ekpyrotic model theory could be just like our universe today, filled with highly developed matter and energy. Or, it could contain just empty space.

In this scenario our universe would have been pretty large already at the moment of creation, rather than expanding like an explosion from a point. But it would still have been expanding from the start, and so share much in common with older theories. It's just that no special model of universal super fast inflation would be necessary to explain how it got from a point to the size it is today.

Although huge periods of time could separate brane collision events, the cycle likely does and will repeat eventually. If our universe participated in another collision, everything in it would likely be destroyed, and a whole new and different universe be created.

Of course, one implication of that is that practically all the branes floating around the fifth dimension are likely filled with matter and energy just like ours-- at least after all this cosmic machinery has operated long enough-- and so the infinity of possible universes idea from various sci fi works finds yet another way to be true. Of course, any universe that gets to last long enough will also eventually use up all its energy, and see its matter break down, until it's become a featureless black void once again.

-- A cosmic new theory on universe's origins By Faye Flam, April 10, 2001, INQUIRER; phillynews.com; Philadelphia Newspapers Inc.

We might get plenty of warning if another brane gets close enough in 4-D space to set off another Big Bang, and wipe out our universe. The warning would come from changes detected in the gravitational constant of our universe. If we see that, we'll know that our universe has only some billions of years left before it's utterly destroyed and made into a different image again.

-- Big bang by Govert Schilling; New Scientist Online News; 10 April 2001

Another source writing about M-theory says the two flat colliding surfaces were both four dimensional, floating in a five dimensional space.

This idea becomes more plausible as we ourselves draw ever nearer to learning the recipe too. Some of the basics seem to include creating a black hole via a highly energetic manipulation of around 10 kilograms of mass. Given a few other necessary conditions, a whole new universe will form and begin inflating inside the black hole, to possibly generate billions of galaxies and last for billions of years.

-- Findings Give Big Boost to Big-Bang Theory ["http://abcnews.go.com/sections/scitech/DailyNews/bigbang_030514_csm.html"] By Robert C. Cowen; The Christian Science Monitor, Inc/abcnews.go.com; accessible online 1-30-04

-- Universe may be younger than previously thought, researchers say By ALEX DOMINGUEZ, Nando Media/Associated Press, September 22, 1999, http://www.nandotimes.com

The minimum age of the universe appears to be 12.5 billion years, with a margin of error of 3 billion years.

One or more universal phase transitions may have occured very soon after the Big Bang. The energies created by certain of these transitions may at least partially explain the inflation rates of the early Universe, and the anti-gravity effects to be observed much later by humanity of the 20th century. Almost immediately after the Big Bang, a phase transition involving the separation of the electroweak and strong forces may have occured. Others seem to have followed. The last may have been when free quarks began forming into neutrons and protons.

-- deflating ["http://www.scitec.auckland.ac.nz/~king/Preprints/book/upd/umar99/cosinf/def.htm"], citing Curious correlation by Marcus Chown, New Sci 12 Dec 98 17, found on or about January 15, 2000

Soon after birth, the universe rippled with waves. Those waves which grew too large collapsed due to gravity over time, into dark halos. The gravity of these dark halos drew in gases present in the void, pressurizing them, and thereby creating the suitable conditions for the formation of galaxies. By around 5 billion BC most all galactic clusters in the universe were more or less complete, and stable.

Now the nuclear fusion reactors which will provide most of the power for the universe for some time to come (stars) are beginning to fire up.

-- The Cosmos Was Alive With the Sound of Matter By K.C. COLE, Los Angeles Times, May 11, 2000, URL: http://www.latimes.com/news/science/science/20000511/t000044636.html

The Universe now cools to some 4500 degrees Kelvin. Electrons lose their excess energy to become captured by nearby nuclei, thereby forming atoms. The disppearance of most of the free electrons clears the way for photons at last, thereby rendering the Universe visible to any theoretical internal observers.

Quasars seemed to appear long before most stars coalesced in the universe. The core black holes of galaxies seem to be remnants of those quasars.

Black holes already existed when the universe reached about 1 billion years in age (the peak of quasar period).

Much less than 1% of the mass of an average galaxy resides inside black holes. In terms of mass, black holes seem to be more energy efficient than stars by an order of magnitude (10 times).

-- Galaxies and black holes; EurekAlert!; 16 FEBRUARY 2001; US Contact: Sally Pobojewski pobo@umich.edu 734-647-1844 University of Michigan

"...the universe is 13.7 billion years old...[and]...primordial stars did indeed ignite when our universe was only 200 million years old."

The universe could be 50% to 66% bigger than we thought, based on a new analysis of the total energy absorbed by interstellar dust.

Only some 5% of the mass in the Universe coalesces into the stars, planets, and gases making up all the galaxies and other easily detected elements of the Universe. The other 95% of the Universe goes into the creation of matter and energy which will be practically invisible but for gravity effects to 20th century human science.

Roughly 33% of this virtually invisible Universe may consist of randomly distributed clumps of cold dark matter. About 62% may be a uniformly distributed dark energy. 0.1% may be composed of hot dark matter-- basically neutrinos.

-- Planets, Stars And Gases Make Up Only 5% Of Universe By Steve Bradt, 01-Feb-2001, UniSci Daily, unisci.com

Our young universe circa 12 billion BC was filled with black holes-- upto 300 billion perhaps. Other types of bodies existed, but maybe the majority of massive objects in space at this time consisted of black holes.

Quasars seemed to appear long before most stars coalesced in the universe. The core black holes of galaxies seem to be remnants of those quasars.

Black holes already existed when the universe reached about 1 billion years in age (the peak of quasar period).

Much less than 1% of the mass of an average galaxy resides inside black holes. In terms of mass, black holes seem to be more energy efficient than stars by an order of magnitude (10 times).

"Dark energy", something with an effect like anti-gravity, seems to be pushing all the masses in the Universe away from one another. Maybe 65% of the universe consists of dark energy.

At least some asteroids boasted liquid salt water within two million years of the coalescence of the solid bodies of the solar system from the initial dust cloud. Thus, not long after 4,570,000,000 BC at least some spots in the system were already conducive to life formation.

-- Salt Crystals Point to Wet Start of Solar System By Maggie Fox, Yahoo!Reuters, June 8 2000

It's believed that around 4.6 billion BC items of the Oort cloud formed in roughly the region of Jupiter's orbit today. Then over the next 100 million years Jupiter's gravity caused portions of the cloud debris to spiral into the Sun or spin out beyond our solar system, with everything else settling into the Oort cloud's present location. The comets within the Oort cloud could number in the trillions.

Neptune and Uranus appear to have formed closer in to the Sun than their orbits of 2000 AD would make it seem. Apparently interaction with the gravity of Jupiter wrenched them from their original orbits to others much further from the Sun. There doesn't seem to have been sufficient gas to create such planets in those far orbits early on.

Neptune and Uranus likely formed in a swath of the early proto-solar system disk shared with both Juptiter and Saturn (the other gas giants). Jupiter likely enjoyed the innermost position, and so largest meals of dust and debris from which to grow. Ultimately its greater gravity (perhaps with an assist from Saturn too) whipped the lesser worlds of Neptune and Uranus out into the further reaches of the system.

All this occured quite some time before the formation of the Earth itself.

Scientists disagree about the two planet's (Uranus and Neptune) original distance from the Sun, and the violence with which they were moved to new orbits. Some think the orbital shift was a gradual one.

-- ABCNEWS.com : New Theory on Uranus, Neptune Births By Pamela Sampson, ABC News Internet Ventures/The Associated Press, Dec. 8, 1999, http://www.abcnews.go.com/

Some scientists believe Jupiter may have originally formed somewhat further out from the Sun than it exists circa 1999 AD. Jupiter and Saturn with their substantial gaseous atmospheres are considered 'gas giants' while Neptune and Uranus are classified more as 'ice giants', with thinner atmospheres. All four may have begun in same approximate orbital band now (20th century AD) owned by Jupiter and Saturn alone, with the smaller Neptune and Uranus thrown clear during the later stages of formation or after. Jupiter itself may have been pushed inwards towards the Sun, in a reaction helping to balance the momentum changes to the system overall. The beginnings of all four may have been in one huge proto-Jupiter several times the mass of circa 1999 AD Jupiter-- which soon became unstable, breaking up into Jupiter, Saturn, Uranus, Neptune, and perhaps still more, lesser bodies.

Computer simulations suggest Uranus and Neptune followed somewhat chaotic orbits about the Sun for maybe half a million years, then gradually settled into more stable orbits. This period of orbital shift could also have lasted much longer, like millions of years.

Among the implications of all these early solar system games of musical chairs regarding orbits, is that the Earth itself may have moved too, since its formation.

-- BBC News | SCI/TECH | Jupiter gave birth to Uranus and Neptune By Dr David Whitehouse, 8 December 1999, http://www.bbc.co.uk/

The composition of Jupiter's atmosphere suggests it and perhaps other planets (like Saturn, Uranus, and Neptune) may have begun forming quite some time before the Sun ignited.

By contrast, comets formed after the Sun's ignition.

An alternative explanation for Jupiter's atmosphere is that it originally formed further out from the Sun (beyond the orbit of Neptune circa 1999) and only later moved inwards to its longer term orbit. But this seems unlikely.

At least some asteroids boasted liquid salt water within two million years of the coalescence of the solid bodies of the solar system from the initial dust cloud. Thus, not long after 4,570,000,000 BC at least some spots in the system were already conducive to life formation.

-- Salt Crystals Point to Wet Start of Solar System By Maggie Fox, Yahoo!Reuters, June 8 2000

Some scientists believe Mars has always been a dry world. That it began as an unfinished 'embryo' of a planet, situated in the early asteroid belt (which itself spanned from 0.5 to perhaps 4 AU distance from our Sun-- a considerably wider girth than the belt takes up circa 2004). The Mars embryo grew with accumulated collisions involving smaller comets and asteroid fragments while Earth grew more from much larger planetary embryos coming together. The larger chunks hitting Earth possessed far more water than those striking Mars-- hence Mars ended up getting less--perhaps far less- than 30% the water Earth did.

-- Moon Probably Split From Earth In Collision - NASA, Reuters; http://dailynews.yahoo.com; March 16 1998

The Moon will show signs in 1994 AD that it has not yet lost quite all its molten interior from younger days.

A gamma burster occuring close to our embryonic solar system (perhaps within 300 lightyears) may have helped accelerate or otherwise affect its formation, by melting dust grains and facilitating their coalescence into larger bodies. If so, then perhaps all the beady iron/silicon chondrules which would later contribute to the creation of planets like Earth formed within mere minutes.

The scientists responsible for this study believe only one out of a thousand Sun-like stars in the galaxy would undergo similar processes during system formation. If this is true, then the formation of rocky planets like Earth in other systems might be pretty rare, leaving the galaxy overwhelmingly populated with systems consisting mostly of gas giants and miscellaneous debris like comets and asteroids-- with few chances for Earth-like life to begin and thrive.

Most experts in this field don't subscribe to any theory where all the solar system's chondrules formed simultaneously, in a single event-- but acknowledge there's presently insufficient information to be certain as to exactly how they were created.

-- A violent blast of radiation spawned the planets by Robert Adler, New Scientist ["http://www.newscientist.com"] issue 11th September 99/EurekAlert!, UK Contact: Claire Bowles claire.bowles@rbi.co.uk 44-171-331-2751 US Contact: New Scientist Washington office newscidc@idt.net 202-452-1178

A new theory on Moon creation suggests that only a single impact occured rather than two, that the Earth was rendered completely molten through and through by the collision with a Mars-sized body. The other planet was completely destroyed, with portions contributing to the Moon and perhaps the reformed Earth as well.

The Moon may have formed by only about 100 years after the collision. The blow could have given an extra spin to the Earth, with days lasting only around five hours. Since then the Moon has slowly moved further away from Earth, helping to slow the Earth's rotation rate and lengthen its days.

There could have been over a dozen total Mars-size planets in the early solar system that ended up as no part of today's known planetary family. It could be gravitational slingshot effects threw them out of the system entirely, or at least to the far outer edges, where it might take us years or decades more to detect them.

At least the above is what scientists thought before they acquired new information through the Mars Global Surveyor program. Now the problem of what happened to Mars' atmosphere appears to be more complex than that described above.

The cosmic bombardment Mars received early in its history may have thrown off a large part of its atmosphere-- perhaps as much as 99 percent. The magnetic component of the solar wind may also have caused a slow trickle drain of the atmosphere into space, over time.

It may be that Mars was able to replenish some of its lost atmosphere from internal reserves after the intial big loss. And Mars seems to have enjoyed its own geomagnetic field too early on, which would have acted as a shield against losses due to the solar wind. But as Mars' internal heat ran down, so did the internal dynamics spawning the magnetic shield-- and the losses to space increased. The failure of the shield came about in Mars' youth-- not recently.

There's a strong possibility that Mars was never warm enough for liquid water in any normal sense; it could be that water only flowed briefly in various locations due to catastrophic cosmic impacts or volcanic eruptions. And those brief moments have been captured forever in the landscape observable in 2000 AD. Long term landshaping could have occured with flowing water underneath protective ice sheets over millennia, with the ice sheets finally collapsing and all the water thereafter evaporating to space or seeping into the crust.

At best Mars might occasionally experience unusual periods of 10,000 years or so at a time of warmer temperatures due to massive outgassing (volcanic eruptions?), along with liquid water. But such brief stints would seem to be very limited in regards to encouraging widespread and complex lifeform development.

Mars' most interesting period may have been its first billion years of existence.

- Mystery of the missing atmosphere by Oliver Morton, New Scientist issue: 20th November 99 Source: Geo-Marine Letters (vol 18, p 285), New Scientist (http://www.newscientist.com) and EurekAlert! ["http://www.eurekalert.org/"]

Evidence has been found for either or both a wetter and more geologically active young Mars.

Similar processes may well have been available on a multitude of other worlds early on, including Mars.

-- View Inside Mars Reveals Rapid Cooling And Buried Channels ["http://www.sciencedaily.com/releases/2000/03/000315080133.htm"], 3/15/2000, citing NASA/Jet Propulsion Laboratory (http://www.jpl.nasa.gov)

There are magnetic indications that Mars at one time enjoyed a dynamic interior and protective magnetic field similar to Earth-- including related characteristics like plate tectonics and volcanism.

However, such geological and magnetic dynamism appears not to have occured in the planet's earliest history, but rather sometime later.

This may be evidence for Mars enjoying its greatest dynamism due to gravity tide effects from its shifting orbit around the time of the collision of Orpheus with Earth One and afterwards. Further evidence may lie in the fact that Mars dynamism seems to have only lasted a short time too, once it began. If most all the dynamism was due to orbit changes related to the Earth One/Orpheus collision, then that could well have made such dynamism short-lived.

Evidence from Earth's Moon however suggests that internal dynamism might require several hundred million years to get started after initial formation, anyway, regardless of other factors.

Volcanic gases which have cooled to 150 to 300 degrees C may spontaneously form rudimentary hydrocarbons from carbon monoxide and hydrogen wherever magnetite compounds are available to serve as a catalyst. Such hydrocarbons represent part of the recipe for life formation. Other items needed for life emergence may also find such environmental conditions to be fertile for their development. Indeed, the circumstances for such developments may actually have been better in Earth's early history than they will be later, after the planet possesses a much higher level of atmospheric oxygen, and its typical lava temperatures have declined.

Similar processes may well have been available on a multitude of other worlds early on, including Mars.

-- Children of the volcano, ExoScience - News - Science / ["http://www.exosci.com/main/news/shownews/?id=1202"] by David Watanabe, March 27th, 2000

Around 4.4 billion BC- 4.3 billion BC it appears Earth had already recovered sufficiently from the Moon collision and ongoing asteroid and comet bombardments to possess a solidified crust, continents, and oceans, as well as a relatively cool temperature overall (hovering around 100 degrees Centigrade), considering the circumstances. Indeed, the planet was cooling far more rapidly than many scientists expect it should have. Could this perhaps be due to a very thin or nearly non-existent atmosphere during much of this primordial period?

The newly formed Earth of some four billion BC had a day 14 hours long and an atmosphere consisting of (1) carbon dioxide, (2) nitrogen, (3) methane, and (4) sulfur.

Regular impacts by asteroids vaporize all the oceans and combine with the heat of the Earth's own interior to re-dissolve large sections of the crust into molten rock again (not that the Earth needs help re-melting regions of its crust; it likely happens frequently around 4 billion BC even without impacts to help). Large asteroid impacts serve repeatedly to raise surface temperatures on Earth to 1700 degrees Celsius, and keep them that way for millennia afterwards.

By the early 21st century the crust in continents will typically be five times as thick as that of seabeds. It'll also usually be a lot older. The oldest seabed crust of the time will appear to be 200 million years old, with over 50% of the continental crust almost 3 billion years old.

At least the above is what scientists thought before they acquired new information through the Mars Global Surveyor program. Now the problem of what happened to Mars' atmosphere appears to be more complex than that described above.

The cosmic bombardment Mars received early in its history may have thrown off a large part of its atmosphere-- perhaps as much as 99 percent. The magnetic component of the solar wind may also have caused a slow trickle drain of the atmosphere into space, over time.

It may be that Mars was able to replenish some of its lost atmosphere from internal reserves after the intial big loss. And Mars seems to have enjoyed its own geomagnetic field too early on, which would have acted as a shield against losses due to the solar wind. But as Mars' internal heat ran down, so did the internal dynamics spawning the magnetic shield-- and the losses to space increased. The failure of the shield came about in Mars' youth-- not recently.

There's a strong possibility that Mars was never warm enough for liquid water in any normal sense; it could be that water only flowed briefly in various locations due to catastrophic cosmic impacts or volcanic eruptions. And those brief moments have been captured forever in the landscape observable in 1999 AD. Long term landshaping could have occured with flowing water underneath protective ice sheets over millennia, with the ice sheets finally collapsing and all the water evaporating or seeping into the crust.

At best Mars might occasionally experience unusual periods of 10,000 years or so at a time of warmer temperatures due to massive outgassing (volcanic eruptions?), along with liquid water. But such brief stints would seem to be very limited in regards to encouraging widespread and complex lifeform development.

Mars' most interesting period may have been its first billion years of existence.

The same collision which created the Moon may also have altered the tilt of the Earth's axis.

-- One theory solves two ancient climate paradoxes, EurekAlert! ["http://www.eurekalert.org/"] 14 DECEMBER 1999, Contact: A'ndrea Elyse Messer aem1@psu.edu 814-865-9481 Penn State

The majority of the Earth's continental crust is composed of granite, and that granite appears to have formed in relatively fast episodes lasting no longer than 1000 to 100,000 years at a time. The formations may have occurred catastrophically. Tens of thousands of relatively abrupt subterranean eruptions of granite-forming magma ultimately coalesced into sheets of rock appearing on the surface of the planet and stacking one atop another to form the continents.

The continents began forming around 4,000,000,000 BC.

-- Earth's Continental Land Masses Created In Short, Fast Bursts, Scientists Say ["http://www.sciencedaily.com/releases/2000/12/001207140240.htm"], ScienceDaily Magazine, citing University Of Toronto (http://www.utoronto.ca), 12/8/2000, Contact: Janet Wong, (416) 978-6974; jf.wong@utoronto.ca, Alexander Cruden, U of T Department of Geology, (416) 946-7284, cruden@geology.utoronto.ca

Microbial surface life on Earth could thrive for lengthy periods during the Late Heavy Bombardment period of Earth's formation, with their growing periods punctuated perhaps only once every 30 million to 100 million years with impacts severe enough to threaten all microbial life worldwide. And, of course, sub-surface microbial life would have seen dire threats to their global presence even less often.

Keep in mind that microbe-sized life is much more robust than larger, more complex life forms like plants or animals. Cosmic impacts sufficiently large to threaten global microbe populations had to be powerful enough to vaporize the upper layers of the world's oceans, at the very least. During this same period asteroids similar in size to the object which will later wipe out the dinosaurs are striking Earth about once every several 100,000 years-- with most microbes barely taking notice of the events.

Even in the case of the worst events, Earth-based microbes (and the Earth itself) appear to fully recover within only several tens of thousands of years after each.

Any potential fossil remains of life from that time may rest within these sedimentary formations.

-- Science report: sedimentary rocks on Mars may suggest an ancient land of lakes, EurekAlert!, Contact: Ginger Pinholster gpinhols@aaas.org 202-326-6421 American Association for the Advancement of Science, 4 DECEMBER 2000 and 8 December 2000 are both post dates associated with this article

-- Wind or volcanic action, like water, may also form sedimentary rock. But indications are Mars' rocks were likely formed by water.

-- Lakes on Mars, Willow Lawson and the Associated Press contributors, Dec. 4, 2000, ABCNEWS.com

-- Sedimentary rock on Mars suggests large, ancient lake beds By Richard Stenger, CNN, December 4, 2000

-- Old Arctic Water May Hold Clues to Origin of Life; http://dailynews.yahoo.com; Reuters, Science Headlines, December 16 1999

At least the above is what scientists thought before they acquired new information through the Mars Global Surveyor program. Now the problem of what happened to Mars' atmosphere appears to be more complex than that described above.

The cosmic bombardment Mars received early in its history may have thrown off a large part of its atmosphere-- perhaps as much as 99 percent. The magnetic component of the solar wind may also have caused a slow trickle drain of the atmosphere into space, over time.

It may be that Mars was able to replenish some of its lost atmosphere from internal reserves after the intial big loss. And Mars seems to have enjoyed its own geomagnetic field too early on, which would have acted as a shield against losses due to the solar wind. But as Mars' internal heat ran down, so did the internal dynamics spawning the magnetic shield-- and the losses to space increased. The failure of the shield came about in Mars' youth-- not recently.

There's a strong possibility that Mars was never warm enough for liquid water in any normal sense; it could be that water only flowed briefly in various locations due to catastrophic cosmic impacts or volcanic eruptions. And those brief moments have been captured forever in the landscape observable in 1999 AD. Long term landshaping could have occured with flowing water underneath protective ice sheets over millennia, with the ice sheets finally collapsing and all the water evaporating or seeping into the crust.

At best Mars might occasionally experience unusual periods of 10,000 years or so at a time of warmer temperatures due to massive outgassing (volcanic eruptions?), along with liquid water. But such brief stints would seem to be very limited in regards to encouraging widespread and complex lifeform development.

Mars' most interesting period may have been its first billion years of existence.

-- Mystery of the missing atmosphere by Oliver Morton, New Scientist issue: 20th November 99 Source: Geo-Marine Letters (vol 18, p 285), New Scientist ["http://www.newscientist.com"] and EurekAlert! ["http://www.eurekalert.org/"]

Adding to this the time shown by Earth's own evolution to be required for the development of higher lifeforms makes it appear the earliest that carbon-based intelligence may have evolved would have been around 75% of the Universe's present age-- or maybe 3,000,000,000 BC (this is assuming a 12 billion year age for the Universe).

-- The Oldest Life-Form By Ray Villard, Special to space.com, Sep 20 1999, http://www.space.com/

Gamma ray bursters are massive explosions of radiation rivaling the Big Bang itself in some ways, which may serve to nearly sterilize entire galaxies on a fairly frequent basis. So frequent, in fact, that all by itself the phenomenon may have served to keep the evolution of intelligence 'bottled up' in the Milky Way throughout its entire history-- until only recently. Gamma ray burster frequency seems to have decreased the last few hundred million years or so, making it safe for certain apes on Earth to start talking to one another and crafting tools to make their lives better. For further details see below:

Over the past five years alone 1700 inexplicable bursts of gamma rays have been detected from the void.......These mysterious bursts come from all around us, in every direction-- but they are usually extremely distant; a billion or more light years away; perhaps even outside our galaxy. Space Today and the Washington Post, on or about 12-18-96

6-1-98 Newz&Viewz: A mind boggling explosion 12 billion years ago rivaled the Big Bang itself in power

I wrote here months ago (maybe years) that it seemed to me the huge explosions producing the gamma ray bursts seemed potentially dangerous to possibly the entire galaxy that happened to host one-- only now am I starting to see mainstream articles noting this danger as well-- like the one cited at the end of this newz item.

Unfortunately, it appears sooner or later we WILL have a possibly fatal gamma ray burst nearby, that could kill off or severely damage all life on Earth (but for certain microbes).

But couldn't we protect ourselves somehow, like we might against an asteroid? Well, if a burster occured within 3000 lightyears of us, the only potentially safe places would be a quarter-mile or so underwater or underground-- YIKES! Even worse, we might get even less warning about a burster than we might about a dangerous comet or asteroid-- indeed, the radiation could have begun falling on us when you began reading this article, and many of us would already be fatally poisoned before our scientists realized what was happening....

But if we did have super refuges deep underground/undersea to protect us, how long might we have to stay there before we could return to the surface? Only "...many millions of years..."-- or until we learned how to turn ourselves into wholly inorganic machines which were impervious to the killing radiation.

Obviously, if such a near burster's radiation reached us any time before maybe 2600 AD, we'd be goners-- extinct.

Luckily, the stats so far suggest near bursters happen only about once every 100 million years on average-- so we might have a few million years breathing space (or not). -- "Recently Discovered Cosmic Blast May Be Biggest Since Big Bang" by MALCOLM W. BROWNE, 5-7-98, The New York Times

3-6-99 Newz&Viewz [edited]: The Fermi Paradox Resolved?

The Fermi Paradox basically asks "where are all the aliens"?

Well, just maybe the answer is natural cataclysms which have been sweeping the entire galaxy clean of higher life forms every few million years up until recently.

I'm talking gamma ray bursters here folks. Those mighty galaxy-shaking explosions that have been mystifying scientists now for about 30 years. Long-time readers might remember me writing here maybe a couple years ago that these enormous explosions and gamma radiation baths might be terrible news for the inhabitants of whatever galaxy where they occured. Now mainstream researchers are starting to say the same thing in their papers.

The gist is that these awful radiation bursts may have been occuring just often enough to stop the development of potential star farers in their tracks, throughout all of the history of the universe so far.

Apparently the only adequate protective measure for land-lubbers is being on the shadowed side of a planet when such a radiation bath occurs. Only life sheltered by many tons of seawater might survive on the gamma lit side.

Luckily most bursts won't usually last very long, so an entire planetary hemisphere (the shadowed half) worth of land-based life might escape more or less intact in many cases. But of course then the biosphere has to cope with half a dead planet; an entire hemisphere of dead and rotting corpses, of both plant and animal matter, and likely much dead in shallow sea waters as well. Imagine the awesome forest fires where entire continents of deadwood are set ablaze by lightning storms for decades afterwards. The smoke from these fires might create a brief global nuclear winter type condition, leading to even more death. It's likely a world would lose 30-50% of its total species in the event (since many species exist only locally, and half a world would be killed). And the rampage of disease...! It's a pretty good bet that the planet's climate would be changed significantly for centuries, maybe millennia, after the event. And the overall biosphere? At best it might only be set back by some 5 to 50 million years or so.

But there's still more to consider. In our own case, for millions of years, humanity's predecessors existed on a single continent on one side of the planet: Africa. If that side of the Earth had been fried by gamma rays during that time, present-day humanity likely wouldn't exist at all.

Similar 'dead-ends' in the evolution of intelligent life galaxy-wide could also have happened over the past several billion years. And remember that a single gamma ray burst severely damages the entire galaxy all at once in this fashion. So hundreds or even thousands of potential sentient races could have been wiped out or set back by a single burst at any time during the past.

And apparently there's been not merely one gamma burst over that time, but possibly hundreds or thousands, and possibly with a frequency of one every few million years in the earlier history of our galaxy.

So the great majority of potential intelligent races in our galaxy have almost certainly been killed off or at least severely stunted in development during much of past galactic history.

Now though, finally, the frequency of gamma bursters looks to be decreasing, and thereby giving folks like us a chance to actually crawl out of the muck and into space in a significant way, before we get wiped off the map.

And not only us, but perhaps many other races throughout the galaxy too.

It could well be that the gamma ray bursters have forced many intelligent races throughout the galaxy to begin reaching for the stars all more at less around the same time.

Yes, we're talking the parallel, roughly equivalent development technologically of at least dozens to hundreds of different civilizations now, in something similar to how the Terrans, Vulcans, Romulans, and Klingons seem to have developed in the Star Trek TV series, where none (or few) have a truly decisive headstart over the others.

Yet another implication of all this though would seem to be that sea-based intelligence (which might enjoy better wholesale protection from gamma bursters), might have enjoyed a vastly greater continuity of evolution and technological development than land-based civilizations like our own during the onslaught. In extreme scenarios of virtually 100% ocean worlds, where intelligent squids or something similar lived typically fairly deep in the seas, the core civilizations might have been damaged very little if at all-- with only outposts on land, orbiting stations, and spacecraft/aircraft in transit suffering casualties from any burster in passing.

So the most advanced civilizations in the galaxy might turn out to appear pretty darn alien to us after all, if we ever encounter them.

-- "Cataclysmic Explosions May Have Held Up Alien Visitors", Author: Robert Matthews, New Scientist magazine issue 23rd Jan 99

What if heavier elements (like carbon) were created too during the big bang, rather than merely lighter elements? Present knowledge makes this appear unlikely. But if they were, and sufficient amounts were produced, then carbon-based life could have developed much earlier in the Universe's history than science has so far supposed.