Monday, January 30, 2017

Maybe we are the first

I've said several times that it is possible that the human species is the first species in the Milky Way galaxy to evolve to our level of intelligence and technology.  This opinion is based on information about just how much needs to happen to allow for the spark of life in conjunction with the apparent rarity of our own solar system.  The recent study Relative likelihood for life as a function of cosmic time seems to confirm this idea.

A basic premise is that life requires stars for two different purposes.  The study states,
Life requires stars for two reasons. Stars are needed to produce the heavy elements (carbon, oxygen and so on, up to iron) out of which rocky planets and the molecules of life are made. Stars also provide a heat source for powering the chemistry of life on the surface of their planets.[001]
This means that rogue planets aren't likely to spark or support life.  This also means that Population III and most Population II stars systems will not have life either, because they are unlikely to have the elements necessary to form terrestrial planets.  That pretty much leaves us with Population I stars.

Rogue Planet - artist concept
Rogue planet, artist concept
Population III or II stars, article concept
Population III or II stars, artist concept
What's all this about "Population"? It's a name for stars at various stages of galaxy development.  
  • Population III stars are the stars that likely formed right after the Big Bang.  They have not been directly observed, so their existed is estimated.  They were made up of mostly Hydrogen and Helium.  As such, they are unlikely to have any planets.
  • Population II stars are stars that are still made up of mostly Hydrogen and Helium, but have higher concentrations of elements such as Oxygen, Silicon, Neon, etc.  Typically, such star systems are still unlikely to contain terrestrial planets.  Many Population II stars still exist in our galaxy, though in regions without access to many heavier elements.
  • Population I stars are stars that are yet again still made up of mostly Hydrogen and Helium, but have much higher concentrations of the more stable element Iron and other heavy elements.  Population I star systems are much more likely to contain terrestrial planets.  The Sun (Sol) is a Population I star.
Why is this discussion about "Populations" important to the discussion about the arrival of human-like intelligence?  At the risk of oversimplifying this a bit, I'll state that Population III stars lead to the formation of Population II stars, and Population II stars lead to the formation of Population I stars.  As each generation of stars lived out their lifespans, they made way for the next generation to arise.  Population I stars could not have formed 13.5B years ago; there weren't enough heavy elements around.  Just as today, it is extremely unlikely that Population III stars could arise now; there's too much heavy elements around.

Life is very unlikely to have occurred until Population I stars formed and supported terrestrial planets.  Terrestrial planets in the Goldilocks Zone around their star then had to have the necessary events and composition to allow for the spark of life to occur, and subsequently support life until species of higher intelligence evolve.

Is Earth ahead of the curve for the development of life?

The previously mentioned study suggests that Earth may have developed life to the human-level a bit earlier than average.  The study concludes that, "life around low mass stars in the distant future is much more likely than terrestrial life around the Sun today."[001]  Life throughout the galaxy may be far more common billions of years from now than it is today.  That also means that there may not be any/many other alien species with which we can contact and interact right now.  The study puts our odds at 0.1%.[001]

This could explain why we've not seen evidence of extraterrestrial intelligent life in our galaxy.  Maybe we are among the very first. Others like us are so rare, we will not be able to contact each other.

Maybe a billion years from now, a future intelligent species will evolve on some future (yet to exist) world, and when they point radio telescopes into their  night sky, they receive a song of hundreds of thousands radio signals from just as many other civilizations.  Maybe, if our species is able to continue evolving, our long-from-now-posterity becomes the evil invaders of other worlds, rather than our world being the one constantly invaded, as Hollywood would have us imagine.  Maybe we are the monsters in waiting.

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Monday, January 23, 2017

"Goldilocks zone of metallicity" on a galactic scale

What does the night sky look like to a planet within the Galactic Bulge?  Cool Cosmos describes it as,
Stars in the Galactic Center are so concentrated that they typically are only a few light weeks away from each other. In contrast, our local neighborhood of stars are separated from one another by light years. If we found ourselves on a planet near the Galactic Center, our nighttime sky would light up in a blazing display every night, filled with stars as bright as the planet Venus looks to us.[001]
However, would there be a habitable planet from which to see this sight?  Is it possible to have life-supporting planets near the Galaxy's center?

The concept of Habitable Zones around stars has been studied for a couple of decades.  Life similar to ours can only exist on planets that are a certain distance from their sun.  This is due to the amount of energy from the sun that is received by the planet.  Too much energy, the planet is too hot.  Too little energy, the planet is too cold, hence the Goldilocks reference.

There's another type of Habitable Zone at the galactic scale which uses a somewhat different set of criteria.  Solar systems which have planets that can support life must themselves be made from material that has a lot of elements that are heavier than Helium.  In astronomy, elements heavier than Helium are often referred to as metals.  Metal content of a star is called its metallicity.  The danger is that is if a solar system is made from material that is too rich in metallicity, Earth-sized planets may not be able to exist due to the likelihood of much larger (heavier) worlds displacing those Earth-size planets.  Hence, "Goldilock zone of metallicity" is the idea that certain regions of a galaxy may be too metal-rich and other regions may be metal-poor in order to allow for the presence of Earth-like worlds.[002]

It's not just the metals

Metallicity is not the only factor, however.
Early intense star formation toward the inner Galaxy provided the heavy elements necessary for life, but the supernova frequency remained dangerously high there for several billion years.[002]
If a solar system is too close to the galactic core, the intense supernova frequency in a young galaxy might've keep many worlds from supporting life.  This is because they would have experienced numerous blast waves, cosmic rays, gamma rays and x-rays that are fatal to lifeforms.[002]  As the collective of solar systems age and die, they would have contributed to increasing metallicity.  This means, the right conditions for life on Earth-like planets may have never happened near the galactic core.  Stars that are too close to the galactic core never had and never will have the right conditions to support Earth-like worlds with Earth-like life.

Where can solar systems with habitable planets reside within the Milky Way?  According to the study The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way, the inner bulge component, diffuse halo component, and a thick disk component of our Milky Way Galaxy would not likely allow for Earth-size planets to exist within the right timeframe.[002]  So, the Habitable Zone of our Milky Way Galaxy isn't even really based on distance from the galactic core.  It's a somewhat washer-shape region in between all the places that Earth-sized planets cannot exist within solar systems.

Current Habitable Zone of Milky Way 

Given all of these factors, the authors of the study The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way state,
We identified the Galactic habitable zone (GHZ) as an annular region between 7 and 9 kiloparsecs from the Galactic center that widens with time and is composed of stars that formed between 8 and 4 billion years ago.[002]
Galactic layout © Matthew Lorono 2016

Knowing our Milky Way's Habitable Zone helps us in the search for life on other worlds.  We can focus more efforts on this space.  This isn't to say that this is the only space where life can and does reside.  The Galactic Habitable Zone is just our safest bet for finding evidence of life.

Primary reference:
C. H. Lineweaver,Y. Fenner, B. K. Gibson, Science 303:59–62, DOI: 10.1126/science.1092322, The galactic habitable zone and the age distribution of complex life in the Milky Way

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Monday, January 16, 2017

Hypotheses, Theories, Laws and all that jazz

When I was in high school, I learned about hypotheses, theories, laws and principles.  The problem is that I was taught that these were hierarchical.  It took a long time for me to learn on my own that is not the case. They aren't necessarily stages in the understanding of our Universe.  A single hypothesis does not become a theory.  A theory does not eventually become a law.  A law does not eventually become a principle.  Furthermore, this list is missing the category of models.  Each of these are different things that serve the Scientific Method in different capacities.  Berkeley University of California states,
"Hypotheses, theories, and laws are rather like apples, oranges, and kumquats: one cannot grow into another, no matter how much fertilizer and water are offered. Hypotheses, theories, and laws are all scientific explanations that differ in breadth — not in level of support."[001a]
Question mark
A hypothesis is a proposed or suggested explanation for a phenomenon.  The hypothesis is stated in such a way as to allow for scientific testing for specific expectations.  The hypothesis must be testable in a falsifiable manner.  That means, to test the hypothesis, you must be able to conceive of and test methods that can potentially disprove the hypothesis.

The value of the hypothesis is that it allows us to simplify initial observations into a testable statement so that we can determine if the basis for the hypothesis is true or false.  You can test to find supporting evidence for the hypothesis.  You can also test to find refuting evidence which disproves the hypothesis.  

Hypotheses are typically formed by one or a few persons who then conduct tests as experimenters to prove and disprove it in the pursuit to solve a problem.  A hypothesis is often not a single point in research.  Experimenters may test and reject several hypotheses before solving a problem.  Disproving one particular hypothesis is just as important to Science is proving another hypothesis.[001b]

There is a subcategory of hypotheses called working hypothesis, which have some evidence to support them.  As such, they are tentatively accepted as a basis for further study.

Barbara McClintock in her lab conducting genetic research
A theory is a substantiated and unifying explanation for some aspect of the natural world.  Substantiation is acquired through the Scientific Method, with repeated testing and confirmation using written and predefined protocols for observations and experiments.

Theories are testable and make falsifiable predictions.  They allow for predictions to be made about a phenomenon, and they also explain the causes for the phenomenon.  

Science historian Stephen Jay Gould said, 
“...facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world′s data. Theories are structures of ideas that explain and interpret facts.”[002]
Theories are typically formed by consensus by many different people over a substantial period of time.  Theories aren't just thought up by one individual and then magically accepted by everyone else.  They are often heavily debated while they are being formed.  This debate drives further hypotheses and experimentation that eventually helps develop the theory.

Theories are not absolute points.  Once you have a theory, that doesn't mean the matter is settled.  It just means that the evidence up to that point allows you to create a structure that provides both reliable predictions and explanations for phenomenon.  Theories are often modified or replaced when better structures allow for better predictions and explanations.

A classic example of the process of debate to come to an eventual consensus is the Big Bang vs. Steady State theories debate, in which experimentation on both sides eventually lead to a much better understanding of our Universe.[003]

Atmosphere composition diagram representing a scientific model
A model is a often overlooked scientific tool to make a particular aspect of the natural world easier to understand, define, quantify, visualize or simulate based on commonly accepted knowledge.  Modelling requires selecting and identifying relevant aspects of a situation in the real world, then applying techniques such as conceptual models to better understand, operational models to operationalize, mathematical models to quantify and graphical models to visualize the subject.

A model seeks to represent empirical objects, phenomena, and physical processes in a logical and objective way. All models are in simulacra, that is, simplified reflections of reality which allow for useful approximations.

A model is evaluated by its consistency to empirical data.  Inconsistency or irreproducibility of observations must force modification or rejection of a model.  A model must be able to explain past observations, predict future observations and have refutability, just like theories from which the models are typically built.

Thermodynamics and negative resistance
A law is a description of a phenomenon in a particular situation without considering the cause.  Peter Coppinger of Rose-Hulman Institute of Technology states,
"Laws are descriptions — often mathematical descriptions — of natural phenomenon; for example, Newton’s Law of Gravity or Mendel’s Law of Independent Assortment. These laws simply describe the observation. Not how or why they work."[004]
Laws are compact generalizations about data.  As with other scientific elements, laws are not immutable.  As more information is learned, laws can be changed.

It is important to note that laws can exist without theories.  Sometimes laws exist for many years before theories explain their causes.[005]

A principle is really just a law that is true by definition.  The terms law and principle are often used interchangeably in Science.  A principle is not a higher grade above a law.  In fact, if you look up "Scientific Principle", your searches will inevitably lead to information regarding laws.

Some persons have suggested that laws can typically be reduced down to precise math formulae, such as the Laws of Thermodynamics and Ohm's Law.  Conversely, the suggestion is that principles are more general descriptions of the nature world.[006]  Examples of such principles are Principle of Original Horizontality and Pareto Principle.

However, even this comparison is not an absolutely held distinction.  For example, Heisenberg's Uncertainty Principle is highly mathematical in nature. Conversely, the Law of Superposition has no mathematical reduction.  So even math provides no real distinction between the use of the words principle and law in Science.

I guess the confusion about the relationships between laws, principles, hypotheses, theories and models is that it is not hierarchically ordered.  It seems counter-intuitive that Science, being the mechanism that has brought so much order to our understanding of the world, is itself not similarly ordered.  But, there's good reason for this.  Science doesn't work in absolutes.  Nothing is absolutely knowable.  As such, everything we know is subject to be revised based on what we later learn.  Having some sort of truth gradient would slow down the progress of learning since managing such grading would be an unnecessary distraction from the search for knowledge.

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Thursday, January 12, 2017

Factors a planet needs for suitability of life; perhaps

There are many notions about what life might be like on other worlds.[001]  However, from the limited examples of what we know about life, it would seem to us that there is a preference for life that is based on carbon and water.  As the study On the probability of habitable planets says,
...exploring the wide field of modern chemistry and challenging the most open-minded chemists reveals that with our present knowledge it is difficult to imagine any alternative chemistry approaching the combination of diversity, versatility and rapidity afforded by liquid water-based biochemistry. This results from the unique ability of carbon to form complex species, and the unique characteristics of water as a liquid solvent...[002]
Another factor is that that carbon and the molecules that are formed from carbon seem to be very common in our galaxy, being found in interstellar space, other planets, comets, asteroids and space dust.  Organic material seems to be everywhere.[002]  There is a nebula that is practically made of alcohol.[003]

Perhaps are search for exoplanet life needs to extend beyond simply looking for water.  Maybe our search should include crosschecking with a search for carbon.

Concept illustration of Kepler-22b, which may be a good
place to search for life
According to On the probability of habitable planets, there are four types of habitability on planets that may harbor life in some form.

  • Class I - Habitats where conditions allow for water on the surface, and where energy is primarly provided by the planet's sun.  This is the most Earth-like class.
  • Class II - Habitats where the planet may have had water on the surface early on, but conditions did not allow the planet to retain that water.  This is most Mars-like class.
  • Class III - Habitats where significant water exists below the surface, and where such underground oceans can interact with a silicate-rich core.  This planets may be too far from their sun to have surface liquid water, but via some process, such as geothermal heating, liquid water is present within the planet.  This is the most Europa-like class.
  • Class IV - Habitats where a lot of liquid water exists above an icy layers. Oceans may actually be sandwiched between ice layers.  Ganymede and Callisto may represent this class.
Is complex and even intelligent life possible on any of these classes?  It seems that the most likely class that would have complex life is Class I.  But, of course that is based on assumptions and biases born from our own example.  Classes II, III and IV may extend the limits of what is considered to be the Habitable Zone around a star.

Another factor is the CO2 cycle.  Perhaps the CO2 content of a planet will allow that planet to retain more heat from its sun.  
It turns out that a thick CO2 atmosphere may be one of the most efficient solutions for keeping a planet warm. This is not only due to the properties of the CO2 gas itself.
However, taking into account the radiative effects of the CO2 ice clouds, which tend to form in such thick CO2 atmospheres allows further increases in the warming of the surface thanks to a cloud “scattering greenhouse effect”.  Taking into account this process, the outer edge of the habitable zone has been extended as far as 2.5 AU.[002]
In other words, CO2 in the right mixture within a planet's atmosphere may extend the outer limit of how far a way a planet can be from its sun and still be warm enough to support life.  But, other factors must be explored.
[A planet] staying in the habitable zone is obviously not sufficient for a planet to continuously maintain liquid water on its surface: it must have an atmosphere which keeps the surface pressure and the surface temperature (through its greenhouse effect) in the right range, for billions of years.[002]
In addition to forming the correct atmosphere necessary to support life, a planet must also be able to keep that atmosphere for a very long time. Also, that atmosphere may need to change over time in order to adjust to changes in stellar output.  For example, a planet has to be large enough (or have enough gravity) to keep its atmosphere from escaping, not just as a result of simply drifting away, but also to counter the effect of stellar wind and other star related phenomenon.[002]

Plate tectonics is another factor that may be important to a planet's ability to support life.  Plate tectonics manage planetary cycles, such as CO2.[004]  The process of how a planet develops plate tectonics on a global scale is not well understood.  However, when examining the two examples of planets of similar size within our own solar system, Earth and Venus, the key difference appears to be water.  Perhaps the higher water content of Earth enables plate tectonics.  How special is Earth, after-all?[002]  

Would an equivalent to plate tectonics be necessary on class III and IV planets?  For those same classes, atmospheres may not be a factor at all, since oceans would be underground.  What other cycles would be necessary in such classes?  How many class I planets with a long term atmosphere and plate tectonics are in Habitable Zones?  There's a lot of open questions.  Another question I have, would we be able and willing to seed Terran lifeforms on these other classes planets (and moons), even within our own solar system, even if we do not intend to colonize them for ourselves?

Pirmary reference:
F. Forget. International Journal of Astrobiology, 13, Issue 3, July 2013, pp. 177-185, arXiv:1212.0113 [astro-ph.EP], On the probability of habitable planets


Monday, January 09, 2017

Copying mapped network drive locations to email for someone that doesn't share your mapping

For the better part of score years, I've been fumbling around to copy mapped network folder locations to emails for those people within the same organization who do not share my network mappings.  This is particularly annoying when the files are too big or too many to simply email.

It's not obvious in Windows on how to copy the raw network location, such as \\\Shared1$\MyPlace when that same folder is mapped on the current computer as simply S:\MyPlace.  To allow another person to see my files at MyPlace, I need to somehow copy the "UNC" or raw address, so that I can paste it into my email.

I finally discovered how to do this.  It's not hard, but discoverability is nearly zero.

  1. Open Windows Explorer.
  2. Within Windows Explorer, navigate to the network folder location that you wish to share.  (This assumes you've already set up that folder to be shareable.)
  3. Start a new email from Outlook.
  4. Make sure both Windows Explorer and your email windows are open and visible on the screen.
  5. Within Windows Explorer, right-button click and hold on any file within the shared folder, or right-button click and hold on the folder icon to the far left of the address field.
  6. Folder icon of address bar
  7. While still holding down the right-mouse button, drag the selection over to the body of your open email and release the button. A new dialog appears.
  8. Copy here dialog
  9. From this dialog, select Create Hyperlink Here.
  10. Voile!  You automatically have a hyperlink to your folder location.

Friday, January 06, 2017

First round of life in the Universe might have been possible extremely early

Cosmic background radiation
I've posted other articles about the possibility of life in our Galaxy based on what is known right now.  For this article, after going into some concepts from a somewhat recent study, I'm going to speculate a bit based on the suggestion by that study that life was possible for a very specific period of 10 million years to 17 million years after the formation of the Universe.  The study is The Habitable Epoch of the Early Universe.

What is significant about this very specific period after our Universe's formation?  According to the study, the cosmic microwave background provided a uniform heating source that was between 0 to 100°C (the melting point and boiling point of water at 1atm) during 10-17 million years after the formation of our Universe.  This means that there was no Habitable Zone around stars since the entire Universe was one gigantic habitable zone (except maybe being too close to a star).[001]
Hypothetical earliest stars in our Universe
Hypothetical earliest stars in our Universe

Challenges for Earliest Stars and Planets

There's a catch.  Stars that formed immediately after the Big Bang were very different than the stars we now see.  The only two elements available in the Universe were Hydrogen and Helium.  These early stars are referred to as being metal-poor, lacking access to elements heavier than than Helium.  There is speculation that the very first stars where actually extremely metal-poor.  Material from which terrestrial planets could have formed simply wasn't available yet.  When these first stars died, they produced the elements necessary for the formation of planets and metal-rich stars.  The death of these stars had to happen very quickly in order to meet the criteria necessary to consider life being possible so early in our Universe's existence.
In order for rocky planets to exist at these early times, massive stars with tens to hundreds of solar masses, whose lifetime is much shorter than the age of the Universe, had to form and enrich the primordial gas with heavy elements through winds and supernova explosions.[001]
Cosmic simulations suggest the formation of massive early stars that explode relatively quickly.[001]  Gravitational lensing also suggests the formation of such stars in the earliest galaxies.[002]  Given the possibility for such stars and such explosions of such stars, planet formation early in the Universe was also possible.[001] Given the cosmic microwave background heat of the Universe, the likelihood of planets with water on their surface was again also possible.

On the plus side for these planets, once the cosmic microwave background cooled down after the 17 million year mark, the planets themselves may have been able to keep warm enough on their own for quite awhile, even without a nearby star.
[Thermal gradients needed for life] can be supplied by geological variations on the surface of rocky planets. Examples for sources of free energy are geothermal energy powered by the planet’s gravitational binding energy at formation and radioactive energy from unstable elements produced by the earliest supernova. These internal heat sources (in addition to possible heating by a nearby star), may have kept planets warm even without the cosmic microwave background, extending the habitable epoch...[001]


Although the study The Habitable Epoch of the Early Universe suggests that life may have been possible in the early Universe, much of that life may not have survived past 17 millions years after the Big Bang unless it was lucky enough to be in the Habitable Zone within a solar system that included a very stable star.  However, even if the life didn't survive, the organic matter from which the life formed may have survived.  The survival of this life or its material could have seeded the later Universe, drastically increasing the chances of life reemerging.   Some speculate life on Earth originates from extra-solar system sources.  Perhaps the material necessary for the emergence of life was already in the mix from which our Sun formed.  The mechanism for such transference of life and materials is called Panspermia, or specifically, Pseudo-panspermia and Lithopanspermia.

What if aliens have been around much longer than us? Would we be able to find them?It seems there would have been a substantial gap between the first wave of early life and the next wave of life; this next wave presumably being the epoch within which we find ourselves now.  How might species from the early epoch be viewed by species of the current epoch?

From a Science Fiction perspective, such early life may have evolved to sentience very early in our Universe's existence.  Being so close to our Universe's beginning and having so long to evolve may have allowed these early species to development god-like powers by now.  Such species may be Q of Star Trek: TNG, Time Lords of Doctor WhoNibblonians of Futurama, and perhaps less god-like Precursors of Star Control II and Progenitors, also of Star Trek: TNG.

Would signs of god-like species be discernible to us young species?  We wouldn't likely see evidence in the form of direct radio signals, as such species would have long since evolved beyond such primitive methods of communication.  Perhaps we could catch a glimpse of these early species in the earliest days of their development via EM signals they emitted billions of years ago, from distance galaxies.

We'd have to know where to point our detectors.  Signals from ancient civilizations within our own galaxy would have passed us by billions of years ago.  However, signals from ancient civilizations in galaxies billions of light years away would be reaching us at the same time as the rest of the light from those galaxies.  Such signals would be faint and scattered, but they may be just distinct enough to discern from the background noise.  For example, at certain times of the year, Earth glows at certain EM frequencies much brighter than any other object in our galaxy.  A similar civilization billions of years ago in a galaxy billions of lights away might be obvious to us once we start looking for such phenomenon.

The idea that life may have developed so early in our Universe's existence opens up a Universe of possibilities.  Our understanding of our origins may be even effected by this concept.  On the other hand, maybe life in our Universe wasn't possible at all until very recently.  Maybe we are one of the first species to develop sentience in all of the Universe.  I'll cover more about this in a later article.

Primary reference:
A. Loeb, International Journal of Astrobiology, 13, no. 4, (Sept., 2014), arXiv:1312.0613 [astro-ph.CO], The Habitable Epoch of the Early Universe

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