No Snowballs Out There, but Thank God for Snowballs Here

snowball

Snowballs remind us of the presence of water on Earth—a feature that highlights our planet’s habitability. However, most of the so-called habitable planets in the universe are tidally locked, a problem, it turns out, for the accumulation of snow and ice.

Astronomers typically identify a planet as habitable if it happens to lie at a distance from its host star where the planet’s surface temperature might fall within the range where water could be in a liquid state. However, most of the stars in the universe are much dimmer than the Sun. This lower stellar luminosity means that for the planets orbiting these stars to possibly possess liquid water on their surfaces, they must orbit their host stars more closely than Earth orbits the Sun.

Planets orbiting their host stars more closely than Earth orbits the Sun will experience a substantially stronger gravitational force from the host star on the side that faces its host star compared to the opposite side. The difference gradually forces one side of the planet to always face its host star, an effect known as tidal locking. The closer a planet is to its host star, the more rapidly it becomes tidally locked.

The Earth will become tidally locked to the Sun in about 40 billion years. However, for most of the universe’s planets that have a possibility of possessing liquid water on their surfaces, the time for them to become tidally locked is less than a billion years.

Another Big Problem for Tidally Locked Planets

On August 28 I posted a blog1 where I described two recently published studies that establish additional reasons why it is highly unlikely that any tidally locked planet would ever possess life. Now, three astronomers from the University of Toronto and the University of Chicago have published yet another reason.2 That reason does not necessarily eliminate the possibility of microbes existing on a planet for a relatively short time period, but it does rule out any kind of advanced life or life that remains on a planet for more than about a billion years.

The three astronomers first point out that stars dimmer than the Sun are redder than the Sun. At red and near-infrared wavelengths, the difference between the amount of starlight reflected by ice or snow on a planet’s surface compared to liquid water or exposed land is much less than it is at yellow, green, or blue wavelengths. The team then performed calculations that showed for tidally locked planets the top-of-the-atmosphere ice/ocean albedo (albedo refers to the amount of light reflected away) contrast is even smaller. The three then performed additional calculations that established tidally locked planets—even those possessing extensive surface liquid water and functioning enduring silicate weathering—will “not be able to exist in a snowball state for an extended period of time.”3 A snowball state is where all or most of a planet’s surface becomes covered in ice. The researchers finish their paper with the following conclusion, “We [astronomers] will not find habitable tidally locked exoplanets with an active carbon cycle in a snowball state.”4 No long-lasting life is possible on a planet without a carbon cycle.

Silicate weathering requires a planet with both surface oceans and surface continents where abundant rain falls upon the continents. It is silicate weathering that draws down carbon dioxide from a planet’s atmosphere to a sufficient degree to cool the planet enough for ice to form in spite of the planet’s host star getting progressively brighter as it continues to fuse hydrogen into helium in its nuclear furnace.

Why Snowball States Are Critical for Advanced Life

In my book Improbable Planet, I described how Earth experienced several snowball events.5 I also explained how each of these snowball events transformed the chemistry of Earth’s atmosphere and oceans so as to make possible the introduction of more advanced forms of life. In particular, snowball events resulted in more oxygen being pumped into Earth’s atmosphere and oceans. They also impacted Earth’s geochemistry. Without the greatly enhanced atmospheric and oceanic oxygen and the transformed geochemistry, plants and animals could never have existed on Earth, nor could microbes have persisted for more than about a billion and a half years.

Earth’s snowball events never covered all of Earth’s surface with ice. However, they did cover between 70–90% of Earth’s surface. For comparison, the greatest ice coverage during the ice age cycle that has persisted for the past 2.59 million years was 23%.

Life as advanced as birds, mammals, and human beings would not be possible unless Earth had a highly fine-tuned and perfectly timed set of snowball events. The research achieved by the three astronomers shows that snowball events are not the norm for liquid-water-possessing planets. Furthermore, the kind of snowball events essential for birds, mammals, and humans to possibly exist likely only occurred once in the universe’s history.

Original article: Thank God for Snowballs

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The State And The Sea

Whether a communication with the sea is beneficial to a well-ordered state or not is a question which has often been asked. It is argued that the introduction of strangers brought up under other laws, and the increase of population, will be adverse to good order; the increase arises from their using the sea and having a crowd of merchants coming and going, and is inimical to good government. Apart from these considerations, it would be undoubtedly better, both with a view to safety and to the provision of necessaries, that the city and territory should be connected with the sea; the defenders of a country, if they are to maintain themselves against an enemy, should be easily relieved both by land and by sea; and even if they are not able to attack by sea and land at once, they will have less difficulty in doing mischief to their assailants on one element, if they themselves can use both. Moreover, it is necessary that they should import from abroad what is not found in their own country, and that they should export what they have in excess; for a city ought to be a market, not indeed for others, but for herself.

Those who make themselves a market for the world only do so for the sake of revenue, and if a state ought not to desire profit of this kind it ought not to have such an emporium. Nowadays we often see in countries and cities dockyards and harbors very conveniently placed outside the city, but not too far off; and they are kept in dependence by walls and similar fortifications. Cities thus situated manifestly reap the benefit of intercourse with their ports; and any harm which is likely to accrue may be easily guarded against by the laws, which will pronounce and determine who may hold communication with one another, and who may not.

There can be no doubt that the possession of a moderate naval force is advantageous to a city; the city should be formidable not only to its own citizens but to some of its neighbors, or, if necessary, able to assist them by sea as well as by land. The proper number or magnitude of this naval force is relative to the character of the state; for if her function is to take a leading part in politics, her naval power should be commensurate with the scale of her enterprises. The population of the state need not be much increased, since there is no necessity that the sailors should be citizens: the marines who have the control and command will be freemen, and belong also to the infantry; and wherever there is a dense population of Perioeci and husbandmen, there will always be sailors more than enough. Of this we see instances at the present day. The city of Heraclea, for example, although small in comparison with many others, can man a considerable fleet. Such are our conclusions respecting the territory of the state, its harbors, its towns, its relations to the sea, and its maritime power.

Aristotle: Politics, Book Seven, Part 6, 350 B.C.E.

Primordial Magnetic Fields and Cosmic Creation Secrets

One of the holy grails of modern cosmology is the quest to find the universe’s primordial magnetic fields. These fields, whose strengths typically are measured in units of gauss or tesla (one gauss = 0.0001 tesla which approximately equals the Earth’s magnetic field strength), are thought to arise from the symmetry-breaking events that occurred during the first split second after the hot big bang cosmic creation event.

In the biblically predicted big bang creation model1 the universe begins infinitely or near infinitely small and infinitely or near infinitely hot. This infinite or near infinite heat means that all four of the present four forces of physics (gravity, strong nuclear force, weak nuclear force, and electromagnetism) were united into one superforce.

The universe cools as it expands from the cosmic creation event. As the universe cools, at 10-43seconds after the cosmic creation event the one superforce separates into gravity and the strong-electroweak force. At 10-36 seconds after the cosmic creation event, the strong-electroweak force separates into the strong nuclear force and the electroweak force. At 10-12 seconds after the cosmic creation event, the electroweak force separates into the weak nuclear force and the electromagnetic force. At 10-6 seconds after the cosmic creation event, the universe has cooled sufficiently that quarks can bind together to make protons and neutrons.

At any one or more of these four transition events, a small fraction of the free energy released during the phase transitions could be converted into what later becomes large-scale (size scale exceeding 3 million light-years) magnetic fields. Currently, astronomers possess no other explanation for the possible existence of such large-scale magnetic fields other than their origination in one or more of these very early transition events. Hence, they refer to such fields as “primordial magnetic fields.”

Detecting large-scale magnetic fields in the universe and accurately measuring their properties, therefore, could give us a much more detailed picture of the early history of the universe. That more detailed picture, in turn, could yield additional insights into how the physics and properties of the universe were designed to make physical life, and advanced life in particular, possible.

There is more. If large-scale magnetic fields exist in the universe and if these magnetic fields are as strong as about 0.1 nanogauss (1 nanogauss = one billionth of a gauss) they could explain the suggestion or hint of non-gaussianity in the Planck satellite map of the universe’s cosmic microwave background radiation (the radiation left over from the cosmic creation event). They also could explain the microgauss magnetic fields that astronomers have observed in large spiral galaxies.

Such strong large-scale magnetic fields would predict an earlier first formation date for dwarf galaxies, an earlier time for the reionization of the universe, an earlier time for the formation of structure in the universe, and an earlier and more abundant formation of molecular hydrogen. Earlier and more abundant molecular hydrogen in the universe would mean that Population III stars (the universe’s firstborn stars) would be more abundant and manifest a greater range of masses. Exactly how much earlier or how different the predicted properties would be depends on the strength of these possible large-scale magnetic fields.

The quest to find and measure primordial magnetic fields is the latest holy grail of cosmology because of its potential to deliver a truly detailed big bang creation model. Since the Bible stood alone in predicting the fundamental features of big bang cosmology thousands of years before astronomers discovered these features2, Christians should be excited about the possibility of producing even more scientific evidence that the Bible got it right in its many specific statements about the origin and history of the universe.

Small- and Medium-Scale Magnetic Field Measurements

Earth’s magnetic field is approximately 1 gauss, as is the Sun’s general magnetic field. Jupiter has the strongest general magnetic field of any solar system body at about 10 gauss. The Milky Way Galaxy’s general magnetic field is about one microgauss (0.000001 gauss). Nearby spiral galaxies possess magnetic fields ranging from 1–50 microgauss on size scales 0f 10,000–30,000 light-years. In clusters of galaxies on size scales of 20,000–40,000 light-years, astronomers have detected magnetic fields of a few microgauss.

Astronomers have found indisputable evidence for magnetic fields on all the size scales they have searched except for the very largest. What they have observed, however, is that the larger the size scale, the weaker the magnetic field.

Attempted Large-Scale Magnetic Field Measurements

In 2010 two astronomers, based on the assumption that halos around the gamma-ray images of quasars and blazars are caused by intergalactic magnetic fields, determined that the intergalactic magnetic field on size scales of several million light-years is about 1 femtogauss (10-15 gauss).3 In the same year two other astronomers, based on their nondetection of billion-electron-volt gamma-ray emission from a cascade initiated by trillion-electron-volt gamma rays that they did observe in blazars, established that the strength of intergalactic magnetic fields must be at least 3 x 10-16 gauss.4

Until just a few weeks ago, the best assumption-free measurement of large-scale intergalactic magnetic fields came from analysis of maps of the cosmic background radiation. The Planck Collaboration used anisotropies in the Planck satellite map of the cosmic background radiation to show that large-scale intergalactic magnetic fields could be no stronger than 0.9–5.6 nanogauss.5 (One nanogauss = 0.000000001 gauss or one-billionth of a gauss.) The range of upper limits they determined depended on which hot big bang creation model they chose and what features of primordial magnetic fields they presumed. The POLARBEAR Collaboration based on the POLARBEAR map of the cosmic background radiation established an upper limit of 3.9 nanogauss.6

A New Large-Scale Magnetic Field Measurement

In the September 10 issue of the Astrophysical Journal, three astronomers established a much superior limit on the strength of potential primordial magnetic fields.7 They combined data from the four best maps of the cosmic microwave background radiation, namely from Planck, BICEP2/Keck Array, POLARBEAR, and SPTpol. Their analysis showed that intergalactic magnetic fields on size scales larger than 3 million light-years could not be any stronger than 0.91 gauss.8

Near Future Large-Scale Magnetic Field Measurements

This new upper limit for primordial magnetic fields is tantalizingly close to the values (~0.1 nanogauss) where the cosmological creation model implications get very interesting. Thus, the three astronomers project what we can expect from cosmic background radiation mapping efforts that are already underway and another one that is due to begin shortly.

Those observational efforts already underway that possess the sensitivity to measure primordial magnetic field strengths weaker than 0.1 nanogauss include the South Pole Telescope (SPT)—3G and the Simons Array. The three astronomers demonstrate that by the end of the current decade the combination of the SPT—3G and Simons Array experiments will be able to detect primordial magnetic fields as weak as 0.05 nanogauss.9

Starting in 2020, another experiment, the CMB-S4, will begin collecting data. The three astronomers show that sometime during the 2020s the CMB-S4 will be able to detect primordial magnetic fields as weak as 0.01 nanogauss.10

Detectability at the 0.01 nanogauss level is guaranteed to deliver a much more detailed big bang creation model and much better and more detailed understanding of both the early and later development stages of the universe. Sometime in the 2020s Christians can look forward to an even stronger evidential case for the biblically predicted big bang creation model and for the exquisite—that is, supernatural—fine-tuning of the parameters of the universe that make possible our existence, civilization, and the redemption of billions of human beings from their sin and evil.

Original article: Primordial Magnetic Fields

Stand Back Up

You will make mistakes.

You will say things you should’ve said, and not said things you should’ve. You will be let down and you will let down others.

You may betray and be betrayed.

Get over it.

Forgive when you must and seek to be forgiven when you must.

Purge what needs to be purged. Correct back to baseline.

Stand back up.

Keep going.