Tag Archives: Astrophysics

New study: model of 700 quintillion terrestrial exoplanets suggests Earth is special

The Circumstellar Habitable Zone, where liquid water could potentially exist
The Circumstellar Habitable Zone, where liquid water could potentially exist

This is from Scientific American. (H/T William)

Excerpt:

More than 400 years ago Renaissance scientist Nicolaus Copernicus reduced us to near nothingness by showing that our planet is not the center of the solar system. With every subsequent scientific revolution, most other privileged positions in the universe humans might have held dear have been further degraded, revealing the cold truth that our species is the smallest of specks on a speck of a planet, cosmologically speaking. A new calculation of exoplanets suggests that Earth is just one out of a likely 700 million trillion terrestrial planets in the entire observable universe. But the average age of these planets—well above Earth’s age—and their typical locations—in galaxies vastly unlike the Milky Way—just might turn the Copernican principle on its head.

Astronomer Erik Zackrisson from Uppsala University and his colleagues created a cosmic compendium of all the terrestrial exoplanets likely to exist throughout the observable universe, based on the rocky worlds astronomers have found so far. In a powerful computer simulation, they first created their own mini universe containing models of the earliest galaxies. Then they unleashed the laws of physics—as close as scientists understand them—that describe how galaxies grow, how stars evolve and how planets come to be. Finally, they fast-forwarded through 13.8 billion years of cosmic history. Their results, published to the preprint server arXiv (pdf) and submitted to The Astrophysical Journal, provide a tantalizing trove of probable exoplanet statistics that helps astronomers understand our place in the universe.

Discover magazine, which is all in for Darwinism and aliens everywhere, says this about the study:

Zackrisson found that Earth appears to have been dealt a fairly lucky hand. In a galaxy like the Milky Way, for example, most of the planets Zackrisson’s model generated looked very different than Earth — they were larger, older and very unlikely to support life.

[…]Zackrisson’s work suggests an alternative to the commonly held assumption that planets similar to Earth must exist, based on the sheer number of planets out there.

[…]One of the most fundamental requirements for a planet to sustain life is to orbit in the “habitable zone” of a star — the “Goldilocks” region where the temperature is just right and liquid water can exist. Astronomers have, to this point, discovered around 30 exoplanets in the habitable zones of stars. Simply extrapolating that figure based on the known number of stars suggests that there should be about 50 billion such planets in the Milky Way alone. Probability seems to dictate that Earth-twins are out there somewhere.

But according to Zackrisson, most planets in the universe shouldn’t look like Earth. His model indicates that Earth’s existence presents a mild statistical anomaly in the multiplicity of planets. Most of the worlds predicted by his model exist in galaxies larger than the Milky Way and orbit stars with different compositions — an important factor in determining a planet’s characteristics. His research indicates that, from a purely statistical standpoint, Earth perhaps shouldn’t exist.

Time for me to list out some of the things that are required for a galaxy, solar system and planet to support complex embodied life. Not just life as we know it, but life of any conceivable kind given these laws of physics.

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits

It’s not easy to make a planet that supports life. For those who are interested in reaching out to God, he has left us an abundance of evidence for his existence – and his attention to detail.

Related posts

How the WMAP satellite confirmed nucleosynthesis predictions and falsified atheism

Prior to certain scientific discoveries, most people thought that the universe had always been here, and no need to ask who or what may have caused it. But today, that’s all changed. Today, the standard model of the origin of the universe is that all the matter and energy in the universe came into being in an event scientists call “The Big Bang”. At the creation event, space and time themselves began to exist, and there is no material reality that preceded them.

So a couple of quotes to show that.

An initial cosmological singularity… forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity… On this view the big bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.

Source: P. C. W. Davies, “Spacetime Singularities in Cosmology,” in The Study of Time III, ed. J. T. Fraser (Berlin: Springer Verlag ).

And another quote:

[A]lmost everyone now believes that the universe, and time itself, had a beginning at the big bang.

Source: Stephen Hawking and Roger Penrose, The Nature of Space and Time, The Isaac Newton Institute Series of Lectures (Princeton, N. J.: Princeton University Press, 1996), p. 20.

So, there are several scientific discoveries that led scientists to accept the creation event, and one of the most interesting and famous is the discovery of how elements heavier than hydrogen were formed.

Nucleosynthesis: forming heavier elements by fusion
Nucleosynthesis: forming heavier elements by fusion

Here’s the history of how that discovery happened, from the National Aeronautics and Space Administration (NASA) web site:

The term nucleosynthesis refers to the formation of heavier elements, atomic nuclei with many protons and neutrons, from the fusion of lighter elements. The Big Bang theory predicts that the early universe was a very hot place. One second after the Big Bang, the temperature of the universe was roughly 10 billion degrees and was filled with a sea of neutrons, protons, electrons, anti-electrons (positrons), photons and neutrinos. As the universe cooled, the neutrons either decayed into protons and electrons or combined with protons to make deuterium (an isotope of hydrogen). During the first three minutes of the universe, most of the deuterium combined to make helium. Trace amounts of lithium were also produced at this time. This process of light element formation in the early universe is called “Big Bang nucleosynthesis” (BBN).

The creation hypothesis predicts that there will be specific amounts of these light elements formed as the universe cools down. Do the predictions match with observations?

Yes they do:

The predicted abundance of deuterium, helium and lithium depends on the density of ordinary matter in the early universe, as shown in the figure at left. These results indicate that the yield of helium is relatively insensitive to the abundance of ordinary matter, above a certain threshold. We generically expect about 24% of the ordinary matter in the universe to be helium produced in the Big Bang. This is in very good agreement with observations and is another major triumph for the Big Bang theory.

Moreover, WMAP satellite measurements of mass density agree with our observations of these light element abundances.

Here are the observations from the WMAP satellite:

Scientific observations match predictions
Scientific observations match predictions

And here is how those WMAP measurements confirm the Big Bang creation event:

However, the Big Bang model can be tested further. Given a precise measurement of the abundance of ordinary matter, the predicted abundances of the other light elements becomes highly constrained. The WMAP satellite is able to directly measure the ordinary matter density and finds a value of 4.6% (±0.2%), indicated by the vertical red line in the graph. This leads to predicted abundances shown by the circles in the graph, which are in good agreement with observed abundances. This is an important and detailed test of nucleosynthesis and is further evidence in support of the Big Bang theory. 

“An important and detailed test”.

For completeness, we should learn how elements heavier than these light elements are formed:

Elements heavier than lithium are all synthesized in stars. During the late stages of stellar evolution, massive stars burn helium to carbon, oxygen, silicon, sulfur, and iron. Elements heavier than iron are produced in two ways: in the outer envelopes of super-giant stars and in the explosion of a supernovae. All carbon-based life on Earth is literally composed of stardust.

That’s a wonderful thing to tell a young lady when you are on a date: “your body is made of stardust”. In fact, as I have argued before, this star formation, which creates the elements necessary for intelligent life, can only be built if the fundamental constants and quantities in the universe are finely-tuned.

Now, you would think that atheists would be happy to find observations that confirm the origin of the universe out of nothing, but they are not. Actually, they are in denial.

Here’s a statement from the Secular Humanist Manifesto, which explains what atheists believe about the universe:

Religious humanists regard the universe as self-existing and not created.

For a couple of examples of how atheistic scientists respond to the evidence for a cosmic beginning, you can check out this post, where we get responses from cosmologist Lawrence Krauss, and physical chemist Peter Atkins.

You cannot have the creation of the universe be true AND a self-existing, eternal universe ALSO be true. Someone has to be wrong. Either the science is wrong, or the atheist manifesto is wrong. I know where I stand.

Positive arguments for Christian theism

How the discovery of the cosmic microwave background radiation falsified atheism

Prior to certain scientific discoveries, most people thought that the universe had always been here, and no need to ask who or what may have caused it. But today, that’s all changed. Today, the standard model of the origin of the universe is that all the matter and energy in the universe came into being in an event scientists call “The Big Bang”. At the creation event, space and time themselves began to exist, and there is no material reality that preceded them.

So a couple of quotes to show that.

An initial cosmological singularity… forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity… On this view the big bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.

Source: P. C. W. Davies, “Spacetime Singularities in Cosmology,” in The Study of Time III, ed. J. T. Fraser (Berlin: Springer Verlag ).

And another quote:

[A]lmost everyone now believes that the universe, and time itself, had a beginning at the big bang.

Source: Stephen Hawking and Roger Penrose, The Nature of Space and Time, The Isaac Newton Institute Series of Lectures (Princeton, N. J.: Princeton University Press, 1996), p. 20.

So, there are several scientific discoveries that led scientists to accept the creation event, and one of the most interesting and famous is the discovery of the cosmic microwave background radiation.

Here’s the history of how that discovery happened, from the American Physical Society web site:

Bell Labs radio astronomers Arno Penzias and Robert Wilson were using a large horn antenna in 1964 and 1965 to map signals from the Milky Way, when they serendipitously discovered the CMB. As written in the citation, “This unexpected discovery, offering strong evidence that the universe began with the Big Bang, ushered in experimental cosmology.” Penzias and Wilson shared the Nobel Prize in Physics in 1978 in honor of their findings.

The CMB is “noise” leftover from the creation of the Universe. The microwave radiation is only 3 degrees above Absolute Zero or -270 degrees C,1 and is uniformly perceptible from all directions. Its presence demonstrates that that our universe began in an extremely hot and violent explosion, called the Big Bang, 13.7 billion years ago.

In 1960, Bell Labs built a 20-foot horn-shaped antenna in Holmdel, NJ to be used with an early satellite system called Echo. The intention was to collect and amplify radio signals to send them across long distances, but within a few years, another satellite was launched and Echo became obsolete.2

With the antenna no longer tied to commercial applications, it was now free for research. Penzias and Wilson jumped at the chance to use it to analyze radio signals from the spaces between galaxies.3 But when they began to employ it, they encountered a persistent “noise” of microwaves that came from every direction. If they were to conduct experiments with the antenna, they would have to find a way to remove the static.

Penzias and Wilson tested everything they could think of to rule out the source of the radiation racket. They knew it wasn’t radiation from the Milky Way or extraterrestrial radio sources. They pointed the antenna towards New York City to rule out “urban interference”, and did analysis to dismiss possible military testing from their list.4

Then they found droppings of pigeons nesting in the antenna. They cleaned out the mess and tried removing the birds and discouraging them from roosting, but they kept flying back. “To get rid of them, we finally found the most humane thing was to get a shot gun…and at very close range [we] just killed them instantly. It’s not something I’m happy about, but that seemed like the only way out of our dilemma,” said Penzias.5 “And so the pigeons left with a smaller bang, but the noise remained, coming from every direction.”6

At the same time, the two astronomers learned that Princeton University physicist Robert Dicke had predicted that if the Big Bang had occurred, there would be low level radiation found throughout the universe. Dicke was about to design an experiment to test this hypothesis when he was contacted by Penzias. Upon hearing of Penzias’ and Wilson’s discovery, Dicke turned to his laboratory colleagues and said “well boys, we’ve been scooped.”7

Although both groups published their results in Astrophysical Journal Letters, only Penzias and Wilson received the Nobel Prize for the discovery of the CMB.

The horn antenna was designated a National Historic Landmark in 1990. Its significance in fostering a new appreciation for the field of cosmology and a better understanding of our origins can be summed up by the following: “Scientists have labeled the discovery [of the CMB] the greatest scientific discovery of the 20th century.”8

It’s the greatest scientific discovery of the 20th century.

In the New York Times, Arno Penzias commented on his discovery – the greatest discovery of the 20th century – so:

The best data we have [concerning the Big Bang] are exactly what I would have predicted, had I nothing to go on but the five books of Moses, the Psalms, the bible as a whole.

Just one problem with the greatest scientific discovery of the 20th century: atheists don’t accept it. Why not?

Here’s a statement from the Secular Humanist Manifesto, which explains what atheists believe about the universe:

Religious humanists regard the universe as self-existing and not created.

For a couple of examples of how atheistic scientists respond to the evidence for a cosmic beginning, you can check out this post, where we get responses from cosmologist Lawrence Krauss, and physical chemist Peter Atkins.

You cannot have the creation of the universe be true AND a self-existing, eternal universe ALSO be true. Someone has to be wrong. Either the science is wrong, or the atheist manifesto is wrong. I know where I stand.

Positive arguments for Christian theism