Today’s New Reason To Believe

by Dr. Jeffrey Zweerink

NASA scientists recently published a stunning reproduction of the Milky Way Galaxy using data taken with the Spitzer telescope. As seen in the image below, two large spiral arms emanate from a central bar and encompass a number of smaller arms and substructure.

The fact that the Sun resides in a spiral galaxy instead of the more common elliptical galaxies highlights a number of design characteristics essential to life.

First, stars in elliptical galaxies generally have more radial orbits that frequently take the stars in close to the center of the galaxy. The density of stars in galactic centers causes large gravitational disturbances to any putative planetary system around such stars. In contrast, spiral galaxy stars exhibit more circular orbits that significantly decrease the possibility of gravitational disturbances from other stars.

Second, the spiral structures reflect regions of higher density stars and the region between the spiral structures exhibits a lower density. The Sun’s orbit in the Milky Way minimizes the number of passages through the spiral arms which, in turn, minimizes the chance for gravitational disruption of the planetary orbits.

Third, and perhaps most importantly, the existence of the spiral arm structure goes hand-in-hand with ongoing star formation. However, for a galaxy to continue forming new stars for more than ten billion years, it must continually receive new supplies of gas to replenish the gas used up by previous stars.

A paper published in the Astrophysical Journal found evidence that shows where the Milky Way received its supply of fresh gas. Using a detailed study of the stars in the halo around the Milky Way, a team of astronomers discovered that the halo exhibits a high degree of “clumpiness.” This clumpiness provides strong evidence that the Milky Way absorbed a large number of smaller dwarf galaxies during its history. The dynamics of these collisions would transfer the gas from the dwarf galaxies into the disk of the Milky Way, providing fuel for more star formation. In fact, it appears that such a process is occurring now in a location called the Virgo Stellar Stream.

Evidence consistent with the idea that Earth was designed to support life continues to mount. Not only does Earth orbit the right distance from a just-right star, it also resides in a just-right galaxy that collides with enough dwarf galaxies to continually form new stars and maintain its spiral structure. But, the collisions are not so frequent that they disrupt the planets orbiting around the sun.

by Jeff Zweerink

One biblical message Reasons To Believe consistently echoes is the mandate to weed out false ideas by testing everything. Jeremiah 33:25 makes a testable statement about the laws which govern heaven and earth, namely that they do not change. Two teams of scientists have developed the most precise clocks to date. In doing so, they have provided a powerful way to test for any variation of one of those physical laws, the electromagnetic force.

For years, atomic clocks that used a transition in cesium atoms stood as the best time-keeping devices available. However, the precision of atomic clocks depends on the size of the transition, with larger transitions giving better precision (assuming all other effects remain equal). Two papers recently published in Science describe new atomic clocks based on optical transitions five orders of magnitude larger than the microwave transitions in cesium.

The clock from one group uses neutral strontium atoms and checks the precision of the clock with another clock that uses calcium atoms. The other group built their clocks from single aluminum and mercury ions. Both clocks exceed the precision of the best cesium clocks.

All atomic transitions depend on the fine-structure constant, which also determines the strength of the electromagnetic force. Repeated tests over one year of observations with the single-ion clocks constrain variations in the fine-structure constant to less than two parts in one hundred million billion per year.

Other groups have used black holes to constrain variations in the fine-structure constant and have achieved similar results. Furthermore, observations of distant quasars (described in the 2006 Breakthroughs booklet) demonstrate that the value of the fine structure constant early in the universe matches today’s value.

Thus, continued testing affirms one critical aspect of RTB’s cosmic creation model. We live in a universe governed by constant laws of physics.

by Jeff Zweerink

Do graphite whiskers in meteorites require shaving dark energy out of cosmological models?

Consider a familiar scenario. Your child lies on the couch acting unusually calm. You touch your their forehead and it feels warm. The insta-thermometer gives a reading of 101.2^oF from the child’s ear. The traditional thermometer in the mouth gives a reading of 101.4^oF. Without question, your child has a fever.

But does your conclusion change if you discover that the batteries in your insta-thermometer are dying?

Graphite whiskers may represent dying batteries among the evidence for dark energy in the universe. Astronomers use the brightness of Type Ia supernovae to measure the expansion rate of the universe. Because these supernovae each emit the same amount of light (after some straightforward calibrations), astronomers use the measured brightness to determine the distance to each galaxy containing the supernova. Comparing the distance with the redshift provides the expansion history of the universe. Because distant supernovae have appeared dimmer than expected, astronomers concluded that dark energy pervades the universe, causing its expansion to accelerate for the last 5 billion years.

One alternative explanation is that a “grey dust,” proposed to populate intergalactic space, absorbs the supernovae light in a way that mimics the effects of dark energy. By carefully analyzing the oldest remnants of the early solar system—namely carbonaceous chondrite meteorites—scientists from the Carnegie Institution have discovered one potential grey dust candidate. Specifically, the researchers found graphite whiskers in three different parts of the meteorite (see here).

Graphite absorbs light that is characteristic of distant supernovae very efficiently. Thus, if enough graphite whiskers were ejected from star-forming nebulae and/or supernovae out into the intergalactic medium, they might explain the dimness of Type Ia supernovae without needing to invoke dark energy. Much work remains to check the validity of this explanation, but finding the graphite whiskers was a critical first step.

In the bigger picture, the possibility of these results removing the necessity of dark energy remains small. Type Ia supernovae are not the only indicators of dark energy. Data from both the WMAP and the SDSS both provide compelling evidence for dark energy, independent of the supernovae data.

Dark energy stands as the strongest single piece of evidence for fine-tuning in the universe—evidence that effectively argues for the intervention of a supernatural Designer. While scientists may have discovered some dying batteries (the graphite whiskers), rather than shaving dark energy out of the cosmological models, this phenomenon remains charged for the long haul.