NASA Mission Sheds New Light On the Sun

Bale SD et al. “Highly structured slow solar wind emerging from an equatorial coronal hole.”

Howard RA et al. “Near-Sun observations of an F-corona decrease and K-corona fine structure.”

Kasper JC et al. “Alfvénic velocity spikes and rotational flows in the near-Sun solar wind.”

McComas DJ et al. “Probing the energetic particle environment near the Sun.”

Nature, December 2019.

Although the sun sits at the center of our solar system, its most basic behaviors still remain a big mystery. NASA’s Parker Solar Probe, launched in 2018, aimed to address some of the fundamental questions about the sun: Why is the sun’s outer atmosphere, the corona, so hot? Where does solar wind come from, and what causes it to be shot out of the corona? What makes the sun flare up sometimes, shooting even more excited particles out into space? These are some of the questions that scientists hope Parker can answer before its mission ends in 2025. Meanwhile, Parker got very close to the Sun for several days last November and in April 2019. Parker Solar Probe during its two encounters traveled within 15 million miles of the Sun’s surface, far surpassing the 25-million-mile record first set by NASA’s Helios 2 mission in 1976. Parker has also claimed the title of the fastest human-made object in history from Helios 2, as it surfed near the Sun at over 153,000 miles per hour. Its first batch of released results came from measurements of the corona, which is, remarkably, hotter than the surface itself. The corona extends millions of miles from the surface into space. The region is only visible to the naked eye during a solar eclipse as a golden ring hanging in a darkened sky. The corona emits powerful streams of high-energy particles, known as solar wind, which can be felt all across the solar system. Parker’s data shows that solar winds are far more turbulent near the sun than in our own vicinity. The wind drags the sun’s magnetic field out into space, and even bends the field enough for magnetic forces to completely flip around for a few minutes at a time, pointing back at the sun itself instead of into space. The strength of this effect was completely surprising and puzzling. Scientists also found that shifts in the sun’s magnetic field speed up the particles flowing away from the sun much faster than any of their models had previously predicted.

This really highlights the idea that proximity is everything for studying the sun. Parker continues to edge closer to the sun. As its orbit shrinks, it will eventually reach a perihelion distance of just 6.16 million km in 2025, where it will experience temperatures of nearly 1400°C. Thanks to the protection provided by its specially-designed, carbon-composite heat shield, the probe won’t melt and the spacecraft and its instruments will be kept at a temperature of about 29°C.

Science Stands Behind Bilingual Children

Nicoladis et al. “How to use a wide variety of words in telling a story with a small vocabulary: cognitive predictors of lexical selection for simultaneous bilingual children.” Language, Cognition and Neuroscience, October 2019.

A new study shows that bilingual children use just as many words while telling a story in either language as do children who only speak one language. Past research showed that bilingual children score lower than monolingual children on traditional vocabulary tests. However, these new findings may change the understanding of multiple languages and cognition in children. Learning a word is directly related to how much time is spent in each language. For bilingual children, time is split between languages. As expected, they tend to have lower vocabularies in each of their languages. However, this new research shows that as a function of storytelling, bilingual children are equally strong as monolingual children. Researchers examined a group of French-English bilingual children who had been taught two languages since birth, rather than learning a second language later in life. They used a new, highly sensitive measure for examining cognitive flexibility, a participant’s ability to switch between games with different rules, while maintaining accuracy and reaction time. Their study builds on previous research examining vocabulary in bilingual children who have learned English as a second language. Overall, the bilingual children used just as many words to tell a story in English as monolingual children. The children also used just as many words in French as they did in English when telling a story. Their analysis suggests that the number of words that bilingual children use in their stories is strongly correlated with their high levels of cognitive flexibility—the ability to switch between thinking about different concepts. Researchers emphasize that parents of bilingual children do not need to be concerned about long-term school achievement. Vocabulary is a strong predictor of success in education, and so is storytelling. In a storytelling context, bilingual kids are able to use this flexibility to convey stories in creative ways.

New Tomatoes Engineered for Urban Gardens and Outer Space

Kwon CT et al. “Rapid customization of Solanaceae fruit crops for urban agriculture.” Nature Biotechnology, December 2019.

Humanity have a massive problem: feeding our future selves. As a result of rising population, continued destruction due to climate change, and the fact that sustainable land use is becoming ever-more challenging, learning how to grow enough food for everyone is a burning question to address in the agriculture field. In an effort to grow more crops in smaller and less-than-ideal locations, scientists developed new genetically-modified “urban” tomatoes that ripen in compact bunches similar to grapes. These tomatoes resemble a bouquet whose roses have been replaced by ripe cherry tomatoes. They also mature quickly, producing ripe fruit that’s ready for harvest in less than 40 days. Scientist utilized the CRISPR gene-editing technology and produced the new tomatoes by fine-tuning three genes that control the switch to reproductive growth and plant size: 1) the SELF-PRUNING (SP), 2) SP5G, and 3) SIER genes. While the first two genes have the duty prevent growth, flowering and fruiting of the plant sooner, the SIER gene is in charge of controlling the length of the plant’s stems. Altering the first two genes resulted in tomato plants that didn’t produce a lot of fruit and tasted poorly. It was not until the scientists identified the third gene that they were able to produce the desired plant. This study demonstrates that we can produce crops in new ways, without having to tear up our land as much or add excessive fertilizer that runs off into rivers and streams. This could also be a complementary approach to help feed people locally and with a reduced carbon footprint. Climate change is expected to change growing conditions on Earth, worsening conditions for many crops.

Farmers could soon be growing tomatoes bunched like grapes in a storage unit, in a shipping container, on the roof of a skyscraper, and – as humanity stretches out past low Earth orbit toward the moon – eventually, in Mars.

When Did English and Hindi Begin to Differ?

The long-established “comparative method” of linguistics uses vocabulary, the structure of words, and the sound systems of languages to draw language family trees, depicting in what order related languages (such as, English, Hindi, and ancient Hittite) diverged from their mother languages and the relative “relatedness” of sister languages. Dates of divergence are usually referred to dates of historical or archaeological significance. For example, the Romanian language, a relative of Italian, must have been introduced to the region between 112 and 270 AD, when Roman troops occupied Dacia. However, the comparative method does not provide any dates itself, other than those of relative chronology. Lexicostatistics, the rival study for vocabulary change, extracts essential vocabulary from languages, such as “I, three, and hand,” which are assumed to be more resistant to change, and produces a metric of shared cognates and, hence, language kinship. Assuming a constant rate of language change over time, one can extrapolate to pre-history dates for language evolution. For example, one may try to estimate when the proto-Indo-European, the ancestor of English, Hindi, and Hittite, started branching into distinct new languages. Unfortunately, the promise of lexicostatistics (and its method, called glottochronology) became doubtful quickly after its birth. It was criticized very much in the same way as biological phylogenetic analyses were. One example to show the correspondence is that just as the mutation rates of genes (sequences of DNA) may change over time, languages may also be changing faster or slower at certain periods. Lexicostatistics is unreliable, as the similarity between languages could be mere chance convergences, or borrowings, or on the other hand, distant relatives could be unrecognizable after a great deal of divergence. These objections have plagued biology in similar ways.

Phylogenetics and Philology Side by Side

IJeJaEghoManMeHandMainRukaCheriDastHathThreeTroisTriTriaSeTinMotherMereMatMiteraMaderMaNewNouveaunoviykenuryosTazeNeyanoseNezNosMitiNaNak

Figure 1: A partial list

for Indo-European words used by Gray and Atkinson (Dyen, I. Kruskal, J.B. & Black, P., FILE IE-DATA1 at http://www.ntu.edu.au/education/langs/ielex/IE-DATA1)

The recent study by Gray and Atkinson from the University of Auckland, New Zealand, published on November 27 in Nature, uses enhanced methods developed for phylogenetic studies in language tree construction, which produces trees that are consistent with those established by the comparative method. Most importantly, maximum-likelihood models and the Bayesian inference method were employed, both being statistical methods now established in phylogenetics, to counteract any weaknesses found in past attempts of glottochronology. Their method makes it possible to estimate divergence times without a strict rate of change, also enabling the determination of unsubstantiated sections of the tree, and the incorporation of these uncertainties in the calculation of the trees and divergence times. Gray and Atkinson only used fourteen age constraints to calibrate their divergence time calculations in estimating chronology, and after confirming tests eliminated some of these constraints, doubtful cognates, and other problems, they were able to come up with a date for the initial divergence of all Indo-European languages of 7,800 to 9,800 years ago. These dates coincide beautifully with the Anatolian farmer hypothesis, which claims dispersion of Indo-Europeans from Anatolia (modern-day Turkey) with the spreading of agriculture around 8,000-9,500 years ago, a hypothesis now supported by genetic studies that report a Neolithic, Near Eastern contribution to the European gene pool as well.

An Alternative Theory

This study does not extinguish one of the fiercest discussions of this century, which is favored by many linguists, that linguistic evidence favors the Kurgan expansion hypothesis, with Kurgan horsemen invading and spreading from the Asian steppes 6,000 years ago. It is thought that Kurgan horsemen possessed certain advantages, like the knowledge of the wheel and horseback riding, just as the Anatolians knew about farming. These linguists claim that the statistical and computational methods used in biology do not reflect the way languages change, and these methods use only vocabulary, but ignore grammar. This new study is a shot in the arm for the supporters of the Anatolian theory and resurrects glottochronology. Obviously, the discussion is far from being over. To reconcile the two, Gray and Atkinson note that they have observed an intense diversification period in their data at a date of 6,000 years ago, and they refer to an inclusive theory of both Anatolian origin and Kurgan expansion.2

Intertwined Trees

In their article Gray and Atkinson predict the combination of computational phylogenetic methods and vocabulary data to examine archaeological hypotheses in the future, as methods developed for biology continue to establish themselves in social sciences. As David Searls of Glaxo-Smith-Kline Pharmaceuticals concludes in his “News and Views” article in the same issue of Nature,3 “[this work] should stimulate even more cross-fertilization of ideas among those studying the intertwined trees of life and language.”