Dark matter and the cosmic web connect galaxies like city superhighways
Giant filaments crisscross the universe, connecting galaxy clusters like superhighways between cities. Their shape and structure contain vital information about the universe’s contents and history. However, their complex shape makes them extremely difficult to measure. Now, researchers have presented a new method for measuring the mass of these filaments, which could be used to unlock the secrets of dark matter and dark energy.
Geological age of planets: scientists reveal secrets of its determination
Recent advances in geochronology, or rock dating, allow geologists to measure radioactive decay and assign very precise absolute ages to geological events. In another study, scientists found isotopic evidence of a sudden switch to primitive plate tectonics dating back about 3.8 billion years. The discovery suggests that a simple form of subduction had begun at least in one place on the planet by that time. And a tree-lined African lake has provided data on the Earth’s magnetic field for the past 150,000 years.
Solar flares and magnetic storms pose a real danger
About once every thousand years, Earth experiences an extreme solar event that can cause severe damage to the ozone layer and increase ultraviolet (UV) radiation levels at the surface. Over the past century, the north magnetic pole has moved across northern Canada at about 40 kilometers per year, and the field has weakened by more than 6%. Geological records show that there have been periods of centuries or millennia when the geomagnetic field was very weak or even absent.
The Corona Paradox of the Sun
Scientists have long wondered why the hot charged particles in our sun’s atmosphere get hotter as they move away from the sun’s surface. A new study may provide an answer, finding that the super-hot nature of the sun’s outer atmosphere, or “corona,” may be linked to the intriguing behavior of small-scale waves in this hazy plasma. These waves, known to scientists as “kinetic Alfvén waves,” or “KAWs,” are wave-like oscillations of magnetic fields that manifest themselves in motions in the sun’s photosphere.
Magnetic field and sea
German zoologists have found that bottlenose dolphins are as good as sharks and other fish in their ability to sense very weak electric fields, which allows these cetaceans to use the Earth’s magnetic field for orientation in space. Underwater compasses have recorded disturbances in the Earth’s magnetic field deep under water.
Scientists have linked the development of life with a magnetic field and concluded about magnetic fields on other planets
The weakening of the Earth’s magnetic field has led to a dramatic acceleration in the evolution of multicellular life. Fossil evidence has been found in Brazil and South Africa that the strength of the Earth’s magnetic field was about 30 times weaker than today’s values at the end of the Ediacaran period, about 590 to 560 million years ago. One of the defining features of the Earth is its magnetic field. It forms a protective shield against high-energy particles ejected by the Sun, and thus may have provided a safer place for life to grow into the complex array of organisms we see today.
Far-reaching plans – terraforming Mars
The main problem for changing the appearance of Mars is the lack of a strong magnetic field that can protect the atmosphere from solar winds that burn water in it. The magnetic field creates a kind of bubble that protects the planet from the oncoming solar winds. For example, the Earth’s magnetic field prevents most high-energy particles from reaching the planet’s surface.