Posts tagged "science writing"
Could there be oceans of diamond in the outer solar system?
Although diamond is a common material on Earth, its melting point is very difficult to measure—as it’s heated to high temperatures, it physically changes into graphite before melting into liquid. In order to stop this change and find the actual melting point of diamond, researchers raised the pressure as well as the temperature. An experiment led by Jon Eggert of Lawrence Livermore National Laboratory used the powerful Omega laser to blast tiny diamonds just two millimeters in diameter, raising them to temperatures of 110,000 Kelvin and pressures of 4,000 giga Pascals—40 million times the pressure you feel at sea level on Earth. They found that liquefied diamond acts like water. When they reduced the temperature and pressure again, microscopic diamond chunks formed and floated atop the liquid—the solid was less dense than the liquid, just like ice and water. Such ultrahigh temperatures and pressures are found in Neptune and Uranus on the outskirts of our solar system, which are composed of approximately 10% carbon, so it’s plausible that these huge gas giants could contain oceans of liquid diamond. This could help explain the strange orientation of the planets’ magnetic fields, which are out of alignment with the planets’ rotation by up to 60 degrees—it’s the equivalent of moving Earth’s magnetic south pole to Central Australia. Seas of internal liquid diamond in Neptune and Uranus would affect their magnetic fields and therefore could be responsible for the mismatched poles. Eggert suggests that they could have “liquid carbon core surrounded by floating diamond or possibly ‘diamond-bergs’”, but it’s a speculative scenario.
Fractals in Nature
A fractal is a geometric figure that repeats itself on progressively smaller scales, so even if you zoom in an infinite number of times, the pattern will still roughly look like a copy of the whole. Fractals are interesting because they produce irregular shapes that can’t be represented by classical geometry or mathematically described in normal ways. They have the potential to help study galactic clusters, predict natural disasters, create random and organic graphic codes, and understand the movement of chaotic fluids. Fractal patterns also commonly appear in nature, but on a finite scale. They’re found in clouds, mountains, coastlines, snowflakes, crystals, lightning, rivers, cauliflower, and even systems of blood vessels—and by understanding the mathematics that defines them, we can better understand our world.
The Amazing Spider Silk
Spider silk is incredibly strong and flexible, with five times the tensile strength of steel and triple that of the best man-made fibres, but these properties have yet to be replicated artificially—even by fibres produced from pure spider silk proteins. The silk’s protein molecules are long chains consisting of thousands of amino-acid elements, and the interlinking of these chains is how such stable and elastic fibres are created. However, scienctists still don’t understand how the proteins within the silk gland are linked and deployed—they’re thought to have a special storage configuration. Artificially producing spider silk would create enormous engineering possibilities—its ability to sustain selective damage without compromising the entire system could be applied to virtual networks, and its microscopic protein structures could help in stringing together carbon nanotubes. While we’re waiting for science to help us become Spiderman, a group of designers in Austria have created an artistic artificial version of a spider web—made out of 35 km worth of packing tape. The art installation is known as “For Use”, and the cocoons of tape stretched through midair are strong enough for visitors to climb inside and explore—luckily, without becoming ensnared.
Does the Universe have a North?
Humans evolved in an environment with gravity and a magnetic field, so we’re so used to concepts such as up and down, north and south. There is actually no “right way up” in the universe, no universally common axis—because direction relies on the observer. Earth only has a north and south due to its magnetic field created by the rotation of its molten core, and these concepts only apply in a coordinate system. Compass directions or longitudinal lines don’t actually “exist”—they’re purely reference points created by humans for navigation. Australia, for example, is only known as “down under” because our navigational system decided that the southern hemisphere is downwards. Similarly, up and down are concepts that we’ve created to refer to gravity’s pull—‘up’ is away from the centre of gravity and ‘down’ is towards it. In the context of the universe, however, there’s no north or south or up or down. There is no universe-spanning magnetic field, so the universe has no up and down, no centre, no edge (you’re welcome nerdfighters), and no point of reference relative to everything else. So, there’s no intrinsic north in space—it’s difficult to imagine, but the idea that north is ‘up’ and south is ‘down’ is a purely human concept.