World's largest telescope
China spent $180 million to create the telescope, which officials have repeatedly said will make the country the global leader in radio astronomy. But the local government also spent several times that on this nearby Astronomy town, hotels, housing, a vineyard, a museum, a playground, classy restaurants, all those themed light fixtures. The government hopes that promoting their scope in this way will encourage tourists and new residents to gravitate to the historically poor Guizhou province.
It is, in some sense, an experiment into whether this type of science and economic development can coexist. Which is strange, because normally, they purposefully don’t.
The point of radio telescopes is to sense radio waves from space—gas clouds, galaxies, quasars. By the time those celestial objects’ emissions reach Earth, they’ve dimmed to near-nothingness, so astronomers build these gigantic dishes to pick up the faint signals. But their size makes them particularly sensitive to all radio waves, including those from cell phones, satellites, radar systems, spark plugs, microwaves, Wi-Fi, short circuits, and basically anything else that uses electricity or communicates. Protection against (Radio Frequency Interference), or RFI, is why scientists put their radio telescopes in remote locations: the mountains of West Virginia, the deserts of Chile, the way-outback of Australia.
FAST’s site used to be remote like that. The country even forcibly relocated thousands of villagers who lived nearby, so their modern trappings wouldn’t interfere with the new prized instrument.
It is, in some sense, an experiment into whether this type of science and economic development can coexist. Which is strange, because normally, they purposefully don’t.
The point of radio telescopes is to sense radio waves from space—gas clouds, galaxies, quasars. By the time those celestial objects’ emissions reach Earth, they’ve dimmed to near-nothingness, so astronomers build these gigantic dishes to pick up the faint signals. But their size makes them particularly sensitive to all radio waves, including those from cell phones, satellites, radar systems, spark plugs, microwaves, Wi-Fi, short circuits, and basically anything else that uses electricity or communicates. Protection against (Radio Frequency Interference), or RFI, is why scientists put their radio telescopes in remote locations: the mountains of West Virginia, the deserts of Chile, the way-outback of Australia.
FAST’s site used to be remote like that. The country even forcibly relocated thousands of villagers who lived nearby, so their modern trappings wouldn’t interfere with the new prized instrument.
The Five-hundred-meter Aperture Spherical radio Telescope, nicknamed Tianyan, is a radio telescope located in the Dawodang depression, a natural basin in Pingtang County, Guizhou, southwest China. It consists of a fixed 500 m diameter dish constructed in a natural depression in the landscape. Wikipedia
thermochromic cement
Conventional asphalt strongly absorbs the energy from sunlight due to its black colour. The induced high surface temperature on asphalt pavement during summer and fast temperature drop during winter accelerate the rutting and cracking, impairing its long-term durability. Thermochromic materials, substances that can reversibly change their colours in response to temperature, are characterised as high solar reflectance above certain threshold temperature and high absorbance below the threshold temperature.
Results of measurements under hot weathers found that the surface temperature of thermochromic asphalt coating is lower than that of the conventional asphalt coating with the maximum decrease as high as 6.6°C. This helps to improve its resistance to high temperature-related performance degradation (such as rutting and fatigue).
Experimental results during cold weathers indicated that the surface temperature of asphalt concrete covered with thermochromic asphalt coating is generally 1°C higher than that of conventional asphalt coating. This means thermochromic asphalt can potentially delay ice formation on the surface of the road than traditional asphalt. Therefore, the incorporation of thermochromic materials into asphalt pavement will potentially help improve the durability, reduce undesirable environmental impacts, and improve the safety of asphalt roads.
