Las Vegas is understandably one of the brightest cities on the planet, with its famous Strip being easily visible from space. Many other cities do give Las Vegas a run for its money however. However, there are some cities that are more visible at night than others. Las Vegas is just one such example. Light pollution is defined as misdirected or wasted light as there is certainly a lot of this from all the neon signs and fluorescent lighting from the casinos and hotels. Moscow is also famous for its New Years display that lights up the night sky, and Instagram users have flooded the city with photos using the hashtag #MoscowLights.
London’s lights are so popular that they have their own hashtag on social media. The city has more than 62,000 posts on Twitter. Then there’s Buenos Aires, the red wine capital of South America. This city is also known as the Brightest Spot on Earth, and it has an astronomical light pollution level of 12 millicd/m2.
The brightest cities on Earth have a high level of light pollution. This makes it very difficult to see the night sky. Even if you are unable to see any of the stars in the metropolitan areas, you can still enjoy the city’s unique glow, much of it from neon signs that use plasma. For more details on the uses of plasma, consider Thermal Plasma Spray at a site like https://www.poeton.co.uk/advanced-treatments/apticote-800-thermal-plasma-spray/
Scientists often refer to the Bortle Scale to see how much light pollution there is in a particular area. Night Sky Brightness is another indicator of how much light pollution is experienced. This is calculated by measuring the amount of artificial light created and natural light that is present.
It was a result of the Industrial Revolution that began to light cities up at night. In the late 19th century, Paris led the way in bathing city areas in light when an urban planner had 20,000 gas lamps installed along the streets of the capital.
In contrast, the darkest city at night is Pyongyang in North Korea. Hong Kong is another of the world’s brightest cities, emitting 1,000 times more light than the international average for cities! In fact, cities are set to become even brighter as old style lighting makes way for LED lighting. Whilst LED lights have many benefits, such as lower energy consumption and low cost, there are also some downfalls with light pollution being one of them. They can have a high intensity blue lighting that causes glare.
Astonishingly, 80% of the world’s population lives in areas that are bathed in artificial light at night. In the Western world, that figure rises to 99%.