Whether it's more troubling to imagine that the Universe goes on forever in every direction, or that it has an edge, beyond which there is nothing, is hard to say. Astrophysics doesn't provide any guidance as to which flavour of existential crisis we should be having - while we can't say with any level of confidence whether the Universe goes on forever or not, we can say that our observable universe has an edge, in the sense that there's a distance beyond which, whatever may or may not exist, we absolutely cannot see it.
The existence of this cosmic horizon is part of the answer to an ancient conundrum about the darkness of the night sky, reportedly first posed by Johannes Kepler in 1610 but later attributed to fellow astronomer Heinrich Olbers in the 1800s.
Olbers' Paradox asks: if the Universe is infinite, and if there are stars (or galaxies) throughout it, why is the sky dark? Surely, if we look in any direction in the sky, that sightline will, eventually, land on a star. Common sense therefore tells us that everywhere we look, the sky should be as bright as the Sun, constantly aglow.
SOLVING THE PARADOX
Bu hikaye BBC Science Focus dergisinin July 2022 sayısından alınmıştır.
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Bu hikaye BBC Science Focus dergisinin July 2022 sayısından alınmıştır.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Giriş Yap
COULD MARINE CLOUD BRIGHTENING HELP US FIGHT CLIMATE CHANGE?
The theory behind marine cloud brightening is that brighter or whiter clouds reflect more sunlight back into space.
IS IT SAFE TO RUN EVERY DAY, OR SHOULD I DITCH MY RUN STREAK TO SAVE MY KNEES?
A running streak, where you run every day without taking rest days, can be highly motivating and beneficial for overall fitness. Running is great cardiovascular exercise and isn't to be discouraged (and finding a routine with some consistency is great). Getting a bit of exercise as often as possible is also hugely beneficial for your mental health.
WHAT MAKES THE MEDITERRANEAN DIET SO GOOD FOR US?
The Mediterranean diet may help you live longer, especially if you also adopt the lifestyle of people living near the Med during the 1950s.
WHAT IS MEXICO'S BLUE HOLE?
The world's deepest blue hole (marine sinkhole) lies off the coast of Mexico's Yucatán Peninsula. It's at least 420m (1,378ft) deep, but explorers still haven't found its bottom.
HOW CAN I TELL IF I'VE GOT HIGH CORTISOL LEVELS?
Cortisol is a hormone produced by glands in our bodies called the adrenal glands, which sit above the kidneys. It plays a critical role in various bodily functions, including regulating metabolism, reducing inflammation and helping the body respond to stress. While essential for our health, chronic elevation of cortisol levels can lead to several issues.
THE LUNGFISH
In 1836, European scientists discovered a peculiar animal from the River Amazon that they struggled to identify. Its eel-like body was a few feet long and its air-filled lungs persuaded anatomists it must be a reptile.
ARE WE THE ONLY SPECIES TO HAVE BEEN THROUGH A STONE AGE?
The Stone Age might conjure up images of early humans, sitting around a campfire or hunting prehistoric beasts, but evidence shows that we're not the only species that has learned how to work with stone tools. Wild chimpanzees (Pan troglodytes) use stone tools to crack open nuts.
Should we scrap daylight saving time?
Most of us look forward to the extra hour we get in bed every October, but researchers argue that changing the clocks twice a year harms our health
THE INTERNET OF ANIMALS
SCIENTISTS ARE USING ELECTRONIC TAGS AND SATELLITES TO TRACK WILD ANIMALS AND CREATE A DATA NETWORK THAT COULD HELP US ADDRESS THE BIODIVERSITY CRISIS
MUSIC FOR A DISTRACTED GENERATION
The number of things competing for our attention is often overwhelming. Can dreamy soundscapes created with neuroscience help our bewildered brains to concentrate?
