What would happen if the sun disappeared: let’s assume the effects for life on earth

In life there are few certainties. It rains on the day when the predictions gave good weather, the person who wanted you so much ends with someone else, health goes and goes, but on one thing we can be sure: the sun will arise in the morning. On the sun we can count. The sun does not disappear. Ok, but what would happen if it disappeared? In this purely hypothetical scenariowould go down one freezing and perpetual night with temperatures of –70 ° C everywhere in the world. The entire biosphere would collapse, and to survive we should build some underground bunker powered by geothermal and nuclear energy.

If the sun disappeared, we wouldn’t realize it immediately

The relationship between earth and sun is based on severity. It is this fundamental “strength” that keeps our planet linked to its star in a stable orbit that for 4.5 billion years obeys faithfully to the laws of Kepler. If the sun suddenly disappeared, the first thing that would miss the earth would be this gravitational attraction.

The amazing thing is that We would only notice 8 minutes and 20 seconds later! Gravity does not propagate instantly in space, but – in accordance with Einstein’s theory of relativity – does it at the speed of light, which is approximately 300,000 km/s. The earth is just under the sun of 150 million kma distance that at the speed of light is covered in 8 minutes and 20 seconds. This is the time that gravitational information “The sun is no longer there” would use to get to us.

The solar system would “turn off” gradually

Without the severity of the sun, the earth would no longer have any reason to be in orbit. Just like a ball linked to a thread that we rotate, with the breakdown of the gravitational “thread” our planet would start – literally – for the bribe and would begin to travel in a straight line maintaining the speed it had before, that is 108,000 km/h.

The moon would follow us, because it would continue to feel terrestrial gravity. We couldn’t see it anymore, though. The moon appears to us to shine because it reflects the light of the sun, so no sun would mean No lunar glow. To be precise, after the disappearance of the sun we would still see the moon for 1.3 secondswhich is the time that it takes the light to cover the earth-long distance (on average 384,000 km). After this clay beat, however, we could not even count on the moonlight.

Gradually also the planets of the Solar System, which reflect the light of the sun, would disappear from the firmament, especially the more far from the sun. Saturn, for example, which is the most distant planet visible to the naked eye from the land, would abandon us after a couple of hours. The stars, however, who emit their own light, will not disappear: indeed, we could rediscover the Milky Way, the light strip that light pollution made us forget.

A freezing perennial night

A plethora of phenomena depends on the sun that have always accompanied our planet, so much so as to take them for granted. The most obvious effect is that on earth There would no longer be the alternation between the day and the nightbut a perpetual darkness throughout the globe. On the sun also depends on the seasons cycle: no more spring, summer, autumn and winter. The energy coming from our star is then the engine of all meteorological phenomena: farewell to the rain, winds, clouds and so on.

But the most devastating effect would be the drastic drop in temperatures in every part of the world. Solar energy keeps us warm, not only directly but also through the greenhouse effect produced by our atmosphere. Without sun, the earth would begin to cool down, dispersing its internal heat in space: within a week the globe would come to 0 ° C; The mercury column would stop at –70 ° C within a year. In a couple of years all the oceans would freeze.

Life would end (but not all)

However, a world without sun would have another great problem, this time of a biological nature. The whole biosphere depends on the energy coming from the sun. You know the photosynthesis? That process for which plants are maintained in life by producing sugars using sunlight. Here, without sunlight Photosynthesis would interrupt instantly: We should say goodbye to all the terrestrial vegetation within a few weeks.

Animals would not pass it better. As long as you find a solution for antarctic temperatures, oxygen in the atmosphere kindly offered to us by the plants would be enough to make us breathe for millennia: the problem is that without vegetation it would collapse the entire food chain. In fact, what would the herbivores eat? Once they are extinct, what will carnivores eat? The Saprophages – who feed on other dead organisms – would have to eat for a while, but even for them sooner or later the food would end.

However, not all terrestrial life would be destined to disappear. In fact, there are organisms that do not depend on sunlight, and it will not be surprised to know that they are in the ocean seabed. The hydrothermal sources In fact, they provide energy directly from the subsoil and abundance of chemical elements. These two factors have allowed the development of microorganisms that do not need photosynthesis but live thanks to chemosynthesis: that is, they transform heat and chemicals into energy, hydrothermal sources Endeavour2200 meters deep off the island of Vancouver, western Canada. Here are organisms that have no need for sunlight. Extreme ecosystems like this would be the only ones who are not likely touched by the disappearance of the sun.

How could we survive?

In the absence of solar energy, the survival of humanity would be linked to those areas of the world in which it is possible to draw on the other source of energy that we have: that coming from inside the earth. It would be a race to geothermal locations, such as those in Icelandwhere the terrestrial heat could mitigate the frost and offer an energy source. Small human communities could in principle survive by building – very quickly, though – underground shelters self -sufficientpowered by geothermal energy and nuclear energy. For power it could be resorted tohydroponic agriculture. Sooner or later, however, we would have the problem of oxygen, since the atmosphere is frozen. We should heat it and thus free the precious oxygen contained inside.

This apocalyptic scenario is destined to last forever, unless – with an incredible fortune – in the distant future our planet should enter in the orbit of another star At the right distance from the latter to allow temperatures to return comfortable and the life of flourishing. But it would be a very utopian hope: given the vastness of the cosmos, The probability would be infinitesimaland anyway the cup -up long timing.

If it happens, however, new forms of intelligent life could finally walk again on Earth without knowing anything about what happened, if not reconstructing it geological. They would call the earth with a new name, unaware of its history and the star that once had allowed our existence.