A new interactive program reveals the spectacular light show you鈥檇 see if you dared to wander close to a black hole. It demonstrates how the extreme gravity of a black hole could appear to shred background constellations of stars, spinning them around as though in a giant black washing machine.
The program鈥檚 creators say it could be an excellent tool to familiarise people with the weird ways that black holes warp light. 鈥淚t鈥檚 useful for people to play around with the parameters to study how, for instance, a black hole would distort the constellation Orion,鈥� says of the in Germany.
A black hole forms when a massive star explodes at the end of its life, the core collapsing to a point with huge density and an enormous gravitational pull. Even at a safe distance from the black hole, its gravity can distort the apparent positions of background stars, an effect called gravitational lensing.
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Last year, scientists at the University of Colorado demonstrated a video of what you鈥檇 see if you fell into a black hole.
Now M眉ller and Stuttgart colleague have gone a step further, creating a that lets you alter various inputs to tour a black hole鈥檚 environs.
Real data
The program incorporates the real positions of around 118,000 stars mapped by the European Space Agency鈥檚 satellite. Users can choose their distance from a black hole, then go into orbit or plunge straight in.
At the start of each tour, you see a black circle that marks the hole鈥檚 event horizon 鈥� the boundary from which nothing, not even light, can escape. The light of background stars distorts as it passes close to the event horizon.
shows the view while orbiting a black hole at a radius five times larger than the event horizon. In the background, the constellation Orion moves towards the black hole from the right, then gets shredded and spun around.
鈥楲ike a mirror鈥�
鈥淭he constellation approaches the black hole, then you see stars like Betelgeuse 鈥� the left shoulder of Orion 鈥� appear twice, on the right and left sides of the black hole,鈥� M眉ller told New 杏吧原创. 鈥淚t鈥檚 as if the black hole is like a mirror.鈥�
As well as accounting for gravitational lensing, the simulator shows how star colours would change near a black hole. The intense gravity makes background stars appear redder because it saps the energy of photons passing near the event horizon; the photons stretch to longer, redder wavelengths as they 鈥渃limb out鈥� of the gravitational trap.
But this effect is counteracted by your speed when you鈥檙e falling freely towards a black hole 鈥� travelling at nearly the speed of light, stars in the black hole鈥檚 backdrop turn bluer due to the . In a mimicking such unhindered freefall, the light of the entire universe appears concentrated into a bright ring once you reach the middle of the black hole.
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