How we could discover quantum gravity without rebuilding space-time

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MODERN physics has 2 stories to archer astir our universe. The archetypal says it is fundamentally made of space-time: a continuous, stretchy cloth that has ballooned since the dawn of time. The different says it is fundamentally made of indivisible things that can’t determine wherever they are, oregon adjacent when.

Both stories are compelling, describing what we observe with unthinkable accuracy. The large difference, though, is the standard astatine which they apply. Albert Einstein’s mentation of general relativity, which describes gravity, abstraction and time, rules implicit precise monolithic objects and cosmic distances. Quantum physics, meanwhile, governs tiny, sprightly atoms and subatomic particles.

Ultimately, some stories can’t beryllium true. Nowhere is this much evident than astatine the big bang, wherever everything successful the beingness was compacted into an infinitesimally tiny point. Here, you request a azygous mentation that encompasses gravity and the quantum realm. “Why we’re present is the large question,” says Toby Wiseman, a theorist astatine Imperial College London. “It seems that quantum gravity is the lone answer.”

Alas, it is an reply we are yet to find, contempt galore decades of searching. Quantum gravity means a reconciliation of the continuous and the indivisible, the predictable and the random. There are galore ideas, but nary tin wholly incorporated everything. “We’re inactive nary amended disconnected astatine knowing the opening of abstraction and time,” says Wiseman.

Most physicists attempting this statesman with quantum physics, the workhorse of which is quantum tract theory. This describes 3 of the four forces of nature – electromagnetism, the beardown atomic unit and the anemic atomic unit – by “quantising” them arsenic force-carrying simple particles. It …