Quantum theory says that an object can be measured only at the end of it’s journey
There’s an old adage among quantum theorists — if a tree falls in a jungle and no one hears it fall, has it actually fallen? As an extension to this, scientists have conducted an experiment to prove that the world, you, everyone around you, and for that matter, the universe, does not exist till it is measured/seen/experienced.
Australian scientists have recreated a famous experiment and confirmed quantum physic’s bizarre predictions about the nature of reality, by proving that reality doesn’t actually exist until we measure it, reports sciencealert.com. That all sounds a little mind-meltingly complex, but the experiment poses a pretty simple question: If you have an object that can either act like a particle or a wave, at what point does that object “decide”?
But quantum theory predicts that the result depends on how the object is measured at the end of its journey. And that’s exactly what a team from the Australian National University has now found. “It proves that measurement is everything. At the quantum level, reality does not exist if you are not looking at it,” lead researcher and physicist Andrew Truscott said in a press release.
Known as John Wheeler’s delayed-choice thought experiment, the experiment was first proposed back in 1978 using light beams bounced by mirrors, but back then, the technology needed was pretty much impossible. Now, almost 40 years later, the Australian team has managed to recreate the experiment using helium atoms scattered by laser light.
The experiment involves a moving object that is given the choice to act like a particle or a wave. Common sense says the object is either wave-like or particle-like, independent of how we measure it. But quantum physics predicts that whether you observe wavelike behaviour or particle behaviour depends only on how it is actually measured at the end of its journey.
This may sound incredibly weird, it’s actually just a validation for the quantum theory that already governs the world of the very small. Using this theory, we’ve managed to develop things like LEDs, lasers and computer chips, but up until now, it’s been hard to confirm that it actually works with a lovely, pure demonstration such as this one.
