The Weird World- Quantum World

No matter how hard physicists probe, they still puzzle over this, 

the universe's deepest secret

If you'e interested in the smallest things known to scientists, there's something you should know. they are extraordinary ill-behaved. but that's to be expected. their home is the quantum world.

Although they might be found anywhere, the certainly of finding one of these particles in any particular place is zero. Scientists can predict where they might be — yet they never know where they are. (That's different than, say, a baseball. If you leave it under your bed, you know it’s there and that it will stay there until you move it.)These subatomic bits of matter don’t follow the same rules as objects that we can see, feel or hold. These entities are ghostly and strange. Sometimes, they behave like clumps of matter. Think of them as subatomic baseballs. They also can spread out as waves, like ripples on a pond.

“The bottom line is, the quantum world just doesn’t work in the way the world around us works,” says David Lindley. “We don't really have the concepts to deal with it,” he says.

Quantum physics will play an important role in future technologies — in computers, for example. Ordinary computers run calculations using trillions of switches built into microchips. Those switches are either “on” or “off.” A quantum computer, however, uses atoms or subatomic particles for its calculations. Because such a particle can be more than one thing at the same time — at least until it's measured — it may be "on" or "off" or somewhere in-between. That means quantum computers can run many calculations at the same time. They have the potential to be thousands of times faster than today's fastest machines.

Quantum physics isn't just a cool and quirky discovery, though. It's a body of knowledge that will change in unexpected ways how we see our universe — and interact with  it.

A quantum recipe

Quantum theory describes the behavior of things — particles or energy — on the smallest scale. In addition to wavicles, it predicts that a particle may be found in many places at the same time. Or it may tunnel through walls. (Imagine if you could do that!) If you measure a photon’s location, you might find it in one place — and you might find it somewhere else. You can never know for certain where it is.

Also weird: Thanks to quantum theory, scientists have shown how pairs of particles can be linked — even if they’re on different sides of the room or opposite sides of the universe. Particles connected in this way are said to be entangled. So far, scientists have been able to entangle photons that were 1,200 kilometers (750 miles) apart. Now they want to stretch the proven entanglement limit even farther. 

Quantum theory thrills scientists — even as it frustrates them.

is your wit oke?

If quantum theory sounds strange to you, don’t worry. You’re in good company. Even famous physicists scratch their heads over it.

“I think I can safely say that nobody understands quantum [theory],”

 noted American physicist Richard Feynman once said. And yet his work in the 1960s helped show that quantum behaviors aren’t science fiction. They really happen. Experiments can demonstrate this.

Remember Einstein, the German genius? He helped describe quantum theory. And he often said he didn’t like it. He argued about it with other scientists for decades. 

“If you can think about quantum theory without getting dizzy, you don't get it,” 

Danish physicist Niels Bohr once wrote. Bohr was another pioneer in the field. He had famous arguments with Einstein about how to understand quantum theory. Bohr was one of the first people to describe the weird things that pop out of quantum theory.

Welcome the Multi-Universe

As scientists conduct quantum experiments on larger groups of particles, the theory will hold. And those experiments will unveil new aspects of quantum theory. Scientists will learn how their equations describe reality and be able to fill in the missing pieces. Eventually, they will be able to see more of the whole picture.

Maybe our world is one of many. It’s possible that infinitely many worlds exist. If true, then their are many 'you' other than 'you' in other worlds

Quantum theory describes Their may be one thing or another at the same time. And it gets weirder: Quantum theory also predicts that particles may be found in more than one place at a time. If the many-world idea is true, then a particle might be in one place in this world, and somewhere else in other worlds.

This weird idea is called the “many-world” interpretation of quantum mechanics. It is exciting to think about, but physicists have not found a way to test whether it’s true.

Tangled up in particles

Quantum theory includes other fantastic ideas. Like that entanglement. Particles may be entangled — or connected — even if they’re separated by the width of the universe.

Imagine, for instance, that you and a friend had two coins with a seemingly magical connection. If one showed up heads, the other would always be tails. You each take your coins home and then flip them at the same time. If yours comes up heads, then at the exact same moment you know your friend’s coin has just come up tails.

Entangled particles work like those coins. In the lab, a physicist can entangle two photons, then send one of the pair to a lab in a different city. If they measures something about the photon in their lab — such as how fast it moves — then they immediately knows the same information about the other photon. The two particles behave as though they send signals instantaneously. And this will hold even if those particles are now separated by hundreds of kilometers.

As in other parts of quantum theory, that idea causes a big problem. If entangled things send signals to each other instantly, then the message might seem to travel faster than the speed of light — which, of course, is the speed limit of the universe! So that cannot happen.

In June, scientists in China reported a new record for entanglement. They used a satellite to entangle six million pairs of photons. The satellite beamed the photons to the ground, sending one of each pair to one of two labs. The labs sat 1,200 kilometers (750 miles) apart. And each pair of particles remained entangled, the researchers showed. When they measured one of a pair, the other one was affected immediately. They published those findings in Science.

Scientists and engineers are now working on ways to use entanglement to link particles over ever-longer distances. But the rules of physics still prevent them from sending signals faster than the speed of light.      

why to Worry

If you ask a physicist what a subatomic particle really, truly is, “I don’t know that anyone can give you an answer,” says Lindley.

Many physicists are content with not knowing. They work with quantum theory, even though they don’t understand it. They follow the recipe, never quite knowing why it works. They may decide that if it works, why bother going any further?

Others, like Fedrizzi and Leggett, want to know why particles are so weird. “It’s far more important to me to find out what’s behind all of this,” Fedrizzi says.

Forty years ago, scientists were skeptical that they could do such experiments, notes Leggett. Many thought that asking questions about the meaning of quantum theory was a waste of time. They even had a refrain: “Shut up and calculate!”

Leggett compares that past situation to exploring sewers. Going into sewer tunnels might be interesting but not worth visiting more than once.

“If you were to spend all your time rummaging around in the bowels of the Earth, people would think you were rather strange,” he says. “If you spend all your time on the foundations of quantum [theory], people will think you’re a little odd.”

Now, he says, “the pendulum has swung the other way.” Studying quantum theory has become respectable again. Indeed, for many it has become a lifelong quest to understand the secrets of the tiniest world.

“Once the subject hooks you, it won’t let you go,” says Lindley. He, by the way, is hooked.

Zero-Point Energy

Zero-point energy, also known as ground state energy, could be the greatest gift the quantum world can every give us. It's byproduct of the fact that subatomic particles don't really behaves like single particles, but like waves constantly flitting between different energy states

this means even the seemingly empty vacuum of space is roiling sea of virtual particles fluctuating in and out of existence, and all those fluctuations require energy 

If there's as much energy in those fluctuations as some - through definitely not all - physicists believe, and if we could eve lean how to tap into this phenomenon, we would gain access to an unparalleled source of energy .

Zero-point energy could power the planet with the strength of multiple suns, making it easy for us to solve Earth's energy problems forever or to travel beyond the solar system and take our place among the stars

However, we can only guess how much energy is actually contained in the vacuum, with legendary physicists in fierce disagreement on this point

At last i just want to say we don't know enough about the universe to figure out weather zero-point energy -vacuum energy- really is a bombastic fountain of staggering power.  

“Things that right now seem fantastic will be possible.”

-Anthony Leggett