.........contd
In the familiar, human scale reality, an object exists in one well-defined place : Place your phone on your bedside table and that's the only spot it can be, whether or not you're looking for it. But in the quantum realm, objects exist in a smudge of probability, snapping into focus only when observed.
"Before you look at an object, whether it's an electron or an atom or whatever, it's not in any definite location", Carroll says. "It might be more likely that you observe it in one place or another but it's not actually located at any particular place".
Nearly a century of experimentation has confirmed that, strange as it seems, this phenomenon is a core aspect of the physical world. Even Einstein struggled with the notion : What happened to all of the other possible locations where the object could have been and all other different outcomes that could have ensued? Why should an object's behaviour depend on whether or not somebody was looking at it?
In 1957, a Princeton student named Hugh Everett III came up with a radical explanation. He proposed that all possible outcomes really do occur - but that only a single version plays out in the world we inhabit. All the other possibilities split off from us, each giving rise to its own separate world. Nothing ever goes to waste, in this view, since everything that can happen does happen in some world.
For decades, Everett's colleagues mostly brushed aside his explanation, treating it more like a ghost story than serious science. But nobody has found any flaws in Schrodinger's equation; nor can they explain away its implications. As a result, many contemporary physicists - including David Deutch at Oxford University and Max Tegmark at the Massachusetts Institute of Technology - have come to agree with Carroll that the many worlds interpretation is the only coherent way to understand quantum mechanics.
A field guide to many worlds
The many worlds interpretation raises all kinds of puzzling questions about the multiple versions of reality and about the multiple versions of you that exist in them. Carroll has some answers.
If new universes are constantly popping into existence, isn't something being created from nothing, violating one of the most basic principles of physics? Not so, according to Carroll : "It only looks like you are creating extra copies of the universe. It's better to think of it as taking a big thick universe and slicing it".
Why do we experience one particular reality but none of the others? "It's like asking why you live now instead of some other time. Everyone in every world thinks that they're in that world".
Carroll also has a disappointing response for one of the most compelling questions of all : Could you cross over and visit one of the other realities and compare notes with an alternate-world version of yourself? "Once the other worlds come into existence, they go their own way", Carroll says. "They don't interact, they don't influence each other in any form. Crossing over is like travelling faster than the speed of light. It's not something that you can do".
War of the many worlds
One criticism of the many worlds interpretation is that while it offers a colourful way to think about the world, it doesn't deliver any insight into how nature works. "It is completely content-less", says physicist Christopher Fuchs of the University of Massachusetts, Boston.
Fuchs favours an alternative called Quantum Bayesianism, which offers a path to an old-fashioned single reality. He argues that the universe changes when you look at it not because you are creating new worlds but simply because observation requires interacting with your surroundings. No coffee dates, no other lives for you. "In this way, measurement is demoted from being something mystical to being about things as mundane as walking across a busy street : It's an action I can take that clearly has consequences for me", he says.
- Corey S Powell
Two observations of the day
(a) The representatives of the striking farmers have said that in the event of the talks, scheduled with the government on 04 Jan, failing they would be marching with their tractors on the Rajpath on 26 Jan. So two things are getting clear :-
(i) They don't intend coming to an agreement during the discussions on the 4th.
(ii) Their intention is to disrupt the Republic Day parade - where the British PM, Boris Johnson is the chief guest - so that they deride the government and Modi, in particular, to get publicity and score brownie points! Don't they love their country?
(b) Akhilesh Yadav has issued a statement that he'll not let the BJP's vaccine to be administered on himself. What a cheap and narrow minded political statement? By saying so, he has questioned the professionalism of the scientists who have worked hard to make the vaccines a reality.
Tailpiece.
Got up at 6, the chores and was ready by a half past 9.
Participated in the Aazhchakkoottam : Life beyond Covid in 2021 by PP James, Editor-in-charge, 24 News (Flowers TV) from 1600-1730 hrs. It was interesting.
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