Read part 1 of Choices and the Uncertainty Principle here

THE reason that the laws of general relativity break down at the Big Bang is that it does not incorporate the most basic tenet of quantum theory - the uncertainty principle - the element that Einstein could never accept.

Quantum theory tells us that the very early Universe must have had a multitude of choices. It could have formed a black hole, there could have been no expansion of the Universe, the strength of gravity could have been stronger or weaker and there could have been no matter in the Universe, only radiation. All of these choices would have resulted in a still-born Universe.

The multitude of choices and resulting uncertainties form the basis of quantum theory. But the Universe, as big as it is today, is still subject to the uncertainties. It is like a gambler throwing the dice - there are a large number of possible rolls of the dice. It is interesting to note that in a large object such as the Universe, the multitude of choices average out to something we can predict. That is why we can apply Einstein’s theory so successfully to the Universe as a whole.

Scientists also refer to the multitude of choices as multiple histories. The well-known American theoretical physicist, Richard Feynman, has developed a mathematical framework to calculate the most probable outcome of multiple histories. The same formulae can be applied to determine the most likely position of an electron. Again, the closer we determine an electron’s position, the larger its velocity will be.

The uncertainties of the quantum world are not imaginary; they are real. Feynman's multiple histories idea of the Universe is now incorporated into general relativity to form a unified theory which could be used to calculate how the Universe will develop if we know how the histories started.

Perceptions of time

What does quantum theory tell us about time in the Universe? Time does not exist in quantum theory! At least it does not exist in the sense that most of us think about it. There is no clock out there ticking no matter what happens in the Universe. Time in quantum theory is simply the measurement of a process, like the decay of radioactive matter.

Clocks developed to measure such processes cannot measure any duration of time smaller than a billionth-billionth of a second. This is more or less the size of an atom or, more precisely, the time it will take a photon to cross the size of an atom. This interpretation of time is in line with Einstein’s general relativity. Measurement of the duration of processes at the quantum level is subject to the uncertainties and fuzziness typical of quantum theory.

We cannot measure the duration of time it takes a particle to acquire a certain amount of energy. The more accurately we measure the energy, the less accurate can we measure the time it took the particle to gain the energy. This is why the formation of particles (matter) in the early Universe is subject to the uncertainty principle of quantum mechanics.

Feeling uncertain?

People do not like uncertainties and therefore most do not like quantum mechanics. As a scientist put it: “I do not like quantum mechanics, but I use it because it works”. The velocity of particles in the early Universe must have been incredibly high due to the high energy levels. If you use such a particle to determine time, you would find that a particle traveling at the speed of light gives you the age of the Universe as NIL.

All particles must have been traveling at very close to the speed of light. It becomes clear that every particle had its own time. Whose time is correct? All readings of time are correct depending on your velocity and the gravitational pull. Einstein said: “every observer’s time is correct”. There is no intrinsic unchanging time.

What is reality?

I want to end with a few thoughts about our relationship at the macroscopic level with the microscopic world. In everyday life you never see a single photon and the microscopic world seems so remote and unreal. If you think further, you realize that almost everything in our everyday world is the way it is because of the quantum world. Matter has bulk because atoms have size. The colours, textures, hardness and the transparency of materials all depend on the exclusion principle regulating the behaviour of electrons in atoms. The list could go on, but ultimately the macroscopic world is what it is because of the microscopic world.

The quantum world is not something remote. It forms part of all matter. Take this page; look at it at ever smaller distances and time scales and the apparent mad world I have described above will unfold before your eyes. The problem is, currently we can only access the quantum world theoretically because technology has not developed so far that we can access it in any other way.

Frikkie de Bruyn is the Director of the Cosmology
Section of the Astronomical Society of Southern Africa

Related Articles:

• Perceptions of Time
• What happened before the Big Bang?
• The evolution of stars in the Universe

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PERCEPTIONS OF TIME: Time is not as simple as it seems

IF you were abducted by aliens and asked to describe Earth’s air in a language you understood, how would you describe it? It would be equally difficult to describe left and right without any points of reference. The same hypothetical can be applied to time — that dimension we all thought we knew until we were asked to describe it.

It’s natural to think of time as a linear progression. Experience will tell us that we live and we die; that the season’s come and go; that the sun rises and it sets. All these have a beginning and an end.

Quantum physicists will argue differently — that time is far more precarious than we are conditioned to believe. When asked the question “what happened before the Big Bang?” physicists will most likely scoff at the notion and argue that space and time itself did not exist before the Big Bang. Without time, the notion of “before” becomes meaningless. It would be like asking “what’s south of the South Pole” if the Earth was the only object we knew existed.

But there’s no escaping our notion of time. Everything we do or experience takes place at a specific time and point in space. We all “experience” time, but can we ever be sure that it exists, out there, independent of our experience? South African cosmologist, Frikkie de Bruyn, offers some insight into the precarious nature of time to help us better understand its nature.

“Time is experienced in two fundamental ways, explains de Bruyn. It seems to flow like a river, the seconds, days and years passing relentlessly. Our perception of time is also characterised by a succession of moments with a clear distinction between past, present and future.”

We can all confidently say that we have knowledge about out past experiences, but not of the future. However, at any given point in time, our past and future are connected to what we describe as the “now”. Some go as far as to argue that all that exists is the “now”.

Time as Linear or Cyclic

These perceptions of time are closely related to the idea of time being either linear or cyclic. It’s natural to assume that time is linear, with clearly defined beginnings and ends to most human experiences and unique events. “It is like a giant ruler, stretching back into the past marked in scale of years, decades and centuries and it stretches away into the future,” explains de Bruyn. The Big Bang theory also uses this “progressive” perception of time.

However, cosmologists like de Bruyn will argue that most of the time, time appears to be cyclical and not necessarily progressive. Cycles occurring in nature, such as the days, seasons and years can be used to support this perception. Time therefore becomes “the element in which natural events occur,” says de Bruyn.

We have always been limited by our language when it comes to describing something like perception of time, yet it nonetheless remains central to our modern lives. GPS devices would not exist without pinpoint accuracy in timing, computers and networks wouldn’t work and we couldn’t have landed a man safely on the moon.

Changes in perception of time

The invention of the clock and subsequently the watch brought about a new awareness of time. “Our minds process information from clocks and ‘interpret’ that information as ‘being time’”, explains de Bruyn. Another greatly significant revolution in our perception of time was Einstein’s theory of relativity.

“The Newtonian perception of time as separate and independent, ticking away irrespective of human activities, was replaced by the ‘personalised’ relative interpretation of time. Every person had his own time”, says de Bruyn.

At a more cosmological level, we now also know that time slows down as we approach velocities close to the speed of light. Stephen Hawking even described time as coming to a complete end within a black hole.

Einstein’s relativity theory also allowed us to think of time as a measure of the separation of events in space — clearly connected to change. However, time does not exist in the sense of objects and changes. “It is a human invention that provides a mental tool to measure change, and change means events separated in space”, explains de Bruyn.

It should be difficult for anyone to consider time as a human invention; that our concept of time is so closely related to space — the spatial separation of objects and change. It’s even more difficult to comprehend, that outside of this context, time simply has no existence.

It makes one wonder: if we discovered the secret to timeless longevity, where death was not feared as the end, would we still be so obsessed with time?

Source: Frikkie de Bruyn, Director of the Cosmology
Section of the Astronomical Society of Southern Africa.

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GENERAL KNOWLEDGE: DID YOU KNOW …

General knowledge enhancers: Entertainment:

1. The first couple ever to be shown in bed together on
   prime-time television were Fred and Wilma Flintstone.
2. Barbie's measurements if she were life size: 39-23-33 (she would topple over)
3. Donald Duck comics were banned from Finland because he doesn't wear pants.
4. In 1980, a Las Vegas hospital suspended workers for betting on when patients would die.
5. Each king in a deck of playing cards represents a great king from history:
   Spades       -    King David
   Clubs          -    Alexander the Great
   Hearts        -    Charlemagne
   Diamonds -    Julius Caesar

General knowledge enhancers: Food & drink:

• Coca-Cola was originally green.
• Every time you lick a stamp, you're consuming 1/10 of a calorie.
• Nearly all lipstick contains fish scales. Yeech...
• A Saudi Arabian woman can get a divorce if her husband doesn't give her coffee.
• Bubble gum contains rubber.
• Most cows give more milk when they listen to music.
• Research indicates that mosquitoes are attracted to people who have recently eaten bananas.

General knowledge enhancers: Numbers:

1. Every day more money is printed for Monopoly than the US Treasury.
2. 111,111,111 x 111,111,111
   = 12,345,678,987,654,321
3. A 'jiffy' is an actual unit of time for 1/100th of a second.
4. All the numbers on a roulette table add up to 666.

General knowledge enhancers: Language:

• The Hawaiian alphabet has 12 letters.
• Men can read smaller print than women; women can hear better.
• First novel ever written on a typewriter: Tom Sawyer.
• "I am." is the shortest complete sentence in the English language.
• The phrase "rule of thumb" is derived from an old English law which stated that you couldn't beat your wife with anything wider than your thumb. (Read about the origins of more English phrases here).

General knowledge enhancers: People:

1. Intelligent people have more zinc and copper in their hair.
2. The world's youngest parents were 8 and 9 and lived in China in 1910.
3. The youngest pope was 11 years old.
4. The most popular first name in the world is Muhammad.

General knowledge enhancers: Famous people:

• Thomas Edison was afraid of the dark.
• Einstein couldn't speak fluently when he was nine. His parents thought he might be retarded.
• Every time Beethoven sat down to write music, he poured iced water over his head. And he was rather deaf.
• Sigmund Freud had a morbid fear of ferns.

General knowledge enhancers: History:

1. If a statue in the park of a person on a horse has both front legs in the air, the person died in battle; if the horse has one front leg in the air, the person died as a result of wounds received in battle; if the horse has all four legs on the ground, the person died of natural causes.
2. Only two people signed the Declaration of Independence on July 4th, John Hancock and Charles Thomson. Most of the rest signed on August 2, but the last signature wasn't added until 5 years later.

General knowledge enhancers: Vehicles:

The name Jeep came from the abbreviation used in the army for the "General Purpose" vehicle, G.P.

The cruise liner, Queen Elizabeth II, moves only six inches for each gallon of diesel that it burns.

City with the most Rolls Royce's per capita: Hong Kong.

In Tokyo, a bicycle is faster than a car for most trips of less than 50 minutes.

Now you know everything :-)

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