i think it's time

I should let you all know that I am - gasp! - double blogging this. Not as gross as double dipping; maybe a little more like re-gifting, but only because the original gift was so good I couldn't keep it for myself. Anyway, there's a slightly different post on this topic over on symmetrybreaking as well.

"Time, I think, is a little bit like love. It's accessible to all of us; it is intuitively experienced by all of us in the same way; yet it retains its mystery at whatever level you weigh in on it. It is a mysterious force that we all can experience and share." That's how journalist and session moderator John Hockenberry opened "Time Since Einstein," at the World Science Festival in New York a few weeks back.I love this thought. And maybe for a handful of physicists and philosophers, time is also what we love.

Let me quickly note that the World Science Festival was awesome. If you are in New York next year I highly recommend it. I will try to post some more about it later, and Lee has also posted in reference to some of the forty sessions they held all over Manhattan. I'm sorry I couldn't go to more, but while it's not often that such a great event falls in my lap, it's even less often that it coincides with my sister visiting. Whad'ya gonna do?

Hockenberry welcomed to the stage a panel to make any physics junkie drool. It consisted of physicists George Ellis (who co-wrote a book with Stephen Hawking called The Large Scale Structure of Spacetime), Sean Carroll (prominent cosmologist, a fantastic speaker and writer over at Cosmic Variance), Fotini Markopoulou-Kalamara (another great speaker and theoretical physicist investigating a number of fascinating subjects about the nature of our universe) and Roger Penrose (I won't even attempt to tell you everything this man has done for physics, mathematics and cosmology in his lifetime).

(Ellis, Carroll, Markopoulou-Kalamara, Penrose)

 

(Albert, Heller)

 Add to that physics-philosophers David Albert and Michael Heller, and you've got a panel that, honestly, was too big to fit into an hour and half session on such a broad topic. I could easily have listened to each of these people talk alone for an hour and a half. But what a fantastic brew of people to answer whatever questions you might have about time. Or twist every notion you have about time and leave you completely befuddled and doubting your own reality. Either way.

So first thing's first: what was time before Einstein? It was the stage on which everything else took place. It was an absolute and unchanging part of our surroundings. Even space was more flexible than time. We could go backwards and forwards in space; we were learning to control motion through air and water and on land. But it was not within our abilities to change time in the same way; not even to speed it up or slow it down.

That was then. After Einstein, time changed. With relativity time became a player on the stage instead of the stage itself; a player that could be influenced and warped by the other players. Jennifer discusses relativity in one of her posts, so I'll be brief. Einstein's theory of relativity established that no frame of reference is absolute or superior, and that from different reference frames space and time can appear different. While you may think your minutes are ticking by the same as they always have, someone passing you at the speed of light might see your clock hands spinning frantically, the hours and minutes whipping by. All the while, that quickly moving observer would feel no change in her own time. And this isn't just an illusion. Neither reference frame keeps the "right" time because there is no right time. Just relative time. Which brings up the big 'ol question: What is time?

According to relativity, it's a dimension in space-time, but there seems to be more to that question pawing at my brain. The panel of physicists tried to help me out and at least gave me hope that they're looking into it.

If Einstein's theory of relativity had been the end of the story, our investigation into time might have been simpler. But right after Einstein realized time was relative, another group of physicists were realizing that a lot of other things we thought were definite were also not so much. Quantum mechanics crashed the party at about the same time and declared that not only is matter quantized into particles (which cannot be reduced to anything smaller), but the behavior of these particles is not based on cause and effect, but probability, like the roll of a die. Electrons orbiting an atom aren't in any one place; they exist in a cloud of possibilities,until we pin them down and make them chose one. Both theories are revolutionary. Both are correct. Neither quite agrees with the other. 

Markopoulou-Kalamara is trying to figure out how quantum mechanics and relativity can both be right, yet both so different. She's really like a physics ambassador: trying to unite two sides of a conflict, each of which has a pretty strong case. How do we unite them into one peaceful union? One theory, that  Markopoulou-Kalamara helped develop, is called loop quantum gravity and is an alternative to string theory. LQG doesn't include the higher dimensions of string theory, but postulates that space-time is a fabric weaved out of quantized loops, or excited gravitational fields. Sooooo....real complicated.

Markopoulou-Kalamara's work constantly brushes her up against questions about the nature of time. Time is just one issue that general relativity and quantum mechanics can't quite come together on. When physicists realized that matter is divided up into particles and light into photons, the question arose of whether or not time was also quantized. Seconds and minutes mean no more to nature than inches and feet; they are human constructs. Could nature have a quanta of time? According to Markopoulou-Kalamara, yes, if you take the relativistic view and think of time as a dimension of space-time. But if you take a more quantum view and think of time as change, then maybe not. And change is how she prefers to define time.

If time is not quantized, then can we ever really define the past, present and future? Does our notion of this moment, of "now" really mean anything? One audience member asked if we could actually freeze this moment, take a picture of it, and look back and acknowledge that this moment did exist. The problem with this, from the quantum perspective, is that taking a picture of something like an electron causes it to go from a fuzzy cloud of probability, to just one state. You pin down the electron in one place. You open the box and find the cat either alive or dead. But if you didn't take a picture, the box would remain closed. "Now" would consist of an electron cloud instead of those definite states. By trying to define "now" you just might change it and chose one of many possible "nows." But if we could define a quanta of time, we might have a way to single out the moment we live in, compared to the ones we remember and those that have yet to happen.

Panelist Roger Ellis believes there must be a quanta of time. The problem of dividing up time might be related to the problem of dividing up space, as put forth by Zeno's paradox: if you were traveling from point A to point B, you'd have to pass the half-way point between A and B. But if you divided half the distance between A to B in half, and cut that in half, and that in half...you'd find that you could continue dividing the distance between A and B into infinite halves and thus you would cross infinity with each step. How can one ever cover an infinite distance? It suggests that motion should be impossible, but it's clearly not, so we have a paradox. So Ellis relates:

"If you look between my fingers, the question is how many points are between there. And in some views of physics there's not just an infinite number of points, there's an uncountable infinity of points between. I don't believe it. I believe there's got to be a discrete number of points. The same thing happens if I were to say one...two. How many points were between there and there? Was there an uncountable infinity of points? I don't think so. I think there was a discrete number of time events between that point and that point."

The discreteness of time, the difference between then, now and still-to-come, is intrinsic to our human experience. Maybe it will be a notion we'll have to let go of one day.

If time is change, can it really move forward? Could things return to the way they were and essentially take us back in time? Does time move forward at all, or is that just an illusion paired with our human experience? Ellis has this to say:

"There are many theoretical physicists who think the flow of time is an illusion, and I think that's a great mistake...according to quantum physics you don't know the outcome of events until they happen. We know what happened in the past, there's a time called the present when things are happening, and there's a time in the future which is not yet determined. That's my view on it, which is not a very widely supported view."

The Arrow of Time - the idea that there is a difference, intrinsic to nature, between flowing forward in time rather than backward - is a sticky subject. In our macroscopic world, if you took a movie of your life and ran it backwards, it wouldn't look realistic. And upon further investigation, you'd find that running the world backwards would violate some laws of physics. But on the microscopic scale, running the film in reverse doesn't normally violate the laws of physics. Nature doesn't seem to have a preference for the direction of time, at least for the most part. In the late 1990's scientists finally observed some time asymmetric particle processes. These are extremely rare, but they do exist.

But there is one big hitter in nature which supports the arrow of time, and that's the second law of thermodaynamics. Imagine running a video of your life backwards as you made an omelet. It's very easy to take a whole egg and scramble it, but would be incredibly difficult to unscramble it. A whole egg is less chaotic than a scrambled egg, and a better word for chaos is entropy. The second law of thermodynamics says that the entropy will only increase or remain constant, and never decrease, in a closed system. (Most examples of increased entropy such as a broken window, can be fixed because they exist in open systems. The entire universe, however, is closed.) This has profound implications on the life of the universe. It means things are getting more chaotic and cannot return to a more organized state. Eggs are getting scrambled but not unscrambled. Nature does care about the direction of time. I once again point you to a previous post of Jennifer's (she's on the ball). 

But there's so much more to be said. The second law tells us that there is, indeed, a preferred direction of time, but it doesn't tell us why. Will a unified theory of quantum gravity solve the problem? What happens when the entropy in the universe reaches a maximum? Does the arrow of time have a length? A beginning? An end?

Besides writing for Cosmic Variance, cosmologist Sean Carroll is also a soon to be author of a book on the arrow of time, titled From Eternity to Here: A Quest for the Ultimate Theory of Time. I'll pass the buck to him (see the list of related blog posts) and other sources to talk more about the arrow of time.

Here's what Carroll had to say about the notion of a beginning of time:

"Scientists have gotten used to the idea that when people ask us 'What happened before the big bang?' we give St. Augusta's answer: we say there was no such thing as before the big bang. But in very recent times, beyond Einstein, we're realizing that we have absolutely no justification for saying that that's true. We have to move beyond Einstein to understand what happened at the big bang. And the answer might be that the universe came into existence at the big bang: there's nothing before. Or it might not. There could be something before the big bang...cosmologists, people who are working on quantum gravity, are very interested in what we've learned since Einstein to answer these questions and go back and answer St. Augusta's question."

Einstein apparently hated the idea of the "beginning" of time. It does seem rather odd to have a very distinct beginning on one end, and infinity on the other. But Einstein also hated the idea of a probabilistic universe, even after spending years contributing to quantum mechanics. He summed it up in the quote that He (referring to God) "does not throw dice." It's amazing that his ideas were in front of his own human willingness to accept them. 

As the audience tried to wrap their head around all this, Hockenberry tried to wrap things up by asking "What is time?"

"Change," said Markopoulou-Kalamara.

"I'd have to prepare a two semester course," said Heller.

But Ellis Penrose closed it out: "It's what clocks measure."

I know I've probably left you with more questions than answers, but that's exactly how I felt walking out of the session. My friend and I wondered if someone completely unacquainted with physics would think these people knew an incredible amount about time, or nothing at all. And really, both are true. For as much as we've learned since Einstein, we've only found an exponential number of new questions to ask. Hockenberry closed the session with this:

"The Coming of Wisdom with Time," by W.B. Yeats:

Though leaves are many, the root is one;

Through all the lying days of my youth

I swayed my leaves and flowers in the sun;

Now I may wither into the truth.

Comments

[Captain Skellett]

Very interesting - it's all pretty mindblowing stuff. I remember learning for the first time that electrons didn't really exist anywhere, and that they were a mix of matter and energy that kind of flipped between the two on a whim. It's bizzare the think that the world on the smallest scale is so different to the macro world we experience day to day. The Heisenburg Uncertainty Principle is also interesting (I think that's what it's called) - that we can find the position of something by observing it, but in observing it we change it's momentum. And we can observe the moment of something, but in doing so we can't tell where it is. It's like we can NEVER pin these things down.

Maybe there are an infinite number of universes, so the one we're in splits into two everytime you open the box and find out if the cat is alive. Impossible to get your head around.

[sword_of_reason]

TO understand time, it is necessary to understand its components.

Time is energy (virtual), with the same energy density as solid mass. Time is a function of energy, and so identical to energy. Energy in three-dimensional space is understood as mass, energy in the fourth Minkowski axis (the Minkowski axis is a limited mathematical representative model to express a view of time; as mathematical models are abstract, they are easily corrupted, confused or elaborately overly complicated, and generally demonstrate no relation to our physical reality), as time, this means:

Each spatial dimension is held within the next, in this setting, the three ordinary dimensions of space are combined within a single dimension of time, to form a four-dimensional manifold, representing a space-time reality.

Everything is Energy, but it must be understood exactly what all energies are, time, mass, space, plasma, light, life, thought, every known or unknown form of energy ever conceived, they are all information, grains of TRUTHFUL information that interact, transmute, expand, constrict, but always build upon themselves, expanding out in all realities. These energies all follow simple underlying constraints, firstly they are all based on pure dichotomies, and the very nature of realities are always what lies between, secondly energy is in a state of evolution, its constitution needs to ultimately transubstantiate into ever more complex forms of information, thirdly all knowledge is connected, a single ocean of unity.

Additional Information at the home page:

Transfinite Consciousness
Supreme Existence
Time Explained