• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Why is there a "now"?

Zeph

Scholar
Z
Joined
Dec 23, 2010
Messages
80
This is perhaps related to the "hard problem of consciousness" in another forum, but I come to it from science, rather than philosophy. (Actually, it was long ago article in Scientific American which brought this to my attention). And that thread is very long and convoluted, and often quite fuzzy.

I can find nowhere in my knowledge of physics any justification or understanding of the concept of "now" - that moving finger of time. That is, I find no basis for singling out a point in time which is significantly different than all other points in time, and which changes.

Time to a quantum physicist is rather more complex, but for a simple analogy we can easily draw a parabola describing the position of a tossed object over time. For any t, the function will give us x (or x and y...). But the whole curve exists as one piece, and t is just an abstracted variable we can specify at any value equally. A concept of time is well handled in this model, but not the concept of "now", there is no "special" t which represents "now", a time whose position we cannot specify or affect and which moves along the curve without our control, carrying us along.

Certainly we are unaware of any special x,y, or z coordinate in the universe the knowledge of whose moving location is shared by all conscious beings. Time is another dimension, but it has some special universal "now" point quite dramatically different than any spatial dimension. There is an apparently universal "time cursor" but no shared or significant "space cursor".

Is there any scientific sense in which what is happening "right now" as you read this is any more "real" - or in fact in any way different - than what "happened" 100 years ago or "will happen" in 100 years?

(Oops, I may verge a bit further into the philosophical realm next, but be assured that I'm not looking for abstruse academic philosophy, but something that relates to the physical world and science, as much as possible.)

Does "now" exist without consciousness? Imagine a lifeless planet or moon which will never be visited by conscious beings (or a whole universe without conscious beings if you prefer). Of course it has a timeline - a time of formation, physical changes over time, even the time when a meteorite forms a particular crater large or small, or when a particular uranium atom splits, so its history is spread out across billions of years, spanning a dimension not entirely like spatial dimensions. But is there any special point of time in that timeline which is dramatically distinct from all others, and which moves from one end of the history towards the other? Is that history more like a CD as pressed from a mold, with all parts of all tracks equal and undistinguised, or more like a CD in a player, with one moving location on the spiral distinguishing what is being played "now"?

Is there a "read head" to the history of the universe separate from consciousness? What significance does it have in the course or nature of the universe? Can it be calculated or measured?

As far as I can tell, "now" does not exist in the physical or objective universe, only in the subjective; in fact the subjective world is of the essence about "now" (including the accumulated physical residues of the past and imagined prejections into the future, but existing only in the non-physical now).

It is remarkable to me that an experience as ubiquitous as "now" appears to be so far outside the domain of the physical sciences.

Thoughts?

Zeph
 
Good post!
Are you familiar with Brian Greene's description of the "frozen river"?

Chapter five, The Frozen River, deals with the question, "Does time flow?" One of the key points in this chapter deals with special relativity. Observers moving relative to each other have different conceptions of what exists at a given moment, and hence they have different conceptions of reality. The conclusion is that time does not flow, as all things simultaneously exist at the same time.
Click to expand...
LINK
 
Thanks, Perpetual.

The "Frozen River" is what I'm metaphorically referring to (trying to accessible but perhaps clumsily) in regards to looking at at CD as a whole, which is pretty much as far as science takes us. The CD does not flow, it all exists at the same time. I suspect a lifeless universe would fit completely into model.

And yet our experience with reality involves a "now", somewhat as if the CD was in a player. The frozen river accounts for the CD - but what accounts for the "now" concept, or the player? Is that beyond scientific examination?

Let me try another approach. When one says that time does not flow, at a deeper level one is saying that "within the physics we currently understand, time does not flow". You are describing the conclusions of a model of the universe, not the universe itself. The map has no record of a bridge, but the map is not the territory.

Saying that the river does not flow is another way of framing what I was saying - that the phenomenon of "now" appears to be outside of our current understandings of physical science. That is not the same as "if physics can't explain it, it obviously doesn't really exist in any sense of that word".

Yet I cannot find any understanding of consciousness which does NOT involve a central concept of "now". The phenomenon of "now" is not so easily dismissed as being totally explained as an illusion, because physics does not yet have any handle on what it could mean. (This is admittedly a bit abstruse, as I do agree with modern physics that in some senses the flow of time is an illusion. Time isn't quite what it seems. But there is still something to "now" which isn't explained.)
 
I've been seduced by the argument that there really is no real physical thing we call "time." There's just stuff moving around. So "now" is all there is. There isn't any past or future -- they are abstract semantic constructs.

However, I will listen to arguments (or evidence) that "time" is a real thing and not an abstraction we've invented.
 
The concept of consciousness and now seem to be inescapably linked. Is "now" merely a human construct, because of our consciousness, or it is something independent and real in the universe? I don't know if physics and cosmology really have an answer. We know that "now" only has meaning within one frame of reference, so "now" is quite different elsewhere in the universe. It seems that it is only our consciousness that makes "our now" special. In my view, this question is one of the most central and perplexing that deals with our consciousness and our very existence.
 
Hmm, Mr Scott, what do you mean by time not being a real thing? Is space a real thing? Is there a fundamental difference between measuring a time interval with a stopwatch, and measuring a distance interval with a ruler, which makes the latter real and the former not? There seems to be a great deal of evidence for the existence of measurable spans of time; it's even meaningful to say something like "I walked a block block in 55 seconds, so if I maintain the same speed I can walk home in 5 more minutes". (past, future, measurement, proportionality, projection).

I ask because you probably you mean it on a different level than that. Like maybe, "my consciousness cannot exist in the past or the future, only in the present".

Which puts us all on this same central mystery - of consciousness and "now" versus the physical world as we know it. I'm with Perpetual Student on this. I was hoping to get some reflections on this mystery, and see if others find science as limited in this regard as I do (or could refer me to some breakthroughs).
 
Zeph said:
Hmm, Mr Scott, what do you mean by time not being a real thing? Is space a real thing?
Click to expand...

OK, I will try to express my interpretation of the argument.

This universe consists of space, matter, and energy. The matter and energy are moving around in the space. Some of this movement is repetitive and fairly consistent, like the revolving of the earth. We needed ways to measure things like the cycles of seasons and days, so we eventually created clocks and things which tick off regularly to "measure" this abstraction we invented called "time."

But the idea of "time" has gotten so out of control, we started thinking of time travel and the past and present and all sorts of analogies, like time being a conveyor belt we can get off, timelines, and so forth. But the past is only memories, and the future doesn't exist at all but as possibilities.

Anyway, I'm still waiting to hear a convincing argument that time is real.
 
Mr. Scott said:
OK, I will try to express my interpretation of the argument.

This universe consists of space, matter, and energy. The matter and energy are moving around in the space.
Click to expand...
What does "moving around in space" mean if there's no such thing as time?
 
I like it, Zeph.

You are hinting at something anti-bhuddist, which is damn interesting, philosophically, at least. Instead of the notion of "now" being the only real moment in time, it could be the only non-existent moment in time.

Hope you stick around awhile.
 
Zeph said:
Certainly we are unaware of any special x,y, or z coordinate in the universe the knowledge of whose moving location is shared by all conscious beings.
Click to expand...

There is no such special t, either. Conscious being existed in the past, and (hopefully) will exist in the future as well.

I think you've mis-identified the fundamental distinction between time and space. "Now" is analogous to "here", and there's nothing especially mysterious about it. "Now" and "here" are simply where and when you as you express those words.

The mystery isn't about now, it's about why time goes forward and not backwards. That's what distinguishes time from space, and the answer - such as it is - is in the laws of thermodynamics.
 
At every point in our lives, it is "now". So, if you pick any point on the "CD", it will be "now" to you at that point.
 
sol invictus said:
There is no such special t, either. Conscious being existed in the past, and (hopefully) will exist in the future as well.

I think you've mis-identified the fundamental distinction between time and space. "Now" is analogous to "here", and there's nothing especially mysterious about it. "Now" and "here" are simply where and when you as you express those words.

The mystery isn't about now, it's about why time goes forward and not backwards. That's what distinguishes time from space, and the answer - such as it is - is in the laws of thermodynamics.
Click to expand...

I don't believe our sense of consciousness has the same intense feeling of position in space as it does a point in time. Perhaps that's just me and maybe this is more a philosophical/psychological question than it is one of physics.
 
sol invictus said:
The mystery isn't about now, it's about why time goes forward and not backwards. That's what distinguishes time from space, and the answer - such as it is - is in the laws of thermodynamics.
Click to expand...

Hmmm, that brings to mind Richard Feynman's discussion on irreversibility:

... which I was about to redirect here from youtube and now I can't find it!!!! The complete discussion was avilable on youtube and now it isn't! Goddamnit!! :mad:
 
The mystery isn't about now, it's about why time goes forward and not backwards. That's what distinguishes time from space, and the answer - such as it is - is in the laws of thermodynamics.
Click to expand...
There is one other significant distinction between space and time. We cannot say that any point in space has absolute coordinates; no point can be identified as being in the center of the universe, for example. But -- we can and do say the universe is 13.75 ± 0.17 billion years old, which implies that, if our science were more exact, we could say that we are at a particular instant in time in the history of the universe. So, space coordinates are relative, time coordinates are absolute.
It is also significant that we can say how old the universe is but not how big it is. In some ways time seems to be more concrete than space.
 
Last edited:
sol invictus said:
There is no such special t, either. Conscious being existed in the past, and (hopefully) will exist in the future as well.

I think you've mis-identified the fundamental distinction between time and space. "Now" is analogous to "here", and there's nothing especially mysterious about it. "Now" and "here" are simply where and when you as you express those words.
Click to expand...

Thanks, Sol, for that perspective. However, I don't actually see "now" as simply the time analog of "here", except rather superficially.

To return to my CD analogy, there "appears" to be only one "read head" in time, moving more or less synchronously for all the conscious beings we encounter.

If my 'here' is at X, it's completely normal and expected for your 'here' to be at X+5, and somebody else's 'here' to be at X-27. (In fact, your X,Y,Z not only can but pretty much HAVE to be different than mine!). And we can and do all move our "here" freely around in X, forward, backward, crossing each other's X. So there's no special X.

In T, nobody seems to locate their "now" at T+5 or T-27. So far as we know, except in fiction nobody experiences the unfolding of the the universe a few hours earlier than others. We seem to have no choice except to all occupy the same T as our shared "now"; we can't each independently move our personal 'now' around in T. That single inflexibly moving time location which we all share as our "now" IS a very special T of which there is no analog in space.

I have at least temporarily brought multiple people into this to better highlight the difference, but of course we can't move our "now" freely around in T, or even stop it, even when we are alone. The march of "now" along the T axis is still inexorable, and where it is "now" is a special T of which there is nothing similar in X, Y or Z.

I am postponing relativistic effects, by the way, not because I am unaware of them, but because it's clear we need to grasp (at) the fundamentals first.

Zeph
 
You must log in or register to reply here.

Back
Top Bottom