Philosophy Discussion Forums | A Humans-Only Club for Open-Minded Discussion & Debate

[Logic_ill]

Thanks, Wooden Shoe. I agree. It doesn´t make sense that time began with the big bang, which in an indirect way proves that something did not come from nothing. It may also prove that time has always been. I´m not too sure of the latter, but I agree that time is change. Maybe we can broaden the definition somewhat but it is definitely about change.

When it comes to scientific theories of origins of the universe I would not argue because it is not my field and all I have is access to what astronomers study and see. I mean I cannot make direct observations and analysis. And because it is not my field, I am not up to date with their latest findings. I do like to learn from them from time to time.

Mech´s theory is interesting. Maybe the big bang never had to happen as he suggests.

[Philosophy Explorer]

Due to the logic of Kant's paradox, that eliminates the possibility of time being infinite. The next step is to consider finite time so the next question is to ask can time precede the Big Bang?

Any thoughts?

PhilX

[Logic_ill]

Opinion seems divided. Some people believe that time is infinite, others that it is finite. I don´t know and have not much inclination for one or the other. How could I possibly prove it anyway?

There are some people who don´t not believe in time and call it "a human construct."

Those who believe in the cyclical universe, should believe in time...I´m guessing they would think it´s infinite too.

[Bohm2]

The Universe may never have had a beginning. The evidence is ambiguous...

I don't know how valid/convincing his arguments are as I have no background in cosmology but the cosmologist Alex Vilenkin argued that our universe must have had a beginning. The same with other universe models like a cyclical universe, etc. which supposedly avoid a beginning:

Using a mathematical proof, they argued that any expanding universe like ours had to have a beginning... If we assume inflation is eternal into the past — that it had no beginning — the space traveler will eventually reach and overtake the speed of light. A calculation by Borde, Guth and Vilenkin showed that this would happen in a finite amount of time. But according to the laws of relativity, it is impossible for any massive object to reach the speed of light, let alone exceed it. “This cannot happen,” says Vilenkin. “So when you follow this space traveler’s history back in time, you find that his history must come to an end.”

The fact that the traveler’s journey backward in time hits an impasse means that there’s a problem, from a logical standpoint, with the assumption of an ever-expanding universe upon which this whole scenario is based. The universe, in other words, could not always have been expanding. Its expansion must have had a beginning, and inflation — a particularly explosive form of cosmic expansion — must have had a beginning, too. By this logic, our universe also had a beginning since it was spawned by an inflationary process that is eternal into the future but not the past.

What Came Before the Big Bang?
http://discovermagazine.com/2013/septem ... ting-point

Did the universe have a beginning?
http://arxiv.org/pdf/1204.4658v1.pdf

In recent years, however, cosmologists have begun to study a number of new ideas that have similar properties. Curiously, these ideas are not necessarily at odds with the notion of a Big Bang. For instance, one idea is that the universe is cyclical with big bangs followed by big crunches followed by big bangs in an infinite cycle.

Another is the notion of eternal inflation in which different parts of the universe expand and contract at different rates. These regions can be thought of as different universes in a giant multiverse. So although we seem to live in an inflating cosmos, other universes may be very different. And while our universe may look as if it has a beginning, the multiverse need not have a beginning.

Then there is the idea of an emergent universe which exists as a kind of seed for eternity and then suddenly expands. So these modern cosmologies suggest that the observational evidence of an expanding universe is consistent with a cosmos with no beginning or end. That may be set to change.

Today, Audrey Mithani and Alexander Vilenkin at Tufts University in Massachusetts say that these models are mathematically incompatible with an eternal past. Indeed, their analysis suggests that these three models of the universe must have had a beginning too.

Mathematics of Eternity Prove The Universe Must Have Had A Beginning
http://www.technologyreview.com/view/42 ... beginning/

[Mechsmith]

Let me try to explain the "red shift". (Hubbles Constant) and "Doppler Effect) This is important because it is used as evidence that the Universe is expanding. It's also important because a variation on the theme is used by our local law enforcement personnell with their "Doppler Guns". It's also used by sailers and navigators in the southern seas. It's also important in relativity theories. Bicyclers also notice a similar effect while riding in mountainous country. It is such a reliable effect that we even have automatic observatories that are busy cataloging the red shift of most of the visible stars. (google "red shift observatories")

The red shift uses wave theory to describe color. (Let's not get into that. It works with light, sound, and water) With light and sound wave length and frequency bear a close relationship.

A hot object emits light. Think candles, campfires, and comets. The temperature of the emitter CAN be determined by the color which is solely determined by wavelength. (Think spectrograph)

The temperature of the emitter IS determined by whatever is radiating. It can, for our purposes be Carbon, Hydrogen, Iron, or actually most elements and alloys have specific wave lengths (colors)that they radiate. (Think welding) If you run star light through a prism (Think rainbows and suncatchers) it will be broken into a spectrum. There will be several black lines in this spectrum. They are called Fraunhofer lines and they occur at specific wavelengths. The position of these lines when compared to a true spectrum will tell us how much our sample is shifted from a true white light spectrum.

Hubble noticed that light from distance objects is much redder than it was when emitted. He translated this into motion (Doppler Effect) and came up with the Hubble Constant. The further away something is the faster it is receeding. This number came to be known as "z".

However there is another effect called the gravitational effect. (Think uphill and down hill). This is predicted in relativity and was (unsatisfactorily) shown by Eddington in his South African Eclipse experiments. It has since been improved upon since 1024.

Now lets look at starlight from a distance. When it was emitted it has a specific wavelength. As we see it it is redshifted as it loses energy going "uphill". But it's light and can't slow down. So consequently the wavelength gets longer (redder). As it travels (different arguement) through the universe it encounters different gravity fields. As this goes downhill (towards a massive object) it gains energies again (blue shifted, Think bicycling downhill) Since light can't speed up the waves must get closer together. When it comes out(away from the mass) it must again be redshifted. You notice that this is the point where time and gravity become inextricably linked. We cannot change the speed of light so we must change the speed of time.

Since from the point of view of the photon (Don't go there ) it spends much more time and effort going uphill than down hill the total effect is to redshift more the further it travels. Hey, that's what we see Unless we correct for the "gravitational effect" we cannot say that the Universe is expanding.

Actually there are several purely mechanical reasons that light is red shifted. The effect of the mass of the emitter. (Climbing mountains-The bigger and steeper the mountain the harder the climb)

Space dust- (Think red skies at night sailers delight) Loss of energies due to dust and intersteller hydrogen. Simple collisions.

The relative speeds of time due the the differences in mass between the emitter and the observer. Gravity linked to time. The slower the time the bluer the light.

AND to blue shift light it must fall into a gravity well. (Thats us, our sun, planet, and Milky Way) I know of no other natural way to blue shift. If I did we'd have us a perpetual motion machine.

Happy thoughts, M.

[Logic_ill]

And I just found out that perpetual motion machines are impossible because of the laws of thermodynamics and the reality of inertia (friction can be an obstacle). Oh well, I learn some...

Mech has taught me something about light(color), gravity, time...

[Misty]

Infinite time is in the supernatural (meaning: beyond the observable physical world) realm. Finite time is in the natural realm, (physical/observable) universe of life and death. So, there is time that has always been, and there is time that is limited. When we devise a way to observe the infinite realm, we will discover what could cause a big bang or discover God.

[Reactor]

One thing is for sure, the facilitator of life does not depend on human understanding. Human understanding depends on the facilitator of life. The word "begin" is confined to human understanding and may not have anything to do with the existence of the universe/s.

Agreed that any facilitator of life is superior to human understanding or works.

On the other hand, I can envision a co-creation and "beginning" to time and to the universe. Most probably at the same "time" (at the "moment" before time began). Why not?

[Atreyu]

I take Kant to be arguing that an infinite past has no endpoint. Then how is it possible to completely traverse an infinite past and reach the present? Another way of putting it, is the present, by definition, is the endpoint of the past. However, an infinite past cannot have an end. Therefore, either the present has not be reached, or the past is not infinite. I'm also not sure about this argument, but I haven't thought about it.

Ok, Bohm, gotcha. Yes, that is a very interesting point. Good one.

However, the solution is rather simple. If time is circular (cyclical), it indeed is possible to traverse an infinite past and reach the present. In fact, in this view one can go back into the past and reach the future, or go into the future and reach the past.

And dare I say this is the only model that works....

And for those who are positing here about whether or not time is infinite or finite, let me just say this: It definitely is infinite cognitively speaking. Even if there was a first moment of time, we can certainly imagine and visualize time going forever in either direction. So we can imagine a time existing 1000 years before the beginning of the Universe, even though such a statement would not make any sense. Also, we can imagine 1000 years after the end of the Universe, even though this also could not really be so, because before the Universe began, and after it ends, there is no, and was no, time. So we are left with a certain "cognitive dissonance" here --- we cannot imagine how there could be no beginning or ending, yet, at the same time, we can always imagine a time before or after any reference point, including a beginning or ending.

So without arguing either way, the question definitely comes down to thus: Which of our two cognitive constructs is closer to absolute reality --- the one which can visualize time going forever in either direction, or the one that insists on beginnings and endings?

I myself choose the former, because the latter view simply seems to be a subjective and arbitrary way to "reduce" or "narrow" the real world into something we can better manage intellectually, and in light of two possible models I always choose the one that leaves me with a bigger, rather than a smaller, Universe.

[Bohm2]

So without arguing either way, the question definitely comes down to thus: Which of our two cognitive constructs is closer to absolute reality --- the one which can visualize time going forever in either direction, or the one that insists on beginnings and endings? I myself choose the former, because the latter view simply seems to be a subjective and arbitrary way to "reduce" or "narrow" the real world into something we can better manage intellectually, and in light of two possible models I always choose the one that leaves me with a bigger, rather than a smaller, Universe.

Yes, it boils down to the difference between "potential infinity" versus "actual infinity". Some physicists/mathematicians have questioned the validity of an "actual infinity" to argue that the universe must have had a beginning. For instance, the mathematician Hilbert tried to point out the absurdity of "actual infinity" with his "Hilbert's hotel" example:

Consider a hypothetical hotel with countably infinitely many rooms, all of which are occupied – that is to say every room contains a guest. One might be tempted to think that the hotel would not be able to accommodate any newly arriving guests, as would be the case with a finite number of rooms.

Suppose a new guest arrives and wishes to be accommodated in the hotel. Because the hotel has infinitely many rooms, we can move the guest occupying room 1 to room 2, the guest occupying room 2 to room 3 and so on, and fit the newcomer into room 1. By repeating this procedure, it is possible to make room for any finite number of new guests.

It is also possible to accommodate a countably infinite number of new guests: just move the person occupying room 1 to room 2, the guest occupying room 2 to room 4, and in general room n to room 2n, and all the odd-numbered rooms will be free for the new guests.

This results in the hotel being always able to accommodate guests, even though all the rooms were full when the guests arrived.

It gets even more absurd. What happens if some of the guests start to check out? Suppose all the guests in the odd numbered rooms check out. In this case, an infinite number of people has left...and there are just as many guests who have remained behind. And yet...there are no fewer people in the hotel! The number is just infinite. The manager decides that having a hotel 1/2 full is bad for business. This isn't a problem with an actual infinity. By moving the guests as before, only in reverse order, he converts the half-empty hotel into one that is full!

-- Updated September 11th, 2014, 12:07 am to add the following --

Leaving aside the issue of his religious reasons for trying to argue that the universe must have had a beginning, here's a short clip of the "Hilbert hotel" argument against actual infinity. I'm still unsure if this is a convincing argument against an infinite past:

[Atreyu]

Bohm, I think the Hilbert Hotel "thought experiment" is woefully weak, because you simply cannot do the things he posits in the video.

You cannot move all of the guests one room over because there is an infinite number and it would take an infinite time to do that. Nor could you move them two over, or any other number of rooms over. Only with a finite number of rooms/guests could you do this in the first place.

Another way of looking at it is to see that the argument rests on a false view of infinity. If everyone is moving one room over it implies an empty room at the "end" (although there is no end) in which the "last" (although there is no last) person can move into. But there is no empty room at the end, all the rooms are filled.

The entire argument rests on a false presumption.

And the entire reason for all such arguments against infinity is simply because our minds don't like to deal with it --- it's simply too abstract a concept. And the entire reason for that is simply that our minds don't like to view or visualize time as being circular, rather, they insist on a linear view/visualization hence the reason that all timelines are just that --- lines.

Once people can see that drawing a circle is a more accurate (although not complete) representation of what time is, rather than drawing a straight or even a curved line, they will no longer have such a problem with infinity, nor with visualizing or imagining a Universe without any beginning or end.

And, ironically, to get back to your Hilbert Hotel example, what would actually happen in that scenario, although it would take forever to complete, is that that very first room would end up getting occupied by an already existing guest, although our weak minds cannot imagine how that could be so. But that should be no surprise, as our minds cannot really imagine infinity in the first place anyway.

[Mechsmith]

Atreyu

"And the entire reason for all such arguments against infinity is simply because our minds don't like to deal with it."

I agree with that statement. Nobody likes an infinity. Too many not loose ends Personally I spent a long time trying to wrap my mind around the concept of infinity. It's still shaky. My mind, not infinity

M.

[Bohm2]

You cannot move all of the guests one room over because there is an infinite number and it would take an infinite time to do that. Nor could you move them two over, or any other number of rooms over. Only with a finite number of rooms/guests could you do this in the first place.

But I'm not sure this would make any difference. The argument would be that, IF an actual infinite could exist, the situation with this hotel is what we would expect. What is interesting is that infinities do crop up in physics quite often and many physicists interpret this as a failure of our model. John Barrow discusses this here:

Does infinity exist?
http://plus.maths.org/content/does-infi ... st?src=aop

[Felix]

I bet you can always get a room at the Infinity Hotel , and the rates are very reasonable (even if the floor plan isn't). We'll leave the blue light on for you!

Speaking of lights, maybe the universe is like a giant light bulb, that goes off and on - obviously a long life bulb. How many dieties does it take to change a light bulb?

[Wooden shoe]

Bohm.

No matter which example we use it is only going to work in a limited way to get our heads to understand infinity. I like to use the river idea, an endless flow of "now", always changing. It is easy to confuse infinity with timelessness, but we only experience the always changing moment and it is a safe bet to say that for everything that exists there is only the same regardless whether it is aware or not.

I believe that when time is looked on as something more than another word for change we complicate the concept.

Regards, John.