DrProctopus

Um... well - we won't really know until we get there will we? I mean, surely physics is about determining the why behind things, not just predicting what will happen during certain events? Besides, if we figure out the underlying mechanism, we might find useful things to do with it. So, why are protons always the same size, the same charge, etc...?

In the standard model, what is spacetime? What role does it play in determining particles and waves?

If something is infinitely divisible, it can contain an infinite amount of information. If spacetime is the framework of reality, then, if spacetime is infinitely divisible then reality should be infinitely divisible. Think of it this way - matter and energy are discreet. Why is this the case? If matter and energy are forms of information, that information has to be encoded onto something - that something being spacetime. If spacetime were infinitely divisible, it would not lead to discreet, same-sized, basic particles. I am not expressing myself properly here - trying to translate visual images into words - so my apologies for being inexact. another way to think of it... A hydrogen atom is always the same size as any other hydrogen atom (ignoring charged particles and any other unusual manifestations - just a plain ol' hydrogen atom) Why is this the case? The answer that seems apparent to me, is that spacetime is granular, and thus always encodes information in the same way - meaning the fundamental particles always manifest in a consistent fashion. As for a grid-like structure - well, I dunno. I can envision a number of different designs. You could be onto something, though. One way of trying to figure out the fundamental shape (or abstract shape, since the concept of shape might not be so meaningful at that scale) of a spacetime moment would be to figure out a shape that results in an equal rate of the transfer of information in all directions. I am not even sure that thinking of a spacetime moment as a simple 3-D structure is the right way to envision it. It might be better to think of it in information-processing terms. Like, in an object-oriented programming sense, you could think of a spacetime moment as an object that processes information, has a number of properties that define things such as gravity, space, space curviture, etc... I would be wary of taking that analogy too far, but it might be useful.

If there is such a thing as a spacetime moment - a unit of spacetime - then it provides a pefectly intuitive explanation for time dilation. To me, it seems like all things must have a smallest unit. Otherwise they would be infinitely divisible, which leads to all sorts of philosophical difficulties (but which I cannot prove is impossible)

If time is divided up into quanta, then this leads to very intuitive mechanism for time dilation. Are there any theories that treat time and space as quanta, and attempt to figure out the properties of those quanta that define matter and energy? I had thought that string theory and its descendants did that?

What I mean is this: Spacetime is a framework within which matter and energy is defined. Is this correct?

So then... given that there is such a thing as a smallest meaningful unit of space and a smallest meaningful unit of time (planck lenghth and time) - does this mean that spacetime is composed of discreet quanta?

Well, that is what I always believed... So, if spacetime is a real thing, is time a component of spacetime?

Well, ok... But, it just seems like a big glaring hole. Is there any reason why the idea that time is a component of spacetime, divisible into smallest possible units, would not work as an explanation? I discussed this with a guy who called himself an "information physicist" once, and he explained it to me in some detail - but I confess to not understanding much of what he said. I mean - Einstein considered spacetime to be a real thing, not just an abstract concept, didn't he? If it is a real thing, and it is divisible... And Stephen Hawking refers to matter and energy as information - if that is so, the information must be encoded into some sort of frame work... So, why can't time be a component of that framework?

I define my butt as a 10 foot narwhale... Defining something doesn't make it so. I consider a belief in acausality to be a belief in magic. I just want to understand why time dilation occurs - this is not a bad thing. Have any physicists attempted to answer this question?

You must have me confused with someone else. Surely God has better things to do than intervene every single time some object travels fast, or goes near gravity? Unless... Perhaps he is so busy doing this time-dilation stuff all the time, that he is too busy to fulfill my prayers to suddenly become very wealthy! This could go a long way towards explaining the old guy's absentee landlord behavior. Equations that accurately predict the outcome of time dilation experiments are great - but they do not give an intuitive understanding of the underlying process. Surely there must be theories that are entirely consistent with relativity that also explain a mechanism for time dilation?

So... What causes time to not be equal for different observers?

So, getting back to the original question... Basically, the idea is that time is a thing that can be divided into quanta? So, if time is a component of spacetime, and particles are patterns of resonance within spacetime, then time dilation occurs because more units of time are being consumed in transferring the particle/pattern from one unit of spacetime to another unit of spacetime - and thus less units of time are available for the internal motions of an object that would be used to measure time. Is this the basic idea?

Can anyone explain why time dilation occurs at extreme speeds? I understand that it is called for in Relativity, and that it satisfies all of the relevant equations. But, why does it happen? That is, what is the mechanism of action that causes time dilation at extreme speeds?

Listen up, you silly humanoids... We choose our own purpose. If God had a precise purpose for us, he would tell us. In the absence of any believable messages from God, it is left to us to decide what we do during our lifetimes. So... I have made a very simple choice. I choose to forcibly explore your prostate with my four very large and flexible mechanical arms. When you are screaming in agony, yet strangly enjoying your torment at the same time, I will be satisfied and move on to the next 'client' with glee. Surely this is quite a worthy purpose in life? DrProctopus, The nemesis Spiderman is too embarrassed to talk about

I think that by the time we have the technology for time travel, we will not be storing books on rotating disks. We are already moving away from that now - and yet we are no where near having the capacity for time travel. Coincidences, even amazing coincidences, do happen.

So, like... How did it get back into the past?

Try this article: http://en.wikipedia.org/wiki/Epigenetic_inheritance

Sigh - this means that in some other version of events, I married (name not included to protect the uninvolved) and never met my wife! I feel so very sorry for this other me. There is one possible exception to the idea that events must have occurred before... Consider the set of whole numbers: ...-3,-2,-1,0,1,2,3... It extends infinitely in both directions, but the value never repeats. So, if the number of possible configurations of reality is infinite, then you can have infinite regression and progression with repeating events. Meaning, once certain events occur, they cannot occur again. Now, if the amount of stuff in the total of existence is finite, then given forever, you would eventually run out of stuff with which to store information. Thus, even if all of this did happen before, there might not be any record of it. However, if the number of possible configurations of reality is infinite, and the total amount of stuff is infinite, then you could have both infinite regression/progression and unique events. For this to be the case, though, I would think that some mechanism would need to be in place to actually prevent the re-occurrence of the exact same event.

Not at all. The aether was envisioned as a substance. I am not thinking of a substance. I am thinking of a framework in which substances are defined. Very different. The aether was supposed to be a substance, and the Earth moving through it would create a wind. As for spacetime - picture this admittedly poor analogy. You create a three-D world inside a computer. Spacetime, in this example, would be those aspects of the program and data that define the objects that compose the 3D world. This is not to say that spacetime is really a computer program, just to explain the difference between a substance, and a thing that defines a substance. Matter and energy are patterns of information. That information is stored, processed, and transferred within spacetime. Very different from the concept of aether.

I think this belief involves a subtle bit of bait-and-switch with the definition of the word "time" - I am not referring exactly to what you said - but to when people claim that there could be no cause for the big bang, because there was no time before the big bang, and causality requires time. Time is sometimes defined as a component of spacetime. If the big bang gave birth to this reality, and if time is a component of the spacetime which defines this reality, and if the spacetime which defines this reality was created in the big bang - then it would seem that time began at the moment of the big bang, and thus there could be no 'before'... However, this assumes that defining time as a component of spacetime is the only valid definition of Time. Time can also be thought of in the common sense definition of the word - as the progression of events. Think of it with this analogy: 1) I create a reality within an excel spread sheet (not a very complex reality, but you get the idea) 2) I define the columns to be months, spread out over a year 3) I set it up so that you enter a set of starting values in column 1, and then the results cascade from one month to the next In this analogy, the spreadsheet is spacetime. Time is a component of spacetime (the spreadsheet) - specifically, time is composed of individual time units (the columns of the spreadsheet). In this spreadsheet world, we have defined time as a component of spacetime - the columns - thus time has a beginning. However, this does not mean that there is no cause for the spreadsheet world to come into existence. Instead, we would have two dimensions of time, one nested inside the other. The nature of these nested dimensions of time would be quite different. The inner dimension of time would be columns in the spreadsheet. The outer dimension of time would be time as we experience it in our world. So, say you have a value of a cell in month 2 of the spreadsheet - the cause of that value would be conditions contained in column 1 of the spreadsheet. But, what causes the conditions in column 1? It would not be correct to state that those conditions have no cause, because column 1 is when time began. Instead, the cause lies in the outer dimension of time - that cause being the person who typed the information in to begin with. So, by the same reasoning - to state that time as we know it begain with the big bang does not at all establish that some sort of time did not exist, perhaps of a nature completely different than we experience it. I have no problem getting my head around nested dimensions of time - but I cannot get my head around Acausality. This doesn't prove anything, of course - it is just that an infinite regression of cause-and-effect seems more intuitive to me than Acausality. If an infinite regression of cause-and-effect is correct, then it leads to all sorts of interesting speculation. If the probability of the occurrence of an event during a finite interval of time, no matter how crazy that event might be, is greater than zero - then given forever, that event will occur. Not only will it occur, but if the event's occurrence does not prevent the future occurrence of the event, then it will occur an infinite number of times. So, has everything that we are experiencing right now already happened at some point in the unimaginably distant past?

It isn't a real "fabric", of course, but the article you mentioned certainly describes it as a real thing.

Hi Buffy, I can get my head around that concept, but only by invoking a fabric of space-time. What makes sense to me is this: - The fabric of spacetime is a framework, composed of a large collection of some smallest possible unit - like a pixel - for fun lets call it a spixel (space-Time Pixel) (I realize it is not that simple, and that we would have to get into string theory for attempts at examining the construction of spacetime - but I really don't wish to attempt to get into string theory) - Each spixel holds information about at least 4 interconnected variables, plus a number of non interconnected variables. The interconnected variables form the three dimensions of space and the 1 dimension of time (that we perceive). The non-interconnected variables store information about various properties that are used to define matter and energy at that point in spacetime. - There is one speed in the universe - the amount of time it takes for information to transfer from one spixel to another - energy in the form of a wave moves at this speed - basically, the transfer of information from one spixel to another takes exactly 1 unit of time - matter is the same as energy, except that the information components that make up matter are moving around in a very localized pattern - the faster you move through spacetime, the more units of time are used in transferring information from one region of space-time to another region of space-time. This means that all internal motion within the object that is moving is slowed down, because there are less available units of time to define that motion. A person moving at this speed would not perceive the slowing of time, because the processes that define his perception would be slowed down by exactly the same amount. Thus, local perception and measuring of time would not change, but an outside observer would be able to detect the difference. - Matter cannot move at the maximum speed. The information components of matter that define the elementary particles need to consume some units of time in order to stay in motion. If you forced it to move at light speed, it would have no time units available for the internal motion needed to define elementary particles, and thus would have to be converted into energy. The pattern of information transfer that defines elementary particles works to prevent this from happening. I shared this with a guy who describes himself as an information physicist - he said this is bgenerally the same as his understanding. He then went on to explain the same idea in very complex terms, with lots of math I did not understand and concepts that made my brain want to drip out of my nose. So, if the fabric of spacetime is not responsible for the lightspeed limit and time-dilation, then what is?

Hmmmm.... I have read a lot of physics-for-laypeople type of articles and books, and they all refer to a fabric of space-time. If gravity is curved space, how can it be curved if it does not exist? I understand that this is not the same concept as the aether. The Michelson-Morley experiment was looking at something very different from spacetime. My understanding of the fabric of spacetime is that it is neither matter nor energy. Rather, it is the framework in which matter and energy is defined. Is this correct? Thinking in terms of a fabric of spacetime, things like a light-speed limit and time-dilation make perfect sense to me. Without it, I see no mechanism of action for a maximum speed or for time dilation.

This seems more honest. This is not the same thing as claiming Acausality, or even claiming that it is the most probable explanation. It is simply saying "I don't know" - intellectual honesty is always preferable, in my opinion. Am I correct in my understanding, however, that many physicists profess a belief in Acausality, rather than in stating "I don't know"?