Did the universe pop out of nowhere and nothing?

[Nearly Sane]

I was just mentioning what he said - which, you must admit, sounds surprisingly modern, even if it was wrong.

And it, with much of the discussion here, has echoes of the divide between Heraclitus and Parmenides.

[Outrider]

'Depth' could just be a human concept to describe relative position in space.

Depth is a purely human concept, that developed in an arena where it was conceived there was an absolute 'up/down' in relation to what transpired to be a purely local gravitational effect.  Over time we've adopted the term as a convenient bit of terminology to use in depicting three orthogonal physical direction which we tend to apply in a purely relative fashion in the absence of any overall directional constant.

If you are static and look at the night sky are you observing deep into space or high into space?

That rather depends on how you set up your reference frame - the point is though, not whether or not it should be called 'depth' but rather if I close my eyes does it disappear.  Sriram was suggesting that time was illusory, and change was the reality, I invoked 'depth' (and put in quotes to show it was a particular usage) as a corollary.  It's an imperfect analogy, of course, but then most analogies are.

When the observing mind disappears  so does the concept.

Yes, but the underlying reality that the concept crystallises in our though processes doesn't.  Distance doesn't cease to exist because we aren't looking any more.

Similarly, time could just be a concept used to indicate and compare relative changes e.g. the decay of a caesium particle or the movement of a clock hand or a photon.

It could be, but in periods of no change we still have time passing.  In cases where we move at different speeds, constant rate of change processes change at different relative rates - that requires an independent time variable, it can't be solely change happening because it's happening differently with respect to...?

Stasis is another concept which implies absence of change.  If this were to be absolute then time as a concept ceases to have meaning and existence would be changeless and non time-dependant.

How would it?  We might know, because our mental activity would mean that there wasn't stasis, but why would stasis mean time didn't exist. If time didn't exist, how could the stasis have anything to exist within?

O.

[bluehillside Retd.]

Stranger,

And it, with much of the discussion here, has echoes of the divide between Heraclitus and Parmenides.

Yes I know, but while Heraclitus make the flashy signings to get to the European championships Parmenides always do better in a penalty shoot-out.

Or have I misunderstood something?

[ekim]

(1)  It could be, but in periods of no change we still have time passing.

(2) How would it?  We might know, because our mental activity would mean that there wasn't stasis, but why would stasis mean time didn't exist. If time didn't exist, how could the stasis have anything to exist within?

(1) Assuming that there are periods of no change, how do you measure the passing of time?

(2) As an absolute It could be self existent, eternal, timeless, omnipresent and changeless, and 'time' as a mental concept to measure change would only be relevant to the mental activity you mention, but in such stasis the mental activity would not exist and in its place another omni ... omniscience.

[Outrider]

(1) Assuming that there are periods of no change, how do you measure the passing of time?

That I don't have a means to measure it doesn't mean it's not there.

As an absolute It could be self existent, eternal, timeless, omnipresent and changeless, and 'time' as a mental concept to measure change would only be relevant to the mental activity you mention, but in such stasis the mental activity would not exist and in its place another omni ... omniscience.

As an absolute what could be self-existent?

O.

[Sriram]

If I don't move, depth doesn't disappear - that it's only made apparent to us in certain circumstances doesn't mean that it's not there when we aren't paying attention.  Time is, without time we couldn't have anything. Existence is time-dependent - without change you have stasis, but stasis is also a description with respect to time.  Time is.

O.

How do you know? We use time as a tool to measure change. But why do you say that something absolute called Time continues...on and on...regardless of change and observer? 

[bluehillside Retd.]

Sriram,

How do you know? We use time as a tool to measure change. But why do you say that something absolute called Time continues...on and on...regardless of change and observer?

First, it’s spacetime – not just time.

Second, surely the more pertinent question is why wouldn’t it?

[Stranger]

How do you know? We use time as a tool to measure change. But why do you say that something absolute called Time continues...on and on...regardless of change and observer?

It's not about knowing, it's about the fact that, on the one hand we have your totally unsupported and scientifically illiterate assertions, and on the other we have extremely well tested scientific theories.

To a rational mind, it's really not hard to decide which is more likely to be the closest to reality...

[Outrider]

How do you know? We use time as a tool to measure change. But why do you say that something absolute called Time continues...on and on...regardless of change and observer?

It's the point of reference - change occurs WITH RESPECT TO TIME... no time, no change.  No change, maybe time maybe not... one is required for the other, but that doesn't work in reverse.

O.

[SteveH]

And it, with much of the discussion here, has echoes of the divide between Heraclitus and Parmenides.

I saw that Parmenides down the Dog and Duck a few months ago - he was pissed, as usual.

[Sriram]

It's the point of reference - change occurs WITH RESPECT TO TIME... no time, no change.  No change, maybe time maybe not... one is required for the other, but that doesn't work in reverse.

O.

We don't see Time anywhere. We only see matter & energy. Matter and energy are in constant flux and change. To an observer that creates an impression of time.

No change...no time. Time is a mental construct. Change and observer are necessary for time to exist.

[Outrider]

We don't see Time anywhere.

We don't see gravity, but people don't seem to be floating away...

We only see matter & energy.

We don't see sound.  We don't see temperature.  There are a number of things that we don't see that we have other senses for, and a number of things that we don't have any senses for - magnetic fields, for instance. Why should the fact we don't have a sensory apparatus for it preclude its existence?

Matter and energy are in constant flux and change. To an observer that creates an impression of time.

And to a physicist that requires time in which to happen - you can't have change without time.  You have state A, and a change to state B - the separation between those two states is a measurement of time.  Change makes it apparent, but change doesn't create it, change happens within it.

No change...no time.

No.  No change, no evidence of time, but space-time is regardless of whether we're here to watch it or not.

Time is a mental construct. Change and observer are necessary for time to exist.

No.  There is time, and there is our conception of time; one of them is independent of us (because we exist in it) and the other is dependent upon us (because it exists within us).

O.

[SteveH]

Time is a mental construct.

Sorry, but as soon as someone uses "construct" as a noun, I know they're talking pretentious bollocks, and stop listening.

[Gordon]

I'd have thought that the need for GPS technology to compensate for relativistic effects would indicate that time isn't just a "mental construct".

[ekim]

I'd have thought that the need for GPS technology to compensate for relativistic effects would indicate that time isn't just a "mental construct".

Could you explain that more expansively, Gordon.  By 'relativistic effects' do you mean relative change?  How does the technology use 'time' to compensate?

[Stranger]

We only see matter & energy.

No, we don't. You can't see energy because (as has been explained to you before) it isn't stuff. Energy is a property of stuff. Things have energy, they can't be energy.

There are also many, many things that we have solid scientific evidence for that we don't see - or even that the average person never even sees the effects of. For example, every second about 100 billion solar neutrinos pass through every square centimetre of your body. Basing what you think exists on what you can directly see (or otherwise sense directly) is totally absurd in the 21st century.

No change...no time. Time is a mental construct. Change and observer are necessary for time to exist.

More totally unsupported assertions. The existence of space-time is scientifically well established and backed up by plentiful evidence. Your assertions are backed up by nothing.

It's really odd how common this particular bit fuckwittery is on forums - and not always from the religious either. I guess saying that "time doesn't exist, only change", sounds profound in a way, so people who know nothing of the science can pretend, to similarly unformed people, that they've had some great insight.

[Gordon]

Could you explain that more expansively, Gordon.  By 'relativistic effects' do you mean relative change?  How does the technology use 'time' to compensate?

Time, as measured by a clock, appears to pass faster on Earth than it does on the atomic clocks in the GPS satellites that are moving faster and are less affected by gravity that clocks on Earth (such as the Sat-Nav device in your car), and although the amounts of time are small they increment quickly enough to make GPS unusable unless compensated for.   

But in a relativistic world, things are not simple. The satellite clocks are moving at 14,000 km/hr in orbits that circle the Earth twice per day, much faster than clocks on the surface of the Earth, and Einstein's theory of special relativity says that rapidly moving clocks tick more slowly, by about seven microseconds (millionths of a second) per day.

Also, the orbiting clocks are 20,000 km above the Earth, and experience gravity that is four times weaker than that on the ground. Einstein's general relativity theory says that gravity curves space and time, resulting in a tendency for the orbiting clocks to tick slightly faster, by about 45 microseconds per day. The net result is that time on a GPS satellite clock advances faster than a clock on the ground by about 38 microseconds per day.

But at 38 microseconds per day, the relativistic offset in the rates of the satellite clocks is so large that, if left uncompensated, it would cause navigational errors that accumulate faster than 10 km per day! GPS accounts for relativity by electronically adjusting the rates of the satellite clocks, and by building mathematical corrections into the computer chips which solve for the user's location. Without the proper application of relativity, GPS would fail in its navigational functions within about 2 minutes.

https://www.physicscentral.com/explore/writers/will.cfm

[Stranger]

Could you explain that more expansively, Gordon.  By 'relativistic effects' do you mean relative change?  How does the technology use 'time' to compensate?

Detail here: Real-World Relativity: The GPS Navigation System.

The basic point, however, is that each satellite carries a very accurate clock and the system needs to compensate for the effects of both special and general relativity. In other words the calculations take into account that the satellites' time dimension is "skewed" relative to earth because of its relative speed (see image in my post #233). It also needs to take account of the fact that space-time around earth is curved (gravity). All this is based on a unified space-time manifold in which each "observer" sees time as a different direction through space-time.

[Sriram]

We don't see gravity, but people don't seem to be floating away...

We don't see sound.  We don't see temperature.  There are a number of things that we don't see that we have other senses for, and a number of things that we don't have any senses for - magnetic fields, for instance. Why should the fact we don't have a sensory apparatus for it preclude its existence?

And to a physicist that requires time in which to happen - you can't have change without time.  You have state A, and a change to state B - the separation between those two states is a measurement of time.  Change makes it apparent, but change doesn't create it, change happens within it.

No.  No change, no evidence of time, but space-time is regardless of whether we're here to watch it or not.


No.  There is time, and there is our conception of time; one of them is independent of us (because we exist in it) and the other is dependent upon us (because it exists within us).

O.

Now you are being silly. When I said 'see' I didn't mean only about literally visual phenomena only. I meant experience of it.   

We 'experience' time flowing only in terms of the changes that we experience.....not something called Time in itself. It is only through changes around us that we know of 'time'. If changes don't happen time cannot exist.

And if there is some sort of an absolute time flowing on and on...relativistic aspects connected to time cannot be possible. Only because time is connected to change that its measurement changes with changing situations. Time is relative only because it is not absolute.

[Enki]

Sorry, but as soon as someone uses "construct" as a noun, I know they're talking pretentious bollocks, and stop listening.

Even though I don't agree with Sriram at all on this topic, why would you say the use of 'construct' as a noun is necessarily pretentious?

[jeremyp]

We don't see Time anywhere. We only see matter & energy. Matter and energy are in constant flux and change. To an observer that creates an impression of time.

No change...no time. Time is a mental construct. Change and observer are necessary for time to exist.

We don't see energy. Energy isn't "stuff", it's an accounting number.

[SteveH]

Even though I don't agree with Sriram at all on this topic, why would you say the use of 'construct' as a noun is necessarily pretentious?

It's usually used, in phrases such as "social construct" and "mental construct", by people who don't know what they're tslking about, but want to sound fashionably cynical. I once saw a graffitto on a flyover support that said "Love is a social construct". Ffs!

[Enki]

It's usually used, in phrases such as "social construct" and "mental construct", by people who don't know what they're tslking about, but want to sound fashionably cynical. I once saw a graffitto on a flyover support that said "Love is a social construct". Ffs!

Fair enough, but as far as I can see Sriram was emphasising the idea that time is a mental concept. This seems to me a perfectly valid use of the word, even though, as I said, I completely disagree with him.

[Outrider]

Now you are being silly. When I said 'see' I didn't mean only about literally visual phenomena only. I meant experience of it.

And we do experience time, even if we don't experience change...   

We 'experience' time flowing only in terms of the changes that we experience...

If I sit in a sensory deprivation chamber there is no change, but I'm aware of time passing. 

..not something called Time in itself.

We don't detect magnetism ourselves, only through its effects on other things, that doesn't make it any less real.

It is only through changes around us that we know of 'time'.

How we know about it isn't the same thing as what it functionally is.  Time is, it's part of a four-dimensional space-time in which we exist.  If there was no time, there would be no us.

If changes don't happen time cannot exist.

Even if it required change in order for us to become aware of time, that doesn't mean that time follows the change - post hoc ergo propter hoc and all that...

And if there is some sort of an absolute time flowing on and on...relativistic aspects connected to time cannot be possible.

Time doesn't flow, we flow through time - and the rate at which we do so changes depending on the local gravity and our physical speed through that gravity.

Time is relative only because it is not absolute.

Time is absolute - it's our movement through it that's relative.

O.

[Stranger]

And if there is some sort of an absolute time flowing on and on...relativistic aspects connected to time cannot be possible. Only because time is connected to change that its measurement changes with changing situations. Time is relative only because it is not absolute.

Drivel.

The reason time is relative to different frames of reference is because of the geometry of space-time, which means that different frames of reference regard different slices through space-time to be their time and space coordinates.

There is no absolute time or space because they aren't separate things. The thing that is "absolute" is the space-time manifold.

Again: I am not giving you my opinion - this is what the best tested theory (general relativity) we have is telling us, so it is backed up by plentiful evidence.