koti

I just realized how incredibly dumb my 2 previous comments are. I will leave them to remind me what happens when I do 10 things at once.

Gravity stems from spacetime curvature.

Spacetime with zero mass "in it" is flat and there is no gravity in that scenario. Spacetime with mass "in it" curves and there is gravity present in that scenario. If this is correct how can gravity stem from spacetime curvature, isnt it the other way around?

Gravity stems from spacetime curvature. You are saying spacetime curvature hits spacetime.

 

"Gravity stems from spacetime" is this undoubtedly true?

Spacetime curvature stems from gravity - is this undoubtedly false ?

You are right, I'm getting mixed up here.

 

I had to edit "can" to can't in my previous post.

Let me rephrase...the two are mutually exclusive...you cannot have a tinkering agent and a block universe.

I agree. Plus I rather not involve the the agent in this at all.

 

In all honesty, we would probably not be here discussing this subject if it was not for the fact that the idea of a block universe has some serious scientific credibility. I am not saying we should just sit back and accept it...that is not how science works...plus it is far more interesting to deliberate on it in this fashion.

I agree that it is intriguing - I'm enjoying this deliberation.

Skipping my unscientific affront to this theory, I can't seem to find any serious scientific credibility behind it. If you put me against a wall I'd be more keen to lean over the Moving Spotlight theory which derives from the block universe but as opposed to it, states that only the present moment is definitely present. The key words here are "against a wall" though.

 

 

I'm unaware of anything related to gravity probe B that would count as "hitting" anything. It confirmed effects of the curved geometry used to describe gravity.

 

I know I'm doing a little circle here but if spacetime curves due to mass that counts as gravity "hitting" spacetime to me. There was a doubt a few posts earlier that a human can't be called an entity. I do not share this doubt, I think its a straight path to go full nutts.

 

If we ever come up with a quantum theory of gravity, the exchange particle will be a graviton. Anything explained with spacetime distortion will have an alternate explanation that relies on the graviton, much like classical EM wave explanations give way to photon explanations.

 

I wish I shared your confidence on the look of theory of quantum gravity. Unfortunately I am helpless here.

 

How will spacetime be considered a physical thing when it's no longer part of the model?

As above.

I think this just shows that spacetime is not real; it's a model. Spacetime will go the way of phlogiston.

That might be possible.

To me the block universe is based on a wrong concept of how time behaves.

In the block universe, all events are "existing" in the past, the present, the future.

IOW all spacetime coordinates are occupied by events "once for all".

IMHO it is not correct.

 

I share your view on this. My reasoning - if all spacetime coordinates are occuoied by ALL events once and for all than when was this state established? How long did the establishing of that state take? Was it done isntantly? That seems just plain nutts.

 

For example, in your example with the "external agent", what could prevent the "External Agent" to make a change in the past? He could if he wanted, there is no "physical law" that could prevent him to do that.

What I believe (I cannot prove it, so far) is that the spacetime coordinates are not occupied by events "once for all".

I believe that things translate from coordinate to coordinate and create events. IOW that if the "External Agent" wanted to change something that happened to the Earth on the 25th of August 2016, he simply couldn't, because the Earth is not there anymore.

There are no 2 Earths, one in the present and one in the past. There is only one single Earth changing coordinates in spacetime.

That is how I see it as well.

It feels wrong in terms of our perception of how time behaves, i.e. our reality. That does not disprove the block universe.

 

 

No, the block universe precludes (the word that was used earlier) an external agent to tinker with anything...past, present or future...it is fixed.

I don't think that the Agent, considering him being God, cares about your opinion that the block universe precludes him from tinkering with whatever he wants. In other words - the Agent is not bound by any laws. If he wishes he could remove an event from the block universe and fix the consequences throughout the whole continuum from T-0 to T-~ in zero time. Its nutts, I know.

 

 

They aren't hitting spacetime, they're hitting each other.

Gravity probe B confirmed the frame dragging effect which suggest to me that spacetime is indeed being "hit" Or am I mistaken?

I'm not as bad looking as I let on, I admit it. I'm just mentally depressed. That's the honest truth. I've been on the brink of suicide multiple times in my life. Depression, I'm convinced, is one of the true poisons of mankind. It can really make you feel like there is absolutely no hope, and no value in your life whatsoever. I've always had it. I think there is may be a correlation between depression and intelligence. I seem to be the type who just can't let things be. I have to keep studying something to the point where I could lecture a scientific conference on the topic. I think that also feeds my depression because my mind does not process inconvenient truths very well. Don't get me wrong, I prefer the truth of reality versus a comforting lie, but my mind seems to react by having depression. I also think most of my depression stems from my experiences with other people and the rejection I've experienced throughout my life.

Tampitump, first off let me tell you that I am 42 years old, I'm divorced with 2 kids, I have a third kid with a new woman now, have had multiple girlfriends in my life, have had casual sex doesens of times and...I lost my virginity when I was 24.

Secondly, you are looking for scientific reasons for your problem - you won't find them, because the reasons for the bad place you are in are purely emotional and cannot be answered by scientific reasoning.

Thirdly, you are far from being alone in this. Believe me, there are more people with exactly the same issues than you imagine. In my opinion it is important to interact live with people even if the idea is not comforting to you. This is the fight you have to put up - talk to people (the right people ofcourse, the ones who will not hurt you) about your issues, be sincere which in effect will make the person you talk to open up - draw comfort from these interactions.

Lastly...the issues you are facing are within you and only within you - keep telling that youreself. Getting to know sides to yourself which you haven't explored yet always works well. Facing your fears and insecurities and being comfortable with youreself is the key to well being and these are the qualities that every woman is looking for in a man.

I would suggest one tangible action for you to take - buy a gym membership.

To be perfectly frank, that doesn't really help your position.

I'm not sure but if this comment refers to me I have to clarify that I do not take any positions on this, what I wrote is just a loose, subjective observation based on a very small number of people.

I apologise to be late on my introduction. I did look for an introductory thread a few days ago when I joined but didnt find it, it popped on my phone in recent contents just now - nevertheless a faux-pas so I do apologise.

Im middle aged, I teach engineers as a contractor for a coropration, I'm putting my life together after a 6 year long divorce, I have a 4 month old kid. I build flashlights for fun, I like armwrestling, cars, used to make my libing as a dj, played snooker semi proffesionally. I also like jack & coke and physics.

 

Not at all.

 

In fact I did say that the block universe model has some merits.

 

I have just been trying to find an alternative way to explain why I assert that the block universe contradicts both determinism and chance.

 

 

 

Here is another.

 

Determinism

 

F IFF E IFF D IFF C IFF B IFF A

 

Is an example of a deterministic chain of causation leading from A to F.

 

Chance

 

F OR E OR D OR C OR B IFF A

 

Is an example of a chance chain of events leading from A to F.

 

where A through F are events or points in the block universe.

All clear up untill here.

 

If A leads to F in either route, deleting A will not delete B, C , D, E or F from the block universe, by definition.

This is also clear with the exception that I don't understand why would we want to delete event A from the chain of events which depend on each other. Wouldn't this create a paradox therefore removing any event is not an option?

 

But the only way B, C, D, E or F can occur is if A occurs.

I agree.

 

This is a contradiction.

I agree. Previously I used the word "rubbish" instead of "contradiction" which I agree is more fortunate.

 

Yet another way to put is would be to note that the block universe regards the axis variables as independent and equivalent.

 

They are neither, because there is an additional constraint which reduces the number of degrees of freedom from 4.

I found a very interesting 23 minute video of Lee Smolin talking about what we are trying to crack here. Can I post it here?

Edit:

I will post it without waiting for an answer, I hope I'm not breaching the rules. His speach is actualy 15 minutes long, the rest are comments which I skipped. I find that I deeply agree with Lee Smolin on this:

https://www.youtube.com/watch?v=6Hi4VbERDyI

I haven't learned about frame dragging yet. That is what it was testing ,was it ?

Yes, the results of the frame dragging effect near the Earth were comfirmed.

Or, they're from a different culture. Japan, for example.

That very well might be true but I'm talking about people in Europe.

Do you think the recent Binary Black Hole merger counts as "hitting space time (or rather whatever it is spacetime is modeling) with a hammer" ?

 

It had a physical effect didn't it?

Gravity Probe B seemed to be on that track too ?

Boston Dynamics.

https://www.youtube.com/channel/UC7vVhkEfw4nOGp8TyDk7RcQ

Which I think is owned by Google since 2013.

A loose, non scientific and most probably subjective personal observation:
People who unnaturaly strongly love animals and express it often on social media and in real life tend to be infantile emotionally and tend to be lacking the ability to create sustainable inter-human emotions.

PS. I realy like all kinds of animals.

Because photons interact electromagnetically. If you have something that doesn't interact electromagnetically, a photon won't be absorbed or emitted. But that wouldn't mean the target isn't real, that's a limitation of a photon.

ok, those are facts which I fail to see how exactly correlate with the subject of this thread.

Hypothesising, (because that is what I have to do in order to find out what you mean) you went the alley of trying to define "realness" of spacetime by Interacting or not interacting electromagnetically? Why?

Good question. Probably depends on the physicist, but without thinking about it too much, if it produces or makes a (non-virtual) photon go away, it's probably a physical thing (that test is limited to things which interacts electromagnetically).

Why a photon? Couldnt "it" produce, attract or repel an electron which hass mass and still be "it" ? Why is the test limited to electromagnetism?

The theoretical physicist in this clip from "Through The Wormhole" is seemingly convinced that space-time is a very real model...http://www.sciencechannel.com/tv-shows/through-the-wormhole/building-a-wormhole/

 

@ koti, this is from the same show than the link that I gave in the other thread.

Its always nice to hear that youre not alone

 

 

Of course I will try to make my points more understandable, but it is a good job I waited as it seems you are getting there by your own efforts, which is always better.

 

I wouldn't describe the block universe as rubbish, it has some merits as a model.

 

But it is definitely not exact.

 

In fact it is arguable that the only perfect model of anything is the thing itself.

 

 

Back to the issue at hand,

 

Consider just for the moment the possibility of a super being - Maxwellian Daemon or even a God, external to the block universe.

Or perhaps a non intelligent agent but still external to the block universe.

 

Such an agent could intervene in the future history of any sort of particle and prevent whatever the laws of physics had projected for it unless it was a block universe where that projection co existed with the past and present.

 

Notice I have not said any such agent exists, just that a block universe would preclude any action by that agent.

Studiot, all I can say at this point is Holy Agent!

If things werent complex enough you managed to put another variable in there which makes me totaly lost. I will need to sit on this one for a while.

PS. I do not have problem with hypothesising about an "agent" in this context

 

I said that the block universe refutes both chance and determinism.

 

Both of these are about the process of arriving at a future course ie a process of change.

 

In order for there to be a future course it is necessary for there to be change.

 

But since everything is already set in the block universe and is immutable, but definition, there is no change.

 

Does this help progress here ?

What you wrote above is unclear to me, seems full of contradictions and I can't seem to wrap my head around it. Could you do me the courtesy of explaining to me a conclusion which comes out of what you wrote?

Edit:

I need to analize what you wrote in order to try to understand it:

Block Universe refutes Chance & Determinism -> Chance & Determinism are about the process of Change -> Future to exist needs Change -> Block Universe is set so there is no change present in it.

The conclusion which I am drawing from that logic is that the Block Universe concept refutes change -> in order for a future to exist there has to be change therefore there is either no future (the universe is non-deterministic) or that definition of the Block Universe concept is rubbish or I'm in error here.

 

A model can still be a physical entity.

 

Just because something is a model does not prevent it being an entity.

Yes. I even wrote that myself in this thread couple days ago. While trying to simplify things in my mind in order to answer "the question", I'm having seconds thoughts on this though. I'm afraid that the only conclusion I can come up for now is that I do not have enough knowledge to answer better than I already did.

A model can represent a physical entity.

Obviously yes.

It's a model with measurable parameters; the parameters are the 'real' bits. Those parameters can be reassembled to create new relationships and make another model should the earlier one fail in some area. So, I suppose, one could say the data is real but the concepts that are made from them are just human artifacts.

<Sigh>...

Down the rabbit hole again:

A parameter is a characteristic that defines a system. Equations including parameters are a model of spacetime. Spacetime "reacts with mass and velocity" therefore is tangible to me for that single reason.

Edit:

Ofcourse I am prepared to have my view on this destroyed. Actually, I would love to see a simple, coherent explanation which would undermine my view.

I think is quite straight forward but it would have been, perhaps, clearer to say: Is spacetime real or is it just a model? Or, getting down to the nitty-gritty: what does real mean?

What would be your simplified answer to the question: "Is spacetime real or is it just a model?"