Are we alone in the universe?

[Astro_Dad]

As an aside It’s interesting how these threads can stimulate thought processes and memories  - setting up for a normal Monday morning and just checking in here your post there @ollypenrice took me straight back to reading Children of Prometheus. Thanks for that - I read that book during my PhD years - time flies and thinking moves on…

Edited November 21, 2022 by Astro_Dad

[Xilman]

22 hours ago, Paul M said:

If two supernovae coexisted, one in a galaxy in the Virgo supercluster and one in the Perseus supercluster, they'd never know each other's light. For either one to see the other's light would mean existing hundreds of millions of years later (I'm guessing at the distance between the Perseus and Virgo superclusters, google is stumped).

No need to guess. Simple trigonometry will suffice.

Google will tell you the directions and distances to each ...

[andrew s]

22 hours ago, ollypenrice said:

OK. So the question is refined, but perhaps it becomes rather academic? If you mean by 'in principle', imaginable by beings other than us,  there is precious little difference between your point and Michael's when he suggested that some life forms might be unimaginable. I assume he meant by us.

However, if you meant that we have reached the point of being able to imagine everything, I'd have to ask why you think this. Why have we reached this infinity when chimps have not?

Of course, I don't think you meant either of these things!  What I don't understand is where you draw the line between 'imaginable' and 'imaginable in principle.'  My view is that humans may not be capable of imagining all that can be imaginable in principle.  (Phew, it has taken me a long time to get to a point which I might, with more wit, have reached some time ago...)

Olly

Sorry for the delay @ollypenrice I did a reply yesterday but was unhappy with it and deleted it.

I would split the notion into unimagined ( possible to imagine but no one has done so yet and unimaginable ( impossible for us to imagine).

The first, unimagined, is a large, possibly, infinite set. This covers most of what has been refered to as "unimaginable" in previous posts.

The second, unimaginable,  is an empty set in my view.  I believe this because, given any necessary technological support, we could perceive any life that could possibly exist within the constraints of physical laws. Not to say we can't imagine much that could not exist as sci fi has clearly demonstrated.

These are certainly beliefs not science and drifting into linguistic philosophy something I rejected sometime ago. 🧐

Regards Andrew 

Edited November 21, 2022 by andrew s

[saac]

9 hours ago, ollypenrice said:

A surprising thought: might high technology adversely effect the evolution of high intelligence?  Might higher intelligence evolve without technology than with it?  

There is a debate in evolutionary biology about whether human evolution has stopped, slowed down or speeded up. One school says that we have learned to modify our environment, using technology, so that we no longer need to adapt to it. This makes me wonder whether, in 'outsourcing' many of our mental functions to computers, we have removed a key selection pressure driving the evolution of intelligence. We might argue that the use of IT drives a new kinds of mental function among the engineers, and it might, but they are a minority who might not out-breed the computer-dependent majority.

It's an entertaining thought that technology might put an upper limit on the evolution of intelligence. Usually it's assumed that high technology goes with high intelligence. Maybe not!

Olly

I recall a thread some time ago which posited that our intelligence level hasn't really been subject to the same evolutionary pressure as perhaps the rest of our physiology.  The argument being one of our ancestors from say 10 or 15 thousand years ago would have a comparable intelligence level to today. Of course knowledge and experiences have changed but perhaps intelligence plateaus once it is gained. 

Jim 

[Paul M]

1 hour ago, Xilman said:

No need to guess. Simple trigonometry will suffice.

Google will tell you the directions and distances to each ...

Ok, I get the hint. Where's my slide rule and trig tables....

I still cheated and used an online trig calculator. It's 10 years since I re-learnt trig and it didn't get retained.

Quick values used: Distance to Perseus Cluster = 240  Ml/y , Distance to Virgo Cluster = 53 Ml/y. A rough angular separation 112 deg. The calculator gave forth a distance of 264 Ml/y between the two clusters. That's where they used to be anyway.

Here is a link to the result for anyone wanting to check my thinking   http://cossincalc.com/#angle_a=112&side_a=&angle_b=&side_b=240&angle_c=&side_c=53&angle_unit=degree

A 500 million year wait for a reply is making for a dull conversation!

 

[andrew s]

11 hours ago, ollypenrice said:

A surprising thought: might high technology adversely effect the evolution of high intelligence?  Might higher intelligence evolve without technology than with it?  

There is a debate in evolutionary biology about whether human evolution has stopped, slowed down or speeded up. One school says that we have learned to modify our environment, using technology, so that we no longer need to adapt to it. This makes me wonder whether, in 'outsourcing' many of our mental functions to computers, we have removed a key selection pressure driving the evolution of intelligence. We might argue that the use of IT drives a new kinds of mental function among the engineers, and it might, but they are a minority who might not out-breed the computer-dependent majority.

It's an entertaining thought that technology might put an upper limit on the evolution of intelligence. Usually it's assumed that high technology goes with high intelligence. Maybe not!

Olly

You are a curmudgeonly old astronomer always looking at the downside 😊.

 What technology has done from the printing press onwards has allowed us to share and pool our intelegence.  No longer are we limited to a single brain and the limits of our  individual computational powers and memory. 😁

Regards an unreasonably optimistic old astronomer. 

Edited November 21, 2022 by andrew s

[ollypenrice]

45 minutes ago, andrew s said:

You are a curmudgeonly old astronomer always looking at the downside 😊.

 What technology has done from the printing press onwards has allowed us to share and pool our intelegence.  No longer are we limited to a single brain and the limits of our  individual computational powers and memory. 😁

Regards an unreasonably optimistic old astronomer. 

Heh heh. I'm really quite optimistic! I have, however, given up all hope of  predicting the consequences of new technologies.  The printing press enjoys a revered place in history - and it's hard to argue with that. (Even for me, and I like to think I can argue with anything. 👹)  But... a reasonable person might consider the internet, with its social media, to be a liberating extension of the printing press, a kind of printing press for all.  The reality is, as it seems to me, that it has turned into a means by which raving lunatics unleash themselves upon a collectively compliant collection of lunatic-worshipers.

My optimism envisages, out there, a world in which two terrestrial phenomena never evolve: predation and technology. How serene that might be! It might even be sufficiently sublime to make the possibility of eternal life just about bearable! 

Olly

 

[saac]

I can see a new poem being written

Letters Between an Aging and Curmudgeonly Astronomers

"reach me down my Tycho Brahe said the elder to the curmudgeon,,,,

We two have imagined beyond that which can be,

Beyond footless halls of the void  we have explored the untrespassed  expanse of space

Yet we cannot agree, the extent to which we will see  

 

My apologies to John Gillespie Magee (High Flight), Sarah Williams (The Old Astronomer To His Pupil) and to anyone who knows anything about poetry, and especially to English teachers everywhere (including retired )   

Jim 

Edited November 21, 2022 by saac

[saac]

12 minutes ago, ollypenrice said:

Heh heh. I'm really quite optimistic! I have, however, given up all hope of  predicting the consequences of new technologies.  The printing press enjoys a revered place in history - and it's hard to argue with that. (Even for me, and I like to think I can argue with anything. 👹)  But... a reasonable person might consider the internet, with its social media, to be a liberating extension of the printing press, a kind of printing press for all.  The reality is, as it seems to me, that it has turned into a means by which raving lunatics unleash themselves upon a collectively compliant collection of lunatic-worshipers.

My optimism envisages, out there, a world in which two terrestrial phenomena never evolve: predation and technology. How serene that might be! It might even be sufficiently sublime to make the possibility of eternal life just about bearable! 

Olly

 

I tend to agree with you on the Internet Olly.  It's got that duality thing going on, the positive democratisation of knowledge while at the same time promulgation of banality.  In that way I guess it really does mirror the printing press - it  liberated knowledge to the masses from the powerful while also promulgating a lot of drivel.  How can something have such a positive effect while at the same time be so negative (dangerous even).  Maybe all is not lost though, circling back to evolution and intelligence, maybe the internet is the enabler of the next advance.  Scientific progress now seems to come from large multi discipline, multinational collaboratives rather than the mind of a single "genius".  I'm thinking particularly about fields such as particle physics, cosmology, bio/life science. 

Jim  

[andrew s]

1 hour ago, ollypenrice said:

The reality is, as it seems to me, that it has turned into a means by which raving lunatics unleash themselves upon a collectively compliant collection of lunatic-worshipers.

I would never have described you thus 😮. Regards Andrew 

[Guest]

If we are alone in this universe it surely is one heck of a lot of wasted space. 

[ollypenrice]

6 hours ago, Mike Q said:

If we are alone in this universe it surely is one heck of a lot of wasted space. 

...though in some rarefied regions of theoretical physics it has been suggested that space may be illusory. 

Now, can I imagine a spaceless universe??? And, if I could, where would I put it?

lly

Edited November 22, 2022 by ollypenrice
typo

[saac]

15 hours ago, ollypenrice said:

...though in some rarefied regions of theoretical physics it has been suggested that space may be illusory. 

Now, can I imagine a spaceless universe??? And, if I could, where would I put it?

lly

At the back, way up high, obscured by some useless random stuff such that you can't find it whenever you want it. Isn't that always the way?

Jim 

Edited November 22, 2022 by saac

[Gfamily]

15 hours ago, ollypenrice said:

...though in some rarefied regions of theoretical physics it has been suggested that space may be illusory. 

I can see one way that that could be true ... 

 Let us suppose that there are two options

• There is a real universe with laws and stuff - and we're in this. This Universe is real and exists. 
• We are living in a simulation on some superior intelligence's super computer. We're all here, all existing, all interacting, all seeing, all detecting, all experiencing the simulation's laws and stuff

If we are in the simulation, it's not likely that there's only one instance of the simulation - what would be the point of that? So, we expect that if it were a simulation, there are multiple simulations. 

Even if there are only two, that makes it a 2:1 shot that the universe is illusory - if 100, then it's 99% likely that we live in a simulation, and our experiences are illusory. 

Personally, I don't think there's any evidence that we do live in a simulation - but it's something to consider for a different perspective. 

[Paul M]

15 hours ago, ollypenrice said:

...though in some rarefied regions of theoretical physics it has been suggested that space may be illusory. 

Space, as an empty void, has never made sense to me.

I find it equally difficult to understand why space exists.

As a boy I wondered and worried about why anything exists. Why is there a Universe? So what if the Universe didn't exist, I thought, why would there be such a thing as space? 

I know physics talks about space being created in the Big Bang, but maybe that is a different kind of space that existed before there was a Universe?

But... If time = space and there was an instance of zero time maybe there was zero space. And without time as a yardstick does space mean anything?

[Gfamily]

8 minutes ago, Paul M said:

Space, as an empty void, has never made sense to me.

I find it equally difficult to understand why space exists.

...

I know physics talks about space being created in the Big Bang, but maybe that is a different kind of space that existed before there was a Universe?

But... If time = space and there was an instance of zero time maybe there was zero space. And without time as a yardstick does space mean anything?

Space is a measure of the separation between objects 

Another measure is the separation between events, and this is what we call time.

Relativity tells us that they aren't independent - or at least people who understand relativity tell us this. 

One of the ways of understanding the expansion of the universe is that there is a 'scale factor' that determines how the space between objects is increasing as time progresses. 

I don't understand this either.  

ETA  - But I have a telescope that shows me things, and other people have other devices that show me other things. And they give me joy (and sometimes a pretence of understanding).

Edited November 22, 2022 by Gfamily

[markse68]

49 minutes ago, Paul M said:

And without time as a yardstick does space mean anything?

I think that is key to Roger Penrose's theory of conformal cyclic cosmology- that at the heat death of this universe there will only be photons left and they don't "experience" time so space scales become meaningless and what is infinite can become miniscule and go bang again. Or something like that

[Gfamily]

41 minutes ago, markse68 said:

I think that is key to Roger Penrose's theory of conformal cyclic cosmology- that at the heat death of this universe there will only be photons left and they don't "experience" time so space scales become meaningless and what is infinite can become miniscule and go bang again. Or something like that

Which begs the question of when will the universe know that across the scale of the universe there is nothing else but photons - of course this can never be 'known'  - at least not under the current cosmology.  

[ollypenrice]

9 hours ago, Gfamily said:

I can see one way that that could be true ... 

 Let us suppose that there are two options

• There is a real universe with laws and stuff - and we're in this. This Universe is real and exists. 
• We are living in a simulation on some superior intelligence's super computer. We're all here, all existing, all interacting, all seeing, all detecting, all experiencing the simulation's laws and stuff

If we are in the simulation, it's not likely that there's only one instance of the simulation - what would be the point of that? So, we expect that if it were a simulation, there are multiple simulations. 

Even if there are only two, that makes it a 2:1 shot that the universe is illusory - if 100, then it's 99% likely that we live in a simulation, and our experiences are illusory. 

Personally, I don't think there's any evidence that we do live in a simulation - but it's something to consider for a different perspective. 

It is mainstream physicists, versed in physical laws, who have questioned the validity of our perception of space,  just as they have questioned the validity of our perception of time.

I won't buy the simulation hypothesis at any price for the same reason that I won't buy another well-known hypothesis which simply postpones the question of how all this began.

I spend many happy hours exploring, vicariously, the depths of what we call space so I'm not dismissing it. It exists as a perception, at the very least. It just may not be quite what it seems. A book I read on time made the elegant point that the existence of a past, a present and a future was...  a theory of time.  The same can be said of our three spatial dimensions.

Olly

[Peter Drew]

Despite the advances in technology and vast sums of money spent, naked eye is still the most successful at detecting alien activity.  Just look at the number of UFO's etc that are reported.     🙂

[AndyThilo]

I think life exists on Europa. What stage that life is at is anyone's guess, but more than likely microbial. In the whole universe, it would be narrowminded to believe that other life didn't exist as well as life existing long before us. 

Maybe even closer there will be evidence of previous microbial life on Mars, but it's a pretty slim chance and we won't find out for a good few years until the sample return mission is completed.

[Xilman]

On 21/11/2022 at 18:56, andrew s said:

 What technology has done from the printing press onwards has allowed us to share and pool our intelegence.  No longer are we limited to a single brain and the limits of our  individual computational powers and memory. 😁

It happened long, long before the printing press as we have known the term for the last 1000 years. Unless you consider a cylinder seal to be a type of printing press.

Egyptians and Sumerians had writing by 3000BCE. Some of those documents taught their readers how to perform arithmetic, geometry and accountancy. All of them preserved some of the knowledge of their authors.

[andrew s]

1 hour ago, Xilman said:

It happened long, long before the printing press as we have known the term for the last 1000 years. Unless you consider a cylinder seal to be a type of printing press.

Egyptians and Sumerians had writing by 3000BCE. Some of those documents taught their readers how to perform arithmetic, geometry and accountancy. All of them preserved some of the knowledge of their authors.

I would not argue with that but the printing press made a step change in the availability of recorded material.  It released it from the confines of the monastery, royal libraries or similar repositories and made it available to the population at large.

Regards Andrew 

[Rusted]

2 hours ago, Peter Drew said:

Despite the advances in technology and vast sums of money spent, naked eye is still the most successful at detecting alien activity. 
Just look at the number of UFO's etc that are reported.     🙂

You can tell the aliens are highly advanced:
They can disable any image stabilisation in our cameras.
While simultaneously giving the imager severe Parkinson's.

[900SL]

If reality really is built upon interacting fields, I can imagine 'ghosts in the machine' that are able to operate directly at this level.  

Then you have 'dark matter'. The shadow universe, so to speak. Fields that we are unable to perceive or detect entirely