andrew s

The eye brain system is very good at selecting moments of good seeing. That's how our visual forebears managed to see such fine details on the moon and planets.

Not withstanding a few deluded missteps by some observers. 

Regards Andrew 

I have added counter weights of either roofing lead suitable cut up or small free weights hung on strips of aluminium suitably attached. 

Regards Andrew 

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 

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 

Have a look at this. Regards Andrew 

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. 

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 

1 hour ago, ollypenrice said:

But could you imagine all of them? And, if you had, how would you know?

I think, going back to Michael's point that some things may be beyond imagination, your position and his may be equivalent.  We can imagine an unlimited imagination (because we can say 'unlimited imagination') but that falls short of actually having one - or of proving that anyone has one. Wouldn't it be profoundly unscientific to say, I can imagine anything?  How could it be falsified?  When you asked whether or not there was any evidence for a limit upon the imagination, I guess my answer should have been, 'No, how could there be? Science doesn't work by proving negatives.'  

Olly

Of course I can't imagine everything nor can anyone. However,  that does not mean somethings are unimaginable in the sense they could never be imagined by a human brain.

Obviously,  what is "unimagined" at a given epoch is irrelevant to if they are imaginable or not. Things like transistors or arc lights were imagined. 

What I objected to was an implication that some types of intelligent lifeforms were in principle unimaginable. Maybe I misunderstood. 

Regards Andrew 

2 hours ago, Alien 13 said:

Thing about imagination and invention is that we cant do either unless it has already been discovered/imagined...

...I have tried to think of a single invention that wasn't discovered either by observation of nature or a complete fluke, all are small evolutions of what had gone before.

Alan

 How about complex numbers what were their precursors in your view?

Einstein's thought experiments while trying to understand observed phenomenon resulted in new concepts, for example a universal speed limit.

Regards Andrew 

20 minutes ago, ollypenrice said:

What would be the difference between these statements?

I don't know what it is, but I can imagine it.

I cannot imagine what it is.

Doesn't your position require you to distinguish between them?

Olly

It would depend on the context.

1 I can imagine an omnipotent God but I don't know how it would manifest itself. 

2 I could observe the outcome of some event and not know what caused it. However, on my position I  could imagine possibilities. 

Regards Andrew 

5 minutes ago, Mr Spock said:

You cannot provide evidence of something you are unable to comprehend as it doesn't yet exist (in your mind).

There's no evidence to suggest this, but did primitive Man imagine space flight? I very much doubt it.

But.. ...they imagined gods, angles, celestial spheres and much more.

We will have to agree to differ

Regards Andrew 

24 minutes ago, Mr Spock said:

In doing so we are limited by our imagination. What is out there may be beyond that.

Why is our imagination limited. Is there any evidence of this? Regards Andrew 

1 minute ago, ollypenrice said:

Not sure I agree with this. It is possible to envisage the existence of something without knowing what it is. 'I cannot imagine what made that noise outside.' Language allows us to hypothesize the unknown. You're the mathematician, but doesn't mathematics do the same? Are there not formal proofs of the unknowable nature of a term? 

Olly

I didn't say we know what it is just that we can imagine it. Of course you can imagine something made the noise outside that's all that's needed.

Godels theorems roughly say in theories based on axioms there are true statements which can't be proven from the axioms. We can not only imagine such statements but prove they exist. 

I am not saying we know exactly what these "unimaginable" life forms are like but it seems to me we can imagine them existing just just by being able to make the statement. 

Regards  Andrew 

22 minutes ago, Mr Spock said:

It's life Jim, but not as we know it.

We are still trying to define life and intelligence by our own limited perspective.

Life out there may even be non-corporeal. How could we comprehend such a being? The possibilities for life are unimaginable to us, we are simply too limited in our knowledge and thought processes.

I really don't understand such a position. How can we define anything other than by our standards? It's our language we define words meaning how else could it be? 

In science fiction  there are many examples of no-corporeal beings including Star Trek.

In making the statement "The possibilities for life are unimaginable to us..." you are imaging such life forms! 

Regards Andrew 

1 minute ago, ollypenrice said:

But this is a conversation about potentially unknown life, so a scale which tops out at what we know, or can do, is hardly adequate.  I'm not judging our intelligence at all, in this context, since I have no idea what other intelligences might be like. That's why I don't say that I think we're good at understanding things. We are better, it seems, than bivalves but we have no idea what an upper limit might be.

As always, though, I signal clearly that I see no reason to suppose that advanced intelligence will necessarily lead to advanced technology.

Olly

I am having difficulty grasping  what you intend "intelligence " to mean in this context. 

What characteristic would it have in your view? How would you recognise it at all let alone as more or less advanced.

If you can't imagine what it might be like is it not an empty term or a synonym for different? 

Regards Andrew 

5 minutes ago, saac said:

Their names are unfortunate, in that they may not turn out to be matter or energy. The names are simply placeholders for the properties that are causing the effects we measure.  In time we will either confirm their existence or revise our understanding  on expansion and the rotational speed of galaxies. 

Very true but they are in this regard no different from the more familiar terms like atom or electron. We have been able to probe their properties better but nonetheless they are just names for components of our models. What they "mean" depends on the theory. The idea of an atom in classical physics is different from that in old quantum theory and different again to that in QFT. These are again far different the pondering of Democritus. 

Regards Andrew 

6 minutes ago, Mandy D said:

CERN appear to disagree with Sky at Night, giving an estimate of 27% for dark matter.

Not sure what you mean? 27% of the mass of the solar system? We would be tripping over it. 

The 27% is the total but it is not uniformly distributed as it lacks the EM interaction it can't accreate in the same way ordinary matter does by frictional heating and radiating away energy .

Regards Andrew 

1 hour ago, Mandy D said:

It is very clear to anyone with a good grounding in physics that much remains to be discovered and that surprises await us. So, why not dream and consider what some of those things may be?

I am a counter example to this assertion.  I belive we have probed the the full energy and size ranges realistically accessible to us. We have to look at astronomical events to go further which bring it's own challenges. 

In my view it is not the lack of ideas,  hypothesis and brain power that is the issue but the lact of new phenomena that can guide the thinking.

Yes we have dark energy and matter but they illustrate the difficulty with astronomical observations alone. If I recall The Sky at Night correctly the total mass of suspected dark matter in the solar system is about the mass if a squirrel.  Difficult to experiment on!

Regards Andrew 

PS I forgot to say I have a PhD in physics so I meet the criteria 😊

PPS In the context of the OPs question I find the "are we alone" question deeply uninteresting.  It's grant bait! But, I am an old cynic. 

8 minutes ago, Mandy D said:

We have to pose questions in order to answer them. A hypothesis which is currently unllasifiable may become falsifiable or, indeed proven correct, tomorrow. Did not the alchemists attempt to turn lead into gold? Can we not now do this, albeit by other means than chemical?

Yes and no. Yes it's always legitimate but no it's not science. For it to be science you need to have your hypothesis make predictions which are at least in principle testable. 

Regards Andrew 

"Hey, blue
There is a song for you
Ink on a pin
Underneath the skin
An empty space to fill in"

Joni Mitchell 

Impressive @ollypenrice

Regards Andrew 

Two points.

Flats, properly applied, remove fixed pattern noise due to pixel response differences. The dominant noise a high signal levels. This then makes shot noise the dominant noise.

With some ASI CMOS cameras they have different response at very short exposures compared to 1s or more although in the example both regions were linear.  See C Buils spectroscopy Web site.

Regards Andrew

1 minute ago, zorro64 said:

I would like some decent binoculars with infra red for astronomy any ideas would be welcome thx .

What are you trying to observe? We can't see infra red. Regards Andrew 

It's all mine and just for my use. Never enquired about subletting. I took it all over and set it up with them. Others have just had it delived for them to set up.

Regards Andrew 

2 hours ago, Grant said:

Did you drag the clouds and rain over there with you

 

 No they were there already! Hope it clears soon so I can commission the new set up. 

Regards Andrew 

Just having a trip to Spain for a weeks holiday and take a new instrument to PixelSkies to fit to my telescope.  Nice to be able to fiddle with it again and meet up with Dave and Michelle two of the  nicest and  most helpful people you could wish to meet. I am now their longest serving customer being second in and number one having left.  

Regards Andrew 

PS note double stacked pillars not scopes.

PPS note ex Ian King/ @FLO telescope in the background.