Earth-like exoplanet discovered around Proxima Centauri

[smartcooky]

Well, I have always considered that discovery often stems from belief; that speculation is often the first step on the path to knowledge...

"We wish to pursue the truth no matter where it leads. But to find the truth, we need imagination and skepticism both. We will not be afraid to speculate, but we will be careful to distinguish speculation from fact. The Cosmos is full beyond measure of elegant truths; of exquisite interrelationships; of the awesome machinery of nature."
- Carl Sagan in Cosmos: The Shores of a Cosmic Ocean

 

[SelfSim]

Well, I have always considered that discovery often stems from belief; that speculation is often the first step on the path to knowledge...

"We wish to pursue the truth no matter where it leads. But to find the truth, we need imagination and skepticism both. We will not be afraid to speculate, but we will be careful to distinguish speculation from fact. The Cosmos is full beyond measure of elegant truths; of exquisite interrelationships; of the awesome machinery of nature."
- Carl Sagan in Cosmos: The Shores of a Cosmic Ocean

Yes, I find Sagan to have been widely misunderstood by many, many people.

For example, any ‘truth’ in science, (if there is any such thing), is in the meaning of science's words, because that is all a scientist can ever mean by 'truth' in the first place. Secondly, and being more specific, one can say that the only thing a scientist can ever mean about what is 'true', without ceasing to be scientific, is that what he/she means by 'true’, is always nothing but science's current best tested model. Would you say this is what Sagan meant when he used the term 'elegant truths' in the above quote?

 

[Craig B]

Yes, I find Sagan to have been widely misunderstood by many, many people.

For example, any ‘truth’ in science, (if there is any such thing), is in the meaning of science's words, because that is all a scientist can ever mean by 'truth' in the first place. Secondly, and being more specific, one can say that the only thing a scientist can ever mean about what is 'true', without ceasing to be scientific, is that what he/she means by 'true’, is always nothing but science's current best tested model. Would you say this is what Sagan meant when he used the term 'elegant truths' in the above quote?

No. "True" means corresponding to reality. When a scientist says "true" that's what she or he means. Just as when a jurist says "true" that's what he or she means in a court of law. This is absolutely manifest, because it is possible for a scientist to state that "what the scientific world believed about subject X in year y, as its then current best tested model, was not true" (and we now know better). If what he/she means by "true" can always ever be nothing but "science's current best tested model" then as human knowledge increases over time, we would not say "now we know more, and have discarded this or that older model as untrue"; we would say "truths change".

I have parodied this before as; Aristarchus was the Prime Mover who set the Earth in motion round the Sun.

But it does indeed correspond to the solipsistic idea that the world is generated by the mind, and that being true is not being in accordance with the reality of the world, but with the constructs of the human mind.

No wonder that you think Sagan has been "misunderstood".

 

[Belz...]

So why are so many people using philosophical arguments to make their points?

Heal thyself.

 

[smartcooky]

Yes, I find Sagan to have been widely misunderstood by many, many people.

For example, any ‘truth’ in science, (if there is any such thing), is in the meaning of science's words, because that is all a scientist can ever mean by 'truth' in the first place. Secondly, and being more specific, one can say that the only thing a scientist can ever mean about what is 'true', without ceasing to be scientific, is that what he/she means by 'true’, is always nothing but science's current best tested model. Would you say this is what Sagan meant when he used the term 'elegant truths' in the above quote?

Wot Craig said.

I understood Sagan perfectly well; I have read most of his stuff at one time or another, and watched the original "Cosmos" series a number of times.

You should read "The Demon-Haunted World: Science as a Candle in the Dark" if you want to gain a better idea of what made Carl tick.

 

[SelfSim]

And, here we go again ... Craig B: You really should start a new thread on this. It seems you are desperately holding on to some unevidenced belief that you are unwilling to let go of, which needs to be dealt with in some other thread on that topic.

Yet again, I will state that this will be my one and only post on this, with you, (again). And I will continue in doing that, until you come up with some better place for what will clearly be a very lengthy discussion (which thus far, shows no hope whatsoever, of relieving you of your firmly attached belief).

No. "True" means corresponding to reality. When a scientist says "true" that's what she or he means. Just as when a jurist says "true" that's what he or she means in a court of law. This is absolutely manifest, because it is possible for a scientist to state that "what the scientific world believed about subject X in year y, as its then current best tested model, was not true" (and we now know better). If what he/she means by "true" can always ever be nothing but "science's current best tested model" then as human knowledge increases over time, we would not say "now we know more, and have discarded this or that older model as untrue"; we would say "truths change".

No. We'd say what we meant by 'truth', has changed because we now have a better understanding from our better tested models.
Eg: the 'truth' is now, that we live in a heliocentric Solar system .. but before that model was developed and tested, the 'truth' was that we lived in a geocentric universe, because that's what we meant by the 'truth' (back then).

I have parodied this before as; Aristarchus was the Prime Mover who set the Earth in motion round the Sun.

Your parody might appear as a parody to you, but this is because you are unable to distinguish between Solipsism and what I'm saying.
Let me help: I certainly don't think we can know ourselves!
There ... does that help you? (Probably not .. your denialism is also at play here).

But it does indeed correspond to the solipsistic idea that the world is generated by the mind,

Which is not what I'm saying .. We generate the meaning of 'world' and 'mind' (for example). Do you see that this is fundamentally different from saying 'that the world is generated by the mind'?

.. and that being true is not being in accordance with the reality of the world, but with the constructs of the human mind.

No again. We assign the meanings of 'true' and 'reality' .. not some alien ... nor did we find the meaning of those words hanging on some intergalactic coat-check inside some nightclub on the planet Traal or something. We did it! It came from our human minds! If you don't agree, then perhaps you can tell us all exactly where you think those meanings came from then, eh?
(Oh, and please provide valid reference sources, as well).

 

[Craig B]

The essence of science is not finding meanings of words, but facts about reality. Meanings are indeed a human construct. That's where you're wrong, as I've pointed out before. So I decline your suggestion that I go and find where meanings came from.

 

[SelfSim]

The essence of science is not finding meanings of words, but facts about reality. Meanings are indeed a human construct

.. and science is not 'a human construct', eh?

All of science's definitions are operational .. that also means they are all objectively testable ... and all of that requires human constructs!

What you say, simply couldn't be more wrong (unevidenced).

That's where you're wrong, as I've pointed out before.

One can 'point out' until one is blue in the face, it makes no difference. (The fallacy is, of course, proof by repeated assertion).

Show me the objective test which unequivocally leads to the conclusion that your 'reality' exists independently of the meanings we assign and the scientific process we developed. Until you can do this, you have zero evidence, and you can cling to your fallacious argument, thereby actively demonstrating your deeply held beliefs, while I sit back and observe all of that, as it happens.

So I decline your suggestion that I go and find where meanings came from.

Yep .. whatever you do, don't, under any circumstances, make any objective observations, now.

 

[Craig B]

.. and science is not 'a human construct', eh?

All of science's definitions are operational .. that also means they are all objectively testable ... and all of that requires human constructs!

What you say, simply couldn't be more wrong (unevidenced).



One can 'point out' until one is blue in the face, it makes no difference. (The fallacy is, of course, proof by repeated assertion).

Show me the objective test which unequivocally leads to the conclusion that your 'reality' exists independently of the meanings we assign and the scientific process we developed. Until you can do this, you have zero evidence, and you can cling to your fallacious argument, thereby actively demonstrating your deeply held beliefs, while I sit back and observe all of that, as it happens.

Yep .. whatever you do, don't, under any circumstances, make any objective observations, now.

Wow, you're becoming naughtier and naughtier. Proof by being very very naughty.

Anyway, what can Sagan have meant by "the awesome machinery of nature"? Did he mean, as I suspect, that 'reality' [you never write such nasty words without scare quotes] "exists independently of the meanings we assign, and the scientific process we developed", a proposition that you consistently deny.

 

[Belz...]

.. and science is not 'a human construct', eh?

Science is a human construct but it is a tool we use to get an understanding that approximates reality as much as possible. Reality is definitely not a human construct.

 

[3point14]

All of science's definitions are operational .. that also means they are all objectively testable ...

Hello there.

Could I introduce you to string theory?

 

[JeanTate]

I had assumed this too but your link says that most of the power of a TV signal is in a .1 HZ region. That would make a 7 orders of magnitude difference over what I calculated, but that still doesn't bring many stars in range. I'll read more of your link later, thanks.

YVW (you are very welcome)

One of the more interesting things about that document is that it's so old; the topic we're now discussing was examined - to greater depth than in any of our posts - over 35 years' ago.

As I also already noted, the use of the Moon as a proxy is cool, as is the fact that the "TV hypothesis" was tested (and shown to be consistent with the model).

Oh, and in this thread only one star needs to be 'in range', Proxima Cen.

 

[JeanTate]

Ok, thanks! .. (My question was worth it to understand where you were coming from).

I think Tarter also makes the distinction of nearby vs distant, more specifically:

Yeah, and in this thread, as I just noted, only one distance is relevant, and only one star.

This combined with "acquisition" and "information" might work for communicating here, (although there is a strong sense of purpose (or application) implied in the latter terms, whereas Tarter's are more closely aligned with the observations, rather than the purpose for which those observations are intended to be used).

Not sure that this is relevant at all, in this thread.

I'm not convinced yet, (about the underlined text above) ... Why should I be?

First, I don't quite understand the "10^-28 W/m²", it seems, um, wrong. Perhaps the Tarter document was written rather too many years' ago? But I need to dig into it a bit more ...

Second, astrophysical sources of radio emission are now fairly well understood, certainly those 'close' to us are (i.e. within ~1 Mpc). None have spectra that look remotely like the integrated 'Earth radio emission', as viewed from afar, nor its variability.

If you'd like a quick tutorial on radio astronomy, I'd be happy to help ... but please, not in this thread (already far too many OT posts for my liking).

The issue for me, is not about what might generate the signals (ie: 'TV').
I see the issue being about trying to distinguish one from a background of noise.

I mean, who says some alien astronomer on Proxima b would have any conception of a 'TV signal' to recognise?

See what I just wrote.

It's not so easy to give a visual analogy; the 'optical' is barely 1 dex wide, the 'radio' dozens of dex (I'm OOMing here). The Earth's integrated radio emission, if analogized to the optical, might be something like 'an intense, and variable, orange-yellow, with highly variable spikes in the violet'. No astrophysical source looks remotely like that, even at this qualitative level.

Radio telescopes are generally located rather a long way from where lots of people live. And in their vicinity, there tend to be some rather strict local laws (or equivalent) re electronic equipment etc (though sometimes this has holes; e.g. the recent 'faulty microwave oven' that was identified as the cause of some interesting-looking RFI, at Parkes, IIRC).

The sky's background radio noise is ... not much (once you're well away from the CMB's main frequencies).

 

[JeanTate]

<snip>

Re my underlines: Sure .. those magnificiently 'colourful' words were my touch!

On a more serious note though, once again, Table 1 is also denoted with: "Detectability of Terrestrial Analog Signals by the SKA" (My bold/underline). Ie: its the SETI ("information signal" viewpoint again).

I think you'd learn a lot from getting a good grounding in radio astronomy.

<snip>

Lots ... but these cell sites employ many different transmission and encoding techniques to minimise interference and maximise signal reception. They use spread spectrum techniques for more efficient power distribution across the band, as well as other digital domain techniques. (Not to mention time division GSM and frequency division protocols). Its a completely different kettle of fish to look for these if you're an alien sniffing the spectrum on Proxima b. It would all look virtually indistinguishable from background noise, as would its power spectrum.

Um ... I think, as I said, you'd benefit from learning a bit more about radio astronomy.

Spread-spectrum protocols are interesting. IIRC, it was once widely thought that even millions of phones and tens of thousands of towers/transmitters (outdoors anyway) would produce an integrated signal that would be hard to detect from Earth orbit ('too deeply buried in the noise'). Then someone actually tested this hypothesis (may have even been a skilled ham operator, do you know smartcooky?), and found it to be total bunk.

Sure, unless you're the NSA (or equivalent), you can't pull individual conversations from the radio, but otherwise you sure can tell that it's not just noise.

The other common protocols - e.g. GSM - lead to it being even easier to that the integrated radio emission is not noise.

 

[CynicalSkeptic]

(my bold)

My mistake.

As pointed out, before ~1940 there was very little in the way of artificial radio emissions that would have made it through the ionosphere.

Hasn't anyone in this thread seen Contact? Obviously Hitler opening the Berlin Olympic games will be the first transmission the little green guys detect.

 

[SelfSim]

... First, I don't quite understand the "10^-28 W/m²", it seems, um, wrong. Perhaps the Tarter document was written rather too many years' ago? But I need to dig into it a bit more ...

Please do .. I'd appreciate it.
The Tarter document may well be out of date relative to technology improvements. (I'm always eager to be updated on the latest).
Regardless of the perhaps, (maybe), datedness of the numerical quantity, the search for SETI is fundamentally different from general radio astronomy and I think that was the general backdrop to her paper (at the time she authored it).
ETA: Her paper became available online 5 Nov 2004. See here. (So, yes, I accept its 12 years old ... please feel free to update the figure ..

Second, astrophysical sources of radio emission are now fairly well understood, certainly those 'close' to us are (i.e. within ~1 Mpc). None have spectra that look remotely like the integrated 'Earth radio emission', as viewed from afar, nor its variability.

Then that would count as evidence for a lack of radio-intelligent lifeforms and geophysical Earths within ~1 Mpc then, no?

If you'd like a quick tutorial on radio astronomy, I'd be happy to help ... but please, not in this thread (already far too many OT posts for my liking).

I'm always eager to learn more ... thank you for your offer.
Perhaps we could drill a little more into how SETI ('information signal') searches differ from astrophysical searches. Whilst there may be particular customisations for SETI, Tarter etal are clearly prepared to use any and all techniques to make sense and gather data of interest. (Thank goodness!)
As she points out in that paper, their searches are limited by the amount of time available for any given observation, and thence computer processing technologies (which clearly improves).

(I agree about the OT post count, too).

It's not so easy to give a visual analogy; the 'optical' is barely 1 dex wide, the 'radio' dozens of dex (I'm OOMing here). The Earth's integrated radio emission, if analogized to the optical, might be something like 'an intense, and variable, orange-yellow, with highly variable spikes in the violet'. No astrophysical source looks remotely like that, even at this qualitative level.

Again, perhaps evidence of the apparent scarcity of Earths .. (but perhaps not for long).
I think the distance factor needs to be layered on top of such qualitative comparisons. There are other parameters which come into play at larg(er) distances which in turn, call for models for interpretation.

Radio telescopes are generally located rather a long way from where lots of people live. And in their vicinity, there tend to be some rather strict local laws (or equivalent) re electronic equipment etc (though sometimes this has holes; e.g. the recent 'faulty microwave oven' that was identified as the cause of some interesting-looking RFI, at Parkes, IIRC).

Sure .. Eg: the latest RATAN 600 signal detection calls into question local military sources, too. Also, I notice they were using a receiver with a 1 GHz bandwidth (which produced a flux density of only 0.75 Jy). That's not the way Tarter's SETI organisation goes about 'its business'. (The signal only turned up once in 39 attempts, too).

The sky's background radio noise is ... not much (once you're well away from the CMB's main frequencies).

Sure .. which throws the emphasis back onto the detection method and technologies, because of the noise introduced by the receivers and processing. (Our observational eyes and ears, so to speak).

Eventually, we might get into discussing Optical SETI(?)
(Whose techniques are also becoming relevant for intra Solar System communications .. (just trying to link back to the OP topic here)).

 

[SelfSim]

I think you'd learn a lot from getting a good grounding in radio astronomy.

I think her use of 'SKA' in her table, is coming from the SETI backdrop of experience with the Allen array used in SETI narrowband searches. My, (and her?), reference to 'SKA' is looking at the SKA array as being an extended Allen Array. In other words if she had access to the SKA, they'd use it for their customised SETI narrowband searches and then Table #1 contents acquire SETI significance. (I'll have to chase up on past papers I've read on how SETI adapts general astrophysical radio astronomy to clarify on this ... standby).

Um ... I think, as I said, you'd benefit from learning a bit more about radio astronomy.

Spread-spectrum protocols are interesting. IIRC, it was once widely thought that even millions of phones and tens of thousands of towers/transmitters (outdoors anyway) would produce an integrated signal that would be hard to detect from Earth orbit ('too deeply buried in the noise'). Then someone actually tested this hypothesis (may have even been a skilled ham operator, do you know smartcooky?), and found it to be total bunk.

Sure, unless you're the NSA (or equivalent), you can't pull individual conversations from the radio, but otherwise you sure can tell that it's not just noise.

Yet another OT topic to drill into. No offence intended towards smartcooky or other skilled ham operators .. but coming at such an analysis from a ham perspective doesn't convince me that the nuances of Earth's RF spectrum, when viewed from relevant distances, constitutes a distinguishable bio-sign of Intelligence.

The other common protocols - e.g. GSM - lead to it being even easier to that the integrated radio emission is not noise.

And how much of that conclusion relies on fore-knowledge of those protocols, technology schema and deployment patterns to make that distinction?

 

[SelfSim]

Science is a human construct but it is a tool we use to get an understanding that approximates reality as much as possible. Reality is definitely not a human construct.

Then cite the test (and its results) which will conclusively demonstrate that 'reality is definitely not a human construct' .. instead of just re-asserting the claim, over and over!?

And while you're doing that, I will observe signs of your mind in action (that will be my test of my claim).

(Come on .. show us what you've got!)

 

[SelfSim]

All of science's definitions are operational .. that also means they are all objectively testable ...

... Could I introduce you to string theory?

So, the only thing a scientist can ever mean about what is real, without ceasing to be scientific, is that what we mean by reality, is always nothing but our current best tested model. So if you're asking me, "Are strings real?", all I need to say is that if what you mean by what is 'real', is our current best tested model, then it needs to be asked whether or not 'strings' have met that criteria (or not) ... and I'm sure an interesting conversation would then ensue.
If you mean anything else on the other hand, there is no need to ask me, simply choose your, (or anyone else's), favorite belief.

 

[Brainache]

Then cite the test (and its results) which will conclusively demonstrate that 'reality is definitely not a human construct' .. instead of just re-asserting the claim, over and over!?

And while you're doing that, I will observe signs of your mind in action (that will be my test of my claim).

(Come on .. show us what you've got!)

I would say that 'humans are a reality construct'. We don't make the universe, the universe makes us.

If that is not the case, then who am I communicating with now? Phantoms?