13.8 lightyears?

[saac]

15 hours ago, apaulo said:

the only definate in astronomy is, we definately  know very little. lol

I agree, some do      

Jim 

[Macavity]

10 hours ago, saac said:

All of a sudden new management speak became the fashion...

Sadly so, Jim. The "Big Science" tradition of ad-hoc, friendly (productive!) collaboration between diverse groups:
(Theoreticians, Scientists, Engineers, Technicians, Programmer) is replaced by formal "Service Level Agreements"!
The previously hierachy-free system gets invaded by "job titles", the now, rigidly defined, "seniority structures". 🙁

Office memos get sent round (often to highly qualified staff) telling us we must: "Answer telephone calls within
Three Rings (sic!)... speak politely to "Customers"! Focus shifts to annual appriasals... promotion... "taking credit".
Instead of actually doing stuff, we now spend half a working week reporting to "progress meetings" - Ironically
on overall LACK of progress - 'Cos we are in meetings! Resentment grows... No one does "that little bit extra"... 😔

MAYBE that goes some way to explaining why some of us feel a tad MIFFED, when "Scientists" on Social Media,
seem to be trying to circumvent *Peer Review* - To influence *budget* allocations, by direct appeal to a mottley
bunch of "conspiracy theorists" and "anti-science rhetoricians"? To get OTHER areas of science "cancelled" etc. 😒

Not without odd chuckle tho! Sometimes I checkout the profile of "Super Fans", these folk re-tweet/re-post.
Dunno about "Scientist", but ONE certainly earned the moniker "Biggus D....." Aargh, my eyes! 😱
N.B. It's always worthwhile checking on the company you (appear to) keep?!? lol. 🤣

[mergatroid]

On 31/01/2023 at 01:42, Gfamily said:

We know that there are multiple causes for wavelength shift, because we understand the science.

As a matter of fact a univeristy astronomer said that to me. Maybe he was trying to simplify it for a non-astronomer.
Then he provided a highly technical PDF to me to "justify" this. One could say he was acting like an elitist.
At any rate, perhaps you could elucidate the issue and enumerate the currently known sources of wavelength shift?

[vlaiv]

2 minutes ago, mergatroid said:

As a matter of fact a univeristy astronomer said that to me. Maybe he was trying to simplify it for a non-astronomer.
Then he provided a highly technical PDF to me to "justify" this. One could say he was acting like an elitist.
At any rate, perhaps you could elucidate the issue and enumerate the currently known sources of wavelength shift?

https://en.wikipedia.org/wiki/Redshift

 

[mergatroid]

On 31/01/2023 at 01:57, michael.h.f.wilkinson said:

it just says we are at the centre of what we can observe, because the universe has a finite age

That's a nonsequitur. You're justifying apples by talking about oranges. They aren't causally related.

[mergatroid]

On 31/01/2023 at 02:12, ollypenrice said:

Could you describe in detail what an observation of such half galaxies would reveal, bearing in mind that galaxies are gravitationally bound systems? 

You may've misunderstood.

The claim was made that the 13.8 billion lightyear limit to our view of the universe around us was due to objects receding away from us at more than the speed of light.

If that claim is true (I'm not saying it is), it would follow that some galaxies are moving at exactly the speed of light relative to us.

In the case of such galaxies, which are spinning, part of the galaxy would be moving away from us (i.e. red shifted), and part of it would be moving toward us (blue shifted).

But, because the relative speed is the speed of light, half of the galaxy's light would be too slow to ever reach us and we'd see only half of that galaxy. The part that would visible is the blue shifted half.

Seems pretty obvious.

Edited February 1, 2023 by mergatroid

[Bizibilder]

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