I am curious what scientists say the reason is why we haven't picked up signals from alien civilizations. We can see light from 13.8 billion light years away but we haven't picked up on anything being broadcasted?

because our broadcast technology may be specific to our planet
because we can only monitor small portions of our skies
because there may not be alien civilizations
because its not as easy as tuning into a tv show

not sure if you are trolling, but just in case you are not:

it's an issue mainly of signal strength
just ask yourself why you can lose the transmission signal for your mobile/handy/cell

but also of signal separation
light we see from billions of light years away which is seen as a tiny dot of light comes from maybe millions/billions of suns/objects combined

so there are two key issues:
1. the signal send by one civilisation has to be strong enough to reach another civilisation
2. the technology of a receiving civilisation has to be good enough to filter those signals out from other noise

Yeah you've got it right mainly. However I would dispute the highlighted part; it is simplified and not strictly true in physics.

ah mr wise guy at it again
you expect a detailed analysis rather than a simplified statement?

but:

1. what about 'maybe' don't you understand - english much?
2. images of distant galaxies (consisting of huge amounts of stars and protostars) cover only a few dozen pixels at best in the various spectral bands, eg



now do the math

yeah, science is a bitch

I'm a native English speaker, I word everything perfectly, if you don't understand it then maybe take a few English lessons.

So you concede that your point was not strictly true as a result of simplification.

seems you still don't comprehend - my suggestion would be that you stick to medicine and don't peddle in science
but let me explain my point for dummies (yes, that still needs simplification):

giant telescopes point for hours at a small segment of space and collect photons
for very distant galaxies consisting of millions or even billions of suns the resulting image will result in a few pixels
and it is impossible to distinguish which specific source within that galaxy was the origin of a specific photon

if you think long enough about it, you should understand

Ok, well let's look at your original quote which I rightly disputed.



The images collected from millions of objects result in more than just a few pixels, maybe you misunderstand astronomy or were just simplifying for the op? If the latter, then that's ok.

your english comprehension really is lacking, let's just look at:
" The images collected from millions of objects result in more than just a few pixels"
if millions of objects are clustered within a tiny viewing angle the light emanating from them will result in an image covering just a few pixels
seems you don't understand astronomy

and yes, i responded to the op in my first post in case you didn't notice that

This post was edited by brmv on Sep 13 2014 07:35am

Ok, no problem but you need you make yourself clearer in future. Maybe spend less time arguing and more time on typing coherent English.