Greetings Science Peeps!!
I watch a lot of science shows, talks and what-not. I'm not a scientist, but I think I grasp many of the theories, at lease on a basic level; I won't ever be able to do the higher level calculations.
Most of these talks make me think and consider new possibilities and realities. But more often than not, I have (many) questions about the specifics of one or more of the aspects of these talks.
For instance... in George Smoot's talk, he mentioned that the universe is "almost an perfect sphere". (yes, it's an old(ish) -and long- talks link: [ted.com] )
Now, it's completely understandable if what he meant to say was the "visible" universe... and if that's the case, I'm ok with it, I can move on... I don't like to nit-pick (either metaphorically or literally).
But can anyone tell me how we could possibly know the 'shape of the universe'.
I get that if we consider the big bang to be the truth (or the revised theory of Cosmological Inflation or whatever) that we can presume that, if the universe came from a single 'point' and it expanded in all directions equally and simultaneously, that if may very well be spherical, but we can't be certain.
In the talk, it seems to me that he's basing his assumption on what he can 'see'.
It only stands to reason that we can only 'see' back a certain distance and that it would resemble an almost perfect sphere... but that's not to say there isn't anything past what we can 'see'.
Does that make sense to anyone/everyone?
Is it just me?
Am I wrong?
Am I missing something??
(Be careful how you answer - If I get a satisfying answer, I have LOTS more questions!!!)
2
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9 comments
Feel free to reply to any comment by clicking the "Reply" button.There is no centre of the universe! According to the standard theories of cosmology, the universe started with a "Big Bang" about 14 thousand million years ago and has been expanding ever since. there is no centre to the expansion; it is the same everywhere.as all points in space are simultaneos in all directions. therefore there is no measurable boundry, therefore no "shape" .... that is you could look into sace from the edge of the universe, and it wouldd still look the same. The elephant in the room here is "time" time is not restricted by the speed of light, because it has no mass.
magicwatch
Level 7
Apr 3, 2018
1
Time is a relative observation
I'm going to have to read this comment a few times (more) to really grasp what you're saying. It's a little mind boggling.
Although, if there is no centre, not shape, no boundary... how is there an edge?
I get what you're saying, and it's truly difficult to grasp.
I'm not sure how the elephant fits in either. (kidding)
@Axelsan correct,
Scurry, why do you say "I won't ever be able to do the higher level calculation"? If you can do simple algebra then you can.
Special relativity:
El-loco
Level 7
Apr 3, 2018
1
Thanks for the video!
I've watch the 1st few minutes, but will have to give it my full attention.
Will watch later and will (try to remember to) comment more.
Seriously, though, Thank You!!
@El-loco I've tried to watch twice but I keep getting 'lost'.
Not sure if it's because I was tired or distracted.
...but so far, I'm still thinking that I'll leave the higher math to the folks who are being paid to do it.
I'll give it another go on the weekend - with a strong coffee by my side.
This is an interesting article that came out today about a star that was discovered which is the furthest observable object from us using optical telescopes. It explains the challenges of seeing anything that goes farther than that, and it has to do with redshift and gravitational lensing [bgr.com]
Essentially WITHOUT gravitational lensing we would not be able to see that star. To create the maps of the universe we have to use radio telescopes which gives us very different kinds of data than an optical one would. The farther out you go the much lower definition we have. Once you get past nine or ten billion light years away you get mush, absolute background noise basically.
More on redshift and the cosmic background noise [thecuriousastronomer.wordpress.com]
jperlow
Level 7
Apr 3, 2018
1
Cool! Thanks for the link. Love it! Love this stuff.
It's amazing how well we can 'see' considering...
thanks again.
Dang, you got me thinking, "WWHD"?
What Would Hawking Do?
Emme
Level 7
Apr 3, 2018
2
We can go as far as the extent of the cosmic background radiation which is 13.something billion years old. That is how far the matter has expanded. The universe is not really a perfect sphere and the matter is not distributed evenly. The NASA WMAP project has the best imagery [map.gsfc.nasa.gov]
jperlow
Level 7
Apr 3, 2018
1
Right! Yes!
That's only as far as we can see. and it only appear as spherical by that limitation.
Ok - so I'm not insane - that's always reassuring.
Thanks for the link too!
I am not the brighest bulb on the block, but I am going out on a limb to say that I would compare nature and the universe to what most theist would say about god. God is totally beyond human understanding and so is the universe. We feeble humans try to conceptualize things using our very finite brains (which is all we can do) to try to understand but it is mostly beyond human understanding and comprehension. We just try our best. IMHO
jlynn37
Level 8
Apr 3, 2018
2
I can see that - and I don't disagree at all.
but I think that that's part of what makes us who we are.
Our quest to know, to understand, to quantify and comprehend.
I don't see it as a bad thing.
and it may, indeed be unattainable.
I still thing we should try.
The Universe is infinite and eternal. The big bang just explains how the glaxies we see got into their current positions. The Observable universe has a size and age, and is expanding.
Space can not expand - matter within space are moving apart giving the illusion of expansion.
gater
Level 7
Apr 3, 2018
0
Funny how a profile pic can throw you off track. Hmmm...
So, the infinite and eternal universe of which you speak...
Is this your opinion or is there some evidence to back it up?
I'm not saying I disagree, just would like to know more of the physics behind it.
I agree that the big bang generally attempts to explain where things (galaxies) are, and that we can measure both size and age of the 'observable' universe.
I don't think I tried to claim that it did, but I'm not so sure that space can't expand.
I think it's a valid question - not one that I asked - at least not here - but still valid.
I'm not sure what illusion you're referring to; the universe expanding is not the same thing as space expanding (ie space and universe are not synonyms in this respect), I'll give you that, if that's what you mean...
I am probably the least scientifically minded person to respond. I think its oK to question scientific research and data by experts in their field.
sassygirl3869
Level 9
Apr 3, 2018
2
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