How did we find the location of the Big Bang?

[BrightQuark]

Having observed that each galaxy is rushing away from each and every other galaxy, how exactly did astronomers finally manage to work out where to point their telescopes/instruments to look for the origins of the Big Bang?

 

My limted understanding... is that whatever direction you glance in throughout the night sky, using a powerful telescope of course, the galaxies are always rushing away from one another, so it's difficult to conceptualize how a point of origin for the BB was settled upon?

Edited June 25, 2013 by BrightQuark

[swansont]

They didn't find the location of the big bang, at least not as a single location in today's universe. The big bang happened everywhere in space, because it was the beginning of space.

[BrightQuark]

this sounds familiar, however, I've heard and read that Hubble II will be able to take us back to the moments just after the big bang, and so I thought, this is a point, location, in the record of the night sky, and that the background radiation had already been measured, Or is it the BR that's being observed, assumed that was the same everywhere, so would not require a telescope?

[ACG52]

The CMBR is as far back in time as observation can take us, and it is spread equally, everywhere. There is no point from which everything expands.

[zapatos]

The Hubble II will take us back to a point in time (just after the Big Bang), not a point in space. You can look in any direction to see back to the point in time just after the Big Bang.

Edited June 25, 2013 by zapatos

[swansont]

this sounds familiar, however, I've heard and read that Hubble II will be able to take us back to the moments just after the big bang, and so I thought, this is a point, location, in the record of the night sky, and that the background radiation had already been measured, Or is it the BR that's being observed, assumed that was the same everywhere, so would not require a telescope?

 

Nothing can look that far back, because the universe was opaque until it was cool enough for the particles combined to form atoms. A telescope able to se a greater distance will look back to earlier formations, because of the time it takes for light to reach us.

 

The background radiation has been observed by systems with a wider field of view than Hubble, but you still want to use a telescope.

[BrightQuark]

I've just read up again on the Big Bang and the Cosmological Principle, and your latest posts have just summed up more briefly what I have been reading, and I think I can see where I'm struggling to understand, it has something to do with the "all directions" aspect, furthest galaxies are the oldest, near galaxies new and much younger, and the formation of the atoms aspect, thinking here of the theoretical "primordial atom" vs what we see forming in the universe created much later,.... but it's hard to actually picture why the older universe is seen at a distance, rather than much closer, or close to us in the MW, this "distribution" is tricky to put into perspective.

 

Does this have something to do with the often cited explanation of walking on the surface, and all matter, old and new is in our path....

 

No, that doesn't work either, we have to look deeper or frame this at a distance, and yet those older parts of the uninverse could in theory be on our doorstep, and yet, they are much further away in all directions? If this makes any sense so far, or rather, can you see my confusion regarding this aspect, it's a perspective issue, or observer's point of view, that's difficult to "frame".

Edited June 25, 2013 by BrightQuark

[Delta1212]

You see a lightning flash. 10 seconds later you hear thunder.

 

You see another lightning flash. 30 seconds later, you hear the thunder.

 

The first lightning bolt was closer to you. The thunder represented the sound of something that happened 10 seconds prior.

 

The second lightning bolt was further away. The thunder represented the sound of something that happened 30 seconds prior.

 

 

The farther something is from you, the longer it takes the signal (light/sound/whatever) to reach you. That means that a signal reaching you from far away will be representative of something that happened longer ago than a signal reaching you from someplace nearby.

 

Light from the sun takes 8 minutes to reach us. When you look at the sun, you're seeing what it looked like 8 minutes ago. Light from a galaxy 10 billion light years away takes 10 billion years to reach us. When you look at a galaxy 10 billion light years away, you're seeing what it looked like 10 billion years ago.

 

 

The farther out you look in space, the farther into the past you're peering.

[EdEarl]

If you could ride on a photon that Hubble saw as coming from a galaxy 13.7 Giga LY away, you would travel at the speed of light and experience 13.7 Giga birthdays (13,700,000,000 birthdays).

 

No matter which direction Hubble looks, it can find light 13.7 GYr old coming from a distant galaxy. It is as if we are at the center of the Universe, but we are not.

 

If we lived on another planet, around another star, in any galaxy, that Hubble can see, a similar space telescope Hubble_x could find 13.7 GYr old light coming from any and all directions.

 

It is counter intuitive, and can be confusing.

[zapatos]

...furthest galaxies are the oldest, near galaxies new and much younger...

That is not accurate. You need to remember to make the distinction between the age of a galaxy, and the age of the light from that galaxy that we are seeing now.

 

The light from a distant galaxy has been traveling toward us for a longer period of time than the light from a nearby galaxy. Therefore, the light we are seeing from the distant galaxy is older than the light we are seeing from a nearby galaxy.

 

That does not necessarily mean that the age of the distant galaxy is greater than the age of the nearby galaxy. Galaxies started forming throughout the entire universe at the same time. There are galaxies nearby to us that are older than galaxies far from us, and vice versa. When we look at more distant galaxies, what we are seeing is older light.

 

The same would hold true for someone in a distant galaxy. When we look at them we see light that has been traveling to us for, say, 12 billion years. When they look at us, they see light that has been traveling toward them for 12 billion years. Our galaxies may be the exact same age.

[ACG52]

So when we look at a galaxy 10 billion light years away, we are seeing the light which left it 10 billion years ago (ignoring expansion time), which means we are seeing it as it was 10 billion years ago, when it was much younger.

[BrightQuark]

So when we look at a galaxy 10 billion light years away, we are seeing the light which left it 10 billion years ago (ignoring expansion time), which means we are seeing it as it was 10 billion years ago, when it was much younger.

 

based upon what Zapatos has set out above, I assume therefore, that even though that light is 10 billion years old, we can interpret that light and confirm that we are dealing with a galaxy that is either older or much younger than our own based upon say, the spectrographic content of the light, so even though the light has taken 10 billion years to get here, as Zapatos has pointed out, you have to be careful not to confuse the light and the age of the galaxy?

 

My, albeit incomplete understanding, had always been that the further away you look, the older the universe is, if I've understood Zapatos' explanation, we have to factor in the time the light has taken to get here before we ascertain the age of the galaxy, and that -- and this is the aspect that is confusing, but my original statement that Zapatos copied in suggested that further = older, and that closer = newer with respect to the age of galaxy -- and that's, it seems... incorrect?

 

Are we effectively saying we that we have much older galaxies on our doorstep, with light that only took 4 billion years to arrive here that we are able to study as examples of the early universe? *Again, whilst not confusing time for light to travel to us with the actual age of the galaxy.

 

I always assumed that further meant older and that was because the light had taken so long to get here, and that's how we are able to see the older universe, and that we are hoping to look further back with Hubble II,

 

 

 

Edit to add:

I've just dipped in and missed the earlier posts by Ed and others, so will have to come back and read over these more carefully.

Edited June 26, 2013 by BrightQuark

[EdEarl]

based upon what Zapatos has set out above, I assume therefore, that even though that light is 10 billion years old, we can interpret that light and confirm that we are dealing with a galaxy that is older or much younger than our own?

Light from a galaxy 13 GLYr distant shows up on a Hubble image as one or maybe two pixels. Except for the age of the light and position in the sky, nothing else is known AFAIK. The Webb space telescope may be able to analyze the light using a spectrometer, and learn more.

[zapatos]

I'll address some of your questions but I'm a bit concerned that you might lose the forest for the trees. Be sure the keep the overall structure of the universe in mind when you are trying to understand the details.

 

The universe is similar everywhere. We are not in a unique position where we are near the 'young' part and further away is the 'old' part. We are not in the middle, or on the edge. The way things look from here are the way things look from elsewhere. Stars, galaxies, and other structures are forming, changing, and dying, everywhere at the same time.

Nothing happens here that doesn't also happen elsewhere. The complexity comes in because the universe is LARGE, and that affects our observations. (I am leaving out complexities due to expansion, etc.)

My, albeit incomplete understanding, had always been that the further away you look, the older the universe is

The further away you look, the older the light is. The universe is the same age everywhere.

...if I've understood Zapatos' explanation, we have to factor in the time the light has taken to get here before we ascertain the age of the galaxy...

Imagine your friend in California takes a picture of his child and sends it to you. Snail mail being what it is, you receive the picture 10 years later. You are seeing the child as he was 10 years ago. Same thing with the distant galaxy. We are seeing a picture of the galaxy as it was when the light was sent to us.

Are we effectively saying we that we have much older galaxies on our doorstep...

Sure. Galaxies form throughout the universe. Some form sooner than others. Some of the earlier formed galaxies are near us, as are some of the later formed galaxies.

...with light that only took 4 billion years to arrive here that we are able to study as examples of the early universe?

That statement is a bit confusing for me. If we want to study examples of the early universe we need to look at distant parts of the universe. The further away we look, the older the light. The older the light, the closer it was to the beginning of the universe.

I always assumed that further meant older and that was because the light had taken so long to get here, and that's how we are able to see the older universe...

Further means older light because it took longer to get here, and that is how we are able to see the universe as it was near its birth, when it was quite young.

[ACG52]

But again, OLDER LIGHT means we are seeing the object at a younger stage in it's existence.

[BrightQuark]

Guys, this makes sense and fits with what I'd understood prior to our discussions, there are a few aspects, such as the fact that there are older galaxies or galaxies of different ages fairly close to us!

 

The light that we receive from extreme distances, which could be 10 billion years old (and yet shows the star as it was, not as it is now makes complete sense) and so interestingly, we are always out of date, the sky we see is a universe that existed out there at various stages, a little like watching TV on our sets from the 1960s, instead of today, and we'll have to wait a long time to receive The Sopranos, or The Wire.

 

What's the oldest light we can detect and how close to the BB is that light? (perhaps Ed had answered that with his pixels example)

 

I know that they are trying to replicate the conditions that followed the very early stages of the BB at CERN, but what is interesting is that I'm wondering what exactly I've heard now about Hubble II, I understood that it was going to be able to detect light that was very close to the very first state of the universe, whilst the BB was still hot and atoms weren't behaving as they do now, perhaps, what was being said was still a great deal of time after BB, but still very useful and would open up new understanding, it just sounded as though they were going to be able to see lgiht that was litearlly from seconds after the BB, rather than light years, later?

 

I'm have a scout around and see if I can find an example of what I've been listening too, and post it up if it's any good!

 

Thanks again guys, I think we're on the same page at last.

Edited June 26, 2013 by BrightQuark

[zapatos]

What's the oldest light we can detect and how close to the BB is that light? (perhaps Ed had answered that with his pixels example)

ACG52 answered that in post #4.

[BrightQuark]

Light from a galaxy 13 GLYr distant shows up on a Hubble image as one or maybe two pixels. Except for the age of the light and position in the sky, nothing else is known AFAIK. The Webb space telescope may be able to analyze the light using a spectrometer, and learn more.

This rings a bell, I'm sure that I was listening to an explanation quite a while back that said that the light we get from such distances, is as small as that, I'd tended to assume that the light would always produce a picture (through the most powerful telescopes) taht showed at least a sort of nebulous scattering of light which could be worked on or manipulated by various types of interpreation - artists' sketches, or by way fo chemical composition, to give us a picture of a galaaxy, or nebula or some other type of object.

 

ACG52 answered that in post #4.

Okay, I'll reread that post, thanks.

 

 

CMBR:

Light that is 380,000 years older than the BB itself.

 

But again, OLDER LIGHT means we are seeing the object at a younger stage in it's existence.

Yes. Just looked at Wiki's CMBR article and NASA's page on James Webb, which explains what the new satellite will be able to see. And read up on WMAP, too. I was also looking at a few articles on magnification.

Edited June 26, 2013 by BrightQuark

[EdEarl]

CMBR:

Light that is 380,000 years older than the BB itself.

 

Light that is 380,000 years older younger than the BB itself. We cannot observe anything before the big bang, or for the first 380Ka thereafter.

[BrightQuark]

Oh, my slip, I meant 380,000 years "after" the BB.

[swansont]

But again, OLDER LIGHT means we are seeing the object at a younger stage in it's existence.

 

No, because galaxies did not necessarily all form at the same time. You could have 10 billion year old light of a galaxy that was formed 3 billion years earlier and 5 billion year old light from a galaxy that was just formed, i.e. it's much closer. The younger light is an earlier snapshot.

[ACG52]

No, because galaxies did not necessarily all form at the same time. You could have 10 billion year old light of a galaxy that was formed 3 billion years earlier and 5 billion year old light from a galaxy that was just formed, i.e. it's much closer. The younger light is an earlier snapshot.

In that case you're comparing two different galaxies. Older light from AN object means that we are seeing THAT object when it was younger.

[BrightQuark]

Swansont, if we ignore the age of the light for a moment, and enter a Carl Sagan type of Spacecraft that can zip us around to each and every point of the universe, wherever we choose, so we'll meet up with star nurseries, and nebulas, and young galaxies, and older galaxies, and some of those will be closer to the date of the BB, say, 12 billion years old, others yet, only 8 or 3 billion years old... what do we know, or what theories have there been to date - if any - about the distribution patterns of the same?

 

I'm aware of the example of the balloon where we use a marker pen and scribble small dots of black and then we inflate it, and the spots expand and move away from one another, but that doesn't really assist with "distribution" of old and young galaxies....

 

Or is it much simpler than that, if we look around the Milky Way, only, we see new stars forming, older suns and planets etc, so we have "young material" appearing amongst and around what exists.

 

To clarifiy, the point about the time the light has taken to get here is not one of "how old the galaxy or objext is" ... it's only a record of older information effectively, so we have to be able to date that galaxy or object from analysis of the light. However, having done that and let's say, we find a galaxy that is only 5 billion years, we then have to remember that if the light for that galaxy took around 10 billion years to get here, we don't really know what the galaxy would look like now, At its point of origin.

 

Or I presume we could model it if we had a computer powerful enough and the data, and then watch it age, taking into account the small inconvenience that we'd have to know everything about it, impossible of course.

Edit to add:

Actuallly, this just raises more questions, we have the date of a galaxy, but that won't assist with how we date the earliest material in that galaxy, there will be older suns, and newer stars forming as it evolves, yes?

 

And if CMBR is distributed throughout the universe, evenly, I presume that the radiation that James Webb is seeking to see in the IR spectrum, is the early or "earliest" radiation, as the radiation we see that is closer, has had more time to dim in intensity? I'm entirely speculating here?

 

Krauss... in a lecture I was watching earlier explained how we exist at a fortunate time in the evolution of the universe, if we'd turned up a few billion years earlier, we would interpret the state of the atoms and form our views based upon that evidence, and if later, we'd not see any trace of the CMBR, so, it would be a case of bye-bye BB theory, we also wouldn't know that our part of the universe wasn't particularly special and see a far more benign universe, as it would be a universe without any CMBR, that would lead to different theories about the formation or nature of the universe/early universe....

 

... anyway, enough, I'm babbling away here....

Edited June 26, 2013 by BrightQuark

[swansont]

In that case you're comparing two different galaxies. Older light from AN object means that we are seeing THAT object when it was younger.

 

"Older" is a relative term, so it implies two different ages and two observations. The age of the light and the age of the object when the light left are distinct ideas.

[BrightQuark]

Yes, that's how I've always understood it.

 

And on that note, I'll back away and return to reading, as I don't wish to emulate the proverbial dog chasing its proverbial tail.

Edited June 27, 2013 by BrightQuark