seeing the big bang

[jamey2k9]

if you get a telescope for example hubble and look deep enough into space you see light and images from billions of years ago would it be possible if we looked far enough we could see the big bang?

[SwampeastMike]

While I consider it unlikely, I must ask:

 

For what and where would you look?

 

Under the expanding universe theory, a point at the center formed the locus, but in the distanceless environment of the universe how can a single central point exist?

[Klaynos]

The big bang happened everywhere, you could look anywhere.

 

I honestly can't remember, I've only ever seen short presentations on this, but I seem to recall that there is some phase of the early universe that we cannot see past due to very large absorption of photons....

[SwampeastMike]

The big bang happened everywhere

... except where it was.

[NowThatWeKnow]

...but I seem to recall that there is some phase of the early universe that we cannot see past due to very large absorption of photons....

Isn't the CMB thought to be the photons from the early universe?

[GDG]

The big bang happened everywhere, you could look anywhere.

 

I honestly can't remember, I've only ever seen short presentations on this, but I seem to recall that there is some phase of the early universe that we cannot see past due to very large absorption of photons....

 

Prior to July 4 of year 379,000 , the universe was full of free charged particles (electrons, protons, nuclei), which would be opaque to light of all frequencies. When things cooled down enough for neutral atoms to form, the universe became transparent.

[Airbrush]

When the universe became transparent, did the expanding mass of atoms have a color or just pure white light, of all wavelengths?

[SwampeastMike]

While transparent, I'm not positive there would be any discernable difference in light at this point. We have atoms (not molecules) and certainly no stars. While the atoms are extraordinarily hot thus perhaps glowing in some fashion, they would likely all be glowing at the same level and what you would "see" is the same shade of grey (not pure white and not pure black) everywhere save perhaps one or two points (in the entire universe) of black or perhaps one point of black and one point of white.

[Gag Me]

The big bang happened everywhere, you could look anywhere.

 

Took the words right out of my mouth.

Darn, I`m not fast enough ]=

[Martin]

When the universe became transparent, did the expanding mass of atoms have a color or just pure white light, of all wavelengths?

 

That is a really good question. The temp was 3000 kelvin, so it was more orange than the surface of the sun, which is 5800 kelvin.

 

There are stars which are less massive than the sun, which burn a little cooler, and whose surface temperature is 3000 kelvin. Their light would be that color.

It is a blackbody thermal mix of wavelengths.

 

Actually the tungsten filament of an oldstyle 100 watt bulb operates at about 3000 K. You know how incandescent lightbulb light is slightly more yelloworange than clear sky sunlight? Your eye adapts quickly so we think of a pure white piece of paper as the same color indoors as outdoors but if you measure the mix of wavelengths in daylight it will be a different lopsided bellcurve distribution from what comes off the paper under artificial illumination.

 

Graphics designers sometimes describe different types of "white" light by their temperature. The closer to 5800 the closer to daylight. There's actually more to the story. It's kind of interesting.

 

Maybe have a look at the Pedia on "black body radiation"

http://en.wikipedia.org/wiki/Black_body

at each temp there is a standard mix of wavelengths for that temp radiated by a generic object. sunlight is well described by the same blackbody formula (but for 5800 kelvin) as also describes the invisible heat spectrum in an oven (at whatever kelvin baking temperature) you just plug a different temperature in but it is the same blackbody formula and similar looking curve---sort of lopsided bell. Good to know about this.

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Merged post follows:

Consecutive posts merged

Prior to July 4 of year 379,000 , the universe was full of free charged particles (electrons, protons, nuclei), which would be opaque to light of all frequencies. When things cooled down enough for neutral atoms to form, the universe became transparent.

 

Good way to put it! Independence day that year was the day all the photons got free and could run forever.

 

Before that, the fog was dense enough that they were constantly being absorbed and re-emitted and scattered.

 

So on July 4 they gained their liberty.

Edited May 23, 2009 by Martin
Consecutive posts merged.

[CygnusX1]

To answer your question Jamie..., the answer is no..., we will never be able to observe the Big Bang directly. The Cosmic Microwave Background (CMB)..., also known as the Surface of Last Scattering, is the farthest we will ever be able to penetrate into the history of our universe because of the inpenetrable dense fog of super heated, ionized gas that existed up until that point. After the cloud of gas cooled enough..., light became liberated and we observe this as a microwave raditation due to the stretching of that light from the expansion of the universe over the past 13 billion years. That is a good question though.

[Martin]

we will never be able to observe the Big Bang directly...

 

observing with photons is limited by scattering---we only see back to about year 380,000 and then there's the hot fog.

 

but what about observing with neutrinos? What are your thoughts on that? How far back in time might that permit observation? How close to the start of expansion, do you think?

[CygnusX1]

I think thats a good thought..., about observing further with neutrino's. They would pass right through the fog because of their ability to pass right through matter with a very small chance of interacting with it. But therein is the problem..., they are very difficult to detect. Another issue might be distinguishing which neurino's were actually created as a biproduct of the big bang. I like the thought though. It might end up being a possibility after all..., when we refine our techniques enough to study them. For now..., we are left studying the ripples (sound waves) of the surface of last scattering and extracting theories from them on the development of our early universe. To me..., thats enough in itself..., because it actually gives us a deep insight into the stucture and properties of the universe at that time. When I think about how pockets of dark matter were causing an ebb and flow of baryonic matter, pulling it in and out from the pull of gravity, which then caused these great ripples of sound waves traveling 2/3 the speed of light across an atmosphere of primordial soup.., it truly blows my mind. Sometimes it seems that however we think the universe should reveal itself to us..., its always in the subtleties of creation that we are able push the envelope of knowledge further along. Thats my humble opinion though...