The Known Universe

[Sheeple Profile]

The Known Universe - from the Himalayas through our atmosphere and the inky black of space to the afterglow of the Big Bang

http://www.youtube.com/watch?v=17jymDn0W6U

[Sheeple Profile]

The Map of the Known Universe - Seb Chevrel
http://www.seb.cc/mapuniverse/index.html

[Sheeple Profile]

In Big Bang cosmology, the observable universe consists of the galaxies and other matter that we can in principle observe from Earth in the present day, because light (or other signals) from those objects has had time to reach us since the beginning of the cosmological expansion. Assuming the Universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction—that is, the observable universe is a spherical volume (a ball) centered on the observer, regardless of the shape of the Universe as a whole. The actual shape of the Universe may or may not be spherical. However, the portion of it that we (humans, from the perspective of planet Earth) are able to observe is determined by whether or not the light and other signals originating from distant objects has had time to arrive at our point of observation (planet Earth). Therefore, the observable universe appears from our perspective to be spherical. Every location in the Universe has its own observable universe which may or may not overlap with the one centered around the Earth.

The word observable used in this sense does not depend on whether modern technology actually permits detection of radiation from an object in this region (or indeed on whether there is any radiation to detect). It simply indicates that it is possible in principle for light or other signals from the object to reach an observer on Earth. In practice, we can see objects only as far as the surface of last scattering, before which the Universe was opaque to photons. However, it may be possible in the future to observe the still older neutrino background, or even more distant events via gravitational waves (which also move at the speed of light). Sometimes a distinction is made between the visible universe, which includes only signals emitted since the last scattering time, and the observable universe, which includes signals since the beginning of the cosmological expansion (the Big Bang in traditional cosmology, the end of the inflationary epoch in modern cosmology). The radius of the observable universe is about 2% larger than the radius of the visible universe by this definition.

The age of the Universe is about 13.7 billion years, but due to the expansion of space we are now observing objects that are now considerably farther away than a static 13.7 billion light-years distance. The edge of the observable universe is now located about 46.5 billion light-years away.

Estimates of the matter content of the observable universe indicate that it contains on the order of 10^80 atoms. The vast majority of the energy density is contributed by dark matter and dark energy.

[Spoetnick Profile]

Thanks for the message. I saw it and I am wondering what you want with this story, what does it tell you?

[Sheeple Profile]

Thanks for the message. I saw it and I am wondering what you want with this story, what does it tell you?

For me, it is about the term "infinity".
If really the total number of atoms is very big but not infinite, like approx. 10^80 atoms, the question is, why exactly this number, and what would happen if there was an extra atom added to it?
If, however, the universe is truly infinite, there are at least two parts in it that will never interact with each other, so they do not exist for each other, is this possible?

[Sheeple Profile]

Where is the centre of the universe?
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. Yet there is no centre to the expansion; it is the same everywhere. The Big Bang should not be visualised as an ordinary explosion. The universe is not expanding out from a centre into space; rather, the whole universe is expanding and it is doing so equally at all places, as far as we can tell.

In 1929 Edwin Hubble announced that he had measured the speed of galaxies at different distances from us, and had discovered that the farther they were, the faster they were receding. This might suggest that we are at the centre of the expanding universe, but in fact if the universe is expanding uniformly according to Hubble's law, then it will appear to do so from any vantage point.

If we see a galaxy B receding from us at 10,000 km/s, an alien in galaxy B will see our galaxy A receding from it at 10,000 km/s in the opposite direction. Another galaxy C twice as far away in the same direction as B will be seen by us as receding at 20,000 km/s. The alien will see it receding at 10,000 km/s:

From A: 0 km/s 10,000 km/s 20,000 km/s
From B: -10,000 km/s 0 km/s 10,000 km/s

So from the point of view of the alien at B, everything is expanding away from it, whichever direction it looks in, just the same as it does for us.

[Spoetnick Profile]

So the dark ages are just beyond the afterglow, we will never see beyond that I think.

But interesting is:
Will we get a big rip one time? And when will that happen?
The universe is growing, while we speak.

Can we not combine to two threats?? Can any moderator combine these two?

the-known-universe-in-hd-t13482.html

Thanks.

[Sheeple Profile]

There was also another thread: http://www.disclose.tv/forum/our-known-universe-t13431.html.

Super Moderators, we (sheeple, pauldamo, spoetnick) would appreciate if you merge the messages from two other threads:

http://www.disclose.tv/forum/our-known-universe-t13431.html
http://www.disclose.tv/forum/the-known-universe-in-hd-t13482.html

with this earliest one,

http://www.disclose.tv/forum/the-known-universe-t13375.html

because the initial video and the topic appear to be the same.

[Sheeple Profile]

[Johnsmith Profile]

The Biggest Number of All
'Al-Gore-rithm, n. a mathematical operation which is repeated many times until it converges to the desired result, especially in Florida.'
- The Grapevine

Astronomers are used to huge numbers. They are challenged to explain to outsiders just what billions and billions of stars really means with some homespun analogy. It was only when the American national debt grew to astronomical levels that there were suddenly numbers in the financial pages of newspapers that were larger than the number of stars in the Milky Way or galaxies in the Universe. [30] Yet, curiously, if you want really big numbers, numbers that dwarf even the 10^80s of Eddington and Dirac, astronomy is not the place to look. The big numbers of astronomy are additive. They arise because we are counting stars, planets, atoms and photons in a huge volume. If you want really huge numbers you need to find a place where the possibilities multiply rather than add. For this you need complexity. And for complexity you need biology.

In the seventeenth century the English physicist Robert Hooke [1635-1703] made a calculation 'of the number of separate ideas the mind is capable of entertaining' [31]. The answer he got was 3,155,760,000. Large as this number might appear to be (you would not live long enough to count up to it!) it would now be seen as a staggering underestimation. Our brains contains about 10 billion neurons, each of which sends out feelers, or axons, to link it to about one thousand others. These connections play some role in creating our thoughts and memories. How this is done is still one of Nature's closely guarded secrets. Mike Holderness suggests that one way of estimating [32] the number of possible thoughts that a brain could conceive is to count all those connections. The brain can do many things at once so we could view it as some number, say a thousand, little groups of neurons. If each neuron makes a thousand different links to the ten million others in the same [neuron] group then the number of different ways in which it could make connections in the same neuron group is 10^7 x 10^7 x 10^7 x ... one thousand times. This gives 10^7000 possible patterns of connections. But this is just the number for one neuron group. The total number for 10^7 neurons is 10^7000 multiplied together by 10^7 times. This is 10^70,000,000,000. If the 1000 or so groups of neurons can operate independently of each other then each of them contributes 10^70,000,000,000 possible wirings, increasing the total to the Holderness number, 10^70,000,000,000,000.

This is the modern estimate of the number of different electrical patterns that the brain could hold. In some sense it is the number of different possible thoughts or ideas that a human brain could have. ..."