Sean Carroll on Cosmology and Particle Physics Lecture 1 of 5

[StrydarXtheXGrim]

thanks for the responses, know it must seem like a trivial question, but its something im really trying to sink the ol' grey matter into and would like as comprehensive an understanding of the subject as possible. cheers kii. i wanted food for though, you served up a banquet :)

[billbrett365]

The Carroll Effect: Whatever can go right, will go right at the most expedient time. Corollary: Life in general - Gravity.

[StrydarXtheXGrim]

what i dont get, and please do correct me when im probably wrong but.... isnt the usiverses expansion SLOWING relative to its size... even looking at that graph it seems blindingly obvious. the universe was concentrated and dense at its beginning as it expands the volume increases but the scale of it closes. so when they say the universe is expanding faster, dont they mean realative to its size. or has something been overlooked here. if so then surely its max size should be calculable right?

[kii78]

@StrydarXtheXGrim As the universe expanses the matter dilutes over time where as the energy density of empty space does not. So dark energy dominated universe and exponentially expanding universe seems to be inevitable. Also there is no known boundary to universe as we can observe. Pick any two galaxies in observable universe and draw a circle (sphere in 3d) with radius of 46 billion light years and you will notice how both galaxies observe the universe differently.

[ObamaFace]

Yay cosmology!

[THEHARMONIKZ]

Great lecture. Thanks for the upload. :)

[majestic93]

Thanks for uploading. Fascinating stuff.

[sbergman27]

22:30 Strictly speaking, the space between gravitationally bound objects *is* expanding. It's just that local gravity can almost completely compensate for it. The Earth's orbit around the sun is an ever-so-tiny bit wider than it would be otherwise. It is not *increasing* due to cosmic expansion. But it is a tiny bit larger than it would be, by an amount which can be calculated, but probably not measured today

[tunghoy]

When and where was this held? Wish I could have been there, so thanks for uploading it to YT.

[iasedu]

@tunghoy CERN, 2005.