This amazing summary of our latest understanding of cosmology, by Lawrence Kraus, will blow your mind. It's what the majority of physicists now believe about the universe. It's the most informative hour I've ever spent in my life. You've GOT to see this!

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@ Danielle and Dave,

Dark matter and dark energy are NOT confirmed. They are hypotheses to explain the discrepancies in cosmological math. WIMPs (Weakly Interacting Massive Particles) is the leading candidate but the search is still on. Here's what Wikipedia has to say about WIMPs.

"In astrophysics, weakly interacting massive particles, or WIMPs, are hypothetical particles serving as one possible solution to the dark matter problem. These particles interact through the weak nuclear force and gravity, and possibly through other interactions no stronger than the weak force. Because they do not interact with electromagnetism they cannot be seen directly, and because they do not interact with the strong nuclear force they do not react strongly with atomic nuclei.

This combination of properties gives WIMPs many of the properties of neutrinos, save for being far more massive and therefore slower.

Since Lawrence Kraus assigns 70% and 30% of undetected mass to dark energy and dark matter, respecitvely, I assume they're not the same hypothetical stuff.
Nope, dark matter and dark energy are two separate items.

Dark matter is a term used for whatever it is that we cannot see/detect that is exerting gravitational influence on matter that we can see. We know it (whatever it is) exists, we just do not know what it is. Maybe it's WIMPs. Maybe not. When we find out, we'll know what its name is. (Or we'll name it)

Dark energy is used for whatever the source of the accelerating expansion of the universe is. Einstein's cosmological constant. We don't know what it is, but something is behind that acceleration, and whatever it is, we're calling it dark energy. When we do find out what it is, it won't be dark energy anymore, it'll be ... whatever it is. Gravity from other branes, whatever.

Dark matter and dark energy are like the term UFO. Once you find it, it's not unidentified anymore.
Oh, and I should add that Danielle, being a lofty grad student to my undergrad experience (very outdated undergrad experience at that) is encouraged to correct me where I am wrong. :)
I've watched it twice and will surely watch it again. Best line was "forget Jesus, stars died so that you could live". Classic!
That line was indeed awesome, I laughed a good one. The video in general was very intriguing. I particularly like the ending and how we're not all that important, I couldn't agree more.


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