<blockquote><font class="small">In reply to:</font><hr /><p>Bonz, I agree with your answer. I would have posted something similar. Dark matter exists only because the graity-only equations say that it has to.<p><hr /></p></p></blockquote><br /><br />Dark matter has little to do with dark energy.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>tdamskov: Based on our understanding of redsh[ift,... Well, that's the rub, eh? What if redshift IS NOT accurately understood? What if the universe IS NOT expanding? (At any rate, accelerating or otherwise!) What if redshift DOES NOT equal distance, as Edwin Hubble himself warned? What if, instead, redshift were an INTRINSIC characterisitc of astronomical objects? What if redshifts exhibit QUANTIZED behavior? Would that matter?<br /><p><hr /></p></p></blockquote><br /><br />Glad to see you took the hook, sinker and all ;-)<br /><br />This is about how science works. True, we can't know for sure that our understanding of redshift is right. If we're completely on the wrong track, things will look different and dark energy may not be needed to explain observation.<br /><br />BUT... Redshift IS established science, every empirical evidence shows that our understanding of how it works is correct. It doesn't mean phycisists won't keep looking for new experiments to verify theory. But until something radical happens all science will have to work on the assumption that we DO understand redshift.<br /><br />Cosmologists simply have to build on the work of other scientists - just like other scientists have to reconcile their theories with cosmological observations. I can assure you many scientists are not happy with the concept of dark energy and are pouring their energy into explaining the puzzle or coming up with alternatives.<br /><br />You make it sound as if scientists "need" dark energy - they don't!! There are simply observations which need to be explained one way or another.