Phil, did the red shift data match the acceleration in a fairly linear and proportional manner? Luminosity can be impacted by many factors, though with many different supernovae, the number drop, but the different rates of acceleration would have different red shift amounts. I’ve not heard of any paper that offers the view of reconciling the two observations, only the lower magnitude.

CJSF

So assuming I am right about supernovae in the local group, what does the expansion rate over time curve look like? Is it linear?

Also I just realized this post is from 2006, so I’m not holding my breath on getting an answer.

I thought you worked from home. What “office” did you stand up and exclaim in, then?

I love reading about this stuff. While I may never truly grasp the maths involved, the concepts and progress of understanding leaves me awestruck and proud, nonetheless. Proud that we can describe and model the Universe and still be in love with it.

And also, I have a similar question to @VinNay. Shouldn’t closer supernovae seem farther away than expected compared to more distant ones?

CJSF

“By comparing the brightness of distant, far-away supernovae with the brightness of nearby supernovae,” Botner continued, “the scientists discovered that the far-away supernovae were about 25 percent too faint. They were too far away. The universe was accelerating. And so this discovery is fundamental and a milestone for cosmology. And a challenge for generations of scientists to come.”

If dark energy is driving the expansion to accelerate over time, shouldn’t closer supernovae (as opposed to further) be fainter than expected because they happened more recently than far away supernovae (expansion was slower in past)? Or are the “close” ones in the local group, and is the local group gravitationally bound such that the accelerating expansion isn’t yet strong enough to overcome the gravity?

If that is the case, do we see “normal” close supernovae, “very faint” far supernovae, and “slightly faint” super-far supernovae? Does this question make sense?

Even as an atheist, one begins to wonder how all this is even remotely possible (invoking God simply pushes the problem back one future step and so is irrelevant). The mind truly does boggle at the astounding facts and theories we have already uncovered and the prospect of discovering more in the future is an exciting one.

Now, if only we could find a practical way to circumvent that pesky speed-of-light issue, we could really start to explore the Universe! Until then, astronomers and cosmologists will have to do the heavy lifting for us.

Ivan. …(No relation to Blind Freddy).

But that’s another story.

Also remember–Science is all about posing an explanation for a physical occurance / phenomenon, and describing a physical test an “experiment”) to test the hypothesis.

Without that “try-fail-try-fail again-try-AHAH! ” approach, we’d still be living in caves.
Dr..P Reilly

Isn’t language fun?