Starship Asterisk*

Why trust type Ia, as a standard candle?

A post that bystander made, http://asterisk.apod.com/vie ... 31&t=18732
Which makes me think, How can we trust that what we see in a ''standard candle'' Type Ia supernovae be, what they seem to be?

''Chandrasekhar limit with a mass of at least 2.1 times that of our Sun - give or take 10%''.

''Type Ia points to dark energy

Cosmologists use Type Ia supernovae as 'standard candles' to measure distances to faraway galaxies because of their uniform intrinsic brightness. This, in turn, can be used to measure the expansion of the universe by observing the supernovae as they fade away''.

So yet again, something pointing to rules being broken. Which makes me wonder, if the speed of light can not keep up with expansion, How did the Dark Flow keep up with expansion? over six billion light years.

''Type Ia supernovae were therefore instrumental in inferring the presence of 'dark energy', when it was discovered that the expansion of the universe was accelerating rather than slowing down, as should have been the case if gravity were the only force influencing the evolution of the universe''.

If even the template of expansion based on the Type Ia supernovae where in question, How can we be sure about the things we think we know?

''According to Bart Pindor, a cosmologist from the University of Melbourne, in Australia, the findings highlight the need for care when accepting Type Ia supernovae as 'standard candles' for measuring the expansion of the universe''.

Did red shift confirm a standard candle that was questionable, and is now red shift at risk?

Thanks bystander. You made me go looking.

http://asterisk.apod.com/vie ... 02#p118202

See the article Measuring a Monstrous Supernova

A subclass of Type Ia supernovae that explode with greater than Chandrasekhar mass immediately raises questions about how standard Type Ia standard candles are. While superbright Type Ia’s are automatically excluded from cosmological surveys, and while brighter-than-assumed candles don’t argue against the accelerating expansion of the universe (although they could lead to underestimates of acceleration), uncertainty could interfere with important calculations concerning the nature of dark energy.

(emphasis mine)

mark swain wrote:Did red shift confirm a standard candle that was questionable, and is now red shift at risk?

No to both. We trust (with some reservations) that we know the intrinsic brightness of most Type Ia supernovas because we think we understand their cause and the important elements of underlying theory. The fact that there might be classes within these supernovas that haven't been recognized until recently doesn't change things much, except for going back and looking closely at specific cases.

Certainly, I can think of no observational evidence that even remotely casts doubt on the interpretation of redshift.

I sat here waiting patiently for your reply Chris. Before posting the full link.

http://www.cosmosmagazine.com/news/3362 ... page=0%2C0

Enjoy.

mark swain wrote:I sat here waiting patiently for your reply Chris. Before posting the full link.

Exactly. It says what I said. Did you infer something else?

You said it yourself.

Chris Peterson wrote:that we know the intrinsic brightness of most Type Ia supernovas because we think we understand their cause and the important elements of underlying theory. The fact that there might be classes within these supernovas that haven't been recognized until recently doesn't change things much, except for going back and looking closely at specific cases.

Thanks Mucker.

We also think that you aren't an amorphous silicoid blob with a naturally evolved modem but nobody has actually looked.

Wayne wrote:We also think that you aren't an amorphous silicoid blob with a naturally evolved modem but nobody has actually looked.

Very good, Wayne. You are just beginning to form a new hypothesis.