Recent content by CSSlemaker

Good evening Chill Factor. I must be missing something here. Are you saying that it is impossible in principle to station an observer at a position and in a manner such that he is at rest with respect to the black hole? Am I missing something when I read in the textbooks that to an observer...

to: jimgraber Thanks, Jim, for the quick reply. However, I'm still somewhat dissatisfied. You state that the infalling material isn't seen to pass through the horizon; rather, that the horizon "jumps out" and engulfs the material. But either of these constitutes a change in the relative...

I have a few issues concerning black holes and this seems to be an appropriate thread to address them. The following are my understandings, inferences based on those understandings, and a few questions. I would welcome any corrections and answers which you can provide. 1. For a massive...

To both clamtrox and Lino: Thank you very much. I had composed a detailed reply to both of you, but the damned site timed out (with no warning) and I lost it all! I just don't have the energy to recompose it. Thanks again and have an enjoyable Thanksgiving (if you're in or from the U.S.)...

Thanks clamtrox. Unfortunately, the dialogue is straying away from my original concern: the algorithm for converting a type Ia SN light curve as observed into a "distance" (not how to convert one type of "distance" into another), and which type of "distance" is the immediate result based...

Hi George. Sort of along the lines of my reply to clamtrox, I have read that a model-independent adjustment must be made to the observed apparent magnitude (only in the case of a light emitter which is at a cosmologically significant distance/redshift). In a static universe, the relation of...

Hi Clamtrox. Expansion of space during the time it takes the radiation from the SN to reach Earth has stretched each radiation wave by a factor of (z+1). But it also has stretched the entire wave train, from explosion to peak to disappearance, by this same factor. In other words, the...

Thank you very much, George. But if you don't mind, could you please indulge me in one last clarification? You state: "Suppose we observe a Type Ia supernova that has apparent magnitude 23.8, and we know that its absolute magnitude is -19.2. We calculate (the model-dependent) luminosity...

Thanks George. Please let me start over. First, I assume that apparent magnitudes of the SN light curve are corrected for redshift dimming and the time axis of the light curve is corrected for time dilation and that these are done before determining absolute magnitude of the SN. Correct...

P.S. - Time dilation is a simple function of Z. A time period of N days, as measured by an observer on Earth for a galaxy at redshift Z, would actually have been N/(1+Z) days as measured in that remote galaxy.

Thanks Lino. But I doubt that redshift is ever used to determine distance to a type Ia supernova. Rather, it is these supernovae, serving as "standard candles", which are used to calibrate the redshift-distance relation. In fact, it was SN 1997ff at a lookback time of 11.3billion years and...

The light curve of a type Ia supernova in a cosmologically remote galaxy requires two particular corrections. The time axis must be corrected for time dilation, and the apparent-magnitude axis must be corrected for redshift dimming. It is my understanding that the "distance" determined...