APOD: Hickson 91 in Piscis Austrinus (2016 Mar 24)

[joinpep]

"On a cosmic timescale the result will be a merger into a large single galaxy, a process now
understood to be a normal part of the evolution of galaxies"

"On a cosmic timescale" - means there is NO POSSIBLE way to observe this hypothetical fiction.

Who wants to be responsible for "understood to be a normal' part of the evolution"?
Are we writing about human evolution? Please open a dialog on this fictional subject.

On the other hand, there are billions of objects (galaxies) that DID NOT come from a
hypothetical fiction. Why isn't anyone studying fission? Citizen Science Alliance has 10,000
paired-object systems for you to start with on your journey of discovery.

[rstevenson]

"On a cosmic timescale" - means there is NO POSSIBLE way to observe this hypothetical fiction.

True, but starting with what can be observed, it is possible to build models and do calculations which make sense, and which can be used to create predictions for observations which then either pan out or not, and so on... . In other words, it is possible to do science -- as opposed to, say, throwing around opinions and guesses. To the best of our current knowledge (and that's very good indeed, and provably so) the process as described in the APOD text is reasonable and likely.

Rob

[starsurfer]

"On a cosmic timescale the result will be a merger into a large single galaxy, a process now
understood to be a normal part of the evolution of galaxies"

"On a cosmic timescale" - means there is NO POSSIBLE way to observe this hypothetical fiction.

Who wants to be responsible for "understood to be a normal' part of the evolution"?
Are we writing about human evolution? Please open a dialog on this fictional subject.

On the other hand, there are billions of objects (galaxies) that DID NOT come from a
hypothetical fiction. Why isn't anyone studying fission? Citizen Science Alliance has 10,000
paired-object systems for you to start with on your journey of discovery.

We can observe examples of the stages along the so-called "cosmic evolution" in many different galaxies, a lot of work has been done on interacting galaxies for more than half a decade with many simulations matching observed examples.