Are Quasars Really THAT Far Away?

"Scott Miller" wrote in message
...
wrote:
Are Quasars Really THAT Far Away?

The red shifts of light from quasars are so large, it is commonly
believed that quasars are a great distance away. Yet some vary in light
output within a very short time. These quasars must be small enough
that the variations can occur across the quasar without breaking the
speed of light, yet produce enough luminous energy that they can still
be seen from that great a distance. A bit of a stretch of the laws of
physics. Another problem with this theory is the great distance also
implies a great antiquity. Where are the recent quasars? Are we to
believe that the quasar is some ancient mythological beast that only
existed in a distant galaxy a long time ago?

[nonuseful speculation deleted for brevity]

The light variability of quasars is well understood to be due to the
finite speed of light and how far light can travel in a finite time
period. An object can vary in brightness no faster than light can
travel across the object. This leads to the conclusion that quasars are
in fact small.

Observations show them to be the cores of distant galaxies, some of
which are in collision (thanks to HST imagery). Such collision were
more common in the past than today - thus we do not see quasars near to
us.

Finally, there are quite a few examples of quasars in gravitational lens
situations - those types of gravitational lensing of quasars can only
occur if they are at great distance compared to the lensing object.

In other words, it is time for you to get into recent knowledge, as
suggested by another commentator to your note.

*Sock alert!*