How do you define "reality"?
Reality is not just what you see but what is real. If it was just what
you see then the sun when it's down doesn't exist, but it does. So
reality is defined by what can be physically observed at all times.
Even if it was the sun, you can physically observe the sun from a
different place. You might say that because you can't physically
observe the vast expanse of the universe at this current moment,
you still can go to a different place in space and observe it. even
things like holograms that aren't real, they still are a part of
reality because they are able to be physically observed.
Holograms are still real since if you have your perspective in a
micro format, you'll see that the waves that make the image are
still being observed even though now you're so small that you can
see the subatomic waves that make up a hologram it still is being
physically observed.
Is it fixed, or can it be altered?
Reality isn't fixed since I could basically change reality right at
this one moment bye either deciding to go get a popsicle or drink
a Pepsi right now. A better example is that I could just scratch the
table and boom now the subatomic particles that make up reality
have been altered they've been pushed away they've been
changed.
Do we all have the same reality?
We all live in the same reality, but it is what we perceive as real
that is different. If we're talking about what we see and what we
think is real, well then we all do have different perspectives of
what is real. But if we're talking about reality itself then everyone
lives under the same roof in that category. Even animals that are
millions of light years away on planets that we don't even know
exist in solar systems that we don't no exist their reality is still the
same as ours but again their perception of what is real is different.