Op dinsdag 17 juni 2014 08:13:56 UTC+2 schreef Jos Bergervoet:
On 6/15/2014 3:21 PM, Nicolaas Vroom wrote:

IMO all what is written about multiverses, parallel universes,
bubbles is unfalsifiable.

Some things, like 2x2=4, are unfalsifiable, since they
are "trivially correct".
Concepts like our numbering systems 1,2,3 ets and concepts
like 2*2=4 belong to our "mathematical tool box".
Concepts we all agree upon.
As such they are "true" by definition

But surely, Nicolaas, you don't
mean to apply that to all three concepts you mention?!
They are in a certain sense neither falsifiable nor
unfalsifiable.

The biggest problem is the clear definition of each
(about something we all agree....)
of the three concepts.

"Bubbles" are things that happen in phase transitions,
we all agree on that.
Bubbles happen when you boil water, to describe the behaviour
of lava, but that is not what we are discusssing here.
Bubbles as described in the previous text, like:
" multiverse with an infinite number of bubbles, in which the
" cosmic and physical properties vary from bubble to bubble.
are descriptions of physical phenomena which are completely
unclear to me.
IMO this whole subject is speculation if it is something
outside Our Universe.

If the energy differences are big
between the phases then the metric of space must be
affected, as GR tells us and we all agree on that.
I doubt if GR describes anything that happens outside our Universe.
If .... that is the subject

In some of those cases the metric gives us a child universe
(with just an evaporating black hole left in the parent
universe) since that's what the Einstein equations tell
us. It's as 2x2=4.
What is a child universe ?

Is it falsifiable? Surely, if the fields don't include
phase transitions with sufficient effect on space-time
metric, then the above does not happen! We may not now
be able to probe the necessary energies, but we surely
are studying quantum fields (currently the quark-gluon
plasma, including bubbles, droplets etc.) So in principle,
at appropriately higher energies the same can be done.
If anything of these processes happen as part of the evolution
of our Universe (after the Big Bang) than it makes sense to
discuss them.
If not than you should clearly indicate that.

If you are interested I have written comments about the
book "The Mathematical Universe" by Max Tegmark
http://users.telenet.be/nicvroom/Max.Tegmark.htm

Nicolaas Vroom
http://users.pandora.be/nicvroom/