Why are there no white holes to be found in the universe?
Why don’t you define the term “white hole” before you ask us whether there are any in the universe? Yeah, there is a standard definition for it, but it’s not clear if that’s what you’re asking about. Let’s make sure what you’re asking about.
And are you asking why they don’t exist, or why we conclude that they don’t exist?
I’m asking why none have been observed so far.
Because anyone who is capable of answering my question would already know that.
Why do you think there should be?
The existence of a white hole is a theoretical construction. While you can do the math on how one would operate, you cannot show how to form one, how one would form, or show that there is any reason why they must exist.
How about we start by confirming the premise? Have we never observed a white hole? Do we currently believe that there are none?
Probably because they do not exist. If they were out there we would expect to be able to see them since they’d probably stand out (I am guessing they’d look something like a quasar).
What mechanism would allow one? We know matter has the property of mass and mass is connected with gravity. So, matter likes to clump together. In a black hole matter is so tightly packed that gravity overcomes all other forces and holds it together. So there is no reason to think a white hole would exist that squirts out matter. The very nature of a black hole is that it very, very strongly hangs on to matter and does not let it go.
We could postulate a time-reversed black hole but we’ve never seen time run backwards and have good reasons to think it won’t (time’s arrow).
We could postulate that a black hole is really just a portal to another part of space or another universe, like a wormhole. So matter goes in here and out the other side (wherever that is). If that were so though then black holes would not exist for very long as they squirt everything that holds them together out to somewhere else. That would lead to the black hole’s comparatively quick collapse as it gave up the very thing that allows it to exist in the first place.
There are mathematical constructions that can describe a white hole.
In a non-inflating universe with eternal black holes, they may be a necessary feature, in an inflationary universe with “temporary” black holes, they may be possible, but would not be necessary.
While there have been a few observations that some have claimed were constant with white holes, science certainly is not at a consensus about it.
Science doesn’t rule them out, but also does not say that they must exist. We have no definitive observations of one, so the consensus, I believe, that there are probably not any.
Interesting. I always thought black holes were as such simply because light merely travels in space and never stops, and because of no real light source other than stars, that any excess light is absorbed by the darkness.
What is this mysterious “darkness” that can absorb light?
You mean, like dust clouds and stuff? Yeah, stuff can absorb light. Things that are not stuff cannot absorb light, that’s what makes them not stuff. So a photon will go on forever until it hits some stuff, and then it gets absorbed. And maybe the stuff that absorbs the photon will emit another photon, for some reason, and that photon will keep going until it hits some stuff.
Just to add, and in an inflating universe like our own, that photon will become more and more redshifted, until its wavelength is greater than the size of the observable universe.
Then it’s pretty much gone, or at least is not longer detectable.
Thank you gentlemen and or ladies.
I and others have now learnt something about white holes, even if they do not actually exist, which was the purpose of my question. 
Since you refused to answer the question, i’m going to define “white hole” such that I can answer “The sun is a white hole.” Glad to help.
If you define the Sun as a white hole, then we’re forced to conclude that the Sun, as you’re defining it, doesn’t exist. The whole concept of language just sort of falls apart if you start assuming willy-nilly that things don’t have definitions.
A white hole?
Spewing time into the universe?
So, what is it?
They do, in fact you can go observe one right now
Look up, its called Sun.
Black hole = emits no light, gravity too high, cant escape
It looks like a black hole in space hence the nick name
So white hole would be a normal star, unless you have something weird in mind?
Again, no, the Sun is not a white hole, unless you’re just using words to mean random things.
No, what he and the other poster were doing is pointing out that there may be some ignorance of whether or not there exists a technical term “white hole” that is well-defined in astronomy/cosmology/physics, and if there exists such a term, what its definition actually is. If no such well-defined term exists, then we can take “white hole” to mean anything we want it to for which those words are at least apt descriptors.