Can Any Two Things Be Identical???

they do differ by location... but you don't know that till you open the pod.

a thought, if discussed at great length, could possibly be the only identical pairing.. everything else is just exactly similar. if you have two of anything the word identical cannot solely be used to describe them.

woah.. are you implying (and this is simply stated) that for things to be "identical" they have to occupy the same space? i would imagine then that they are the same thing and not two separate things. do they not need to be two separate things to be considered identical? even if they aren't, i figure the first step to deciding the identical issue is to first establish that there are at least two of these things.. I may have missed something here.

To put it simply, the only way two things can be identical would be if they were the same exact thing including location...which is of course pretty much impossible. In order to consider something "identical" you would have to generalize to some degree and over look certain aspects.

Would it be possible out in space?

I would think that the same would apply out in space just as it would anywhere else. Do you think differently?

I was specifically thinking about the black hole where nothing can escape.

I'm afraid I don't really understand, are you suggesting that black holes are possibly identical or that everything is sucked in a black hole the same?

Black holes are identical.

Are they all exactly the same size?

It depends on what you mean by size? There are many physicists who say black holes are identical. I can only trust their judgement.

Are you referring specifically to just black holes, because there are also supermassive black holes. Black holes are expected to form when heavy stars collapse in a supernova at the end of their life cycle. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may be formed. So it's size and all of that depends on the size of the star that collapsed, it's surroundings that it can absorb, and other things.

But size is never static.

I don't believe I stated other, but you are correct. I stated that they actually grow by absorbing matter around them and even become a "supermassive black hole" (great song btw). It changes size based on the amount of matter that it's absorbing. In order for another black hole to be identical, the original start that collapses would have to be exactly the same size, collapse and go through the Supernova process at the same time and absorb the same amount of matter at exactly the same time...the odd on that are very very very very very very very very....(you get the point) slim.

The limitations set by this question seem to want to pre-determine the answer as no. Insisting upon occupying the same space at the same time omits any type of matter whatsoever, if it can be assumed that you are talking about reality as the setting for your question. The only “real” (in the sense of mainstream physics) objects that could possibly be identical are Bosons and then only Bosons of the same class with equivalent energies. So two .511 MeV photons are identical in QM. There is no way to tell them apart nor is any way even theoretically possible. This would also apply to the Z-zero’s, W+, W-, colored gluons.

You seem to miss the importance of function as a central concept to define what is being what, and in that sense you miss the point...(Space and Time come into the table only for that reason)...otherwise your observation is just a bit of fair common sense aside the bosons unneeded technicality...

no. the properties (location) are different.

There are really two issues concerning "two things being identical." The first is how we see things through our eyes. From this perspective, we can see things as identical. If we look at things from the atomic level (chemical elements), things are identical. If we use location, only the environment changes, but the identical objects under question is still the same.

i was looking at it on atomic scale.
picture two atoms, (impossible) of the same element. their electrons are moving in exactly the same motion, at the exact same speed. identical, in every way, but location... because if there were no distance between them, then they would either be the same atom, or different elements.

When you bring location into the picture, you are deviating from the original premise.