On the age of different things in our Universe....Part of a recent conversation with a friend:

There was a discussion about whether everything we see is of different ages or all the same age. Like: Is a rock on Earth older or younger than a distant star? So I wrote this:

.........." Once the stuff of the Universe was made "condensed" just after the big bang it was mutated into everything that exists today in a multitude of constantly changing forms: Ordinary matter, dark matter and all the rest of energy.. The age of all is the same. A house may be made of bricks....the bricks have an age so the house or any portion of the house is also the same age. You may grind up the bricks and remold them but the material is still the same age. We assume that all the material came from the same source and so everything made of it is the same age. We need to think at the quantum level here. Quantum is the Latin word for amount and, in modern understanding, means the smallest possible discrete unit of any physical property, such as energy or matter. Quantum came into the latter usage in 1900, when the physicist Max Planck used it in a presentation to the German Physical Society. Rearrangements may have different ages but the stuff that is arranged is all the same age. My body is a temporary "hologram of particles", all of the same age but which pass in, out and through the arrangement of my body at any point in time. Hence the phrase: "We are are all made of Stardust"....but so much more! We are made of quantum particles."

So now try this link: https://www.forbes.com/sites/startswithabang/2016/08/19/is-everything-in-the-universe-the-same-age/#4a3d4f8a1a1d

My friend replied: "How old are you Dave?"

I replied: "Around 13.7 Billion years, at any point in my life-time!  But soon I will be dispersed!.....i.e. the stuff I will be made of at the time of my 'death' will be. But it will be the same age approximately and continue to be."

My Friend: "Dave, you said, "We need to think at the quantum level here" WHY? It seems this leads only to pedantry. Taken to its logical conclusion, this reasoning dictates that all questions of the age of physical entities must be answered "+/_13.7 billion years."

Manage

I replied: "Yes all matter and energy...not entities....Entities can be temporary formations of matter and energy but matter or energy is all of the same age. You and I are entities made of different matter and energy at different points in time. Like we are a river or lake but with different water all the time. First law of thermodynamics – Energy can neither be created nor destroyed. It can only change forms. (Hawking will have some extras here related to the time between the Big Bang and the initial expansion (which was a very, very short time...seconds) but The Law is still generally accepted as true)."