Nobody knows the size of the universe, as only a portion of it is observable. If the universe happens to have an infinitely large size, then its mass could also be infinite.
It is only the mass of the observable universe that can be in the purview of scientific enquiry.
What is of interest to physicists is the density of matter in the universe, as it is important in determining the fate of the universe: whether it will collapse one day or whether it will continue expanding forever.
The density of matter in the universe can be estimated by various means such as by studying the fluctuations in the Cosmic Microwave Background, superclusters, Big Bang nucleosynthesis, etc.
According to these estimates, the density of matter in the universe is about 3 x 10^(-30) g/cc. By comparing with the density of atmospheric air of ~1.23 g/cc, it becomes clear that the density of space is very close to that of vacuum.
Again, this density includes the contribution of dark matter. The density of luminous matter that we see as stars and galaxies is only about one-tenth of the figure given above.
The size of the observable universe is ~ 14 billion light years.
Using the above value of density gives a mass of about 3 x 10^55 g, which is roughly 25 billion galaxies the size of the Milky Way.
No body knows what lies beyond the 25 billion galaxies and how it could impact the mass and density calculations.
- If there are three observers at 0 c, 0.5 c and 0.9999 c, their observations of the universe would be different. This is relativity. If observers see the same universe differently, then how can the universe be said to have a single nature?
- If a universe cannot have a single nature that it can present consistently to all observers, then there can be no unified theory of everything. If there is nothing fixed to refer to, then there is no standing ground for a theory. To arrive at the theory of everything, experience of constant existence at all frame of reference would be necessary. Interpretation of an observer at 0 c of the experience at 0.5 c, may not necessarily be true for the observer at 0.5 c.
- Thought experiment: Can relativity be applied on to quantum fields? If the large hadron collider is moving is at 0.9999 c with respect to the observer, would the experimental results still be valid?
- There are two different states of unconsciousness:
- Death state of unconsciousness: Atman/Soul has left the body and reengagement with mind/body is not expected. Person is truly dead and appears so.
- Pre-death state of unconsciousness: Atma/Soul has not left the body and reengagement with mind/body is possible. Person appears dead or in a coma to the world but is not truly dead.
- In between the two states of unconsciousness, pre-death and death, exists the clue to understand the bare essential functioning of the soul/atman. In this free state, the soul remains closer to its pure form, without having the need to engage the constructs of mind or the sense organs or the world outside or the need to look for a different body to live-in next.
- Like a person is standing at the door step of the house from where he can go inwards or outwards, the soul is free to engage the mind in the subtle body and go inwards into a given body and its experience or abandon the current body and seek another body more suited to the current evolved needs of the subtle body. If the current needs are zero, there should be no need for another body.
- When the soul decides to “go inside the house” by engaging the mind and the current body, the rules for extent of such engagement must be set. The sages (gyani) who study the soul (not so much the world) say that this engagement must be limited for it doesn’t matter how big the house and how deep one goes into it, the exit must happen. The scientists (vigyani) who study the world (not so much the soul) say this engagement must be maximum, for this one freak opportunity to learn the world should not be wasted. The sage says do not engage, for engagement creates karma and births. The scientist says engage with all your might or else your only go at life would be wasted.
- The scientists says, the universe is eternal but consciousness comes and goes. The sage says, consciousness is eternal and the universe comes and goes.
So, what are you? Are you a blip of consciousness that will be forever extinguished at death? Or are you eternal consciousness that will repeatedly come and go into the playground of universe till you learn to destroy your ego and burn your karma?
What is your world view? A fixed universe with random meaningless blips of consciousness and life forms? Or an eternal consciousness soul that craves for varying experiences in a semi-real universe?
And then there’s the essential character of the universe. It is this mechanical system of laws and particles and principles. Utterly devoid of a moral or personal agenda, and instead being an expression of mathematical interactions. Now that could be the signature of a math-centric geek god. But if the cosmos is impersonal and indifferent, that removes any character from creation. We don’t need a god to explain it. Just a big textbook.
Reproduced from https://www.quora.com/If-an-atheist-claims-that-God-does-not-exist-isnt-the-burden-on-him-now
If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.
Accept all that happens, even that which is unpleasant, because everything is a part of the health of the universe and the wealth of God.