In a world dominated by magical thinking, superstition and misinformation, give yourself the benefit of doubt. This is one skeptic's view of the Universe.
"Tell people there’s an invisible man in the sky who created the universe, and the vast majority believe you. Tell them the paint is wet, and they have to touch it to be sure."
“If people are good only because they fear punishment, and hope for reward, then we are a sorry lot indeed”.
“Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.”
The person who is certain, and who claims divine warrant for his certainty, belongs now to the infancy of our species. It may be a long farewell, but it has begun and, like all farewells, should not be protracted.
Science is still struggling to understand what space and time actually are. Are they real physical entities or simply useful ideas? If they’re real, are they fundamental, or do they emerge from more basic constituents?
What does it mean for space to be empty? Does time have a beginning? Does it have an arrow, flowing inexorably from past to future as common experience would dictate?
Brian Greene, The Fabric of the Cosmos (via whats-out-there)
Chris Hadfield, An Astronaut’s Guide to Life on Earth (via thedragoninmygarage)
Astrophysics is a branch of space science that applies the laws of physics and chemistry to explain the birth, life and death of stars, planets, galaxies, nebulae and other objects in the universe. It has two sibling sciences, astronomy and cosmology, and the lines between them blur.
In the most rigid sense:
-Astronomy measures positions, luminosities, motions and other characteristics
-Astrophysics creates physical theories of small to medium-size structures in the universe
-Cosmology does this for the largest structures, and the universe as a whole.
In practice, the three professions form a tight-knit family. Ask for the position of a nebula or what kind of light it emits, and the astronomer might answer first. Ask what the nebula is made of and how it formed and the astrophysicist will pipe up. Ask how the data fit with the formation of the universe, and the cosmologist would probably jump in. But watch out — for any of these questions, two or three may start talking at once!
Goals of astrophysics
Astrophysicists seek to understand the universe and our place in it. At NASA, the goals of astrophysics are “to discover how the universe work, explore how it began and evolved, and search for life on planets around other stars,” according NASA’s website.
NASA states that those goals produce three broad questions:
How does the universe work?
How did we get here?
Are we alone?
It began with Newton
While astronomy is one of the oldest sciences, theoretical astrophysics began with Isaac Newton.
Prior to Newton, astronomers described the motions of heavenly bodies using complex mathematical models without a physical basis. Newton showed that a single theory simultaneously explains the orbits of moons and planets in space and the trajectory of a cannonball on Earth. This added to the body of evidence for the (then) startling conclusion that the heavens and Earth are subject to the same physical laws. [Related: How Isaac Newton Changed the World]
Perhaps what most completely separated Newton’s model from previous ones is that it is predictive as well as descriptive. Based on aberrations in the Newtonian orbit of Uranus, astronomers predicted the position of a new planet, which was then observed and named Neptune. Being predictive as well as descriptive is the sign of a mature science, and astrophysics is in this category.
Milestones in astrophysics
The way I understand it, which is humbly, matter and mass did not exist in that ‘pre-universe’ state. What you had was infinite potential energy to form matter, which formed some 300,000 years afterward, as the universe cooled. Also, the whole idea of a point in space for this density to occupy loses it’s meaning when there isn’t even any space. It was nowhere and everywhere at the same time.
It’s important to realize that our common conceptions of time, spatial dimensions, matter and the forces that would pertain to squishing all the matter into a tiny space; they’re all useless for understanding the singularity at the front of the Big Bang as they did not exist yet. The theory itself is about how the universe expands, not so much about how it was compacted before it expanded. Mainly because, so far, our empirical reach has only taken us back to within a fraction of a second after the expansion had already begun. The singularity really represents a point, in rewinding the expansion of the universe, where the maths break down.
Cosmology 101: Big Bang - http://youtu.be/xsQ1XmqEe6M
What Is The Evidence For The Big Bang? - http://youtu.be/xtrYF_hxxUM
This series will explain the key concepts and processes in the theory as well as the observational evidence and current areas of research in the theory- http://m.youtube.com/playlist?list=PL6150D61BB71657A6
I don’t think there is a way of measuring time beyond, or prior to, the Big Bang as time is part of space and neither existed. As far as we’ll ever know or as far as it will ever apply to us, measurable time began at the moment of expansion (the Big Bang).