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u/luminiferousethan_ · 5 pointsr/cosmology

I can see you were a bit put off by some of the responses, so I'll try my best to show you why your idea doesn't work.

The main reason why your idea is being dismissed is simply because there is no evidence to suggest that is the case.

Cosmology is a really complex science that dates back as far as human history. I'll copy and paste a comment I made some time back about the history of astronomy/cosmology, what people figured out, how they figured it out. It's a bit long, but if you're really interested in understanding, I suggest you slug your way through it! There are some helpful links as well that can point you to more information on any given discovery. It' specifically about finding the distances to stars, but that is a major part of the big bang theory.

This is a long answer, but you need to know a bit of the history of astronomy to understand how astronomers figured out how to calculate the distances to stars. Astronomy is the oldest science there is. It goes back to the most ancient civilizations, the Messpotamians were looking up at the sky and studying it. Even they noticed that the stars were not all there was. The stars themselves, sure, lots and lots of dots. But there are also 5 planets, the sun and the moon and all of those things move across the sky as time passes. The stars all moved together, but the planets were different. They didn't follow the same path across the sky as the stars did.

Ancient thinkers like Aristarchus and Eratosthenes calculated surprisingly accurately the circumference of the earth and the scale between the earth, the moon and the sun. The used measurements from lunar and solar eclipses, geometry, etc to make really, really good estimates for the time.

In the 1400's or so, attempts to understand what we saw in the sky were made by people like Johannes Kepler. He saw the sky as layers of geometric shapes or crystal like... things, that rotated around the earth. A model he build looked like this with earth in the center, the sun above it, the moon above that, mars above that and so on until you got to the stars which was the biggest enclosure. He tried for many years to figure out why mars retrograded, that it appeared to stop, move backwards, stop, then move forwards again over time in the sky. He eventually figured out that it was because the planets didn't move in perfect circles like people thought, but that they moved in elipses or ovals

Nicolaus Copernicus was one of the first to propose that the earth revolved around the sun, and not the other way around, using what Kepler figured out which was that the planets do not move in circles, but elipses (ovals).

Galileo Galelie with an understanding of Keplers and Copernicus' work was the first person to point a telescope (invented a few years earlier by someone else) at Jupiter in the sky. He discovered that Jupiter had 4 moons that orbited around it and he could observe and measure it. This was further proof that the earth went around the sun and not the other way around.

There are also sometimes rare events, which give us invaluable information used to calculate astronomical distances. One such event being a transit. That's when one of the planets close to the sun, Mercury or Venus, passes in front of the sun from earths point of view. Here it is in 2012 Astronomers could use this information to calculate the distances to the planets, and determine the size of the solar system. In 1761 and 1769 Hundreds of scientists from all across the world planned for the transit. Some traveled half way across the world, not an easy feat in the 1700's to get the data. Then they all collaborated it (which took years) and this gave us a much better understanding of the size of the solar system and the distances involved.

In the late 1700's William Herschel and Charles Messier were cataloguing stars and nebula. It turns out that what looks like just dots with the naked eye have a lot of differences when viewed through a telescope. Some are brighter, some dimmer, some are bigger, some are smaller and even some of different colors. Many stars will also fluctuate in how bright or dim they are over time, like a very slow pulse. It also turned out there were objects that weren't stars in the sky. But they were too dim to see with the naked eye and only visible in a telescope. Messier cataloged over 100 galaxies and nebula and produced a guide still used today. The telescope also enabled astronomers to figure out that there weren't about 5000 or so stars that we could see with the naked eye, as everyone in history before then thought, but that there were millions upon millions (and as telescopes got better, billions upon billions) of other stars, too dim to see with the naked eye. All this can be measured, recorded, compared and calculated. The invention of the telescope gave astronomers lots and lots (and lots and lots) of data to work with.

Here's where we get to the specific of your question.

In the late 1800's Henrietta Leavitt employed as a "computer" (someone who just "computes", or records, analyses and does the math of data collected about stars) discovered the relation between the luminosity and the period of Cepheid variable stars. She figured out how to determine the distance to astronomical objects. First calculating the Large & Small Magellanic Cloud, two small galaxies outside that were thought to be just clouds of dust.

Edwin Hubble, namesake of the Hubble Telescope used Leavitt's data and method to figure out that the universe was expanding, by measuring the redshift of galaxies outside our own. This was the biggest step towards the big bang model of the universe.


But what we know about the universe today is everything learned in many fields across lots and lots of time. If you're really interested in a great "history of science, what we know and how we know it" I'd recommend A Short History Of Nearly Everthing by Bill Bryson. It does a great job of explaining all this and more in easy to understand laymen terms.

__

Still with me? NOW! Let's get to the Big Tear idea you had. In science, it is always better to first observe, to look at something, and then try and figure out why it is the way it is. It is.... less better... for lack of a better term, to come up with an idea, and then look for evidence to support it. Of course new ideas and interpretations are welcome and encouraged, but they rarely lead to anything not already explained by current theories.

It's the difference between asking

>This is what I observe about the universe. How did it come to be that way?

vs

>I think the universe is this way. What evidence can I find to support that?

The first question is the correct way to look at science and scientific findings.

>but in three dimensions, with the material all ripping away from an initial point and moving outwards at great speed

My first question I'd posit to your Big Tear theory is, what is the "material" that ripped? So far, we have only been able to observe inside our observable universe. We can not observe outside the observable universe (by definition), and if we can't observe it, we can't know anything about it. Your idea sounds very similar to the idea of Luminiferous Aether (what my username is named after!). That idea stated that "space" outside of earth was made up of some sort of matter or material through which waves (gravity waves, light waves) propagate, like how water waves propagate on the matter/material of water (lake, puddle, whatever). That was disproved when we discovered gravity and light can propagate through space itself. Space wasn't "made" of anything. It was just space.

The big bang theory explains our observations. It explains the red shift and blue shift (the doppler effect of light) observed in distant galaxies. It explains the CMBR, the cosmic microwave background radiation. It explains the seemingly random distribution of matter. It explains how galaxies form and cluster.

In order to be taken as a legitimate idea worth investigation, your Big Tear hypothesis would have to explain all of that too, AND provide evidence as to why it is a better explanation than the big bang.

I hope some of this can help you obtain a better understanding of cosmology, astronomy, the big bang, and the universe we live in. If you have any questions about it, please feel free to ask!

u/josephsmidt · 9 pointsr/cosmology

Even though you want the full tensor treatment, I would first go through Ryden and make sure you understand the basics well. This is a great undergraduate standard written at the level for those who know "calculus, linear algebra and classical mechanics" and teaches the undergraduate level basics as well as anything.


After this, the standard modern graduate texts are Modern Cosmology by Dodelson and Physical Foundations of Cosmology by Mukhanov. Both use tensors and the full GR treatment with the former, in my opinion, being an easier text (which I think have some great initial chapters describing GR) but Mukonov going through some very advanced concepts like renormalization in quantum field theory, etc...

In addition to textbooks, Baumann's lecture notes on inflation are very good.

Good luck.

u/Jonny-Kast · 1 pointr/cosmology

https://www.amazon.co.uk/Why-Does-mc2-Should-Care/dp/0306819112

I'm currently reading this. It's called "E=mc2 and why should we care". It's by Brian Cox and another chap who make the equation easy to understand and why it is what it is. Although it's not strictly cosmology, it does make it easier to understand certain theories. Also, it's nicely written.
There's some great books out there by Brian Cox (if you're familiar with him?) about the universe etc...

Happy Hunting and I hope your friend goes far

u/quantumhed · 3 pointsr/cosmology

Lee Smolin is awesome for explaining stuff to the layman. This is by far the best book I read from him. Enjoy.

http://www.amazon.com/Three-Quantum-Gravity-Science-Masters/dp/0465078362

u/antonivs · 11 pointsr/cosmology

Sagan and Tyson aren't even in the same league. Sagan's Cosmos is much better, scientifically, educationally, and from an entertainment perspective.

However, if you're interested in cosmology specifically, neither series will get you very far. They cover a range of topics, some of which are prerequisites for cosmology (like relativity), others which aren't really cosmology (e.g. astronomy, astrophysics, other kinds of physics.)

Some books that are good for an accessible introduction to issues in cosmology are:

u/ketarax · 3 pointsr/cosmology

PBS Space time is a good place to get your feet wet.

You need a solid foundation in mathematics and physics; at the very least the first, but preferrably 2-3 years worth of university level studies. Something like this is covered over the first year when studying physics: it's an introduction of the essential topics, which are then developed over the 2nd and 3rd year.

Introductions / first year studies in astrophysics are generally another 500-1000 pages, but I don't have a reference in english.

General Relativity

Quantum Mechanics
The Stanford University channel also offers lecture playlists on cosmology and general relativity.

As if the above isn't intimidating enough, I'll finish with an opinion that this could easily be ~5 years worth of active studies, depending of course on the starting level of the student. If math is already your second language, I can imagine one could start a PhD project after three years.

I'm not referring to sources on the math side, but generally there are two approaches (depending on the university): you study math from the math department, or you study math from the physics department. My path was the former, but the latter would've worked better for me. People differ in this regard, some of my fellow students thrived with the more rigorous maths treatment we were getting. Me, I was failing with "easy" proofs & stuff in maths tests while having little to no problems with utilizing mathematics as a tool on the physics courses.

Disclaimer: finished physics studies 20years ago, been digging deeper into ~all of the above as a hobby ever since.

u/LuminiferousEthan · 1 pointr/cosmology

Some of my favorites

Coming of Age In the Milky Way

Chasing Venus

The Hole In The Universe

Atom A Single Oxygen Atom's Odyssey from the Big Bang to Life on Earth... and Beyond

u/oneona · 2 pointsr/cosmology

Once you have read that you will probably be thirsty to dig a bit deeper. Weinberg hast to be a good option. He is probably one of greatest physicists of our time. Andrew Liddle has another book that takes things much further. It is still very accessible even though it goes into quite a lot of depth. The one downside is that there are quite a few mistakes in it.