Big Bang
esiegel | January 7, 2017“We are part of the universe that has developed a remarkable ability: We can hold an image of the world in our minds. We are matter contemplating itself.” -Sean Carroll
If you take a look at our Universe today, you can learn all sorts of things about it. How the matter in it is distributed, what the radiation is doing, how many and what types of black holes we’ve formed, how much entropy there is, etc. You can also learn how all of those things are evolving into the future and how they were different in the past!
The far distant fates of the Universe offer a number of possibilities, but if…
esiegel | January 4, 2017"Every philosophy also conceals a philosophy; every opinion is also a hideout, every word also a mask." -Friedrich Nietzsche
If you want to see all the way back to the Big Bang -- to the cosmic microwave background -- that means looking back through billions of light years worth of space. While individual point sources like stars and distant galaxies are relatively easy to exclude, the most catastrophic interfering factor is the Milky Way itself. Gas, dust, spinning molecules, magnetic fields, stars and more are all known to play a role.
The alignment of neutral hydrogen (white lines) with…
esiegel | December 20, 2016"Because philosophy arises from awe, a philosopher is bound in his way to be a lover of myths and poetic fables. Poets and philosophers are alike in being big with wonder." -Thomas Aquinas
Sure, you've studied a little physics. You know about Einstein and General Relativity, the quantum nature of the Universe and the fundamental particles and their interactions. You know about the Big Bang, and you've read up on the latest theories and ideas. So how did you wind up believing in many (or even all) of these scientific myths out there?
Light and ripples in space; as the light passes through non…
esiegel | December 16, 2016“First, you should check out my house. It’s, like, kinda lame, but way less lame than, like, your house.” -Lumpy Space Princess, Adventure Time
Billions of years ago, before the Universe contained clusters, galaxies, stars or even neutral atoms, everything was uniform. Almost perfectly uniform, where the densest regions weren’t even 0.01% denser than average. Over billions of years, those overdense regions have attracted more and more matter and grown under the influence of gravity.
Both simulations (red) and galaxy surveys (blue/purple) display the same large-scale clustering patterns.…
esiegel | November 24, 2016"If a fellow isn't thankful for what he's got, he isn't likely to be thankful for what he's going to get." -Frank A. Clark
There’s a lot to be thankful for, and some of those things are truly universal. The world we share, the Sun we orbit, the galaxy we reside in and the Universe itself plus the laws that govern it are cosmic stories we all share. And if you think about it really hard, you’ll realize that there are a whole slew of cosmic steps that needed to happen that are worth giving thanks to.
An infrared view from ESA’s Herschel observatory of a new star-forming region. Image credit:…
esiegel | November 18, 2016"We are actually living in a million parallel realities every single minute." -Marina Abramovic
Ever since quantum mechanics first came along, we’ve recognized how tenuous our perception of reality is, and how — in many ways — what we perceive is just a very small subset of what’s going on at the quantum level in our Universe. Then, along came cosmic inflation, teaching us that our observable Universe is just a tiny, tiny fraction of the matter-and-radiation filled space out there.
The observable Universe might be 46 billion light years in all directions from our point of view, but there's…
esiegel | November 5, 2016"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." -Frederick S. Perls, quoting Einstein
The Universe we can see and access is certainly a big place. We see that it goes on for 46 billion light years in all directions, full of stars, galaxies, matter and radiation wherever we look, consistent with an origin in a hot Big Bang. But beyond what we can see, there ought to be more Universe just like our own, originating from either the same Big Bang, or possibly, if inflation is correct, from other Big Bangs at later or earlier times…
esiegel | November 3, 2016"Cosmology is the study of the origin, evolution, and fate of objects in the observable universe. [...] The key to the birth and evolution of such objects lies in the primordial ripples observed through light shining through from the early universe." -Wayne Hu
The Big Bang’s leftover glow -- the cosmic microwave background (CMB) -- is the great cosmic gift that keeps on giving. When it was first discovered in 1965, it validated the Big Bang and taught us that our Universe as-we-know-it had a birthday. When we measured that the CMB looked hotter in one direction and cooler in the opposite, we…
esiegel | October 20, 2016“Man is something that shall be overcome. Man is a rope,tied between beast and overman - a rope over an abyss.What is great in man is that he is a bridge and not an end.” -Friedrich Nietzsche
There are only two types of singularities that General Relativity predicts the existence of in our Universe: one at the centers of black holes, which form from the collapse of matter, and one at the very birth of space and time, at the origin of it all. All of the information that falls into a black hole from our 3D Universe gets encoded on the black hole’s 2D event horizon, which is both fascinating and…
esiegel | October 8, 2016"There have to be moments when you glimpse something decent, something life-affirming even in the most twisted character. That's where the real art lies." -Martin McDonagh
There is a whole lot of cosmic detective work we can do to figure out the history of the Solar System. By examining the fossil record, geological deposits, the surface of other planetary bodies, meteors, asteroids and comets, the physics of the Sun, and the various components and layers of Earth, we can reconstruct when and where our planet and the rest of the Solar System came from.
A massive collision of large…
esiegel | October 7, 2016“What is wild cannot be bought or sold, borrowed or copied. It is. Unmistakeable, unforgettable, unshamable, elemental as earth and ice, water, fire and air, a quintessence, pure spirit, resolving into no constituents.” -Jay Griffiths
At the earliest times, we can trace the history of our Universe back to an inflationary state, where the energy inherent to space itself caused a rapid, exponential expansion. At the latest (current) times, billions of years after inflation ended and the Big Bang occurred, dark energy has come to dominate the Universe’s expansion. These two states are very…
esiegel | September 13, 2016“We can only see a short distance ahead, but we can see plenty there that needs to be done.” -Alan Turing
The Cosmic Microwave Background data gave us an unprecedented picture of our Universe in terms of accuracy, with the latest Planck results showing us our Universe is 68% dark energy, 13.8 billion years old and is expanding at a rate of 67 km/s/Mpc. Too bad, then, that the Cosmic Microwave Background isn't the only way to measure the expansion rate, and that direct measurements -- using the cosmic distance ladder -- disagree with that significantly.
A map of star density in the Milky Way…
esiegel | September 11, 2016“With the first link, the chain is forged. The first speech censured, the first thought forbidden, the first freedom denied, chains us all irrevocably.” -Aaron Satie, Star Trek
It’s been a remarkable week at Starts With A Bang, and I'm especially proud of the stories we've run on Proxima b, Hubble's limits, the dream of Warp Drive and the Cosmic Neutrino background. If you missed any of them (or any of the others), here's what the past week has held:
When will the Sun make Earth uninhabitable? (for Ask Ethan),
What is the biggest black hole as seen from Earth? (for Mostly Mute Monday),
Ten…
esiegel | September 9, 2016“When you see how fragile and delicate life can be, all else fades into the background.” –Jenna Morasca
The hot Big Bang — proposed seventy years ago — is a tremendous success story. Predicated on the assumption that the Universe was hotter, denser, more uniform and expanding faster in the past, it’s allowed us to predict the rate of cosmic expansion over distance and time, the primeval abundances of the light elements, the formation and evolution of large-scale-structure, and the existence and properties of the cosmic microwave background: the leftover photon glow from the Big Bang.
An…
esiegel | August 27, 2016"The oldest and strongest emotion of mankind is fear, and the oldest and strongest kind of fear is fear of the unknown." -H.P. Lovecraft
There’s a unique relationship between everything that exists in the Universe today -- the stars and galaxies, the large-scale structure, the leftover glow from the Big Bang, the expansion rate, etc. -- and the amount of time that’s passed since it all began. When it comes to our Universe, there really was a day without a yesterday, but how do we know exactly how much time has passed between then and now?
The Universe's expansion rate is determined by the…
esiegel | July 30, 2016"The world you see, nature's greatest and most glorious creation, and the human mind which gazes and wonders at it, and is the most splendid part of it, these are our own everlasting possessions and will remain with us as long as we ourselves remain." -Seneca
Asking where in space the Big Bang happened is like asking where the starting point of Earth’s surface is. There’s no one “point” where it began, unless you’re talking about a point in time. The reality is that, as far as space is concerned, the Big Bang occurred everywhere at once, and we have the evidence to prove it.
Our view of a…
esiegel | July 14, 2016"Go, then. There are other worlds than these." -Stephen King
We think of the Universe as all there ever is, was or will be. But, in fact, there's a limit to the most distant galaxies, stars, matter and radiation we can see. The hot Big Bang occurred a finite amount of time ago, and hence the amount of the Universe accessible to us through any observational means is necessarily limited.
Artist’s logarithmic scale conception of the observable universe. Image credit: Wikipedia user Pablo Carlos Budassi.
What lies beyond that? According to our best explanations and theories, there's more…
esiegel | June 24, 2016“Those who know that the consensus of many centuries has sanctioned the conception that the earth remains at rest in the middle of the heavens as its center, would, I reflected, regard it as an insane pronouncement if I made the opposite assertion that the earth moves.” –Nicolaus Copernicus
There are certain words that simply get people’s hackles raised, shutting off the part of their brain that normally responds to reason and instead results in an emotional response taking over. For some, that word is “theory,” one of the words with the biggest gap between its colloquial and scientific uses…
esiegel | June 13, 2016“It surprises me how disinterested we are today about things like physics, space, the universe and philosophy of our existence, our purpose, our final destination. It’s a crazy world out there. Be curious.” –Stephen Hawking
In the beginning, before even the Big Bang, all that we had was space and time, expanding rapidly according to the rules of cosmological inflation. Today, we've got an observable Universe full of stars and galaxies, tens of billions of light years across, with at least one instance of intelligent life: on Earth.
The Earth and Sun, not so different from how they might have…
esiegel | May 26, 2016“[The black hole] teaches us that space can be crumpled like a piece of paper into an infinitesimal dot, that time can be extinguished like a blown-out flame, and that the laws of physics that we regard as ‘sacred,’ as immutable, are anything but.” -John Wheeler
Dark matter is one of the biggest mysteries in the Universe. We can feel its gravitation, we can see its effects on galaxies, clusters and the large-scale structure of the Universe. But when it comes to very small scales, we haven't been able to detect dark matter, either directly or indirectly, leading us to wonder at what it's…