The Birth of the Big Bang and the Timeline of Everything We Know

Modern scientific thought owes itself to the contributions of many great men and women. Without these individuals, our universe would (literally) look quite different. However, there are two scientists in the field of cosmology who stand out among all the rest: Edwin Hubble and Georges Lemaître. By 1930, other cosmologists had concluded that the static (non-evolving) model of the universe was unsatisfactory.

This discovery is largely due to the efforts of Edwin Hubble. Using the world’s largest telescope, which is located at Mt. Wilson in California, he showed that the distant galaxies all appeared to be receding from us. What"s more, these far flung galaxies were traveling away from us at speeds proportional to their distances -- Enter Lemaître -- Lemaître used these findings to draw attention to his earlier paper, in which he explained the relationship between the distance of a galaxy and the recession velocity of that same galaxy. By putting together Hubble’s observations with Lemaître’s paper, a majority of astronomers became convinced that the universe was indeed expanding. This revolutionized the study of cosmology.

Why was this find so notable? Shortly after this discovery, Lemaître reasoned that traveling back in time should lead to an epoch in which all the matter in the universe was packed together in an extremely dense state – a primeval atom. And this was the birth of Big Bang cosmology.

So, let us take a moment to delve into the Big Bang--into the timeline of everything that has ever existed...

Image:
NASA/ESO

Hubble Variable 1: The Star That Changed the Universe

Today we know that the Universe is filled with billions upon billions of galaxies, but in the early 1900s, it was widely accepted that the Milky Way was a single collection of stars with nothing beyond it. Andromeda, and other galaxies, were believed to just be ‘spiral nebulae’ lying within the Milky Way. However, there were telltale clues that astronomers could use to determine the distance between Andromeda and Earth, one of which is Cepheid variable stars. Stars of this type have very predictable patterns of brightness, which we can derive a light curve from -- thus making variable stars reliable distance markers.

This gave way to the discovery of many of the most fundamental concepts in modern astronomy.

Learn about how one star was able to revolutionize how we saw the universe, at
http://www.fromquarkstoquasars.com/hubble-variable-1-the-star-that-changed-the-universe/

Image Credit: S. Beckwith & the HUDF Working Group (STScI), HST, ESA, NASA

Is Absolute Zero Absolute?

Right now, as I type this sentence, Earth"s Northern Hemisphere is tilted away from the bright ball of light that is the Sun, and it’s cold here (relatively speaking). Humans have long recorded and measured the temperature of their environment, and for good reason. Keeping constant watch on a thermometer helps us prepare for the potential dangers of cold weather. Take zero degrees Celsius, for instance. At such temperatures, water begins to freeze. In some cases, the pipes that the water runs through malfunction, and then there"s the various life-or-death afflictions that can be brought on by this cold temperature. However, zero degrees Celsius is pretty warm compared to zero degrees on the Fahrenheit scale (after all, water freezes at 32 F).

Yet, neither of these can compare to the temperature known as absolute zero.

Learn about the coldest of the cold, and how scientists surpassed absolute zero, at:
http://www.fromquarkstoquasars.com/is-absolute-zero-absolute/

Image:
WikiMedia, public domain

Activity from Ancient, Invisible Galaxy Observed

Behold, the light of a gamma-ray burst that took place more than 13 billion years ago!

As most of you are aware, the universe is expanding at an ever-increasing speed, which in turn, pushes all galaxies farther away from us. Ultimately, this will result in these galaxies receding so far away, to the point that some of them eventually disappear forever, traveling too fast (located too far away) for their light to ever reach us. However, many of the galaxies that are now too far away were once much closer, offering us an opportunity to study distant, ancient galaxies as they appeared long before our planet was conceived.

s such, astronomers were recently able to detect a destructive event from one such galaxy, located 12.7 billion light-years away. Meaning we are observing the galaxy as it appeared almost 13 billion years ago; basically when the universe was still in diapers, more or less. The galaxy is generally too far away (and too red-shifted as a result of the universe"s expansion) for us to be capable of observing closely

So.. how was this galaxy detected? Find out: http://www.fromquarkstoquasars.com/light-from-an-invisible-galaxy-appears/

Image Credit: Gemini Observatory / AURA / Lynette Cook

MOND: Trying to Solve the Problem of the Missing Universe

One of the greatest mysteries of astronomy is the problem of the missing universe. Well, the universe isn’t exactly missing, but a lot of its mass is. Ultimately, all of the matter scientists can see in the universe accounts for only a small percent of the observed gravity. Everything on Earth, everything we’ve ever observed with our instruments, all normal matter—it all adds up to less than 5% of the Universe. Essentially, some unobservable something in influencing the motions of the cosmos.

Astronomers often use dark matter to explain this missing matter. However, the dark matter interactions that scientists believe they observed remain inconclusive. Thus, scientists have yet to definitively determine that dark matter exists. In fact, we may never actually be able to detect it... and it isn"t ideal at predicting all manner of situations. As you see, dark matter does have some problems.

Some researchers think that the problem is really our understanding of gravity. In order to explain why the universe seems to behave as if there"s so much more matter in it, some scientists advocate MOND (Modified Theory of Newtonian Dynamics) instead of dark matter.

Learn about this alternative at:
http://www.fromquarkstoquasars.com/mond-trying-to-solve-the-problem-of-the-missing-universe/

Image source:
http://astroweb.case.edu/ssm/mond/DMtrees.html

The Search for Dark Matter: The Preliminary Results of the LUX Dark Matter Detector

Dark matter: it is a difficult and troubling concept for many who try to understand it. After all, how can something that is so crucial to our existence exist, yet we cannot see it? Well, as a crude analogy, the very air we breathe fits into this same category. We cannot see air, but no one here is disputing the premise that air exists. Of course, this is because we can prove that air is there; however, we were unable to really see or define it for years--for centuries. In fact, we didn"t even discover oxygen (the third most abundant element in the universe that makes up nearly 21% of the earth"s atmosphere) until the 1770s. In a similar way (but using a very different approach than the one used to define air), we have started to get verification for dark matter through the scientific method.

According to our model of cosmology, dark matter is thought to make up 26.8% of the total energy density of the observable universe. This is in stark contrast to regular matter, which comes in at just 4.9%. Subtracted from the total energy density of our homogeneous universe, dark matter would come in at a whopping 84.5% of the total matter of the universe, utterly dominating it. Thus, in order to truly understand the cosmos, we need to define and understand its existence.

To read about dark matter and our quest to understand it, see:
http://www.fromquarkstoquasars.com/the-search-for-dark-matter-the-preliminary-results-of-the-lux-dark-matter-detector/

Image source:
http://www.symmetrymagazine.org/image/april-2012-dark-matter-underground-2