Evidence for the Big Bang

planck-attnotated-580x372The Big Bang Theory has been the dominant cosmological model for over half a century. According to the theory, the universe was created approximately 14 billion years ago from an extremely hot, dense state and then began expanding rapidly. After the initial expansion, the Universe cooled and began to form various subatomic particles and basic elements. Giant clouds of these primordial elements later coalesced through gravity to form stars, galaxies, and eventually planets.

And while it has its detractors, most of whom subscribe to the alternate Steady State Theory – which claims that new matter is continuously created as the universe expands – it has come to represent the scientific consensus as to how the universe came to be. And as usual, my ol’ pal and mentor in all things digital, Fraser Cain, recently released a video with the help of Universe Today discussing the particulars of it.

big_bangAddressing the particulars of the Big Bang Theory, Cain lists the many contributions made over the past century that has led this so-called theory to become the scientific consensus has come to exist. They are, in a nutshell:

  1. Cosmic Expanion: In 1912, astronomer Vesto Slipher calculated the speed and distance of “spiral nebulae” (galaxies) by measuring the light coming from them. He determined most were moving away. In 1924, Edwin Hubble determined that these galaxies were outside the Milky Way. He postulates that the motion of galaxies away from our own indicates a common point of origin.
  2. Abundance of Elements: Immediately after the big bang, only hydrogen existed and compressed into a tiny area of space under incredible heat and pressure. Like a star, this turned hydrogen into helium and other basic elements. Looking out into the universe (and hence back in time) scientists have found that great distances, the ratios of hydrogen to basic elements is consistent with what is found in star’s interiors.
  3. Cosmic Microwave Background (CMB) Radiation: In the 1960’s, using a radiotelescope, Arno Penzias and Robert Wilson discovered a background radio emission coming from every direction in the sky, day or night. This was consistent with the Big Bang Theory, which predicted that after the Big Bang, there would have been a release of radiation which then expanded billions of light years in all directions and cooled to the point that it shifted to invisible, microwave radiation.
  4. Large Scale Structure: The formation of galaxies and the large-scale structure of the cosmos are very similar. This is consistent with belief that after the initial Big Bang, the matter created would have cooled and began to coalesce into large collections, which is what galaxies, local galactic groups, and super-clusters are.

These are the four pillars of the Big Bang Theory, but they are no means the only points in its favor. In addition, there are numerous observational clues, such as how we have yet to observe a stars in the universe older than 13 billion years old, and fluctuations in the CMB that indicate a lack of uniformity. On top of that, there is the ongoing research into the existence of Dark Matter and Dark Energy, which are sure to bear fruit in the near future if all goes well.

big_bang1In short, scientists have a pretty good idea of how the universe came to be and the evidence all seems to confirm it. And some mysteries remain, we can be relatively confident that ongoing experimentation and research will come up with new and creative ways to shed light on the final unknowns. Little reason then why the Big Bang Theory enjoys such widespread support, much like Evolution, Gravity, and General Relativity.

Be sure to check out the full video, and subscribe to Universe Today for additional informative videos, podcasts, and articles. As someone who used to write for them, I can tell you that it’s a pretty good time, and very enlightening!

News From Space: Big Bang Vs. Black Hole

big bang_blackholeFor decades, the Big Bang Theory has remained the accepted theory of how the universe came to be, beating out challengers like the Steady State Theory. However, many unresolved issues remain with this theory, the most notable of which is the question of what could have existed prior to the big bang. Because of this, scientists have been looking for way to refine the theory.

Luckily, a group of theoretical physicists from the Perimeter Institute (PI) for Theoretical Physics in Waterloo, Ontario have announced a new interpretation on how the universe came to be. Essentially, they postulate that the birth of the universe could have happened after a four-dimensional star collapsed into a black hole and began ejecting debris.

big_bangThis represents a big revision of the current theory, which is that universe grew from an infinitely dense point or singularity. But as to what was there before that remain unknown, and is one of a few limitations of the Big Bang. In addition, it’s hard to predict why it would have produced a universe that has an almost uniform temperature, because the age of our universe (about 13.8 billion years) does not give enough time to reach a temperature equilibrium.

Most cosmologists say the universe must have been expanding faster than the speed of light for this to happen. But according to Niayesh Afshordi, an astrophysicist with PI who co-authored the study, even that theory has problems:

For all physicists know, dragons could have come flying out of the singularity. The Big Bang was so chaotic, it’s not clear there would have been even a small homogenous patch for inflation to start working on.

black_holeThe model Afshordi and her colleagues are proposing is basically a three-dimensional universe floating as a membrane (or brane) in a “bulk universe” that has four dimensions. If this “bulk universe” has four-dimensional stars, these stars could go through the same life cycles as the three-dimensional ones we are familiar with. The most massive ones would explode as supernovae, shed their skin and have the innermost parts collapse as a black hole.

The 4-D black hole would then have an “event horizon”, the boundary between the inside and the outside of a black hole. In a 3-D universe, an event horizon appears as a two-dimensional surface; but in a 4-D universe, the event horizon would be a 3-D object called a hypersphere. And when this 4-D star blows apart, the leftover material would create a 3-D brane surrounding a 3-D event horizon, and then expand.

planck-attnotated-580x372To simplify it a little, they are postulating that the expansion of the universe was triggered by the motion of the universe through a higher-dimensional reality. While it may sound complicated, the theory does explain how the universe continues to expand and is indeed accelerating. Whereas previous theories have credited a mysterious invisible force known as “dark energy” with this, this new theory claims it is the result of the 3-D brane’s growth.

However, there is one limitation to this theory which has to do with the nearly uniform temperature of the universe. While the model does explain how this could be, the ESA’s Planck telesceop recently mapped out the universe and discovered small temperature variations in the cosmic microwave background (CBM). These patches were believed to be leftovers of the universe’s beginnings, which were a further indication that the Big Bang model holds true.

big_bang1The PI team’s own CBM readings differ from this highly accurate survey by about four percent, so now they too are going back to the table and looking to refine their theory. How ironic! However, the IP team still feel the model has worth. While the Planck observations show that inflation is happening, they do not show why the inflation is happening.

Needless to say, we are nowhere near to resolving how the universe came to be, at least not in a way that resolves all the theoretical issues. But that’s the things about the Big Bang – it’s the scientific equivalent of a Hydra. No matter how many times people attempt to discredit it, it always comes back to reassert its dominance!

Source: universetoday.com, perimeterinstitute.ca

News from Space: New Map of the Universe Confirms The Big Bang!

planckAfter 15 months of observing deep space, scientists with the European Space Agency Planck mission have generated a massive heat map of the entire universe.The “heat map”, as its called, looks at the oldest light in the universe and then uses the data to extrapolate the universe’s age, the amount of matter held within, and the rate of its expansion. And as usual, what they’ve found was simultaneously reassuring and startling.

When we look at the universe through a thermal imaging system, what we see is a mottled light show caused by cosmic background radiation. This radiation is essentially the afterglow of the Universe’s birth, and is generally seen to be smooth and uniform. This new map, however, provides a glimpse of the tiny temperature fluctuations that were imprinted on the sky when the Universe was just 370,000 years old.

big_bangSince it takes light so long to travel from one end of the universe to the other, scientists can tell – using red shift and other methods – how old the light is, and hence get a glimpse at what the universe looked like when the light was first emitted. For example, if a galaxy several billion light years away appears to be dwarfish and misshapen by our standards, it’s an indication that this is what galaxies looked like several billion years ago, when they were in the process of formation.

Hence, like archaeologists sifting through sand to find fossil records of what happened in the past, scientists believe this map reveals a sort of fossil imprint left by the state of the universe just 10 nano-nano-nano-nano seconds after the Big Bang. The splotches in the Planck map represent the seeds from which the stars and galaxies formed. As is heat-map tradition, the reds and oranges signify warmer temperatures of the universe, while light and dark blues signify cooler temperatures.universe

The cooler temperatures came about because those were spots where matter was once concentrated, but with the help of gravity, collapsed to form galaxies and stars. Using the map, astronomers discovered that there is more matter clogging up the universe than we previously thought, at around 31.7%, while there’s less dark energy floating around, at around 68.3%. This shift in matter to energy ratio also indicates that the universe is expanding slower than previously though, which requires an update on its estimated age.

All told, the universe is now believed to be a healthy 13.82 billion years old. That wrinkles my brain! And also of interest is the fact that this would appear to confirm the Big Bang Theory. Though widely considered to be scientific canon, there are those who dispute this creation model of the universe and argue more complex ideas, such as the “Steady State Theory” (otherwise known as the “Theory of Continuous Creation”).

24499main_MM_Image_Feature_49_rs4In this scenario, the majority of matter in the universe was not created in a single event, but gradually by several smaller ones. What’s more, the universe will not inevitable contract back in on itself, leading to a “Big Crunch”, but will instead continue to expand until all the stars have either died out or become black holes. As Krzysztof Gorski, a member of the Planck team with JPL, put it:

This is a treasury of scientific data. We are very excited with the results. We find an early universe that is considerably less rigged and more random than other, more complex models. We think they’ll be facing a dead-end.

Martin White, a Planck project scientist with the University of California, Berkeley and the Lawrence Berkeley National Laboratory, explained further. According to White, the map shows how matter scattered throughout the universe with its associated gravity subtly bends and absorbs light, “making it wiggle to and fro.” As he went on to say:

The Planck map shows the impact of all matter back to the edge of the Universe. It’s not just a pretty picture. Our theories on how matter forms and how the Universe formed match spectacularly to this new data.

planck_satThe Planck space probe, which launched in 2009 from the Guiana Space Center in French Guiana, is a European Space Agency mission with significant contribution from NASA. The two-ton spacecraft gathers the ancient glow of the Universe’s beginning from a vantage more than a million and a half kilometers from Earth. This is not the first map produced by Planck; in 2010, it created an all-sky radiation map which scientists, using supercomputers, removed all interfering background light from to get a clear view at the deep background of the stars.

However, this is the first time any satellite has been able to picture the background radiation of the universe with such high resolution. The variation in light captured by Planck’s instruments was less than 1/100 millionth of a degree, requiring the most sensitive equipment and the contrast. So whereas cosmic radiation has appeared uniform or with only slight variations in the past, scientists are now able to see even the slightest changes, which is intrinsic to their work.planck-attnotated-580x372

So in summary, we have learned that the universe is a little older than previously expected, and that it most certainly was created in a single, chaotic event known as the Big Bang. Far from dispelling the greater mysteries, confirming these theories is really just the tip of the iceberg. There’s still the grandiose mystery of how all the fundamental laws such as gravity, nuclear forces and electromagnetism work together.

Ah, and let’s not forget the question of what transpires beneath the veil of an even horizon (aka. a Black Hole), and whether or not there is such a thing as a gateway in space and time. Finally, there’s the age old question of whether or not intelligent life exists somewhere out there, or life of any kind. But given the infinite number of stars, planets and possibilities that the universe provides, it almost surely does!

And I suppose there’s also that persistent nagging question we all wonder when we look up at the stars. Will we ever be able to get out there and take a closer look? I for one like to think so, and that it’s just a matter of time!

To boldly go!
To boldly go!

Sources: universetoday.com, (2), extremetech.com, bbc.co.uk