[GUEST POST] There and Back Again: A Scientific Journey Through Space and Time

This week, "New @ MPL" is proud to showcase the writings of local teens and young adults from MPL's very own Teen Writing Group. (Our Teen Writing Group meets every Monday afternoon at the Library.)

Today, enjoy this entry from Bruce Howard, who takes us on a tour of very ancient history:

The "nearby" Andromeda Galaxy -- located  2.5 million light-years away

It is almost quintessentially human to ponder matters of history and to perceive the passing of time.  In my early twenties, it’s sometimes easy to feel like you’ve been around a while.  I’ve been through 16 years of schooling (with about seven more to go before I’m done).  I’ve also witnessed several world-, nation-, and life-changing moments in history.

However, I did not just suddenly appear out of nowhere, a newborn baby in a foreign universe.  The rules of physics might have a few problems with that scenario.  I’ve been alive for less than .0000002% of the time the universe has been around, and inevitably, that which came before me factors into who I am.

Obviously, I directly owe my existence to the fact that my parents met.  If that were the only factor, though, this wouldn’t be much of a story.  Stepping a bit further back, I can trace my ancestors to World War II, World War I, the Civil War, and even the American Revolution.  War is quite obviously a dangerous thing, so it might seem a bit odd to note that had my ancestors not been in these conflicts, I might not be here.  Consider this: a young soldier heading off to war would have to put starting a family on hold for the duration of his service.  If not for that setback, perhaps that soldier would never have had a child when they had your mother, father, grandmother, grandfather, and/or other ancestor.  One might even say that every little thing that has happened since the rise of humanity has, in some way or another, affected today’s world.  There is that famous quip about how going back in time and killing a single animal could drastically change the present.  But I don’t want to stop this tour of history at the rise of humanity.

There are approximately 13 billion years of universal existence.  So let’s start a bit further back than the mere dent in time that is human existence.  Shortly after the universe was created some 13 billion years ago, in what is called the Big Bang, the universe had expanded a bit, enough that the universe was able to cool some and allow particles to combine.  Thus, the first atoms were formed.  These were mostly hydrogen, with only small amounts of a few other elements (like lithium) forming.  If only these very light atoms had formed in the Big Bang, one might wonder how it is that the atoms we’re made of formed.

Drawing an atom

As the universe continued to expand, gravity did its thing, pulling the hydrogen and trace elements together.  Eventually, these elements had formed clumps.  Then, in time, these clumps had condensed enough to reach the conditions necessary for nuclear fusion.  These giant balls of mostly hydrogen gas had become the universe’s first stars.  Stellar nuclear fusion is the process by which stars continually produce their energy.  A few nuclear processes steadily convert hydrogen atoms into helium atoms, giving off other things as well.  Among these are light, along with somewhat elusive particles called neutrinos that have been the focus of intense study recently.  Indeed, this has been the focus of my research experiences.  The process of converting the maximum amount of hydrogen to helium takes varying amounts of time.  However, after this process is complete, the star will then convert helium to heavier atoms, and then those atoms to heavier atoms still.  This process will continue on until the star runs out of fusion material.  If the star has enough material, it will continue undergoing fusion until reaching iron.  Due to nuclear properties, it stops being energetically preferable to fuse elements heavier than iron.  This concludes the fusion process.  Big stars, those several times the size of our sun, will supernova after ending its fusion process.  The supernovae produce incredible energies, allowing elements heavier than iron to form.  In the process, the star’s material is ejected into the vast … space … of space.

So, after these early stars went supernova, their heavier elements (among them oxygen, carbon, iron, and others necessary for life) mixed in with other hydrogen nuclei.  By approximately five billion years ago, some of the mix that had been made by prior stars had collapsed to form the Sun and its satellites.  Contained on Earth were carbon, oxygen, iron, and the other elements necessary to produce life as we know it.  Fast forward upwards of five billion orbits of the Sun, and here we are, inhabiting the Earth today.  We are literally made of star atoms.

The closest star to Earth -- our Sun

So, clearly, both human history and cosmological history play quite prominently in determining how it is that a person came to be here and now.  The cosmic story doesn’t end with us, though.  What about the future of the universe?  Our sun has about five billion years of hydrogen-burning left.  Once it starts to fuse helium, it will swell, making Earth uninhabitable.  If we can find a way to inhabit another planet or another system by then, the story of humanity can continue with that of the cosmos.  Who knows when the end of the universe will be?  A lot of that depends on certain parameters like dark energy -- which, notably, was only discovered 14 years ago.

I feel that it is a very neat thing that we can trace our lineage to the stars.  As you can see from this musical YouTube video below of several talks put together, I’m not the only one.  However, while it is easy to get caught up feeling small when thinking of the universe as it is, there are some important things to remember.  We may not have a long life span in terms of the life of the universe, but that doesn’t mean we can’t do beautiful things with it.  What we do in our lives can affect both the world itself and the generations to follow.  These effects can, in turn, affect the generations to follow them.  Who knows?  One day, those effects might even be carried to other planets or other star systems.  It’s the human perspective that guides our lives, not the cosmic perspective, from which we appear to be mere mayflies.  And remember, you’re all stars in my book.

-- Post by volunteer Bruce Howard

(For more on the history of space and time, check out MPL's cosmology collection.)

[GUEST POST] The Space Shuttle: Thirty Years of Space Exploration

This week, "New @ MPL" is proud to showcase the writings of local teens from MPL's very own Teen Writing Group. (Our Teen Writing Group meets every Monday afternoon at the Library.)

Today, enjoy this entry from Allen H., sharing some of his in-depth knowledge about the history of the Space Shuttle, and its role in our space program:

One-hundred thirty-five missions.  One-hundred thirty-three successes, two failures.  These are just a small number of the many statistics that the five space shuttle orbiters -- Columbia, Challenger, Discovery, Atlantis, and Endeavour -- have played a part in.

First launched in 1981, the space shuttle was the first reusable spacecraft.  Prior to this launch, however, there were approach and landing tests.  A sixth shuttle, a prototype called Enterprise, flew these tests.  It was carried on the back of a modified Boeing 747 and jettisoned off the back to test the landing feature of the space shuttle.  At an altitude of 300 feet, the shuttle would lower its landing gears and gently touchdown on a runway.  There were a number of runways the shuttle could land at: Kennedy Space Center Shuttle Landing Facility, Edwards Air Force Base, and White Sands Space Harbor, just to name a few.

During the thirty-year campaign, the shuttle has seen many great accomplishments.  One of the most notable was the deployment, and subsequent repair of, the Hubble Space Telescope.  After the launch of the Hubble Space Telescope, it was discovered that the main mirror was ground to the wrong specifications, making the pictures blurry.  NASA was faced with two options: leave the telescope in its state, or send a space shuttle to repair it.

The Hubble telescope in orbit

Finally clearing a shuttle mission to fix it, NASA put together an elite crew, who had all been to space.  They conducted multiple spacewalks and even did back-to-back spacewalks.  After the repairs, Hubble started to fulfill its promise of peering into the past and uncovering the origins on the universe.  This mission proved that NASA could use the space shuttle to its full potential.

After the initial repair, Hubble has been serviced several times -- the most recent, and final, in 2009, when Space Shuttle Atlantis flew the STS-125 mission.

After the success of the repairs, NASA got involved in an international project: the International Space Station.  Partnering with the Russian Space Agency, European Space Agency, and countless others, construction was started on the space station.  The orbiting outpost was constructed on opposite sides of the world and then put together for the first time in space.  Crews are rotated by Russian Soyuz, and, at times, the space shuttle.  The space shuttle also carried most of the heavy cargo to the station, being the only space vehicle that could lift enormous payloads.  Having been completed in 2011, the space shuttle was retired at the conclusion of the last flight.

A spacewalk outside the International Space Station

Success was not met without failure, however.  During the thirty-year career, two space shuttle missions ended in tragedy.  On January 28th, 1985, space shuttle Challenger broke up 73 seconds after liftoff.  The accident resulted in the death of all seven astronauts, including the first teacher in space, Christa McAuliffe.  Space shuttle Discovery would fly the return-to-flight mission in 1988.

The second failure happened on February 1st, 2003.  Space shuttle Columbia was returning from a science mission.  Sixteen minutes before landing, the space shuttle broke apart, killing all seven astronauts.  The subsequent investigation showed that a piece of foam struck the orbiter during the ascent that made a hole in the underside of the shuttle.  This caused it to lose the thermal protection and break apart during the high temperatures of reentry.  Space shuttle Discovery again flew the return-to-flight mission in 2005.

Even with these failures, NASA continued to move forward.  Eileen Collins said it best: “We want to explore. We're curious people ... We believe in what we're doing. Now it's time to go.”  NASA has made major security improvements, including requiring the shuttle to perform heat shield inspections (which include flipping 360 degrees on flights to the Space Station), as well has having a secondary method of returning the astronauts from space.  After these requirements, NASA has not experienced any major problems with a spacecraft.

In July of 2011, the space shuttle was retired from flight, with these words from Chris Ferguson at the final landing: “Mission complete, Houston. After serving the world for over 30 years, the space shuttle found its place in history. It's come to a final stop.”  The International Space Station is complete, the space shuttle retired; now it is time to move on.  Back to the moon, and then -- to Mars.

The space shuttle Endeavour

-- Post by teen volunteer Allen H.

(For more on the history of the space shuttle, check out Space Shuttle: The First 20 Years - detailing the astronauts' experiences in their own words.)