Author Archives: flora iranmanesh

A Universe is Born

Posted on November 6, 2016 | Leave a comment

A century ago the topic, the birth of the universe, was considered unfit for scientific study. It wasn’t until Hubble’s discovery that the universe was expanding, that this topic was scientifically investigated1. The expansion of the universe led to idea that the universe sprang to existence from a single point in time, in an event called the Big Bang.

YouTube Preview Image

With the advancement of science and technology we have been able to investigate our universe within fractions of a second after the Big Bang. By exploring the early universe we can gain new insight on how our universe was shaped and what the universe could look like in the future.

Figure 1. Solar system formation outline Source: Docstoc.com. http://pics-about-space.com/solar-system-evolution-timeline?p=1#img278342502844603781 (accessed Nov 6, 2016).

Figure 1. Solar System Formation Outline
Source: Docstoc.com. http://pics-about-space.com/solar-system-evolution-timeline?p=1#img278342502844603781 (accessed Nov 6, 2016).

The study of the early universe is called the Big Bang Theory1. A second after the big bang the universe was a 10 billion degree sea of protons, neutrons, electrons and other particles2. At the first fraction of a second the universe was so hot that particles were constantly being created and annihilated, preventing the formation of stable and neutral atoms. It wasn’t until about 10-10 seconds after the Big Bang, that it became “cool” enough for atoms to actually form1. Putting this into perspective, the “cool” temperature was about 1012 kelvins1.

Figure 2. Particle creation (a)and annihilation (b). Particles being converted to photons, and vice versa. Source: Wesley, A. Nuclear Energy. http://hendrix2.uoregon.edu/~imamura/122/lecture-6/nuclear.html (accessed Nov 6, 2016). Copyright by Wesley, A.

Figure 2. Particle Creation (a) and Annihilation (b). Particles being converted to photons, and vice versa.
Source: Wesley, A. Nuclear Energy. http://hendrix2.uoregon.edu/~imamura/122/lecture-6/nuclear.html (accessed Nov 6, 2016). Copyright by Wesley, A.

However, even at this point the atoms created weren’t stable. Finally, five minutes after the Big Bang, when the temperature of the universe was about a billion kelvins (109 k), the protons and neutrons were able to fuse together to form heavier nuclei1. For about 380,000 years the universe was a mush of opaque hot plasma2. According to NASA, the early universe wasn’t transparent because “the free electrons […] caused light (photons) to scatter, the way sunlight scatters from the water droplets in clouds3.”

Figure 3: Summary of the Big Bang Theory Source: The Birth of the Universe; The Kingfisher Young People's Book of space. http://www.crystalinks.com/bigbang.html (accessed Nov 6, 2016)

Figure 3: Summary of The Big Bang Theory
Source: The Birth of the Universe; The Kingfisher Young People’s Book of space. http://www.crystalinks.com/bigbang.html (accessed Nov 6, 2016)

Although a lot of questions about our universe are still unanswered, having some insight on the first few seconds and minutes after the Big Bang is incredible. This insight is what allowed us to determine the age of our universe. We all know from thermodynamics that our universe is constantly becoming more disordered, perhaps with further research we can understand this disorder and investigate the birth of our universe more and possibly determine the future of our universe.

Until our next Journey, live long and prosper.

By Flora Iranmanesh

Sources:

  1. Bennet; Donahue; Schneider; Voit. The Cosmic Perspective: Stars & Galaxies; Pearson Learning Solutions, Boston, 2015; pp 306-325.
  2. NASA Science Beta. Universe: The Big Bang. https://science.nasa.gov/astrophysics/focus-areas/what-powered-the-big-bang (accessed Nov 6, 2016)
  3. com. What is the Big Bang Theory. http://www.space.com/25126-big-bang-theory.html (accessed Nov 6, 2016)

 

 

 

 

Leave a comment

Posted in uncategorized

Tagged ,

PLUTO IS DEAD

Posted on October 16, 2016 | 4 comments

On August 24, 2006 Pluto died1. Okay maybe it didn’t exactly die, but Pluto the planet died and Pluto the dwarf planet was born. I remember hearing the news in the beginning of grade five and I was FURIOUS. Not because of Pluto’s demotion, but because my mnemonic for memorizing the planets names no longer made sense. “My Very Educated Mother Just Served Us Nine Pizzas” had become “My Very Educated Mother Just Served Us Nine.” Nine what?!

Planet Mnemonic Source: Simplyilka. http://simplyilka.com/2014/10/23/5-science-jokes-everyone/ (accessed Oct 16, 2016)

Planet Mnemonic
Source: Simplyilka. http://simplyilka.com/2014/10/23/5-science-jokes-everyone/ (accessed Oct 16, 2016)

The decision to demote Pluto was very controversial, many scientists and people, including myself, saw the nine planets as fixtures in the sky that represented our small section in the universe. So why did Pluto get demoted after 75 years of being a planet and why was the decision so controversial?

Unlike all the other planets Pluto was an oddball to begin with. Pluto’s eccentric orbit crosses Neptune’s orbit for about 20 years out of its 248 year orbit2. No other planets cross orbital paths! The only other objects that do, are comets and asteroids.

In 2005, Caltech astronomer Mike Brown aka Pluto Killer announced the discovery of Eris, an object in the Kuiper belt that was similar in size to Pluto3. NASA defines the Kuiper Belt as “a disc-shaped region of icy bodies- including Pluto- and comets beyond the orbit of Neptune4.” So if we considered Pluto a planet then Eris would have to become the tenth planet. However, since the discovery of Eris, more objects in the Kuiper Belt were identified as having masses comparable to Pluto. That’s when the International Astronomical Union (IAU) had to step in and redefine the term planet.

Other Objects in the Kuiper Belt Source: Amos, J. Pluto flyby: Meet the 'King of the Kuiper Belt,' BBC News. http://www.bbc.com/news/science-environment-33500681 (accessed Oct 16, 2016)

Other Objects in the Kuiper Belt
Source: Amos, J. Pluto flyby: Meet the ‘King of the Kuiper Belt,’ BBC News. http://www.bbc.com/news/science-environment-33500681 (accessed Oct 16, 2016)

The new definition of planet needs to meet three criterion5: (1) must orbit the sun, (2) have sufficient mass to be round, or nearly round, (3) has cleared the neighbourhood around its orbit.

Unfortunately Pluto did not meet the last criterion because it shares its orbital neighbourhood with other objects in the Kuiper belt. Alan Stern, leader of NASA’s New Horizon mission, along with many other scientists were not happy with this new definition of planets. Stern told SPACE.com. “A river is a river, independent of whether there are other rivers nearby. In science, we call things what they are based on their attributes, not what they’re next to3.” However Stern may have some bias on the subject because he was leading the New Horizon Mission to Pluto, which was launched in early 2006. Leading a launch to a planet is much more exciting then leading one to a dwarf planet.

After doing all of this research and understanding the arguments each side was making, my opinion on Pluto’s status as a planet changed. Although it would be nice for my mnemonic of the planets to make sense, our knowledge of the universe is constantly changing and evolving, and along with it definitions for our universe need to change too.

Until our next journey, live long and prosper…unless you’re Pluto

By: Flora Iranmanesh

References:

(1) Inman, M. Pluto Not a Planet, Astronomers Rule. National Geographic [online], August 24, 2006. http://news.nationalgeographic.com/news/2006/08/060824-pluto-planet.html (accessed Oct 16, 2016)

(2) Spaleta, S. Neil deGrasse Tyson’s Case Against Pluto’s ‘Planet-hood. video file, Space.com, July, 14 2015. http://www.space.com/29949-neil-degrasse-tyson-s-case-against-pluto-s-planet-hood-video.html (accessed Oct 16, 2016)

(3) Wall, M. Five Years Later, Pluto’s Planethood Demotion Still Stirs Controversy. space.com [online], August 24, 2011. http://www.space.com/12709-pluto-dwarf-planet-decision-5-years-anniversary-iau.html (accessed Oct 16, 2016)

(4) Solar System Exploration NASA Science, Kuiper Belt: Overview. http://solarsystem.nasa.gov/planets/kbos (accessed Oct 16, 2016)

(5) Howell, E. What Is a Planet? space.com [online], May 22, 2014. http://www.space.com/25986-planet-definition.html (accessed Oct 16, 2016)

 

4 Comments

Posted in uncategorized

Tagged ,

Black Holes Don’t Suck!

Posted on October 10, 2016 | 2 comments

As a mega fan of sci-fi movies and astronomy I am always confronted with the bitter taste of space ignorance. One of the most common misconceptions–not only in sci-fi movies but also in our pop culture–is about black holes. Ever heard of the phrase “getting sucked into a black hole?” Newton’s law of gravitation tells us that masses in gravitational fields orbit each other in ellipses, parabolas and hyperbolas. Notice how “sucking” isn’t on this list.

YouTube Preview Image

 

For us to have a better understanding of the universe we live in, we must get rid of misconceptions in science and replace them with facts. So if a black hole doesn’t “suck” then what does really happen at a black hole?

Before we can take this journey through space together, some elements need to be defined for the less nerdy astronomy readers.

Black holes are the remaining cores of massive stars. So, basically a lot of mass squeezed into a tiny space, which results in a strong gravitational pull. This strong gravitational pull arises from the curvature of space. Imagine if the universe was a giant rubber sheet with objects of different masses spread throughout it. Heavier objects would curve the rubber sheet more than lighter objects. A black hole on this sheet would be like a bottomless pit—a hole in the observable universe.

On the left, an optical image from the Digitized Sky Survey shows Cygnus X-1, outlined in a red box. Cygnus X-1 is located near large active regions of star formation in the Milky Way, as seen in this image that spans some 700 light years across. An artist's illustration on the right depicts what astronomers think is happening within the Cygnus X-1 system. Cygnus X-1 is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star. New studies with data from Chandra and several other telescopes have determined the black hole's spin, mass, and distance with unprecedented accuracy. Credits: NASA/CXC/M.Weiss Source: http://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html

An artist’s drawing of the black hole Cygnus X-1, pulling in matter from a nearby blue star. Credits: NASA/CXC/M.Weiss Source: http://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html

 

An illustration of the “rubber sheet” 2-D simplification of gravity’s effect on space-time, with a 1-D profile of the shape of the curve along any one direction. Image Credit: BenRG, public domain Source: https://medium.com/starts-with-a-bang/astroquizzical-how-does-gravity-escape-from-a-black-hole-5ef156bf048d#.v1pxirpaz

An illustration of the “rubber sheet” 2-D simplification of gravity’s effect on space-time, with a 1-D profile of the shape of the curve along any one direction.
Image Credit: BenRG, public domain
Source: https://medium.com/starts-with-a-bang/astroquizzical-how-does-gravity-escape-from-a-black-hole-5ef156bf048d#.v1pxirpaz

So passing by a black hole we wouldn’t get sucked in, unless we were unfortunate enough to get pulled into its gravitational field. If we did managed to get pulled in, we would disappear from the observable universe. This is because the gravitational pull is so strong that not even light can escape a black hole. Thus being given the name “black” hole.

To our friends outside the black hole it may seem that we did in fact get sucked in because we vanished from sight. But we know this isn’t true, and sadly we can never leave the black hole to tell our friends. So as we frantically wave our arms and call out to our friends for help, they head back home and tell everyone that black holes do in fact suck. 🙁

Until our next journey, live long and prosper.

By: Flora Iranmanesh

2 Comments

Posted in uncategorized

Tagged ,

Image

Black Holes Don’t Suck!

As a mega fan of sci-fi movies and astronomy I am always confronted with the bitter taste of space ignorance. One of the most common misconceptions–not only in sci-fi movies but also in our pop culture–is about black holes. Ever heard of the phrase “getting sucked into a black hole?”

Newton’s law of gravitation tells us that masses in gravitational fields orbit each other in ellipses, parabolas and hyperbolas. Notice how “sucking” isn’t on this list. So then what would really happen if you were to approach a black hole?

Before we can take this journey through space together, some elements need to be defined for the less nerdy astronomy readers.

Black holes are the remaining cores of massive stars. So, basically a lot of mass squeezed into a tiny space, which results in a strong gravitational pull. The escape velocity is the speed required to leave the orbit of an object. This depends on both the mass and the size of the object. The smaller the size of an object, the stronger the gravitational pull, and as a result a higher escape velocity would be required to leave the orbit.

On the left, an optical image from the Digitized Sky Survey shows Cygnus X-1, outlined in a red box. Cygnus X-1 is located near large active regions of star formation in the Milky Way, as seen in this image that spans some 700 light years across. An artist's illustration on the right depicts what astronomers think is happening within the Cygnus X-1 system. Cygnus X-1 is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star. New studies with data from Chandra and several other telescopes have determined the black hole's spin, mass, and distance with unprecedented accuracy.

An artist’s drawing of the black hole Cygnus X-1, pulling in matter from a nearby blue star. (Credits: NASA/CXC/M.Weiss)

So passing by a black hole you wouldn’t get sucked in, unless you were unfortunate enough to get pulled into its gravitational field. The escape velocity would be too high for you to ever be able to escape. In fact the gravitational pull is so strong that not even light can escape a black hole. Thus being given the name “black” hole.

It’s also interesting to note that people outside the black hole would never see you spiraling into the black hole. They would just see you suspended in space, stuck in time. To them, time would stop for you because of the significant increase in the force of gravity. So theoretically if you didn’t vanish from sight, you would never age to the people outside the black hole.

Now that we’ve taken this journey to the great unknown together, we can conclude that black holes don’t go around sucking up moons and stars like some cosmic vacuum.

Until our next journey, live long and prosper.

By: Flora Iranmanesh

Sources:

Bennet; Donahue; Schneider; Voit. The Cosmic Perspective: Stars & Galaxies; Pearson Learning Solutions, Boston, 2015; pp 211-212.

Weiss, M. Cygnus X-1. http://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html (accessed Sept 26, 2016). Credits: NASA/CXC/M. Weiss

Leave a comment

Posted on September 26, 2016 in uncategorized

Tagged ,