Tuesday, April 30, 2013

Z is for the Zoo Hypothesis


Since this is the last day of the challenge, I wanted to have a little fun.  That's why I decided to post about the Zoo Hypothesis.

The Drake Equation is useful for calculating the possible number of intelligent civilizations in our galaxy.  The answer garnered varies depending upon the values used for each variable (we know some values fairly well, while some are more of an educated guess), but it's a fun intellectual exercise even if we don't get any solid answers from it.

I believe there's life elsewhere in the universe.  It's too large and amazing for me to think otherwise. Still, I'm not holding my breath while I wait for a spaceship to come down and take me for a ride, no matter how cool it would be!

There's debate over whether we've ever been visited by extraterrestrial life.  Some contend we have, while the official consensus is that we haven't.  Those who believe in alien life often claim that we haven't been visited due to large cosmic distances, but this isn't the only hypothesis out there.

The Zoo Hypothesis speculates that intelligent alien life hasn't contacted us in order to allow for us to evolve and mature on our own without interference.  If they observe us at all, we're like animals in a zoo (except we don't know we're in a zoo and we can't see those who are watching us).  Maybe it should be renamed the Prime Directive Hypothesis.  That name seems more appropriate to me.

And for a little bit of fun and deep thinking, here's a clip from Star Trek TNG where the crew of the Enterprise debates the scope of the Prime Directive.  Enjoy!

Monday, April 29, 2013

Y is for Yellow Sun


Our yellow sun is an average star.  In the cosmic sense of things, it isn't anything special, though it will always be special to us since it keeps us alive from day to day.  Even though it is decidedly average, there are a lot of things about the sun that you may find quite interesting.  Have a look!



The following is a time lapse video of the sun.  It's kind of neat to see how the surface of the sun changes over a period of time.

Saturday, April 27, 2013

X is for X-Ray Astronomy


X-rays have a shorter wavelength and higher frequency than visible light.  Most people encounter x-rays for the first time in a medical setting, but x-rays are extremely useful for astronomical purposes as well.  That's because plenty of objects emit x-rays.

Here's a video that discusses the history, present, and possible future of x-ray astronomy.


Friday, April 26, 2013

W is for Wavelength


Electromagnetic waves bombard us from every direction each second of every day.  One of the important properties of EM waves is the wavelength. We can only visually observe waves of a certain wavelength, which is often referred to as the visible spectrum.  

To learn more about the higher and lower wavelength EM waves you cannot see, watch the video below.




The following video gives a brief explanation of the Doppler Effect, which deals with the shift in wavelength observed when the object emitting the waves is in motion relative to an observer.

Thursday, April 25, 2013

V is for Variable Star


As I mentioned in an earlier post, parallax is a method of measuring the distance of nearby stars. The next step on the cosmic distance ladder is a kind of star known as a Cepheid Variable.  This video explains what these stars are and how they're used to determine cosmic distance.  There's also a little bit about the history of women in astronomy, which I think is cool.  Enjoy!

Wednesday, April 24, 2013

U is for Universal Time


What is Universal Time, and how did it come into being?  First off, it's the basis for all civil timekeeping, and it is frequently referred to as Greenwich Mean Time (GMT).  To learn more, watch the dandy little video below!

Tuesday, April 23, 2013

T is for Trans Neptunian Objects


Our solar system is pretty nifty and fun to study.  We have our sun and planets, and those planets are filled with such variety that they keep people studying for a lifetime.  Yet, there's more to our solar system than the planets that orbit our sun.  Trans Neptunian objects far outnumber the planets, and they inhabit the region beyond Neptune (hence their name).  These little icy worlds warrant our attention too.

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Monday, April 22, 2013

S is for Scales of Size



The universe is so grand in scale that the human mind can scarcely imagine its size.  Nevertheless, we try to find ways to make sense of that incomprehensible size.  Here are a couple of videos that boggle the mind and stimulate the imagination.  And the second one (which I posted on this blog months ago) is narrated by Morgan Freeman!


Saturday, April 20, 2013

R is for Relativity


Einstein stunned the world with his insights into the cosmos.  I remember when I first learned about the specifics of both the Special Theory of Relativity and the General Theory of Relativity in college, it was almost enough to make my head spin.  I'm in awe that anyone could be so in tune with the universe that they could come up with these concepts through thought experiments.

These videos break down the concepts in relativity and make them easier to understand.  Feel free to watch them all (though it may take more than one sitting to do so), or watch until it feels like your head might explode.  (Trust me, the feeling that your head may explode is a perfectly normal reaction.)

This first video deals with the examples of relativity we see in daily life.  These are easily observable and were adequately handled by classical physics.  We knew these things before Einstein, but knowing this stuff sets up a foundation that helps you understand the more bizarre things to come.










Friday, April 19, 2013

Q is for Quarks



Have you ever wondered what a quark is?  Here's a catchy song that will answer questions you may never have thought to ask!

Thursday, April 18, 2013

P is for Parallax


Astronomers use different methods for measuring the distances of stars.  As you may imagine, cosmic distances can be tricky to pin down accurately given how impressively far apart everything in the universe is, but with the right measurements and a little mathematical prowess, it can be done.

One method for measuring stellar distances is parallax.  Parallax refers to the apparent change in position of a star that occurs as the Earth orbits the sun.  The shifts are tiny given that we're dealing with such large distances, and they grow smaller as that distance increases.  That's why parallax, while useful, is limited to our cosmic neighborhood.  Anything too far out requires other means of measurement to determine distance.

By P.wormer (Own work) [CC-BY-SA-3.0 or GFDL], via Wikimedia Commons

If you're interested in learning how to determine parallax, you can watch these videos.  They spell out the process as clearly as possible and should give you a good idea of how it's done.  Yes, they're a bit long, but they're packed with information!  (And yes, I personally watched all of them all the way through!)

Wednesday, April 17, 2013

O is for Olympus Mons


I've always had a fascination with Mars, and I don't think I'm alone in this.  The red planet not only has an appealing color, it also once had liquid water on its surface.

Image source: Forsetius/ Flickr.
As a kid though, I had a particular love of Olympus Mons.  The amazing size of it impressed me.  It stands at about 3x the height of Mt. Everest.  It's so tall that it sticks out of the Martian atmosphere. When compared to anything on Earth, Olympus Mons dwarfs it all.

© SĂ©mhur Wikimedia Commons / CC-BY-SA-3.0

To give you and idea of just how large the base of this volcano is, here's what it might look like if it were on Earth.

Image Source: Lunar and Planetary Institute/ Flickr.

And lastly, since I wanted to give you a video of some kind, here's a neat one showing how Olympus Mons might look to a human who's landed there.  Maybe one day soon, someone will get to see this sight in real life!  Fingers crossed!

Tuesday, April 16, 2013

N is for NASA



NASA was founded in 1958, the year after the Russians put Sputnik, the first artificial satellite, into orbit around the Earth.  The space race was on, and the hard work and dedication of those working for NASA took America into space.  That's something worth celebrating.




You can also find more information on the NASA's founding HERE.

Monday, April 15, 2013

M is for Milky Way vs. Andromeda



We live in the Milky Way galaxy, which is a spiral galaxy.  Our neighboring galaxy, Andromeda, is also a spiral.  Andromeda is also the only galaxy moving toward us while all other galaxies are moving away.  It's been predicted that billions of years from now, the Milky Way and Andromeda will merge to form a new galaxy altogether.  To see some spectacular predictions of how that will occur, watch the video below.

Saturday, April 13, 2013

L is for Lagrange Points



Lagrange points are great for astronomy.  These points in space give us a nice, stable spot to keep telescopes and things.  However, I don't feel like I can give a proper description of what Lagrange points are.  I'll let Phil Plait, also known as The Bad Astronomer, explain what they are and why they're important.

Friday, April 12, 2013

K is for Kepler's Laws of Planetary Motion



Kepler's Laws of Planetary Motion are a basic that any student of physics and astronomy must know. When Johannes Kepler derived them from the motions of the heavens, they revolutionized our understanding of the solar system.

First, here's a brief biography of Kepler.




Next, let's learn more about the laws themselves.  Who better than Carl Sagan to introduce the specifics of Kepler's Laws of Planetary Motion?

Thursday, April 11, 2013

J is for Jupiter



Growing up, I was fascinated by all the planets.  Most of all, though, I had a soft spot for Jupiter. Maybe witnessing the impact of comet Shoemaker-Levy 9 in July 1994 played a role in this fascination.  I was eight years old, and I'll never forget that excitement.

Wednesday, April 10, 2013

I is for Isaac Newton



Yes, I'm going by the first letter of his first name rather than by last name.  Either way, I say it's okay for me to do that, and I'm going to do it anyway.

Isaac Newton contributed greatly to scientific understanding.  Neil deGrasse Tyson credits him with being the greatest physicist of all time, so that's a good endorsement as far as I'm concerned.


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Here's a brief biography about Isaac Newton with the briefest of overviews of his work.

Tuesday, April 9, 2013

H is for Higgs Boson



With the recent discovery of the oft hypothesized but elusive Higgs Boson, I could hardly choose any other topic for H.

When it comes to particle physics, it can be difficult for the layman to make any sense of what these physicists are talking about.  I've met my share of people who think the science community is simply making these things up.  Still, just because a concept can be slippery to grasp, it doesn't mean that it isn't worth the effort.  And luckily, some scientists take the time to adequately explain these matters to the rest of us.



Science can certainly be ambitious, as I think it should be.  However, science also knows how to celebrate.  Next I would like to share two episodes of Star Talk Radio.  These are live episodes that are dedicated to the discovery of the Higgs Boson.  Scientists and comedians come together to make science fun and entertaining for a live audience.  I highly recommend taking the time to listen to these.  I did and it was time well spent.


Monday, April 8, 2013

G is for Galileo Galilei



Galileo Galilei deserves credit for pursuing scientific truth in the face of opposition.  It is this perseverance that makes possible our growing knowledge of the universe.  Here is a brief introduction to his life and works.

Saturday, April 6, 2013

F is for Feynman Diagrams



Physics is full of interesting diagrams.  I always thought Feynman diagrams look cool.  Here's a simple video that will help you learn what those wibbly looking diagrams mean.

Friday, April 5, 2013

E is for the Event Horizon and Beyond



No, I'm not talking about the film, but rather the event horizon of a black hole. A black hole is a singularity, and its gravitational field is so strong that not even light can escape.  The event horizon is the boundary.  At this point, escape velocity is equal to the speed of light, so once you reach that point, you're going along for the ride whether you like it or not.  Though no one can venture beyond this point and report back about what they see, scientific theory lets us speculate about what it would be like to fall into a black hole.

Warning!  Venturing beyond the event horizon of a black hole is for experienced virtual travelers.  Do not try this at home! :)

Thursday, April 4, 2013

D is for Drake Equation



The Drake Equation is well known to most who wonder about the possibility of intelligent life existing elsewhere in the universe.  Personally, I have no doubt intelligent life exists somewhere in the universe.  The only question is, how common is it? 

The Drake Equation is meant to estimate how many intelligent civilizations may exist in our galaxy that have the technological capability to communicate with us.

Background Image courtesy of tungphoto / FreeDigitalPhotos.net

This video gives a good background of the equation and looks at a couple of the estimates that have been made using the equation.

Wednesday, April 3, 2013

C is for Constellations



Throughout human history, we've looked up at the night sky in awe.  Before we had science to explain the things we saw, each culture made up it's own stories about the pictures it saw in the sky.  These stories say a lot about the groups that made them.  Though we know now that the constellations are not actual groupings of stars, but rather appear that way from our perspective, they are still a part of who we are.  We grow up looking at them.  For many, they are our first exposure to the wonders of the cosmos.



Sometimes I find myself wondering about a hypothetical alien race and what they see in the unique images they would see in their own night sky.

Tuesday, April 2, 2013

B is for Big Bang



First of all, I thought I'd share a little fun.  Here's a link to the full theme song from the show The Big Bang Theory.  I highly recommend you take the time to listen to the whole thing if you haven't heard it.

Most people know that the Big Bang is the most popular scientific theory regarding the beginnings of our universe.  Here's a brief summary of how we made it from the moments immediately following the Big Bang to today.  Science is learning more every day, so no summary will ever offer a full picture, but this is still a good overview.



Once you posit that the universe started with the Big Bang, the question naturally becomes "What caused the Big Bang?"  This next video looks at why we ask that question and how we try to answer it.



For anyone who wants to know even more and has a little more than an hour to dedicate to it, here's a link to a lecture given by Andrew Lange at UC Berkeley.  There's a lot more detail here and is, in my opinion, relatively accessible for those who don't have a much of a background in science.

Monday, April 1, 2013

A is for the Andromeda Galaxy

First of all, since the first letter of the alphabet is A, I'd like to give a shout out to Arlee Bird, the creator of the A-Z Challenge.  If it weren't for him, we wouldn't be here for this.  Thank you!



The Andromeda Galaxy, or M31, is our cosmic neighbor.  As such, it intrigues us with its beauty. We study it in our quest to deepen our understanding of the cosmos.  One day, it will collide with our own Milky Way Galaxy and create something new.  For me, this only adds to its allure.
Photo: Chris Lasley
Flickr
Here's a fun video tour of the stunning Andromeda Galaxy.