Hubble and Doppler Shift

30 01 2013

Edwin Hubble, after whom the Hubble Space Telescope is named, was an astronomer in the early twentieth century. At that time, modern cosmology was still in its infancy and there were many assumptions and false conclusions about the universe.

Probably the most noteworthy assumption of that time was the presence of “island universes.” For years, astronomers had observed strange, rounded clouds in the distant sky. They had assumed that these were other universes, isolated by nothingness. Today, we now know that these are galaxies, collections of billions or even trillions of individual stars, gravitationally bound to each other.

Another assumption was that the universe was static. This is called the “steady-state” model. In this model, all stars and other large objects were fixed in place and the energy and mass densities of the Universe could not change. In this case the energy density is the amount of energy contained within a certain amount of a space, a cubic meter, for example. The same goes for mass density. The Universe’s size was fixed and all matter and energy had to be conserved. Therefore, the density of the Universe remained constant.

Doppler shift

Another basic subject that should be covered here is that of Doppler shift. Doppler shift is a phenomenon that can be observed in every day life. A common example is that of an ambulance driving by with its siren on. As it approaches the listener, the siren’s pitch sounds slightly higher than normal. As it leaves the listener, the siren’s pitch sounds lower. This is because the sound waves are being accelerated by the motion of the ambulance. This causes the crests of the sound waves to become compressed as the approach the listener and expand as the wave source moves away.

In astronomy, the is typically known as “redshift” for receding wave sources and “blueshift” for approaching wave sources. This phenomenon became critical to Hubble’s research in 1929.

Discovery of galaxies

Hubble’s first discovery in 1919 radically altered our understanding of the universe. By identifying several characteristic of certain nebulae, including Andromeda (M31), he realized that these were not the island universes that everyone had assumed them to be. They were, in fact, other galaxies like our own and were much more distant than previously thought. Naturally, there were those in the scientific community who resisted the notion at first, but they were eventually compelled by the evidence.

Redshift of the galaxies

This discovery paved the way for another, equally important, realization that came ten years later. Hubble observed that nearly all the other galaxies were receding from our own. Working from the assumption that the galaxies most similar to ours should have similar types of stars in similar proportions, Hubble observed that most of these galaxies were redshifted, indicating that they were moving away from us with extreme velocity.

Expansion of the Universe

Furthermore, the farther the galaxies were, the greater the redshift. This means that the farther a galaxy is from us, the greater its speed away from us is. This can be represented by the following equation, called Hubble’s Law.

v = H0D

v is the speed with which a galaxy is moving away from us.
D is our distance from that galaxy.
H00 is the Hubble constant, which describes the relationship between the two variables.

The Hubble constant has been changed and updated as new cosmological observations and measurements have been made over the past 90 years. As of research performed with the Chandra X-Ray Observatory in 2006, one current estimate places the current Hubble constant at 77 kilometers per second per megaparsec (77 [km•s-1]•Mpsc-1). That is, that, in one dimension, 77 kilometers of space is being added to each linear megaparsec of space every second. This gives us a rate of expansion of the universe.

Space is expanding at every point in the universe but the expansion is only observable at distances where it can overcome the four basic forces, including gravity.

Hubble sphere

Since Hubble’s law states that recessional velocity will increase with relative distance, this would mean that, eventually, the recessional velocity would equal the speed of light. We could then rearrange the law to find what distance is required for this to happen.

If v = c = H0D,
then D = c/H0.

In this case D could be represented by RHS, the radius of the Hubble sphere, or Hubble volume. The Hubble sphere is a spherical region around an observer that defines the boundary of the observable universe. At this point, the light from distant galaxies becomes so redshifted that we can no longer observe it because they are receding at a rate of speed faster than the light they emit.

We have no way of observing anything beyond the Hubble sphere because the distances are so vast that light is not fast enough to overcome the expansion of the Universe to reach us. There is likely more universe beyond this sphere, but we simply cannot see it.

When we run the numbers, we find RHS to be approximately 13.9 billion lightyears. Since the universe is roughly 13.7 billion years old, any light we see at the edge of the Hubble sphere has been traveling toward us almost as long as the Universe has allowed light to travel.

The difference between the age of the Universe and the size of the Hubble radius can be explained by taking into account the acceleration of the Universe’s expansion. The Hubble constant is actually variable and is increasing slowly.

All of this forms the backbone of modern cosmology. Without Hubble or the work he and his collaborators did, it is likely that cosmology would not be where it is today.


Why I now support the Green Party

8 11 2012

On Election Day of 2012, I did not repeat the vote that I cast for Barack Obama in 2008. Instead, I cast my vote for Jill Stein, the Green Party’s candidate. Dr. Stein was a write-in in the state of Indiana and was not likely to take more that 1% of the national popular vote. So, why? Why did I cast my vote for someone who I knew would lose?

Election Day

Green Party logo

Green Party

I initially decided to vote for Obama, but as the campaign season wore on, it became more and more important that Mitt Romney would capture Indiana’s 11 electoral votes and that voting for Obama would only be a token gesture. This freed me up to vote for who I really wanted, not vote for who I thought would do less damage.

After investigating the candidate from the Justice, Constitution, Libertarian, and Green Parties, I finally decided on the Green Party candidates, Dr. Jill Stein and Cheri Honkala. Their campaign was based around a Green New Deal, a set of commitments and goals that would improve access to and quality of education, higher investments in newer technologies, the fight against climate change, and ending unemployment.

Abandoning the Democrats

Since my first election in 2006, I have typically voted Democrat. I was aware of the third parties from high school but did not pay much attention. After witnessing the gridlock that just got worse and worse after the Democrats took Congress in 2006, I became wearier and wearier of the partisanship and bickering. I also grew tired of what I saw as a false choice: Republican or Democrat. That was when I started looking at third parties.

I voted for Obama in 2008, both in the Primary and General Elections, because I thought he was a new type of politician, one who could unite the factions and get things done. Unfortunately, many of the idea presented and argued by both Republicans and Democrats are typically tired and unimaginative. To make things worse, many of those ideas get attached to partisan debates, watered down, and twisted until they are mostly useless.

With the obstructionism of Congressional Republicans and their subsequent taking of the House of Representatives, I realized that the system that we have had so far has served us well for a long time, but no longer. We need alternative candidates.

Future elections

I will likely vote for Democrats in the future. They tend to be the more left-leaning politicians, even if they are mostly in the center now. Most races don’t have more than two options. Occasionally, a Libertarian will sneak in. I am not a huge fan of the Democrats but I normally like them better than their Republican rivals.

Jill Stein was a registered write-in candidate in Indiana. In fact, she was on the ballot in 39 states and a registered write-in candidate in an additional seven states, Indiana included. I can definitely say that writing in a candidate is not a straightforward process, especially with electronic voting systems. We need more third-party candidates on more ballots and not as write-ins.

We also need to include these candidates in the major Presidential debates, from which they are typically excluded. This year, Jill Stein and Cheri Honkala were arrested trying to enter the Hofstra debate. A candidate could be on the ballot in 80% of the country but be excluded from a major televised debate. This keeps the general population that these people exist and it perpetuates the erroneous notion that there are only two options for President.

I plan on connecting with the Green Party and trying to get their candidates on more ballots in any way I can. I am also planning on contacting the major news outlets and other organizations responsible for the Presidential debates and urging them to include more candidates. I urge you to do the same. The situation is not likely to change unless we work to change the system.

Health vs Growth

10 07 2012

When discussing the environment, I often get into the same argument. I advocate for strengthening environmental protections at the state at federal levels and the other person often opposes those measure, concerned that more regulation would harm economic recovery and growth. I think that the “economy versus environment” argument is a false choice, for two reasons.

First, investing in newer, cleaner technologies will create new jobs, particularly ones in engineering, math, science, and manufacturing, all types of jobs that America desperately needs. Take wind turbines, for example. We need people to design and test them. We will then need trained people to build, transport, assemble, and maintain them. These are all positions that could be occupied by trained, educated American workers.

Second, if we have a planet with unbreathable air and undrinkable water because we polluted the fuck out of it, that 1% increase in last quarter’s profits does not really seem to count for much of it. Saying, “I am okay with relaxing caps on CO2 emissions to help the economy,” is akin to saying, “I will poison myself and everyone else on this planet for money.”

Ultimately, we have to make the decision about how badly we are willing to poison our air, water, and land in order to get some kind of an economic payoff. I would like to think that a properly-informed population would decide to give the environment’s stability more thought that the economy. There are jobs and there is no money in a poisoned world.

Hard to have hope

9 07 2012

I was recently asked what my hopes were for the future. Honestly, I had to think about it for a few minutes because it was a question that I do not ask myself very often.

If I were to have any hope, it would be hope that enough of humanity can come together to create and conserve an environment where future generations can grow and live in good health. I would hope that we use our knowledge and intelligence to avert disasters and minimize one another’s misery.

Unfortunately, that would involve other people, many others, most of whom are strangers to me and my worldview. Pinning one’s hopes on another’s actions or change of heart is ludicrous. The best I can do is do what I can from my end but not necessarily expect recognition or cooperation from others.

Perhaps the fact of the matter is that we are sad, tragic animals. We have our collective future in our hands but do not realize it. Maybe those of us who do genuinely realize the nature of our environmental and political situation are doing the best we can and it just will not be enough. There is no rule written that says the human race has to survive.

Any hope that we can make the world a better place is a hope that other people will practically do an about-face and make radical, difficult changes in their lives. There is hope and then there is false hope.

If had to hope for something, it would be that this blog post has been an illuminating and uplifting experience for you.

Why GMOs aren’t all bad

18 06 2012

Recently, I have been reading Michael Specter’s book, Denialism. In it, he explores the topic of science denial in first-world countries. He dedicates a chapter to the subject of genetically-modified foods (GMOs.) Reading this book and seeing friends’ anti-GMO posts on Facebook made me really start to think about the application of science and how it should be regarded.

Casava roots

Casava (Source: Wikipedia)

There has been talk that corn and other foods are now toxic because of genetic modifications. These claims have been made and disputed. Unfortunately, the result of all this talk and the lack of noise from the scientific community on this topic has caused people to become fearful of all genetic modification.

I am dubious of the motivations of companies like Monsanto. These are massive biotech companies and they work to make a profit. Profit motive should always elicit some skepticism. I do not doubt that they have professionals who want to wield the awesome power of genetics wisely. Unfortunately, some things are created by these companies that should not have been introduced to world.

When I listen to this conversation, it seems like some have forgotten that many of the foods we would not normally think of as GMOs have been bred by humans for thousands of years.

All of the food we eat, every grain of rice and ear of corn, has been manipulated by man; there is no such thing as food that hasn’t been genetically modified.

Denialism, page 3

GMOs are as old as agriculture. Now, the tools are much more precise and only enhance our ability to engineer food to bring out the desired traits. This could mean an incredible opportunity to reduce famine and malnutrition worldwide.

There is a root vegetable from South America called cassava. It is used to make tapioca. It is very starchy and rich in carbohydrates, but not much else. Cassava grows well in dry, arid environments. It has been imported to Sub-Saharan Africa where it is now a staple. Unfortunately, it cannot meet a person’s dietary needs and it has resulted in malnutrition while keeping people from starving.

It is within our capabilities to make a protein-rich version of this vegetable. It may not be able to completely meet a person’s nutritional needs, but it would be better than what they have now.

I think the point I am trying to make here is that all technology is a double-edged sword and it is not fair to completely reject a technology because of a few abuses or mistakes. I willingly admit that there are many things I do not know about. If you think I am wrong, please say something in the comments. This blog does not get many views, but maybe we could start some kind of a conversation here.

Shame and anticompetitive hijinks

24 05 2012

This week, Apple pulled one of Rogue Amoeba’s iOS apps, from the App Store. Reportedly, little explanation was given. I think I might know what’s going on here.

Apple has a history of taking ideas from existing iOS apps, building them into newer versions of iOS, and then making the app essentially useless. It is kind of a dick move when you think about it for half a second. I know people like to associate that “good artists copy, great artists steal,” phrase with Steve Jobs in particular and Apple in general. Unfortunately, when hardworking independent developers get screwed over, everyone loses, even Apple.

Of course, the developer is going to take the brunt of the blow in the form of lost sales. Users who are not aware of the app from whence some iOS feature came will not know that there may be some better alternative, still on the App Store. This might keep the user experience from being as good as it might. In the end, Apple is hurting itself a little by potentially alienating developers. I know, personally, that if I worked my ass off on an app that I was proud of and Apple came along and ripped me off, I would reconsider developing for Apple’s platforms in the future.

Maybe I am completely wrong about all of this and I am just overreacting. I really hope I am. Hopefully, Rogue Amoeba’s app goes back up on the store and they go back to making money from it. Thanks for indulging this rant.

My issues with the Weather Channel

24 05 2012

The Weather Channel is just terrible. In the past, it served a useful purpose. I remember watching it as a kid in the 90s. (I was a weird kid.) It was fairly straightforward with its purpose and implementation. It was a 24/7 cable channel where people could go get weather information for their own area as well as the rest of the country. It had incredible utility and was very good at what it did.

Unfortunately, as television executives are prone to doing, they took a perfectly good thing and fucked it up, royally. They must have had some top-level executive meeting ten years ago where they talked about all the things they could do to remove all but the most subtle signs of utility from the Weather Channel.

First, they added programming. They started putting on shows like “Storm Stories,” where rednecks are interviewed about their impressions of the inside of a fucking hurricane. It is a show that showcases the stories of people either unlucky enough to be in the path of a tornado or stupid enough to sit through a Category 4 hurricane.

Second, they added advertising. Granted, ads were on the Weather Channel for a long, long time. Unfortunately, there are way too many and they get more screen time than the weather itself.

Third, they have a morning show. It has Al Roker, no less. The Weather Channel has a morning show. You might be thinking, “Oh, great! I will get some national news while I get my weather!” Nope. “Wake Up With Al” has as tenuous a grasp on news reporting as Roker’s last show, the horrendous “Today” show on NBC.

There is, however, still weather on the Weather Channel. “Local on the 8s” is the last remaining fragment of TWC’s focused and purposeful lineup. Local on the 8s gives a minute or so of actual weather information every ten minutes.

What really pisses me off about weather reporting in general is the lack of climate change coverage. On TWC and local news channels, they go on and on about how we are having record temperatures, record precipitation, and record drought but do not ever once suggest why these things are happening. I know, it’s the Weather Channel, not the Climate Channel. Still, these two are inextricably linked with one another and with virtually every other area of our lives, yet climate change gets virtually no coverage on a network that is dedicated to reporting the weather. I would not expect much, maybe something like, “Hey, you know it’s 120ºF in shade because…” It should not be a big deal.

In a television world where shows and news coverage is mediocre at best, one would think that we could get something as basic as weather reporting right. Unfortunately, due to focus groups and TV executives trying to appeal to a “broader audience,” we are left with another shitty, half-assed news channel like CNN, Fox, or MSNBC. Of course there alternatives to finding weather information, such as local news stations, NOAA, and the old standby, looking out the god damned window.