Curiosity Self Portraits

I'm sure many of you heard about the Mars Science Laboratory: Curiosity in the news back in August. The rover successfully survived the trip and descent to Mars, landing safely in the early morning hours on August 6th (EST). Much of the scientific community was fretting about Curiosity surviving the landing due to all of the creative engineering maneuvers that needed to go of without a hitch for the rover to survive. Thankfully everything went smoothly and we are now beginning to study the Martian surface! A young girl, who has seen many of the photos the rover has taken, asked me why it keeps taking self portraits. "Why not point the camera at the Martian surface?" she asked. "We already know what the rover looks like. It's almost like he's taking a picture of himself for Facebook!"  There is good reason for Curiosity to take pictures of itself, and that is to make sure that everything is functioning properly. We want to make sure that nothing broke during Curiosity's trip, and we also need to make sure that camera, levers, wheels, etc. are all working as they should. Once we trust that everything is working properly, we can start to move the rover and do experiments. So we expect to see many more close ups of Curiosity on Mars, just as a sort of "check-up". Below is an image of almost the entire rover sitting on the Martian surface. Everything looks good to me!

Image credit: NASA/JPL-Caltech

Is Today Affecting Yesterday?

I came across an article this morning, that’s more about quantum physics than astronomy, but it was so fascinating that I just had to share it with you all. Physicists may have discovered a way that the future can alter the past! Yup, you read that right, what you do today could affect what you did yesterday! How can this happen? Quantum physicists are studying the ideas of non-locality and causality. Non-locality is the idea that two particles can be entangled such that an action on one automatically affects the actions of another. Kind of like two train carts tied together, if I move one the other moves as well. Causality is the idea that tiny particles exist with unknown properties until someone makes a measurement of one of those properties, and these measurements can be strong (I know for sure this is true about the particle) or weak (I think this might be true).

For example, lets say you glance super quickly at an unknown street sign, then look away. You might notice that the sign had a reddish color to it (weak measurement). You look quickly again, and notice there is also some white (weak measurement). Repeat the process and eventually you might figure out that you are looking at a stop sign. Then you stare directly at it for a few seconds (strong measurement) and for sure decide that it is a stop sign. The idea of causality states that the street sign’s properties are unknown (what type of sign is it?) and the signs location is unknown (where is it?) until you look at it and decide it’s a certain one in a certain spot. So how can observing an object properties today affect it yesterday? Try this thought experiment below

A friend and I live in Upstate New York, and we live 50 miles apart. You don’t know where exactly we live, but only that our houses are 50 miles apart and that our bodies are always 50 miles apart no matter what (we are entangles that way). Now you decide you want to figure out where I currently am. You can’t do this by calling or asking me, you have to put tiny bits of information together to figure out where I am (weak measurements). Ok, so you know that I just posted this blog, and therefore, I must be somewhere where there is wifi. You just made one tiny measurement of where I am, without defining exactly where I am. There are tons of place with wifi, so I could be at any one of those places. Measurement number 2, again I’m writing this blog post , so I must be at a computer (for the sake of argument, lets assume it must be a desktop computer). So now, with two measurements, you’ve narrowed down where I am (somewhere with wifi and a desktop computer), but still don’t know exactly where I am. Let’s pretend you were able to make a whole bunch of other measurements and finally figure out that I am at the local library, 10 miles from my house. Now that you’ve made a solid measurement of where I am, you have fixed me in place, and thus fixed my friend in a place exactly 50 miles away from me. Since I am 10 miles from my house, my friend must also be 10 miles from her house (because we are always 50 miles apart). But how did she get there? Sometime in the past, she must have drove from her house, to a point 10 miles away from her house. But we didn’t know or decide that she was 10 miles from home until we figured out where I was located, just now. The act of deciding that I am 10 miles from my house right now, put my friend 10 miles from her house, and thus altered the past in such a way that caused her to drive 10 miles away from her house sometime in the past. So my action of being at the library today, had an affect on what my friend did in the past, or in other words, the future (today or tomorrows actions) had an affect on what happened yesterday!

So what does this all mean? Are your actions today changing the past? Well, physicists aren’t really sure. They think they see this occurring for special particles that are entangled together and have certain kinds of properties. It doesn’t necessarily work on a human scale. But if we understand what’s going on in the quantum world, we may someday be able to use it in the “real” world…

Here is a link to a nice article explaining this in more detail: http://physicsworld.com/cws/article/news/2012/aug/03/can-the-future-affect-the-past

Discovery of the Higgs Boson!

Back on July 4th of this year, physicists working at the Large Hadron Collider (LHC) at CERN announced that they may have a found the much sought after particle called the Higgs Boson. One of the main reasons scientists built the LHC was to look for and hopefully find evidence of the Higgs. But what exactly is the Higgs boson and why is it so important?

To put it simply, the Higgs boson and the accompanying Higgs field are the reason why objects have mass, or in other words, why we take up space. For example, an astronaut in outerspace weighs nothing, as no large body is gravitationally attracting him. But the astronaut still has mass, he still takes up space. But what entity gives him mass, since it's not gravity that is responsible.  The theoretical answer to this is the Higgs field. Physicists think that a Higgs field pervades all of empty space, and Higgs bosons fill this field. When a particle enters the Higgs field, the Higgs bosons crowd around it, making it difficult for the particle to move and thus it feels heavy or massive. Think of it like a celebrity walking into a party. Everyone at the party crowds around the celebrity, making it hard for them to move through the room and thus they feel more massive. The Higgs field interacts with different types of particles in different ways, and the reason for this is not very well understood. But, if we have evidence that the Higgs boson does exist, then we can study it and hopefully answer this and many other questions associated with its discovery!

For a great explanation of the Higgs boson, check out this Ph. D. Comics movie!

Image Credit: Ph.D. Comics

Asteroid Eros as Real Estate?

Eros

Since the only other astronomical body that humans have set foot on is the moon, few laws have been put into place governing who can own what in outer space. Believe it or not, people have tried to claim full ownership of astronomical objects. A man by the name of George W. Nemitz actually tried to claim the near-Earth asteroid Eros as his property! Here's the story: Nemitz worked for a company which helped construct the Near-Earth Asteroid Rendezvous Probe Shoemaker, which landed on Eros in 2000. Nemitz claimed that since he helped build the spacecraft, he could claim ownership of whatever body it landed on, under the Homestead Principle. This principle states that if you discover a new piece of land that is not owned by another person or government (and I'm sure law makers were implying a piece of land on Earth), and you make use of it in some way, you can claim ownership. Thus, Nemitz dubbed Eros as a "spacecraft parking facility" and mailed NASA a $20 parking ticket for landing their spacecraft on "his" asteroid! Can you believe that? To Nemitz's dismay, NASA refused to pay the parking ticket, and a court judge dismissed his case. 

Image Credit:NEAR PRoject, NLR, JHUAPL, Goddard SVS, NASA

How Big is the Universe?

To put it bluntly, the universe is absolutely huge! The study of Cosmology, or how the universe was created and how it has evolved, has revealed some very interesting facts. We now know that the universe is expanding at an increasing rate, and that the universe seems to be roughly uniform. The approximate size of the visible universe is 10^24 miles wide! That's 1,000,000,000,000,000,000,000,000 miles! The image below represents what we believe the universe looks like. Every white spec in the image represents a galaxy, and there are over 350 billion of them! But notice how uniform it looks; there doesn't appear to be any distinct clumps of matter, its all equally spread out. This is somewhat expected  via the current cosmological theories, but also curious. Why should the universe be uniform? What properties of the beginning of the universe lead to this result, and how precise must they have been produce a uniform universe? Cosmologists are working hard on answering these questions, as astronomers continue to probe the most distant parts of the universe!

 Image credit: atlasoftheuniverse.com

Galaxy Superclusters

We live in the Milky Way Galaxy, a beautiful spiral armed galaxy filled with hot gas and young stars.

Did you know that many galaxies, including the Milky Way, actually formed in clusters? Galaxy clusters are groups of 30 or more galaxies that are all gravitationally bound to each other. Galaxy clusters nearby one another can form a supercluster of galaxies, though they may not all be gravitationally bound, just spatially coincident with each other. The Milky Way is part of the Local Group, which contains roughly 40 galaxies. This group is a sub-portion of the Virgo supercluster, which contains over 2500 galaxies within 100 million light years of us! These clusters contain spiral galaxies, like the Milky Way, but also elliptical galaxies which are disk shaped collections of older stars. Some popular clusters you may have heard of are the Fornax cluster, which also lies inside the Virgo supercluster, and the Coma cluster, which is a separate cluster of over 1000 galaxies located over 300 million light years from us. The image above shows some of the superclusters of galaxies in the Universe, with the Virgo cluster at the center. Each white dot is an entire galaxy, so those white regions throughout the image are collections of hundreds of galaxies! 

Image Credit: R. Powell

What Does An Astrophysicist Do?

Apologies for the hiatus in posts these last few weeks, life and work have been very busy. Since I've been swamped with so much work, I thought I'd take the time in this post to describe what  an astronomer or astrophysicist does on a daily basis.

When you think of life as an astronomer, the first thing that comes to mind is telescopes and star parties. You imagine the scientists out late at night staring through their telescopes and taking notes about what they see. While this part of the job, astronomers have much more to do. Graduate students and professors in astronomy spend most of their time teaching, doing research and applying for grant money. They teach or assistant teach college courses, and are constantly writing proposals to different organizations asking for money to fund their research. But what does "doing research" actually mean? In astronomy, research can mean one of three things: taking images with a telescope  and analyzing them using a computer (observational astronomy), writing computer programs to simulate interactions between objects in outer space (theoretical astronomy), or building telescopes, cameras, and detectors for astronomers to use (instrumentation). The first two require you to sit at a computer most of the day and  write computer programs to perform certain tasks. Observational astronomers also spend a lot of time applying for observation time on both space and ground based telescopes. If their proposals are accepted, they receive images from the telescope that they can then analyze to understand the physics and properties of the objects they are looking at. Theoretical astronomers are more like physicists or mathematicians.  They think of a situation that might occur in outer space, write down all of the physics equations  that govern the system, and write computer programs to simulate what's going on. Then they can compare their results with real observations to see if they are correct! The last group of astronomers spend most of their time in labs, building and testing devices for other astronomers to use. This is a more hands on job, and takes just as much engineering skill as it does astronomy knowledge. If it weren't for these people building nice cameras and telescopes, astronomers would be out of a job!

Aside from doing actual science, astronomers spend a good amount of time writing papers about their findings, doing community outreach, and presenting their work at conferences and colleges around the world. Being an astronomer is a lot of work, but also a lot of fun. It's a fast paced and never ending job, and there is always more to learn about outer space!