Archive of Writings

I just want to drop you, my gentle readers, a message to say that yes, I do read all your comments. Sometimes (like this week), I get frustrated that I don’t have the time to respond to all of you. I want to write in response to all your emails, but doing everything is sometimes an impossible balancing act.

If you don’t read PhD Comics, at least check out their latest comic. For me it is currently a careful balance of writing this blog, Astronomy Cast, writing grants, doing research, answering email/comments, being married, and trying to keep up with our 110 year old house. Wheeeeee
Most days I love my life, but all days I feel like I’m behind in everything I want to do. There simply aren’t enough hours in the day. Sometimes, what I end up actually being behind in doing is writing answers to comments from you.
But I always read all your comments…

Astronomers on Earth are limited in how they can look at the universe. We basically have three tools. We can detect light across a broad spectrum of colors. We can capture high energy particles – cosmic rays – that are flung at us from distant events. We can also potentially measure gravity waves (but we’re still sorting out that technology). In all three instances, we are limited by our technology’s sensitivity to an event. This means that faint, small, low energy stuff at any significant distance is invisible as far as our detectors are concerned. And stuff like dark matter… well… it can’t be directly detected at all. When direct detection of something is impossible, it becomes necessary to find indirect methods. We are like Plato, looking to understand reality but only able to see shadows dancing on a cave wall.

Two of the most well defined ways we have of studying the universe’s shadows are the Cosmic Microwave Background (CMB) and gravitational lenses. Both things are scientifically interesting in their own right, and each can be used to indirectly see otherwise invisible content in the universe. Recent papers have shown how the CMB may allow astronomers to study our own solar system’s Oort Cloud (the source of long period comets), and how gravitational lensing effects can be used to map dark matter. Rather than try and discuss both these topics in one post, I’m going to take on gravitational lenses today, and dig into the cosmic microwave background tomorrow. (image credit: Kneib & Ellis w/ Caltech Digital Media Center)

I just finished taking a tour through the latest papers posted on the astronomy preprint server. In general, few things do more to attract a my attention than a good title. One title in particular stopped my casual scrolling dead on its pixels: Redshifted formaldehyde from the gravitational lens B0218+357. Now, I knew beforehand that formaldehyde – the chemical people who store dead things used to use to preserve their specimens – existed in clouds of interstellar material. Other than knowing it is out there, I have to admit that I really don’t know why anyone cares that it exists beyond the “Oh neat” factor. So… I stopped to read the paper. (Image: CASTLES Survey)

Just last week, it seems, Venus was in Gemini and Saturn stood half a sky away in Leo. Seeing Venus and Saturn side-by-side in Leo the past couple days makes me wonder where the days have gone.

When you really watch the sky, it is truly amazing how fast things can move.

One of the concepts that confuses people most about the Universe is the Earth’s location relative to the Big Bang. People constantly ask, “Where is the center of the Universe?” and “Where was the Big Bang relative to us today?” and perhaps the most articulate of all, “Why does the Cosmic Microwave Background appear in all directions if it came from the Big Bang?” We are creatures accustomed to life in a three dimensional universe, and it is extraordinarily difficult to visualize our place in space. It is even harder to visualize that every place in space was once at the center of the Big Bang. (image credit: NASA/WMAP Science Team)