Sorry everyone, but I’m going to have to put off writing a new post until next week. This week, I’m currently at the Pacific Coast Gravity Meeting in UC Davis. And, I also have to defend my undergraduate honors thesis in math this week. So, in short, I’m swamped, even more so than usual when travelling. Sorry about that. See you all next week!
March 2013
cosmology / Geometry / Mathematics / etc.
Receding Horizons: Dark Energy and the Expanding Universe
Astronomy compels the soul to look upwards and lead us from this world to another. ~Plato The history of astronomy is a history of receding horizons. ~Edwin Powell Hubble Last week, I discussed the possible shapes our universe could take. I offhandedly mentioned that not only is the universe expanding, but that that expansion is accelerating. We attribute this expansion to a mysterious phenomenon we call dark energy. This week, I want to explore the history of this idea and the beautiful experiments that tell us all is not as it seems. The Static Universe and Einstein’s Greatest Blunder
cosmology / Geometry / Mathematics / etc.
For There We Are Captured—The Geometry of Spacetime
All about me there are angles— strange angles that have no counterparts on the earth. I am desperately afraid. ~Frank Belknap Long, The Hounds of Tindalos Whoever…proves his point and demonstrates the prime truth geometrically should be believed by all the world, for there we are captured. ~Albrecht Durer I was recently asked: What does it mean when we say spacetime is “curved” or “flat?” The answer lies in the interface between differential geometry and physics. This is the latest in many articles I’ve written on Einstein’s relativity, so you might want to check out my series on faster-than-light
Condensed Matter / Physics / Quantum Mechanics / etc.
How Things Work: The Field Effect Transistor
I don’t know how to do this on a small scale in a practical way, but I do know that computing machines are very large; they fill rooms. Why can’t we make them very small, make them of little wires, little elements – and by little, I mean little. ~Richard Feynman (1959) As of 2012, the highest transistor count in a commercially available CPU is over 2.5 billion transistors. ~Wikipedia In my article on quantum tunneling, I mistakenly claimed that diodes and transistors made use of this phenomenon. In an effort to correct my mistake, I’m going to explain
Uncategorized
Delay Due to Grad School Open Houses
Hi everyone. Sorry for yet another delay. I’m currently visiting graduate schools on the east coast (U Mass Amherst and Stony Brook University). I expected to have consistent internet access the last few days, but I have had almost no internet access and very little time to access the internet anyway. As such, my post may be delayed as late as Wednesday. I will get it up online this week though. Because I’ve spent three weekends in a row visiting various schools or going to conferences, I’m quite behind on my work. This might mean that my posts will
cosmology / Physics / Science And Math
What Is Time? A Simple Explanation
Mastery is achieved when “telling time” becomes “telling time what to do.” ~“Telling Time” This week I’m trying something a little different. I heard about a contest where the goal was to explain time in terms an eleven-year-old could understand. While I didn’t make the contest deadline, I thought I’d share my attempt with you all. What Is Time? What is time? Scientists often think of time as a direction you can travel in. Just as we can move up, down, left, or right in space, we can move in time. Something is wrong with this comparison, though. When
Uncategorized
No Cat Returns
Hi everyone, because I’m at a graduate school open house this weekend and next, I’m having trouble keeping up with everything I need to do. For this reason, I’m going to be posting very short things for the rest of the month. I’m also going to be delayed this week. The main post will probably be up sometime Sunday. Sorry about that. In the meantime, here’s a video of a cat barking. …and here’s a video of a very upset cat. I know, little guy. I’m sorry about the delay.