So I missed my promised deadline for my late post this week. I’m sorry about that, everyone. I spilled water on my computer last night and was thus unable to type anything. The computer came out fine, fortunately. I immediately turned it off, unplugged it, and took out the battery. Then I wiped everywhere I could reach dry and turned it over and let a fan blow warm air on the keyboard overnight. Runs fine now. If I’d waited to turn the computer off, though, something might have shorted. Unfortunately, I’m now really busy with the week’s classwork. I
jonah
Jonah is the author of The Physics Mill.
Uncategorized
Perimeter Institute
So I just got back from visiting the Perimeter Institute as a prospective graduate student in Waterloo, Canada. It was really fantastic! For those of you who don’t know, the Perimeter Institute is a theoretical physics think tank in Waterloo, Ontario. They do a lot of science outreach, too; they’re responsible for the amazing Minute Physics youtube videos (check the links). Anyway, the reason I bring it up is that I just got back after a day of airtravel and thus my post will be delayed until tomorrow evening. Sorry about that, everyone!
Physics / Relativity / Science And Math
Rock Me, Einstein — Some Questions on Special and General Relativity
In 1905 Albert discovered Relativity, in 1906 he invented Rock and Roll ~Yahoo Serious In the last week or two, I’ve gotten several excellent questions on special and general relativity. I’d like to devote this week’s post to presenting and answering those questions. For the sake of anonymity, I will call the people who asked the questions Ms. C and Mr. A. I hope you enjoy! A Question on Special Relativity The first question is by Ms. C, who asked: I’ve read your article “The Speed of Light is Constant.” I’ve… got a question on the speed of light
Uncategorized
slight delay
Sorry for yet another delay, everyone. I’ll get the post up either tomorrow afternoon or late tonight.
Uncategorized
Christmas is Cancelled
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!
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