Here it is: a lifeline to get you through this Pop Physics drought. Professor Brian Cox, host of the excellent BBC series Wonders of the Universe, delivering a fun and insightful introductory Quantum Physics lecture. Complete with celebrities like Simon Pegg, a million-pound diamond, and a breathless northern English accent.
Somewhat coincidentally, I just came across this video of a supposed perpetual motion machine / free energy device via reddit. It’s a coincidence because my last post was all about perpetual motion and why it’s impossible. It may seem like a bit of an archaic problem to tackle, but as the popularity of this video shows, these things still pop up from time to time in real life. This one uses magnets, as most self-respecting perpetual motion con artists do these days.
My favourite part is in the video description: “This technology has been suppressed because it is a threat to the profits of the energy corporations.” Not sure how those tricky energy corporations haven’t managed to get this video taken off YouTube yet, but I suppose it’s only a matter of time.
So why doesn’t it work? (more…)
Scientists have known for some time that the Earth’s magnetic field has undergone significant changes throughout the planet’s history. In fact, about once every few hundred thousand years, it completely reverses – what was once magnetic north is now magnetic south.1
There is a lot of evidence for this, the most convincing of which is the fact that if you dig down a bit, you find magnetized rocks all pointing in the same direction as each other – but that direction changes as you dig deeper, and those changes are consistent in rocks all over the planet.
Scientists are still trying to understand these phenomena, and they need more data showing exactly what the magnetic field has been up to.
Enter Dr. Gillian Turner, a physicist at Victoria University in Wellington. Edible Geography writes that Turner, along with an archaeologist, have made their own versions of old Maori ovens, like the one pictured above. They showed that these ovens could have heated rocks to high enough temperatures that they could have shifted their magnetic orientation to match the Earth’s field.
Read more at Edible Geography.
- The planet’s magnetic poles are a small distance away from the geographic poles, which are defined based on the Earth’s rotation. ↩
Ok, I really should be getting on with the chapter on Energy, but I just had to post this.
Voyager 1, a space probe the size of a small car, will soon become the first human-made object to leave our solar system. Launched in 1977, it is still – amazingly – sending back new data about the mysteries of outer space 10 billion kilometers away, more than 35 years later.
Voyagers 1 and 2 flew past Jupiter and Saturn, taking photos on the way. (Voyager 2 also went by Neptune and Uranus, but its path slowed it down a bit, meaning Voyager 1 is now farther from us.) Then they headed out towards interstellar space with the hope of being found, someday, by intelligent beings. Both probes were equipped with a golden record, which contained music, sounds, and images, as well as instructions on how to properly play the disks. (For more on the audio side of this project, you should definitely listen to this wonderful episode of Radiolab.)
The reason for today’s post is this gallery of images from the records, which I always find mesmerizing.
I wanted to take a quick break from discussing the mysteries of energy to share a mesmerizing video. This NASA-created computer simulation illustrates how moving clouds of dust created in the Big Bang could accrete into the spinning collection of billions of stars that we call a galaxy.
“This cosmological simulation follows the development of a single disk galaxy over about 13.5 billion years, from shortly after the Big Bang to the present time. Colors indicate old stars (red), young stars (white and bright blue) and the distribution of gas density (pale blue); the view is 300,000 light-years across.”
This week, as undergrads and high schoolers everywhere are plunging into the world of Introductory Physics, I wanted to share another great resource for learning this material. It’s a course on Udacity called Landmarks in Physics. Udacity features a free, easy-to-use interface for self-guided courses taught through a combination of YouTube videos, interactive quizzes, and forums.
According to the creator and teacher of this particular course:
The class is introductory. It covers trig, kinematics, Newton’s laws, work/energy/power, simple harmonic motion, a bit of electricity, and the last unit is a very brief intro to special relativity.
The material is covered in a fairly novel way… Each unit tackles some big problem from the history of physics: for example in the first unit we learn trig as we figure out how to calculate the circumference of the earth using only shadows and some geography knowledge.
So if you’re looking for a slightly more mathy approach than Pop Physics has to offer, I recommend giving this one a try.
(Edit: I’ve replaced the original video with a much better one. The original can still be viewed here, but I don’t know why you want to.)
Today being Wednesday, we would normally have carried on with the next chapter of our little textbook. But it’s still summer, and humanity’s got this new car-sized robot on Mars, so I thought I’d share another video. It’s
small and grainy awesome. (Try watching it in fullscreen mode.
For more context on what’s actually happening here (hint: the big thing that flies off at the beginning is a heat shield), you can check out Seven Minutes of Terror (about Curiosity’s insane landing sequence). Or you can watch this video, which combines animation and actual audio.