On August 21, 2017, the moon will cast its shadow across most of North America, with a narrow path of totality tracing from Oregon to South Carolina. Tens of millions of people will have a chance to see something that the continental US hasn’t seen in ages — a total eclipse of the sun. Will you be ready?
The last time a total solar eclipse visited a significantly populated section of the US was in March of 1970. I remember it well as a four-year-old standing on the sidewalk in front of my house, all worked up about space already in those heady days of the Apollo program, gazing through smoked glass as the moon blotted out the sun for a few minutes. Just watching it was exhilarating, and being able to see it again and capitalize on a lifetime of geekiness to heighten the experience, and to be able to share it with my wife and kids, is exciting beyond words. But I’ve only got eight months to lay my plans! Continue reading “Get Ready for the Great Eclipse of 2017”
If you are British, you probably already know where this is going. For the rest of you, it might help to know that The Infinite Monkey Cage is an odd little show on BBC Radio 4 (and they’ve been on tour, too). It is the show that asks a question you probably never asked: “What would happen if a physicist and a comedian had a radio show?”
The answer, it turns out, is some science information that is anything but dry. If you are prone to listening to radio programs or podcasts, you might find some interesting tidbits in the Cage. A two-part episode on general relativity was especially interesting although it isn’t exactly like their regular program.
Continue reading “The Infinite Monkey Cage and General Relativity”
Our story begins a little over one hundred years ago in Bern, Switzerland, where a young man employed as a patent clerk went off to work. He took the electric trolley in each day, and each day he would pass an unassuming clock tower. But today was different, it was special. For today he would pose to himself a question – a question whose answer would set forth a fascinating dilemma.
The hands of the clock appeared to move the same no matter if his trolley was stopped or was speeding away from the clock tower. He knew that the electromagnetic radiation which enabled him to see the clock traveled at a finite speed. He also knew that the speed of the light was incredibly great compared to the speed of his trolley. So great that there would not be any noticeable difference in how he saw the hands of the clock move, despite him being at rest or in motion. But what if his trolley was moving at the speed of the reflected light coming from the clock? How would the hands of the clock appear to move? Indeed, they could not. Or if they did, it would not appear so to him. It would appear as if all movement of the clock’s hands had stopped – frozen in an instant of time. But yet if he looked at the hands of the watch in his pocket, they would appear to move normally. How does one explain the difference between the time of the clock tower versus the time of his watch? And which one was correct?
There was no way for him to know that it would take three years to answer this question. No way for him to know that the answer would eventually lead to the discovery of matter and energy being one and the same. No way to know that he, this underemployed patent clerk making a simple observation, would soon unearth the answer to one of the greatest mysteries that had stumped every mind that came before his – the very nature of time itself.
Now it might have taken Einstein a few years to develop the answer we now know as the Special Theory of Relativity, but it most certainly took him no longer than a few days to realize that Isaac Newton…
must be wrong.
Continue reading “The Spooky Nature of Electromagnetic Radiation”
8 years ago, for the 100th anniversary of the theory of relativity [Tom] decided to test the general theory of relativity.
As he was going to Mt Rainier (5400ft high) with his children for the weekend, he brought in his van 3 cesium clocks while leaving other atomic clocks at his home for comparison. The theory behind the test is that if you’re are at higher altitudes, then your speed (in a galactic coordinate system) is higher than the one you’d have at sea level and therefore time would go “slower” than at lower altitudes.
[Tom] brought 400 pounds of batteries, 200 pounds of clocks and left his car turned on during his 2 days stay in the ‘Paradise Lodge’. He used 120V DC to AC converters and chose to bring 3 cesium clocks to have a triple redundant setup. When he came back home, he had the good surprise of finding a time difference of 23ns. This is a great application for those rubidium sources you’ve been scavenging.
[Thanks Indyaner via Reddit]