Saturday, August 15, 2015

Small notice on CNN

On July 22, 2015, CNN posted an article about the University of Queensland's free online course called Denial 101. The course is developed by John Cook, creator of the website Skeptical Science and to which I contribute illustrations and articles. Many of my illustrations were used in the course and a few of them appear in the video samples included with the CNN article here:

http://edition.cnn.com/2015/07/22/opinions/cook-techniques-climate-change-denial/index.html

The course required some new illustrations and animations from me, and I'll be adding these to the Skeptical Science climate graphics resources:

http://www.skepticalscience.com/graphics.php

A shortened link to my illustrations is here: sks.to/jg

From Denial 101, lecture 4.2.1.1:



jg

Wednesday, July 8, 2015

Life in the Zone, a presentation at the Temecula Library, July 14, 2015

On July 14, 2015, I will be presenting with my fellow Temecula Valley Astronomer Chuck Dyson at the Temecula Library. Our topic is Life in the Zone, a look at the search for life in our stellar neighborhood. The library kindly made this flyer for the event:


jg

Thursday, June 4, 2015

Antikythera Device, modelling its elliptical motion

The Antikythera Mechanism is a hunk of metal fragments found in the Mediterranean Sea over 100 years ago. Numerous scholars have demonstrated that it is the corroded remains of a calculator of celestial motions, built around 2000 years ago.

I've dabbled with a few illustrations of the object and its origin in my show The Astro Time Machine. Since creating this show, I've worked a little on my animation of how this device was thought to portray the motion of the moon's elliptical orbit.

The journal Nature published a description of the use of a pin and slot mechanism to create elliptical motion. I've created an animated version of the pin and slot mechanism on my website (Pin and Slot):


My model is simplified. I'm showing only the pinned and slotted gears, which is enough to show how this arrangement produces elliptical motion.  The actual device would have had a minimum of four gears for the same motion, similar to this exploded diagram:


And using four gears would have allowed the modeling of additional motions, such as the change in axis of the moon's orbit.

I don't claim to accurately show the arrangement of gears used in the Antikythera device. My animation is meant only to show how two wheels with a pin and slot produce the motion of an elliptical orbit. My animated model could easily be replicated with real wheels for a classroom project. Gears could be replaced with wheels connected by belts of elastic cord. With the correct tools, I think it would be easier to build a real elliptical motion mechanism than to program a model, at least for me.

jg

Saturday, May 30, 2015

Worst community safety lighting ever

A community near me endures the worst street lighting I've ever seen. It ranks worse among stiff competition by being the primary lighting for the community.

From an distance, the light fixtures are attractive.


And a close-up shows the ornamentation:

But at night, they turn into glare bombs. Their placement at every corner ensures that every direction a motorists looks includes glare to obstruct a safe view of the street.

Glare bombs, looking west


Glare bombs, looking east (before a car approached). 
Notice the strong shadows, now imagine the same 
shadows between parked cars.

While documenting these lights, a car intruded into my photo, making for a good comparison. Notice how the light and glare from the approaching car is comparable to the glare from the streetlights:

Car approaches from one block away

Car reaches the nearest intersection 
and appears as bright at the street light 
that is a block away.

I know of no one who sees better while in the beam of car headlights. (That's why we have low-beams). Yet, people don't question the same quality of light when mounted for "our safety and protection".

Watch out in these neighborhoods. You may not see the child or pet that foolishly enters the street or the rock or nail that can break your tire. 

jg

Tuesday, May 26, 2015

Rattling a Snake

When I climb through places that could harbor a rattlesnake, I make loud claps to improve the chance that a rattlesnake might hear me and start moving away, or start rattling. Yesterday I had the opportunity to test this method. I encountered a dozing rattlesnake, so I recorded before and after making a loud clap to wake it. The loud clap didn't disturb it in the slightest. I conclude that one shouldn't be confident that making noise will help avoid a rattlesnake encounter.



I will add that most of my snake encounters fall into two categories: One, like this one, where the snake makes no motion or sound, and two, where the snake quickly hides and rattles. These responses appear to have more to do with the mood of the snake than with anything proactive that I can do.

jg

Update: A closeup, as the video didn't capture the snake clearly:

Monday, May 25, 2015

Pluto System Animation (Pre-New Horizons)

I had trouble finding an interactive model of the Pluto system on the Web. There are either two many static illustrations that clutter up search results or not enough of the interactive kind, so I created my own, which is available on my website here:

Interactive Pluto system animation

I used the now archaic Flash to program to effect the animation. I respected the orbit distances and speed of revolution, but didn't attempt to scale the sizes of Pluto and it's moons.



Most important, I wanted a way to compare Pluto to our Earth-Moon system. Buttons will scale to the Earth-Moon system size and display our Moon. You can also tilt the orbits to get an aesthetically pleasing view.

Regrettably, the animation doesn't work on most mobile devices. I'll be working on version that does. The delay in producing the mobile device version will be advantageous in that I can build in any new discoveries made by the New Horizons space probe. Now, my animation may look like an old map of Europe before a world war. In one month, this may be the archaic pre-New Horizons map of the Pluto system.

jg

Update: A great visual summary by Nature: http://www.nature.com/news/pluto-fly-by-a-graphical-guide-to-the-historic-mission-1.17927

Friday, May 15, 2015

Coleman Is Synonymous with Glare Bomb

A few years ago when the company Hostess was in crisis, a problem acknowledged by the company was that their two most well known products, Twinkies and white bread, had become objects of derision. That is how I always felt about Coleman's contribution to the outdoors. Coleman brings to mind an obnoxiously bright light that takes away the enjoyment of camping and the night sky. The typical Coleman lantern is designed to throw light everywhere, compromising the night vision of it's owners, so they require more light, and creating glare for the neighbors. With a Coleman lantern, you can harass fellow campers hundreds of yards away in all directions. Most of my dark sky adventures are impaired by such lanterns because they lack appropriate shielding and are too bright for their task.

It never occurred to me the Coleman would want this association, such that when you think "Coleman" you think "glare bomb",  but recently, I noticed the branding on a Coleman easy-up.




The tarp seems to say, "Remember that obnoxious light? That is our brand".

I'd recommend a slogan to go with it, "Coleman: keeping the outdoors urban" or "Coleman: bring the glare with you".

The solution is so simple: create a lantern that directs light downward and sell a mounting pole accessory to hold the lamp at chest or eye level for adequate illumination of one's campground while preserving the ability for all to see.


jg