9 April 2009
The flight computer onboard the Lunar Excursion Module, which landed on the Moon during the Apollo program, had a whopping 4 kilobytes of RAM and a 74 KB “hard drive.” In places, the craft’s outer skin was as thin as two sheets of aluminum foil.
This quote is from an article at Physorg.com titled Beyond Apollo: Moon Tech Takes a Giant Leap.
The above facts made me curious so I took a quick look at Wikipedia’s page on Apollo’s Guidance Computer (AGC).
This is a photograph of the AGC user interface:
By today’s standards that computer was tiny.
The AGC was used in the Lunar Excursion Module (LEM) – later called the Lunar Module (LM). The LM was the bit that landed on the Moon. Here is a photograph of the LM:
The Apollo program is on my mind because this July it will be 40 years since the Apollo 11 mission. Michael Collins, Buzz Aldrin and Niel Armstrong took that small step – the beginnings of humanity’s journey out of the cradle. You may have guessed that I think this event is significant in the history of humanity. It will still be remembered in thousands of years as one of the major milestones in our development.
Incidentally; the guidance computer was one of the driving forces behind early research into integrated circuits – necessary for development of that computer you are using to read this.
7 November 2008
A colleague sent me this video today.
I am impressed (English understatement there).
6 November 2008
Galloping Gertie (properly known as the Tocama Narrows Bridge) opened on 1st June 1940. It collapsed into Puget Sound on 6th November 1940. The collapse was caused by aeroelastic flutter. To see what that means in practice take a gander at this video:
Since the failure took some time no people were injured. Here is the account of Leonard Coatsworth the owner of the car that went down with the bridge.
Just as I drove past the towers, the bridge began to sway violently from side to side. Before I realized it, the tilt became so violent that I lost control of the car…I jammed on the brakes and got out, only to be thrown onto my face against the curb…Around me I could hear concrete cracking…The car itself began to slide from side to side of the roadway.
On hands and knees most of the time, I crawled 500 yards [450 m] or more to the towers…My breath was coming in gasps; my knees were raw and bleeding, my hands bruised and swollen from gripping the concrete curb…Toward the last, I risked rising to my feet and running a few yards at a time…Safely back at the toll plaza, I saw the bridge in its final collapse and saw my car plunge into the Narrows.
Coatsworth’s cocker spaniel Tubby was lost with the car.
10 July 2008
Thanks to Clark Boyd at The World for cheering me up with this one.
Update: The end credits say the song text is an adaptation of the poem Stream of Life by Rabindranath Tagore.
Stream of Life
The same stream of life that runs through my veins night and day
runs through the world and dances in rhythmic measures.
It is the same life that shoots in joy through the dust of the earth
in numberless blades of grass
and breaks into tumultuous waves of leaves and flowers.
It is the same life that is rocked in the ocean-cradle of birth
and of death, in ebb and in flow.
I feel my limbs are made glorious by the touch of this world of life.
And my pride is from the life-throb of ages dancing in my blood this moment.
Update 2: You can see a higher resolution version of this video at Astronomy Picture of the Day.
11 January 2008
The Bad Astronomer (my favorite blogger) who is attending the American Astronomical Society (AAS) meeting in Austen, Texas has an interview with Chris Lintott at Galaxy Zoo about their project to classify galaxies. People who are participating are asked to classify galaxies. First whether they are elliptical or spiral galaxies and if they they are spiral whether the spiral arms rotate clockwise or anti-clockwise. Strangely people are finding more galaxies that are anti-clockwise than clockwise. This makes no sense at all. We should find approximately the same number of each type. By using a neat trick the project discovered that it is not the Universe that is weird, it is us.
15 October 2007
It must be forty years since I last saw this:
My age is showing. Don’t you just love YouTube.
15 September 2007
Yesterday’s Astronomy Picture of the Day was a detailed image of Saturn‘s Moon Iapetus named after the Titan Iapetus from Greek mythology.
I cannot wrap my brain around that image. The craters all look like they bulge out to me. This is because the sunlight originates from below the scene but my brain insists that sunlight always originates from above a scene. Below is the same image rotated 180 degrees.
The image was taken by the space probe Cassini – part of the Cassini-Huygens spacecraft launched on 15th October 1997. The Cassini part of the name was in honour of astronomer Giovanni Domenico Cassini who was the first to observe four of Saturn’s moons. He also discovered the Cassini division which is the main gap in the ring system. The Huygens part of the name is in honour of astronomer Christiaan Huygens who studied Saturn’s rings. In 1656 Huygens discovered they consisted of rocks.