Moon
I'm spending the day trying to get some work done on the book-in-progress, so I'm avoiding both work- and blog-related stuff. I don't want to leave the site completely quiet, though, so here's a question to ponder, relating to SteelyKid's continuing fascination with Goodnight Moon:
How does a cow jump over the moon?
The father of one of SteelyKid's classmates, who is not originally from the US, asked why there's a cow jumping over the moon in that (or, as SteelyKid puts it: "Cow jumping MOON!!"), and I don't have a good answer. I'm aware of the nursery rhyme and the Tolkien joke, but why…
Grades are in. So, let me just say a couple of trends that I saw on the physical science final exam.
Gravity on the moon
I asked the question: "why is the gravitational force on an astronaut less on the moon than on Earth?"
The simplest answer is that the gravitational field on the moon is smaller than on Earth (I would accept that answer). Why is this? It is because the moon as a much smaller mass even though it also has a smaller radius (that idea is rather complicated for this class - that gravitational force depends on both mass and radius). I would also take "the mass is smaller" as…
What's the application? Measuring the distance from the Earth to the Moon by bouncing a laser off one of the retro-reflector arrays left there by the Apollo missions.
What problem(s) is it the solution to? 1) "How does the distance from the Earth to the Moon vary over time due to things like tidal drag?" 2) "Does the strength of gravity change over time?" 3) "What can we do with a laser to really cheese off people who think the Moon landings were fake?"
How does it work? This concept is simplicity itself. You simply point a laser at the Moon, fire off a short pulse of light, and wait for it…
One of things I like to think about in science is "how do we know that?" It is interesting how one thing builds on another. This is a story of how the Greeks estimated the distance from the Earth to the Sun (an important idea in the development of the model of the solar system). I like this story because it is not too complicated. In fact, one could easily reproduce these measurements themselves. So, here is what I will talk about:
Measuring the size of the Earth.
Determining the distance from the Earth to the moon and the size of the moon.
Calculating the distance (and size) to the Sun…
Dynamic of the Cats as some commentary on the LCROSS landing the moon. The "big news" is the very high confidence now that one can put on the proposition that the moon does have water. Since humans are mostly water by weight, this is very important when assessing the practical difficulties of colonization or settlement. Would have been a drag to lug or synthesize H2O.
tags: moon bombing, science, comedy, humor, streaming video
This silly video was sent to me by Jared from LandlineTV. It is a comedic look at what happened when the earth sent out missiles in search of water.
Featuring Michael Antonucci, Yoni Lotan, Jaime Castillo, Emily Axford, Jared Neumark, Steve Levine, Dan Levine, and Paul Briganti.
Written and Produced by Captain Hippo. Jared is reading comments so I am sure he'd appreciate your thoughts and input.
Moon astronauts urge Mars mission:
At a rare public reunion of the Apollo 11 crew, Buzz Aldrin and Michael Collins said Mars instead of the Moon should be the focus of exploration.
Neil Armstrong, the first man on the Moon, said the race to get to the Moon had been the ultimate peaceful contest.
He said it was an "exceptional national investment" for the US and ex-USSR.
The trio spoke at an event at Washington's National Air and Space Museum to mark the 40th anniversary of their mission.
Mr Armstrong told the audience: "It was the ultimate peaceful competition: USA vs USSR.
Apparently 4 out…
Alluring, enticing, begging us to come pay a visit...
Like a moth to the flame, before there were flames...
Reflecting our reflections...
and echoing in the dreams of Neil Armstrong...
Levitations
Johanna Mueller, 2004
Artists I'm looking forward to seeing at the 10th annual Artomatic, #1: printmaker Johanna Mueller, whose woodcuts resemble the illustrations from a dark and hallucinogenic children's book. No wonder her blog is called "Feverish Art."
Swedish researchers have enlisted the help of artist Mikael Genberg to design a robot that will one day erect a tiny house on the moon. After landing on the lunar surface in 2012, the autonomous robot will scout for a suitable location and build a small red cottage, in keeping with the Scandinavian style.
The flatly-named The House on the Moon project aims to be a symbol of what one man can achieve. Students at the Mälardalen University will design, build and program the robot, although Professor Lars Asplund hinted that the final step may be a leap too far:
"We want to teach students who…
Maybe you can tell I am watching the MythBuster's Moon Special. In the show, the MythBusters go in a plane to reproduce the gravitational forces on the moon. I previously went over this, so here is the link:
[Tutorial on how gravity and weightlessness (zero-g) work](http://scienceblogs.com/dotphysics/2008/09/gravity-weightlessness-and-a…)
Clearly the MythBusters did this before I did (it's just airing tonight though). I just wanted to say that I posted some videos of the Apollo "jump salute" video analysis and also sped it up to "Earth-like" accelerations. I then made a video of my daughter doing the same thing on Earth and slowed it down. Yes, the MythBusters did it better, but I just wanted to say "me too". My analysis is here:
[Undoing Fake Moon Landing Videos](http://www.dotphys.net/files/moon-time.html)
P.S. I also slowed down a video of Kobe Bryant Jumping so he has an acceleration of that on the moon.
Sure, astronomers might not call it a planet anymore, but every schoolchild knows how badass Pluto really is. It's got a giant moon, Charon, and two smaller ones, Hydra and Nix.
In addition to being colder than ice with an average temperature of 44 Kelvin (that's colder than liquid nitrogen), I'm here to bring you the news that despite the fact that it's so cold and so far from the Sun, Pluto has been melting!
Since its discovery by Clyde Tombaugh in 1930, astronomers have been fascinated with Pluto, making very careful observations of it, trying to learn more about this bizarre, icy sphere…
But I didn't want one! Stop your whining, Earthlings. We have a serious question to answer, courtesy of Tamara:
What’s the moon like below its surface, moving into the interior? And what’s the current thought on its formation?
Well, we do know a lot about the Moon's insides the same way we know about the Earth's; just like the Earth has earthquakes, the Moon has moonquakes. These tell us about the Moon's interior. From back when we landed on the Moon, we planted the Apollo seismic experiments and saw 28 moonquakes. From these, we learned that the Moon has a crust about 60 km deep, a deep…
And if the band you're in starts playing different tunes
I'll see you on the dark side of the Moon.
One of my favorite readers, Zrinka, asks us why we're only able to see one side of the Moon from Earth. Seriously, look at the different phases; we always see the same side of the Moon:
How does this happen? Well, the Moon makes one revolution around the Earth about every 29 days, and that's what causes the Moon phases. But the Moon also rotates once every 29 days also. Because of this, the same side of the Moon always faces the Earth:
We call this "being locked." We're not the only system…
...just bring your own air and water. The BBC is reporting that the European Space Agency has determined that Marigolds, when planted in lunar soil, would be able to grow without adding any extra nutrients.
How cool is that?
I was driving home from work at about 6:30 today and noticed the Moon, still orange, hanging low on the horizon. The lower left corner was just starting to be shadowed by the Earth. As it rose a little higher, it turned yellow and then white, as we learned it should.
Then we got clouded out, and right now, during totality, the entire sky is covered in clouds. But I started thinking, "What if I were in space?" Well, the Moon appears red/orange every day during Moonrise/Moonset from Earth, but would appear white from space. But the red/orange during a total eclipse? The Moon would still…
As Bonnie Tyler sang, and later The Dan Band (with more cursing),
Once upon a time there was light in my life
But now there's only love in the dark
Nothing I can say
A total eclipse of the heart
Well, it isn't the heart, but this Wednesday night, beginning at 10 PM Eastern Standard time (8 PM my time, and 4 AM Thursday morning for my European readers), there is a total lunar eclipse. One of the things that's neat about a lunar eclipse, as compared to a solar eclipse, is that you can see it from everywhere on Earth at once! If you watch it, you'll see a full moon begin to be obscured, followed…
The closest you're going to get from me on Valentine's Day is something red, dear readers. As the Moon is now a waxing gibbous and will be for the next week, it will brighten the sky for the majority of the night. But before sunrise, it will dip below the horizon and set. The funny thing is, if you've ever watched this (or watched a waning gibbous rise), you'll notice it changes color! In fact, this composite photo shows you what I'm talking about:
So the Moon, although white once it gets high up into the sky, appears yellow, orange, or even red when it's close to the horizon. I got a…
The Capitol Hill Seattle blog has a great set of lunar eclipse photos on flickr.