Did you know you can remove the outer shell of an egg, leaving a membrane which is tough enough to hold? It is also permeable, thereby letting air and water through.
We did this experiment sometime ago, and it was interesting. Thought I'd post some pics for your intellectual edification—or whatever.
Here we go.
Step One: Take an egg, and drop it in vinegar. The vinegar will interact with the calcium in the outer shell, dissolving it and leaving a membrane. We used apple cider vinegar because we didn't have any of the other stuff.
See the bubbles? Maybe not. Well, trust me, they are there! The shell bubbles off over the course of a day, and soon, you have a shell-less egg. Edmund has it here in his right hand, and an untampered-with egg in his left.
We did this to two eggs, then measured them carefully.
The larger of the two, we put into a thick sugar-syrup. The smaller, we put into water. Eggs are mostly water. If the membrane allows for osmosis, the larger egg should shrink as the water inside it escapes into the syrup, trying to bring the two into a state of equilibrium, until as much water exists inside the egg as outside it (in the syrup). The pores in the membrane are too small to allow the sugar to get inside the egg.
The smaller egg should remain unchanged, as the water in the glass and the water in the egg are pretty much the same amounts.
Here we see day one. They look about the same. The water is on the left and the syrup on the right.
Now here is day two. You can see the egg in the syrup, this time on the left, looks wrinkly and shrunken, while the egg in water on the right, looks normal.
The larger egg shrunk by about a centimeter, but I didn't get a picture of the measurement. You'll just have to trust me on this. Then we stuck it back in water and it reconstituted itself. It was fun to watch the water come out of the egg and form a halo around the it, between the egg and the syrup.
Then we threw it out on the compost heap. An ignoble demise for such a useful educational tool, don't you think?
Friday, October 31, 2008
Dentistry 101
Man's Best Friend
Monday, October 27, 2008
Saturday, October 25, 2008
Ichabod
"And she called the boy Ichabod, saying, 'The glory has departed from Israel,' because the ark of God was taken...."1 Samuel 4:21
I am an American and a patriot. Two watershed experiences shaped me in this way. First, at the impressionable age of 18, when most young women go off to college and experience more freedom than they have ever known, I flew to a Muslim country to live with a local family for a year as an exchange student. My rights and freedoms were voluntarily curtailed, and I gained a new appreciation for the freedom that was mine as an American woman.
Second, when I returned home from my year abroad, I was not quite ready to go to college. Instead, I joined the United States Air Force as a linguist, planning to take advantage of the GI Bill for my university tuition at a later date. I learned in four years of wearing the uniform how much the men and women in our armed forces sacrifice their own freedom to guarantee ours.
I was stationed in South Korea during the first Gulf War. Most service men and women are sent on a couple "unaccompanied" overseas tours of duty—without their families and for no noble purpose other than it is time to do their rotation. Nowadays we point to Iraq and Afghanistan and shake our heads over the separations and dangers that these families face for our sakes. Such separations have happened for years, though, albeit on a more limited basis. In my mind, there seemed to be no rhyme or reason to the assignment for many of these men and women. Mothers were shipped off from their families, fathers sent from theirs, for an entire year. One family I know took years to recover from those twelve months without Dad because of what was happening in their family at the time he was sent. They needed him at home, and he couldn't be both places at once.
What struck me in these situations was that, for the men and women who served, orders were orders. They voluntarily signed up for the military, and they were fully prepared to do what was asked of them, despite hardship on all sides. They did and do have my full support.
Given these two shaping factors of my life, I suppose it's not unusual for me to be a bit more sensitive about what I see are the eroding foundations of American life as I know and love it. Last year the kids and I studied early American history with some intensity. I was deeply impressed by the commitment our forefathers had to freedom, particularly freedom of religion. We are English speaking Americans (as opposed to German or French or Spanish) because a handful of people wanted freedom so badly they were ready to risk everything for it. It could be argued that some had nothing left to risk.
"He is no fool who gives what he cannot keep to gain what he cannot lose."Jim Elliot was writing about giving up his life for an eternal reward, but we might apply it to the first freedom-loving Americans in that they gave up the known to embrace an unknown for which they turned out to be horrifyingly under-prepared. Nevertheless, they persevered to win freedom for future generations. We see echos of this a century or so later, when we began to fight the Revolutionary War. Death was preferable to bondage, and the cry went forth from Patrick Henry's lips defining it for all,—Jim Elliot (American missionary killed in the jungles of South America)
"Give me liberty or give me death!"This reverberated through the years, and by the time of the great westward expansion, men and women went in droves to establish new lives for themselves with not much besides hard work and time. In book after book, we read how our land was built on drops of sweat and perseverance (and, unfortunately, upon the lands of noble people who didn't understand private ownership—but that's a post for another day).
It's interesting to note that underneath the hard work, there was faith. It was faith that drove the Pilgrims to the Mayflower and the New World. It was faith that motivated the patriots in the Revolutionary War. It was faith that accompanied many of the first pioneers, like Aunt Clara Brown—whose faith won her freedom from slavery and whose sweat turned her into the wealthiest woman in the West.
- Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ, through whom also we have obtained our introduction by faith into this grace in which we stand; and we exult in hope of the glory of God. And not only this, but we also exult in our tribulations, knowing that tribulation brings about perseverance; and perseverance, proven character; and proven character, hope; and hope does not disappoint, because the love of God has been poured out within our hearts through the Holy Spirit who was given to us.
- Romans 5:1-5
The land of the free seems to have become the land of the addicted, as people sit upon their couches channel surfing, or at their computers gawking. The home of the brave looks like a nation with its head in the sand or a group of children with their fingers in their ears singing "LA LA LA LA I can't hear you!"
Like the Pilgrims, we are ill-prepared for the winter we now face. I am no prophet, but I see only two options out of our current mess. Either we sign on for hard work and personal sacrifice, or we beg our leaders to be our saviors as we slide down the bank of eroded freedom. Collectively, we don't want to do the hard thing. Practically, we're already crying on the bank.
The glory has departed.
Friday, October 24, 2008
Hope Defined
But our citizenship is in heaven. And we eagerly await a Savior from there, the Lord Jesus Christ, who, by the power that enables him to bring everything under his control, will transform our lowly bodies so that they will be like his glorious body.Philippians 3:20-21
Subscribe to:
Posts (Atom)