Artist’s conception of a large asteroid hitting the earth (click for credit)
One of the many problems associated with an ancient earth is the young, faint sun. In a nutshell, we think we understand the way a star produces energy, and based on this understanding, a star starts off dim and grows brighter over time. Based on what we know, then, the sun should have been about 25% dimmer 3.8 billion years ago, when most evolutionists think life first emerged on earth. However, if the sun really were 25% dimmer back then, the earth would be far too frigid to support life.
This problem has been recognized for more than 40 years now, and evolutionists have worked hard on it (see here and here), but a solution has remained elusive. However, a recent paper has proposed a possible solution, and I found it interesting, because it illustrates exactly how desperate evolutionists are to get rid of this intractable problem.
In essence, the paper says that the way to fix the problem is to have earth pummeled by very large (greater than 100 kilometers in diameter) asteroids. They are so large that the authors call them “planetesimals”:
Planetesimals exceeding 100 km in diameter pummeled the early Earth for hundreds of Myr, resulting in large volumes of melt produced both by immediate depressurization and by subsequent mantle convection driven by the impact.
CRISPR, teamed up with Cas9, is a powerful gene-editing tool. (click for credit)
Not too long ago, a reader sent me an email that said:
I just found out about CRISPR and Cas9. From what I have learned about them they are very powerful and will lead to great things (good and terrible alike).
I was wondering if you could write a blog article on them when you get a chance. I would love to hear your perspective.
The reader is exactly right. CRISPR and Cas9 team up to make a powerful gene-editing tool that has incredible potential. While much of that potential is positive, some of it is quite negative.
To best understand the good and the bad of CRISPR and Cas9, you need to know what they are and what they can do together. CRISPR stands for “clustered regular interspaced short palindromic repeats.” Originally discovered in bacteria, it is a strand of RNA that is hooked to a CRISPR-associated protein, called a “Cas.” Cas9 is just one possible protein that can be associated with CRISPR, but it is the one that is most commonly used.
If your eyes are already glazing over, stick with me, because it’s important to understand how this works. RNA is a molecule that links to DNA. A specific RNA molecule targets a specific sequence of DNA. So, if you construct an RNA molecule correctly, it can search an entire DNA molecule, looking for a specific DNA sequence. It can then attach itself to that sequence. That’s what the RNA strand on CRISPR does. It is sometimes called “guide RNA,” because it guides the Cas9 protein to a specific part of an organism’s DNA. Consider the following illustration:
Illustration of CRISPR-Cas9 finding a DNA sequence
(taken from the video posted at the end of this article)
In the illustration, the guide RNA has found the DNA sequence that it was made to target. Since Cas9 is attached to the guide RNA, it is now positioned at a specific place in the DNA molecule.
The papyrus fragment that is now known as ‘The Gospel of Jesus’ Wife.’ (click for credit)
I am in China right now, and I have been here for almost two weeks. However, internet access is sporadic (at best), which is why I haven’t added any articles recently. Things are a bit better today, though, so I thought I would share my thoughts on a story I recently ran across.
On September 18th, 2012 at the International Congress of Coptic Studies in Rome, Dr. Karen L. King announced the existence of an astounding 4-cm by 8-cm papyrus fragment. It contained what she thought was a 4th-century Coptic translation of a gospel that she suggested had probably been written in the late second century AD. While the discovery of any ancient papyrus that has writing on it is interesting, this particular fragment was especially interesting because it contained the following phrase:
Jesus said to them, ‘My wife…”
As a result, this papyrus fragment came to be known as “The Gospel of Jesus’ Wife.”
Since then, there has been a lot of discussion about the papyrus fragment, and a website was set up to provide all of the latest information about it. Based on subsequent tests done on the fragment and its ink, Dr. King became so convinced that the fragment is authentic that she told Time:
I’m basically hoping that we can move past the issue of forgery to questions about the significance of this fragment for the history of Christianity, for thinking about questions like, ‘Why does Jesus being married, or not, even matter? Why is it that people had such an incredible reaction to this?’
Galileo’s thermometer (left) and a closeup of the tube (right).If you read my two previous posts (here and here), you know that my wife and I were recently in Italy, and I was really inspired by some of the things I saw. The art and history are amazing, but for me, one of the major highlights of this visit to Italy was seeing the Galileo Museum. It is filled with scientific instruments and lecture demonstration equipment from the past, and seeing those things helped me to understand the sheer genius of the natural philosophers (scientists) who learned an enormous amount about Creation without the help of fancy, technological gadgets. Instead, they relied on their creativity and their physical insight.
Consider, for example, the glass piece pictured on the far left. It consists of a small vessel, a long, narrow tube rising up from the vessel, and a small bulb at the top of the tube. Believe it or not, that’s a thermometer. Actually, it is more properly called a “thermoscope,” and the first one was designed by Galileo (with the help of some other natural philosophers) in 1593.* Until that time, it was difficult to make any systematic measurement of temperature. People could tell whether it was hot, warm, cool, or cold, of course, but they couldn’t make precise measurements of how hot, warm, cool, or cold it was.
In the late 1500s, Galileo came up with an ingenious solution. He understood that air expanded when it was warmed and contracted when it was cooled. He decided to use that fact to get an accurate measurement of the change in temperature. He designed a device similar to the one above, in which water filled the bottom vessel and ran partway up the thin tube. When the surroundings warmed up, the air above the water (in the tube and in the bulb at the top) expanded, and that pushed the water down the tube. When the surroundings cooled, the air above the water contracted, and that pulled water up the tube.
In other words, the higher the water climbed in the tube, the lower the temperature. By making tiny marks on the side of the tube (shown in the right-hand portion of the picture at the top of this post), he could assign a number to the water’s height. This allowed him to accurately measure changes in temperature. In my elementary science book, Science in the Scientific Revolution, I have students make a very simple version of Galileo’s thermometer with water, a glass, and a plastic bottle.
A clever variation on Galileo’s thermometer.A major drawback of Galileo’s thermometer is that it must be very tall to measure large changes in temperature. While at the Galileo museum, however, I saw a very clever way of getting around that problem, which is shown in the picture on the left. Instead of a tall, straight tube, this thermometer’s tube is a spiral. That way, the water still can travel a long distance through the tube, but the device isn’t absurdly tall. As soon as I saw this device, I thought, “Of course. What an ingenious way of getting around the height problem.”
Despite the fact that I understood exactly how this variation on Galileo’s thermometer would work and why it was superior to the original design, I doubt that I would have ever come up with it on my own. I’m simply not that clever. However, Galileo and the natural philosophers of his day were. The more I learn about people like Galileo, the more I appreciate how intelligent the great thinkers of the past were. Contrary to popular belief, I think it’s possible that they were actually smarter than we are today.
NOTE:
*Please note that a device like this one is often called a “Galileo thermometer,” but Galileo had nothing to do with its design. Return to Text
Galileo’s tomb in the Basilica of Santa Croce in Florence, Italy (click for larger image)My wife and I are currently in Italy, and I can’t express what it means to actually see some of the things I have been writing about. In one of my elementary science books, Science in the Scientific Revolution, I spend 8 lessons discussing Galileo Galilei, who lived from 1564 to 1642. He was the greatest natural philosopher (scientist) of his day, and he set the stage for Sir Isaac Newton, who would revolutionize the study of physics forever.
While he aided our understanding of many aspect of Creation, he is best known for his contributions to astronomy. Based on a friend’s description of a Danish “spyglass,” Galileo made a telescope and used it in his study of the heavens. He discovered sunspots, the four largest moons of Jupiter, mountains and valleys on the moon, and most importantly, the phases of Venus. The moons of Jupiter as well as the phases of Venus supported the idea championed by Copernicus – that the earth orbited the sun, which sat at the center of the universe.
In an effort to communicate these things to other natural philosophers, he wrote a book entitled Dialogue Concerning the Two Chief World Systems. Even though it was accepted by two different Roman Catholic censors (one in Rome and one in Florence), it was eventually used by certain members of the Roman Catholic church to put him on trial. The ruling based on the trial declared that Galileo was:
…vehemently suspected of heresy, namely, of having believed and held the doctrine – which is false and contrary to the sacred and divine Scriptures – that the Sun is the center of the world and does not move from east to west and that the Earth moves and is not the center of the world…
As punishment, he was placed under house arrest for the remainder of his life.
(If you want a more detailed discussion of this saga, I have one here.)
