Closeby brown dwarf discovered

A brown dwarf star is an almost star. It doesn’t have enough mass to start the process of nuclear fusion in its core to become a star. The newly found brown dwarf (WISE 0855–0714) is only 7.2 light years away, making it the 4th closest star system to the sun. Since it never started fusion, it didn’t get really hot. It started out pretty hot, but without anything to keep it that way it slowly cooled. At this point it’s cooled down a lot. So much, that the ice in your freezer is probably warmer that this star. It’s temperature is -48 to -13 ºC.

The Sun's Closest Neighbors

Artificial Skin

Scientists at King’s College were able to create skin tissue using stem cells. Scientists have done this before, but this time it’s different. Previous artificial skin didn’t have a permeable membrane to keep fluids from leaking out of the body; this one does. This new skin can grow indefinitely, so would be a good source of skin for severe burns. I’m really looking forward to the day we can grow our own replacement organs.

How small are atoms?

My 7th graders are learning about the atom, and that includes how small they are. So I found out how large a mole of water is (18 ml). Then I filled a small flask with that amount of water with food coloring. Then I wrote down how many atoms are in the flask:
1.0866 × 1024 atoms
180,660,000,000,000,000,000,000 atoms
1.8066 septillion atoms
1.8066 yotta atoms
The human brain just isn’t wired to be able to comprehend the scale of these numbers.

The Chestnut is coming back

… but it will take a while. Back in 1900 there were billions of Chestnut trees in the US. Then, over 50 years, they died off, victims of a fungal blight. New trees would grow from the roots of the old, only to succumb themselves. But a few survived. And now it looks like scientists have managed to breed a resistant version. Next year 500 will be planted in Pennsylvania’s Westmoreland County.

5-26-2011a - Chestnut Tree in Bloom

How are we different from Neanderthals?

Our genome (all of our genes) is a fraction of a percent different from our evolutionary cousins, the Neanderthals. Our genomes are 99.84% similar. So what made us so different?

For one, consider how much really needs to be the same. All of the work that cells do needs to be there. How to make the endoplasmic reticulum and other organelles is the same. Heck, our genome and a banana’s are about 50% the same. And the Neanderthals need to have the same body plan, bones, heart, liver, teeth, etc. The genes for building these things are going to be virtually identical–I expect them to be 100% the same.

But it’s how these genes are turned on and off that’s interesting. Most of our DNA isn’t in genes. We used to call it junk DNA. Now we’ve learned that there are things in the DNA that turn genes on and off. And when you turn a gene on can greatly affect the structure of the organs involved. Darwin’s Galapagos finches had different beaks depending on what kind of food they ate. But the genes for the beaks were the same. So how did they have different beaks? The genes were turned on at different stages of development while in the egg. If you turn the gene on sooner, you get a larger, stronger beak, good for cracking nuts open. Turn it on later, and you get a narrow, pointy beak, good for picking insects out of plants.

So, the genes for us and Neanderthals are mostly identical. It’s the switches that turn these genes on and off that’s different.

Building a better axe

The axe has stayed pretty much the same for centuries. But a Finnish inventor has come up with a better design. Your typical axe has the handle directly behind the wedge. This drives it straight into the wood. The new Leveraxe has an asymmetrical wedge that is offset to the handle. This means that the force of the blow causes the blade to twist. This means that the user has to lighten up the grip as it strikes, and that the blade forces the wood apart. There’s a good video of someone easily striking off the sides of a log, and then breaking the log down. This is much easier than splitting wood with a regular axe (and I’ve done it in the past).

Have we found the inner Oort Cloud?

In our solar system, we have the inner planets (Mercury, Venus, Earth, Mars), the Asteroid Belt, the outer planets (Jupiter, Saturn, Uranus, Neptune), and the Kuiper Belt (including Pluto, Sedna, and a few others). There is also the Oort Cloud, which was proposed by Jan Oort. The Oort Cloud is hypothetical — we don’t really know that it exists, but we think it does. Now it looks like we may be finding things in the inner Oort Cloud.

Kuiper_oortThe Oort Cloud is supposed to be a roughly spherical region surrounding the Sun. It contains icy clumps, and is the source for long period comets. The inner part of the cloud is disc shaped, and probably connects to the Kuiper Belt.

Now Chadwick Trujillo and Scott Shepherd have found 2012 VP113 (which they call Biden), another object like Sedna. This is the furthest object found in our solar system. They think that Sedna and Biden may be members of the inner Oort Cloud.

Biden has a diameter of about 450 km, and is about 80 AU at its closest approach to the sun, and about 450 AU for aphelion. It takes over 4000 years to go around the sun once. It’s remarkable that they were able to find it at all given that it is so far away and is so small.

Current models of solar system formation don’t have anything forming in the region where Sedna and Biden are. Either these models are wrong, or these objects formed closer in, and then were flung far out. But I would think that then their perihelion should be much closer in. Hopefully we can find more objects in this region and learn more about it.

Stem cells created from adult skin cells

Scientists have used cloning techniques to create stems cells from adult skin cells. They got donated eggs from women, removed the DNA from the eggs, and injected the skin cells into the eggs. Creating cells from these created the pluripotent stem cells that matched the skin donor DNA. At this point they were able to do this to 77 eggs, creating 2 stem cells, a success rate of 2.5%. They could shake up the medical world by fixing that problem.

Drunken Trees

Drunken_treesWhile drunken trees may sound like a joke, it’s not. There are drunken trees in Alaska, Canada, and Northern Europe. Trees should go straight up. However, if the trees are in places with permafrost, and the permafrost melts, then the ground can collapse and the trees will end up tilted. This leads to trees that look like they are drunk. And it’s happening due to climate change. Other effects are erosion, and depressions in the land (thermokarst). Sometimes the trees can survive, but not always. Birch and black spruce are most affected because they have shallow root systems.

It’s not just trees that are affected by this. It also affects animals in the ecosystem that depend on the trees for food or shelter. The depressions created can be big enough to swallow whole houses, which has happened. Families have had to move, roads have been destroyed, pipelines have cracked. And it’s only going to get worse as the global temperature continues to rise.