The science behind sleep

Well, it seems Monday has come once again a lot faster than I predicted. This last weekend was busy with a friend in town and another friend’s birthday. It seems another “Sunday” is always needed after the original Sunday. Luckily, I went to bed at 9pm last night. Going to bed early is one of my favorite Sunday night activities. Sleep is so important for having mental clarity on Monday morning and starting your week off right – so what exactly is it and why do we need so much of it?

Sleep would seem like an anti-evolutionary trait since we spend so much time doing it, and it leaves us vulnerable for predator attacks. Yet, if a person were to go longer than 2 weeks without sleep, he/she would die. We all know that lacking just one day of sleep leaves us groggy and disoriented. Make it three, and delirium is sure to set in.

Although we are not exactly sure why sleep is so important, we do know that during this time our thoughts re-organize, our muscles and organs restore themselves, and we build memories.

There are also 5 different stages of sleep. See below. (*taken from Discovery Health)

  • Sleep Stage 1
    In this brief stage, which may last only a few minutes, the body drifts to sleep. Brain waves are mostly high amplitude, slow waves and occasional alpha waves (like those found when awake).
    Percent of total sleep time for young adults: 5 percent.
  • Sleep Stage 2
    Heartbeat and breathing slow and the sleep is deeper than in Stage 1. Slow-wave sleep continues with peaks of brain waves (known as sleep spindles) occurring.
    Percent of total sleep time for young adults: 44 to 55 percent.
  • Sleep Stages 3 and 4
    These are the stages of deepest sleep, when brain waves are slowest. During these stages breathing and heartbeat slow further and muscles relax. Dreams are more common than in the earlier stages and sleepwalking and talking may occur during Stages 3 and 4.
    Percent of total sleep time for young adults: 15 to 23 percent.
  • REM
    Rapid eye movement (REM) sleep stages lengthen through the night. The first REM cycle may be only 10 minutes while the last could last as long as an hour. During this cycle the heartbeat increases, breathing becomes shallow, eyes move rapidly, muscles are relaxed, and dreams are most vivid. Brain waves resemble those during waking.
    Percent of total sleep time for young adults: 20 to 25 percent.

    Nothing's cuter than a sleeping kitten
    Nothing's cuter than a sleeping kitten

Want to know some other interesting facts?

– Whales and dolphins only sleep 1/2 of their brain at a time. Therefore, if they are sleeping, one eye will be open and the other closed.

– Getting too much sleep (9 hours or more) or too little (6 hours or less) gives a person a 30% higher death rate than those who sleep regularly every night.

It seems getting your beauty rest is just part of the sleep equation, and there’s numerous reasons why we should sleep more. Don’t worry if you didn’t catch up on all your sleep during the weekend, there’s always tonight to get your full 8 hours. Happy Monday!

Information pulled from: http://health.discovery.com/centers/sleepdreams/basics/basics.html, http://www.abc.net.au/science/sleep/facts.htm, Intellectual Devotional by Kinder and Oppenheim

What are Stem Cells and How are They Helpful?

For me, when I hear the words “stem cell” it’s usually followed shortly after by “research”. I have a very high-level concept of what it means. I know it cures diseases and can be beneficial, and I know it’s controversial. Why? That I am not sure.

So, what is a stem cell?

It is a cell that leads to the growth of other cells – therefore, other cells stem from it.  There are two types: embryonic stem cells and adult stem cells.

We’ll start with adult stem cells. These are found all over the body from our brain, to bone marrow, cartilage, and skin. These cells typically are taken from our own body and are multipotent. Multipotent refers to the cells ability to reproduce more cells, and in particular, the ability for it to only produce cells which are closely related to it. For example, bone marrow cells can only produce from cells which are in its “family” such as bone cells, cartilage cells, and fat cells. Since these cells are taken from our own body, they have less chance of being rejected by our immune system. Adult stem cells have been used for therapeutic reasons for over 30 years now.

Embryonic Stem Cells
Embryonic Stem Cells

Stem cells (embryonic or adult) can greatly aid in regenerating certain damaged parts or our body. They can divide and renew themselves over time, and therefore help rejuvenate certain areas of our body. For example, degenerative diseases such as Parkinson’s, Alzheimer’s, diabetes, and cancer could benefit from placing stem cells in the part of the person’s body that has been most ravaged by the disease. Of course, science is still working on this, and it is not always possible.

Now let’s take a look at embryonic cells. After we take a look at what they are, it will be easier to see the controversy over them.  Embryonic cells typically come from fertilized eggs that have been thrown out after a fertility treatment or were aborted. The stem cells actually come from the blastocyst which is a 5-day old fertilized egg that has divided its cells. These cells within the blastocyst are pluripotent as opposed to the adult stem cells which are multipotent. Pluripotent cells can grow into any type of cell in the body. Hence, they can seem like a scientific treasure mine. It has only been in the last 20 years that scientists have been able to study these cells and cultivate them. Still, we don’t know much about embryonic cells.

So the controversy comes from the fact that these cells are taken from fertilized eggs, and so it holds moral obligations. When does it count as a human being? Is it ethical to do this?

This is a very broad overview, and I haven’t gone into any of the details regarding costs of research, legislation on methods and procedures, or medical benefits.  But from what you do know, what are your thoughts on stem cell research?

Black Holes

Star explosions are interesting. Star implosions also make equally interesting topics to explore. The kind of star implosions I’m referring to in particular are black holes. If you’ve ever seen Star Trek, you probably have an image in your head of a space ship swirling into a dark, black abyss. That can serve as a starting reference point, but other than the fact that a black hole has a strong gravitational pull, there’s not much more accurate information you can take away from that depiction.

So let’s begin. What is a black hole? A black hole is a result of a star imploding into itself and collapsing down to nothing. Its gravitational force becomes so strong, that no matter can survive it. Inside a black hole is nothing, except for “a little nugget of singularity” as physicist Kip Thorne puts it which we don’t understand. This point of singularity is a result of the dying star continually collapsing into itself, becoming denser and denser, until it is a point with no radius and infinite destiny. Nothing escapes the black hole, not even light.

If light cannot escape the black hole or its event horizon (the border of the black hole where the gravitational pull sucks in surrounding matter), then how can we see it? Technically, we can’t. We observe black holes by observing the way they interact with the objects in space around them.

falling_into_a_black_hole

To understand a bit more about black holes, we need to discuss escape velocity. When a rocket ship launches into space, it must go at a high enough velocity (speed)  to escape the earth’s gravitational pull. If it does not have a high enough escape velocity, the ship  falls back down. In a black hole, the escape velocity needed to exit must be faster than the speed of light. This is impossible and thus the area surrounding the black hole is known as the event horizon. If an object falls into an event horizon of a black hole, it gets sucked in. Outside of the event horizon, though, it is OK.

OK, so the question you really want to know: Can we space or time travel through a black hole? You know….the way they do in Star Trek. This idea is not as far fetched as you may think. Some physicists (like Burko in particular) argue that if a black hole has a weak point of singularity, it isn’t out of the question. A weak point of singularity means that it won’t completely crush you or your space ship if you enter, and it may lead you to a wormhole (a tear/tunnel in the space time continuum) and spit you out in some remote part of the universe. Though this idea is very theoretical, there is no evidence to completely disprove that it may work. In science, that counts as a possibility. The closest black hole being 30,000 years away, though, serves as a much bigger problem.