Archive for the 'Science' Category

Life expectancy of an optical disk

Published
by
Phil
on July 14, 2008
in Technology
. 0 Comments

I was wondering today how long the data on my CDs would last. So I did some Googling.

From OSTA, I found that:

  • CD-RWs can be rewritten ~1000 times.
  • The unrecorded shelf life of both CD-Rs and CD-RWs is anywhere between 5 and 10 years.
  • Data on written CD-Rs remain readable from 50 to 200 years.
  • Data on written CD-RWs remain readable from 20 to 100 years.

NIST’s special publication 500-200 gave more concrete values. I trust these numbers more.

  • The life expectancy with storage at room temperature and 90% humidity is from 57 to 121 years. A relative humidity between 40% and 50% should lead to an even longer life expectancy.

Of course, quality varies from one manufacturer to another, and it will likely also improve over time. But these numbers give a good idea. I guess this confirms that the optical disk is still not only the cheapest, but also the most reliable, form of storage. It’s doubtful that I’ll need the information on my CDs in more than 80 years from now - if I even live to be that old. (Frankly, I prefer to die younger and healthy than to die old, decrepit, and dependent.)

String theory and the eleven dimensions

Published
by
Phil
on July 14, 2008
in Science
. 3 Comments

I’ve heard about string theory for some time now, but I’ve never taken the time to learn more about it until now. I basically spent a good few hours watching free videos online, and now I’m telling you about what I did. You’re in for a treat.

First, you might find it interesting to watch these two YouTube videos on the first ten dimensions. They are great illustrations of the concepts found in the first chapter of Rob Bryanton’s Imagining the Tenth Dimension (book, website). If you get lost after about the 5th or 6th dimension, don’t worry - I did too. Re-watching the later parts helps with understanding a little better, though.

Then comes the better part. If you have time to kill, watch NOVA’s 3-hour The Elegant Universe series on string theory and why it’s such an amazing prospect. There actually used to be only ten proposed dimensions, but after five different string theory ideas were introduced, all with very different math, Edward Witten came along and proposed an eleventh dimension to unite all these ideas.

It’s interesting to note how the strings in string theory actually closely resemble Laozi’s ancient idea of a Dao. If I didn’t hate math so much, I think I’d love to be a string theory physicist.

Einstein on religion

Published
by
Phil
on June 16, 2008
in Religion and Science
. 0 Comments

I have always known that Einstein had some pretty cool and unique views on religion, but I haven’t looked into it much until today. I regret not having done so sooner! Found some really great quotes.

Religion without science is blind.

Some people really need some of this sense talked into them!

I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.

The idea of a personal God is quite alien to me and seems even naive.

I have never imputed to Nature a purpose or a goal, or anything that could be understood as anthropomorphic. What I see in Nature is a magnificent structure that we can comprehend only very imperfectly, and that must fill a thinking person with a feeling of humility.

I do not try to imagine a personal God; it suffices to stand in awe at the structure of the world, insofar as it allows our inadequate senses to appreciate it.

I too agree that the idea of a personal, personified God is silly. These quotes precisely illustrate how I like to look at the world myself. Maybe that means I’m a genius too! (ha)

One thing that sets us apart, though, is his definition of “religion,” which is a little too broad for my taste. Take a look at these quotes:

I am a deeply religious nonbeliever. This is a somewhat new kind of religion.

(An extension of the first quote of the post:)

Science without religion is lame, religion without science is blind.

Clearly, when he said “religion,” he wasn’t referring to your classic ones. I think he meant something like a more personal religion or belief system - which I would hesitate to call “religion,” because I find myself in the same boat, and I don’t like to call myself “religious.” Meh, it’s all good!

There’s a nicely related NY Times excerpt from the book The God Delusion by Richard Dawkins that I highly recommend. He seems to share my view on the words “God” and “religion.” (I wanted to excerpt some of it here, but it said I needed the publisher’s permission. Too messy.)

Don’t miss my previous discussion of how religions are simply just tools of cultivation/self-improvement.

If a tree falls in the forest…

Published
by
Phil
on April 11, 2008
in Philosophy and Science
. 2 Comments

treeIf a tree falls in the forest, and no one is around to hear it, does it make a sound?

I remember this question from elementary school. But only just now, in the shower, did I finally come to my own terms with this seemingly paradoxical question.

It’s pretty simple. The way I see it, it all depends on how you define sound. Do you define it as the simple molecular vibrations that happen at certain amplitudes and frequencies? Or do you define it as the electrical stimuli that occur in our nervous systems when our eardrums pick up such vibrations?

If you define it as the former, then by the laws of physics, sound always occurs when a tree falls. If you define it as the latter, then no, there isn’t any sound, because no eardrums or nervous systems are around to detect the vibrations!

I guess epiphanies aren’t always what people make them out to be. The best part is, I’m sure someone else has already come up with this interpretation already.

Discuss this in the community forums.

Inner life of a cell

Published
by
Phil
on March 24, 2008
in Science and Videos
. 1 Comment

A group at Harvard came up with this incredible, realistic animation of the inner workings of a cell. There are two versions. One is a 3-minute animation with (good!) music; the other is an 8-minute animation with narration.

The “story” is about leukocyte extravasation, or the movement of a white blood cell out of the bloodstream and into infected tissue. A fairly decent background in science will be necessary for anyone to get a good grasp of what’s going on in the video, but even the common person will be impressed or even amazed by how intricate our bodies are, down to the very molecules. (I would recommend the 3-minute version if you find yourself short on science background.)

We live in an amazing world, we are amazing worlds, and, in light of this video, each one of our cells is an amazing world. Who knows, molecules and atoms could also be worlds of their own, far more complex than we could ever imagine. Nature works in astounding ways.

3-minute version

If you would like me to remove this video for legitimate reasons, please email me.

The only thing scientists, partially including myself, might have against this is that the animations of the molecular movements are too “perfect.” In reality, molecules wiggle against each other randomly (Brownian motion) until these things happen naturally - more of a chaos really. Of course, if they were to show that in the video, it would probably greatly confuse the viewer, so I can see why they decided against it.

If you’re skeptical about the kinesin motor “walking” protein (and you have every right to be), there’s also a video that breaks down the process of how it “walks,” courtesy of the Milligan lab:

If you would like me to remove this video for legitimate reasons, please email me.

Continue reading ‘Inner life of a cell’