Tuesday, August 28, 2007

Entangled States

9/2/07 – 9/8/07
C. Zaitz

I’ve been thinking about quantum mechanics lately. QM is a branch of physics that deals with the universe on the scale of the very small. On a daily basis, we don’t enter the realm of quantum mechanics, but more and more, scientists are finding that the properties of the very small scale inform the universe on a very big scale. And it’s a quite different universe on the small scale.

On the scale of the tiny, basic laws of “classical” physics break down. We are used to measuring things and describing their positions with numbers. In the realm of atoms, measuring things becomes impossible. You may have heard of Heisenberg’s Uncertainty Principle, the idea that you cannot know both the position and the momentum of an electron orbiting the nucleus of an atom. You can know where an electron is likely to be, but you can’t pinpoint it. The act of doing so would destroy the information you were trying to get. Once you “stop” the electron to study it, you have changed its momentum. And you cannot get around this fact. The measuring and the measured thing are entangled, you cannot separate them. We can intuit that perhaps more easily than other aspects of QM. In art, we say that “negative space” is as important as the object in space. There is a direct and entangled relationship between the object and the space around it. Change the object, and you automatically change the space surrounding it.

It turns out that objects, rather than just being objects, are better described as a series of relationships. You might not be able to know exactly where one particle is, but if it is entangled with another particle having an opposite position, you can know that whatever you do to one particle will always affect its entangled particle. So if one egg is sunny side up and its entangled partner is sunny side down, you can flip one egg and automatically and always flip the other too. This is called “entangled states.”

In quantum mechanics, we have to give up absolutes and accept probabilities. Perhaps that’s why we never notice quantum mechanics in our daily lives. QM says there is a real possibility that all of the atoms in your body could pass right through the atoms of a wall, allowing you to walk right though it. Does that mean Kung-Fu masters can really walk through walls? No, because on the scale of a human being, the probability of that happening is incredibly small, almost non-existent. But on the scale of the atom, it can happen. In fact it does happen, and furthermore, we rely on it happening. It’s called “quantum tunneling” and it’s the basis for our modern electronics and microchips.

Science and philosophy come together in quantum mechanics. We often say that the age of determinism in science, where A causes B through a direct line of events, has been replaced with the age of probability. Einstein hated this idea. His aversion to it shows up in his famous quote, “God does not play dice with the Universe.” Even today many people reject the underlying philosophical ramifications of QM while using its principles and products in every day life. But I find the QM idea of probabilities, relationships and entangled states to be an active and connecting philosophy. And we’ve only begun to explore it.

Until next week, my friends, enjoy the view

Wednesday, August 22, 2007

Dark Ages

8/26/07 – 9/1/07
by C. Zaitz

When we think of the “dark ages” in western history, especially in science, we often think of folks believing the earth was flat and that the stars were little lights attached to a crystal sphere which circled the earth. In reality, just like today, people probably didn’t spend too much time thinking about how the stars were attached to the heavens, since they were busy trying to survive on meager meals and trying to avoid diseases. But there are always a few folks with either the time, or the light headedness from lack of food, who think about the heavens. All was not dark in the dark ages.

If we can get beyond the strong terms of contrast used throughout history like black and white, light and dark, we can begin to see the time period in Europe we generally regard as the “dark ages” more realistically. Between the years 500-1000 AD, or the early Middle Ages, people didn’t stop working, they made things, they communicated, and they thought. The problem with the dark ages, historians say, is that there is very little recorded information. Without recorded events, the time period becomes “dark” to historians. Unfortunately, writers from later times have shaped the way we think about the so-called dark ages, comparing them with what came before, the glorious Roman Empire, and what came after, the High Middle Ages and the Enlightenment. However, it isn’t completely accurate to say that no advancements to civilization came during that period. By the middle ages, most people believed that the earth was a very small part of an immense universe. Folks knew the earth was round, and though the science of the sky was intricately tied to prognostication and astrology, there was a considerable bank of knowledge about the planets and stars.

But in these times, people had to deal with an ongoing scarcity of food, hardships of weather, and now it seems scientists have found evidence that crop failure and a series of very cold summers may have been caused by some catastrophic event, such as volcanic eruption or asteroid collision. The first appearance of the Bubonic Plague came around this time, and before it was done centuries later, it had killed perhaps one half or more of the entire population of Europe. No wonder they didn’t record their history.

I wonder if the folks in the sixth century would have done anything different had they known the plague would kill every other person. I wonder what they would have done to prevent it. Eerily, the same things that may have prevented folks from recording their history then are predicted to happen to humanity again. Are we prepared? There are folks who look to the skies and tell us that we should begin to colonize other planets, but most of us aren’t listening. We are just trying to get through the day with modern day plagues of disease and lack of food and shelter many people worldwide suffer from.

I hope that the visionaries who want to travel to other planets, and the rest of us who support them, will make it happen in our lifetimes. I hope we learn from our history, and that we can keep a light on in the darkness that we all sometimes face.

Until next week, my friends, enjoy the view.

Tuesday, August 21, 2007

Wednesday, August 15, 2007

Disappointment

8/19/07 – 8/26/07
by C. Zaitz

Sometimes when a person takes their first look through a telescope, they get a feeling of, “is that all there is? Where are the colors? Why is it so small and faint?” Ah, you were expecting Hubble Space Telescope photographic quality. How disappointing! Hubble Space Telescope photos are works of art, created from information traveling by radio frequencies over hundreds, thousands, and in the case of the Hubble Deep Field image, billions of light years.

The images are breathtaking. Who can forget the famous “Pillars of Creation,” the image of the Eagle Nebula whose elongated fingers of gas and dust may harbor baby star systems. Or the Deep Field, an image made by opening the Hubble’s photographic eyeball and having it stare at a tiny area of space for a very, very long time. But how do these images get back to earth? Actually, they come to us in black and white, as a series of zeroes and ones, strung along in complicated patterns like strands of DNA. Once they get to earth, computers assemble the information into black and white images. So how did they get so colorful?

Astronomers, or should I say artists, add it later. They use a computer program like Photoshop to color in the gases and clouds with tints they assign. But color is a hard thing to define. We each perceive it differently. Some people have a very keen sense of color, and some are color blind, meaning that the colors they see are different from what most of us see. My dad often confuses red and green, because, he says, red is a very dull color. Most of us don’t see it that way. In the the Pillars of Creation, both hydrogen and sulfur were detected as a red color in the clouds of gas. Astronomers changed the hydrogen to green so it could be distinguished from the sulfur. What we got was a gorgeous, colorful, if not accurate image that filled our imaginations. But what does accurate mean when it comes to color? It’s difficult to define an exact color because it is mostly perception. So how far from red can we stray before it becomes green? Or does it really matter? Dad thought they were still the same color!

How often have I said, “here’s Betelgeuse, a red star,” or, “this is Rigel, a blue star.” No wonder people get disappointed when they are expecting the star to be the color of Bozo’s nose in the sky. I could say, “Betelgeuse radiates light mostly in the infrared and red end of the spectrum, so it’s considered a “red star,” but it is so far away that the very little bit of light we get from it is only slightly tinged orangey-red.” But that’s pretty long-winded! So we oversimplify.

The Hubble pictures are so inspiring that I don’t think the colors are an issue. The only problem comes when people expect to see those kinds of images through a telescope. If you are expecting your view through a friend’s telescope to look like the poster you saw in the mall, you’ll be disappointed. But if you have patience and look with eyes and mind ready to see detail and to absorb what you are looking at, you’re bound to avoid disappointment.

Until next week, my friends, enjoy the view.

Wednesday, August 08, 2007

It's Just a Theory...

8/12/07 – 8/18/07
by C. Zaitz

If science is based on “theories,” how do we know they are true? After all, a theory isn’t necessarily truth or law, is it?

All scientific theories begin as a hypothesis, or a possible answer to a question we ask. For the question, “Why don’t we fall off the earth if it’s round?” we could invent some pretty cool explanations. For example, we have seen how magnets on earth attract each other, and we know that iron can be magnetic. If earth is a big magnet, maybe it pulls the iron in our blood toward it. But then we remember that feathers and leaves also fall to earth and they have no iron in them. Oops, back to the drawing board with our hypothesis.

We will have to gather observations and do experiments to come up with another hypothesis. We have to design experiments that will test exactly what we want to test without introducing too much error. And we have to accept the answers we get, even if they don’t agree with our hypothesis. The key to scientific theories is that they need to be falsifiable. That means that we must be able to test to see if a hypothesis fails. If it does, we have to refine it or chuck it completely. If we make all reasonable tests and it holds up, it may become a theory.

In the late 17th century when Sir Isaac Newton began to think about what made apples fall and held the moon in orbit, he didn’t have a word for the force he was trying to describe. He wasn’t trying to prove a theory; he was trying to find a reasonable hypothesis to explain his observations. He needed a mathematical way to describe how objects move, so he developed calculus. With that tool, he was able to find an equation that worked in every case he tried. Finally he came up with a name for what he was describing, from the Latin, “gravitas,” meaning weight or heaviness. Today we call them the Laws of Gravitation, but they are really theories that have held up over time and trials. But new technology brings new tests.

By the beginning of the 20th century, Albert Einstein was able to test the laws of gravity around a massive object, the Sun, and found that the “laws” needed to be modified. By the time he was done, he had changed the way we think about gravity. No longer do we imagine it as an invisible magnet, but more like a fabric in which we are all embedded. Our movements are shaped by this fabric, which itself is shaped by mass. We follow its curves like golf balls on a putt putt course. Einstein called it spacetime, and scientists are still unraveling the implications today.

The word theory deserves more “gravity” than it is usually given. In order for a hypothesis to be scientific and to become a theory, it has to be tested. That’s why religious or “new age” ideas are often not considered to be in the realm of science. I believe it’s important for us to understand how science works. Otherwise we might never have known how gravity works, and therefore never be able to fly a rocket to the moon. Scientific theories are the only things that let us do that.

Until next week, my friends, enjoy the view.

Wednesday, August 01, 2007

Fiery Skies of August

8/5/07 – 8/11/07
by C. Zaitz

Every August, the earth passes through a part of its orbit where a vast cloud of debris awaits. The debris consists of tiny particles, many no larger than a mote of dust or grain of sand, left behind by a comet. As earth plows through the cloud, the tiny bits of rock are jammed into the thick atmosphere and create spectacular plasma trails as they incinerate. These are the Perseid meteors, and the nights of August 11th and 12th will be the peak this year.

I find it odd that particles so very tiny can make such a fiery fuss in the sky. So do other scientists, and it hasn’t been completely clear what is actually making the light. Scientist study the light from meteors to find out if it comes from ionized gas as the meteorite interacts with the air and melts and sublimates, or if it’s from the compressed and heated air that the meteorite creates as it slams in at over 40 miles per second. It may be both, but meteor spectra tell us that most of the light contains ionized bits of meteorite, making the first explanation more plausible as the main cause.

This year, the event of the Perseid meteor shower is predicted to be good. The moon will not be around to outshine the sometimes faint streaks of light, and if you can find a spot where the sky is not tainted by artificial lights, the chances are great for you to see several meteors a minute. Perseids can go off in any direction, but if you trace the streak back to the source, you will be somewhere near the constellation Perseus. Though the average sighting may be one per minute, often you will see a “clumping effect” where you may see 3-5 in a minute but then experience a lull.

The very best time to see them is always between midnight and sunrise, but that’s inconvenient for most of us. Luckily, anytime after twilight is fine, though if you can stay up, the view will get dramatically better towards morning. You don’t have to know where Perseus is, which is handy since he’s not the most spectacular of all constellations. Look toward the northeast in the early evening, and higher in the north more overhead as night turns to morning. All you really need is a fairly dark sky, perhaps a lawnchair, and some patience.

Meteor showers are one of the most fun things to watch in astronomy. You do not need the aid of binoculars or a telescope to enjoy a meteor shower, but you can try to photograph them if you’re a gambler or just very patient! You can stay out late with friends and count them or just try to be the first to see the biggest and brightest one of the night. It’s always fun to hear someone shout “There’s one” and have everyone sigh because by the time someone says those words, the meteor is usually gone. Meteor showers are social events, and a great way to watch the sky with your loved ones and friends. I encourage you to take your children or parents out for the evening and enjoy the natural show of the Perseid meteor shower.

Until next week, my friends, enjoy the view.