Tag Archives: General Relativity

Physics in 2010: The more we understand, the less we know

27 Tuesday Jul 2010

Posted by in Book Review, Higher Education, History, Lessons of Life, Passionate People, Print Media, Random, Relationships, Science

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by Paul Kiser
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Paul Kiser

Several years ago I decided to update my limited knowledge of physics. I took my high school physics class in the early 1970’s and it was taught by a man who probably learned physics 20 years before he taught me, using a textbook that was a least 10 years old. Needless to say, I was out-of-date before my crash course in 21st Century physics.

I read Brian Greene’s book, The Elegant Universe, and his follow-up book, The Fabric of the Cosmos. I found that even though Greene’s did an excellent job of writing for the common person, my brain would still hurt while trying to grasp the concepts of String Theory, Special Relativity, and General Relativity.

The Elegant Universe by Brian Greene

Some of the things I’ve learned:

The Speed and Time Connection
Speed and time are connected and they have an inverse relationship. The faster a person, let’s call him ‘Bob’ goes, the slower time flows in relation to an observer, let’s call her ‘Audrey’. It’s important to note that 1) Bob or Audrey won’t see the change in the passage of time unless Bob returns to Audrey and, 2) the time difference isn’t noticeable until Bob gets near light speed (670 million miles per hour.) If Bob took a quick one hour trip at 99% of the speed of light he would find that upon his return Audrey will have spent 54 days waiting for him. I would advise that you just accept this concept because it’s the explanation that will make the brain hurt.

The Speed and Mass/Energy Connection
This is where things get interesting. Mass has a relationship with speed. The faster an object moves, the more mass it has, but like the time/speed relationship, it isn’t really noticeable until you get near light speed. The important thing to note is that mass grows to infinity as the object reaches light speed, which means it would take and infinite amount of energy to make the object go faster than the speed of light, which is not possible. Thus an object can’t go faster than light speed.

Here is what I find most interesting. Everything is in motion..the Earth is revolving and orbiting the Sun, the Sun is orbiting the Milky Way Galaxy, all the galaxies are in motion, etc., therefore, everything we can see, feel, and detect (i.e., everything that has mass) is traveling at a speed. If we could figure out the absolute vector and velocity for an object and send it in an opposite vector perfectly matching its forward velocity (i.e.; decelerate it) the object would drop to zero speed. Would that mean that it would lose all its mass and that time (for the object) would pass at an infinitely fast rate?

Gravity and Space
This is where things get fuzzy. Imagine a movie screen. Now imagine the movie screen is invisible unless light hits it. Now imagine that instead of the light reflecting off of the screen surface, the light causes the material of the screen to compress and concentrate in the areas where light hits it and the material reacts the strongest to the brighter the light. A flashlight would cause some compression, but a laser pointer light would cause a higher compression. Still with me?

The universe is made of an invisible, undetectable material that reacts to energy and mass. The greater the mass the more the fabric of space concentrates (gravity) causing a deformation in space/time that influences the path of other objects of mass and can influence the path of even electromagnetic energy, like light. Gravity is a component of the fabric of space/time and yet we, as of yet, cannot determine what gravity is in a physical sense. We can see the result of gravity, but we still really don’t know gravity.

Matter, Mass, and Strings
Scientists can no longer perform experiments on the elemental matter of which everything is made. It is just too small. Atoms  are giants in the new world of physics. Protons and neutrons are made of quarks and quarks and electrons are made of vibrating strings that exist in multiple time/space dimensions. Experimental scientists have had to give way to mathematicians who are able to sort out this micro-micro world, often by mathematically proving what the strings can’t be, based on what we already know.

It is unsettling for many that we have gone beyond easy experiments and analogies to understand this bizarre new world, but the simple fact is that unless you want to become a scholarly mathematician and learn all the proofs and formulas, you have to accept the work of those who are capable of seeing reality through numbers as easily as we see the fly on the fruit. If it makes you feel any better, most of us don’t how to perform brain surgery, and yet we accept a professional neurosurgeon understands what he or she is doing when they perform brain surgery. Physics reached the level of brain surgery in the 1960’s and now they have gone way beyond it.

What’s Next?
I don’t know what we will be able to do once the secrets of String Theory are fully understood. Once we understood Relativity we realized that we could make a bomb that was more devastating than we every had imagined possible. We also learned we could create new elements out of other elements. I suspect that String Theory will open new opportunities that will again go beyond our imagination, both wonderful and terrible. For now, I just marvel at the fact that everything consists of little strings of energy, including the hands and the connected mind writing this, as well as the eyes that read it. Amazing.

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