Lunch With George!

October 18, 2001 - Chili's

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Agenda

• Special Relativity (reading assignment: Six Not-So-Easy Pieces, Chapter Three: Theory of Special Relativity.
• Other topics discussed during the meal...
  • Able Baker
  • Einstein Anecdote
  • Why we don't smell so good
  • New BBEdit Book

Miscellaneous Topics During the Meal

George forwarded a humorous e-mail chain to me which began as a reference to a web site presenting the NATO standard phonetic alphabet (e.g., a license place of AZF-208 would be "Alpha Zulu Foxtrot Two Zero Eight"). Some respondents pointed out the benefit of receiving the e-mail, since Sandeep (a mutual friend of ours) had allegedly been heard to say "B as in Bandicoot"! I remembered that my father knew a different phonetic alphabet from his WWII days, so I decided to go looking. I found several sites, and many referred to the "Able Baker" alphabet used by the U.S. Navy up until 1954. Here it is:

Able Baker Charlie Dog Easy Fox George How Item Jig King Love Mike Nan Oboe Peter Queen Roger Sugar Tare Uncle Victor William X-ray Yoke Zebra

An Excellent Einstein Anecdote
George told a great story about Albert Einstein and his wife, Mileva. They were visiting Mount Wilson Observatory for a tour. After they had been greeted, Einstein noticed a bicycle nearby and asked if they would allow him to ride it. He excused himself from the tour and turned his attention to riding while his wife continued on the tour. Mrs. Einstein pointed to a particularly complex piece of equipment and asked its purpose. Their guide said that it was used to determine the shape of the universe. "Oh," she said, not at all impressed, "my husband uses the back of old envelopes to work that out."

This reminded me that I had just read in a sports page story that Miguel Batista, one of the starting pitchers for the Arizona Diamondbacks (Go D-BACKS!!!), keeps a photograph of Albert Einstein in his locker! He had been impressed by Einstein's assertion that the human imagination was boundless, and used it for constant inspiration. Even so, Miguel probably still cannot tell me how a curve ball really works!

Why We Don't Smell So Good
George says we don't smell so wellbecause human's transition to a bipedal gait took our noses too far away from the ground (where all the interesting smells can be found). As a result, a good sense of smell was no longer a critical survival trait, and diminished as a result.

New BBEdit Book
Well, I bought another book. I create this web site on a Mac using only SimpleText as my editor. Sure-- it's simple, but that's also part of the problem. There is no spelling checker, and it doesn't even have a FIND function. I wanted more features, but I did NOT want a word processor! BBEdit is the answer to my problem. BBEdit, from Bare Bones Software, has been the developer's choice on the Mac for several years, and now it contains powerful HTML tools. I've tried using it a little, but it is very powerful and thus complicated... so I need more help. I could use the on-line manual, but I really prefer a book in my hand when learning, so I bought BBEdit 4.0 for Mac, a Quick Start guide. It still hasn't arrived yet, but I'm very excited! I learned almost everything I know (which obviously isn't much) about HTML from another Quick Start book, so this one should be very helpful.

Theory of Special Relativity

Well, we've both caught up-- we're done with chapter 3. I was particularly interested in the concept that under Special Relativity that as velocity increases, mass increases. As the velocity approaches the speed of light, forces applied to a body do not add much to its velocity, but do continue to add to its momentum. This also increases the inertia. So I was thinking...

Let's say I'm on a spaceship traveling at .99c. I'm holding a cannonball, which to me still seems to weigh about 8 pounds (but to a stationary observer, it appears to mass MUCH more... something near, say, infinity!). According to the theory of special relativity, its mass and intertia are extremely large, yet I have no trouble at all throwing it across the cabin! How can this be??!?!?

Well, George says that to me it seems like I just throw it across the room in no time at all... according to my frame of reference. From the frame of reference of a stationary observer (for whom the mass/inertia of the cannonball seem to be nearly infinite), the force I apply has little or no effect-- the ball cannot even be seen to shift position within his lifetime! Oh yeah... from his viewpoint, time is now moving verrry slowwwwwwly for me. OK, I'll buy it.

More on the Twins Paradox
I cheated a little and read ahead into the next chapter (Relativistic Energy and Momentum). Feynman talks about the Twin Paradox, and answers the question of the "Philospher" (I have to say here that Feynman really trashes philosophers): If one twin is stationary and the other is in motion, how can either one tell which one is moving and which one isn't? Especially since Special Relativity says that when moving in a straight line at uniform velocity, one cannot detect (without looking out the window) that they are moving.

Dr. Feynman says "That's easy!" In order for the twins to be reunited and compare their differing rates of aging, the moving one must slow down and turn around. When he does, everything will get slammed into the other side of the ship, and he'll know he was moving!

George liked this answer just fine, but I can't live without an absolute frame of reference! So I set about thinking again. Here's my new scenario:

My twin and I are each given a synchronized atomic clock, and a sedative that puts us to sleep (we're currently exactly the same age). We're each placed on a spaceship, and sent to an area of space where the light from distant stars is blocked by interstellar dust (i.e., we can't see anything but each other's ship outside our own). Before we awaken, one of our ships is accelerated to .9c. Once we awaken, we can observe that we are moving away from one another at a very high rate of speed. I was instructed that once I awoke, I should apply my thrusters in the direction away from my twin (I guess I'm turning around!). I'm to use the thrusters until our relative velocity is zero. Then we both apply equal thrust to bring our ships together. Once I enter his ship through the airlock, I'm astounded to find that it is my twin's atomic clock that has run slower-- even though I'm the one who applied thrust and slammed everything against the wall of my spaceship! How can this be?

Well, it was my twin's ship that was accelerated to 0.9c, while I remained stationary. I then applied thrust, and caught up with him! So... I do not believe that Feynman's answer is sufficient. In my scenario, the only way we could differentiate between moving and stationary was by the values on the clocks... no experiment could detect the difference. So how did the one clock know to move at a slower pace? It could not do so without the existence of an absolute frame of reference, I don't think!