Tag Archives: time
Last time I introduced you to the idea of a space-time event. In physics, an “event” has the same meaning as when Hollywood blares out about a “major motion picture event” — that is to say, nothing at all special — just something that happens at a specified location and time.
If you attend a social event, it has a location and a time. When we talk about space-time events, all we mean is a specific location and a specific time (hence the name, space-time event).
Today we’ll explore some interesting aspects of such events.
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8 Comments | tags: light, light speed, space, space-time, space-time event, Special Relativity, time, time-space, time-space diagram | posted in Physics
The last two posts introduced and explored the concept of time-space diagrams. This time I’ll complete that exploration by using them to consider motion from two points of view. This will be an exercise in application of our diagrams.
I’m going to connect that application with something I stressed last week: that motion has a symmetrical component. It’s perfectly valid to think of the world moving past the train as it is to think of the train moving through the world.
It happens that here our dueling points of view are resolved by something else I discussed last week. See if you spot it before I mention it.
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11 Comments | tags: diagrams, motion, relative motion, space, space-time, space-time event, Special Relativity, time, time-space, time-space diagram | posted in Physics
3D holograms! Me want!!
Last time I introduced you to the idea of a time-space diagram, which is a kind of map used to describe motion. As with many maps and diagrams, we choose to use a flat, two-dimensional representation. Someday hologram technology may advance to casual use of three-dimensional images, but so long as we use paper and display screens, we’re stuck with two.
Motion is movement in both space and time, so we want to use one of our two dimensions to represent time. That leaves us with only one remaining dimension for space, so our diagrams exist in a reduced one-dimensional world.
Today I’ll explore that world in more detail.
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7 Comments | tags: 1D, 2D, 3D, diagrams, dimensions, maps, motion, space, Special Relativity, time, time-space, time-space diagram | posted in Physics
Last week I introduced you to the idea of relative motion between frames of reference. We’ve explored this form of relativity scientifically since Galileo, and it bears his name: Galilean Relativity (or Invariance). Moving objects within a (relatively) moving frame move differently according to those outside that frame.
I also introduced you to the idea that light doesn’t follow that rule; that light moves the same way to all observers. This is what makes Special Relativity different. It turns out that, if a frame is (relatively) moving fast enough, some bizarre things happen.
Time-space diagrams will help us explore that.
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2 Comments | tags: 1D, 2D, 3D, diagrams, dimensions, Edwin Abbott, Emmy Noether, Flatland, maps, motion, Special Relativity, time, time-space, time-space diagram | posted in Physics
Death Watch. A vigil over a dying person. Waiting. Not knowing which tick of the clock brings change. Tick. This one? Tock. This one?
There are other watches. Surgery watch. That one often brings good news. One can be hopeful. The doctor approaches with a smile; tension releases in a flood of relief.
The only relief here is that someone else, someone you love, is finally free from pain. For the rest there is only loss.
The other side of a life. Birth watch. The watch that brings joy. And cigars and balloons.
Birth. Tick. Death. Tock.
Grains of sand passing through the hourglass of life. Each of us having that brief quick ride through the throat of reality.
And having gone from there to there, at last, coming to rest.
Comments Off on Death Watch | tags: aging, death, loss, love, mom, parents, tick of the clock, time | posted in Life
The strange attractor that centers my universe for now is the growing certainty my parents won’t see another winter. Even the fullness of summer may outdistance them. The spectre came as slowly as time and a well life permits, but a thousand similes paint its implacable gait. Ages turn into years become months, then weeks, days, finally hours and minutes. All clocks stop eventually.
That they shall likely walk off into the Great Unknown almost simultaneously describes in the final act the entire arc of their life. In a word: together. Happily — no, joyfully — married for nearly seven decades. Never cursed with wealth, but ever blessed with love, they were rich beyond measure. They are why, even still, I believe in love.
To the extent I am a good person, look no further than my mother and my father.
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20 Comments | tags: aging, dad, death, loss, mom, time | posted in Life
I woke early to the sound of thunder this morning. It was hot enough earlier in the week to force me back to enclosed air conditioning. Friday, I realized it had cooled off enough to open the windows again. I very much prefer breezes blowing through my place. The weather witches mis-predicted rain Friday and Saturday but got it right Sunday morning.
I lay in bed sleepily thinking how much I enjoy the sound of rain and thunder. That thought was immediately followed by the realization that I needed to wake up and go close some windows! As the rain continued, I began to wonder if the Twins game today would be rained out, but now it’s just partly cloudy, so no problem.
I thundered yesterday, but on Sundays I try to be sunny (or just partly cloudy).
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8 Comments | tags: canine, Canis lupus familiaris, dogs, love, needles, NOVA, phobias, thunder, time, University of Virginia sundial | posted in Life, Science
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