When an object with mass moves at a speed approaching the speed of light, it's inherent properties are changed in surprising ways.
There are three relativistic effects that occur on objects with mass. These are length contraction, time dilation, and mass increase. Relativistic effects occur on any object with mass moving at any speed, but these effects are infinitesimally insignificant unless the object is moving at a noticeable fraction of the speed of light (approximately 3.0 X 10^8 m/s).
One of these effects, time dilation, has been detected on spacecraft orbiting the Earth. A spacecraft such as the shuttle orbits the Earth fast enough and long enough to slow internal clocks by a few seconds in relation to previously synchronized Earth based clocks. One of the easiest ways to understand this effect is to think of objects with mass as traveling through space-time, instead of just space. All objects with mass travel with a constant "speed" through space-time (It's not really velocity, as velocity is motion over distance, not distance and time). If an object is stationary in relation to its surroundings, it is traveling only through time, at it's constant speed. In fact, the object is traveling through time alone at the speed of light. If the object begins to move, it's speed through space-time remains constant, but it's speed through time must slow down to compensate. If the object moves through space at a speed approaching the speed of light, it's speed through time diminishes significantly. If it moves through space at the speed of light, it will stop "moving" through time altogether.
Lack of time is the least of the object's worries though. As an object's speed approaches the speed of light, it's length gets shorter in the direction that it is traveling. If it travels at the speed of light, it will have no length at all! This is called length contraction.
In addition, an object moving at a speed approaching the speed of light will get more massive. If it moves at the speed of light, it will have an infinite mass. In fact, it would take an infinitely large force to accelerate a mass to the speed of light. This is mass increase.
So you might ask, how does light travel at the speed of light if this is so difficult? The answer is that light does not have mass. Photons, the particles that make up light have energy, but no mass. Particles that make up you, me, and the Earth are up quarks, down quarks, and electrons, which each have varying amounts of mass and energy.
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Comments
Jun 12, 2006 3:25 AM
Tyson Yunkaporta
:
hi
i'm the writer for the aboriginal rights section here at suite 101, and i recently did an article using some very basic ideas about relativity to challenge the accepted linear view of time and put forward the possibility that indigenous constructs of time, always referred to as "mythology" are in fact equally as valid and quite possible.
i'd really be interested to see any feedback or expertise you can add to this, which is really out of my field. feel free to link to or blog about the article, or review it, or do a critique or start a discussion or whatever. let me know if you do anything, so i can link to you.
<a href="http://aboriginalrights.suite101.com/article.cfm/linear_vs_circular_logic">Linear vs Circular Logic</a>
tyson yunkaporta
Jun 17, 2006 5:43 AM
Katharine M. J. Osborne
:
I read your article "Linear vs. Circular Logic", and I find this a really interesting topic, though more from a sociological perspective than one of physics.
I do however have one technical criticism. You stated that time changes for objects moving away from Earth because the gravity field of the Earth diminishes. As far as I know, this is not true in this way (if you have a source, I'd like to see it). The passage of time does not change for the object itself (relative to itself), but an observer on Earth will notice that the object will slow its passage through time in comparison to Earth. This has nothing to do with the Earth's gravity, but it happens because the object travels faster than the Earth, relative to the Earth. All objects travel at a constant speed through space-time. If you increase your speed through space, you decrease your speed through time. So it is a pretty straightforward relationship.
Now, as for how time is perceived by people (western or otherwise), it is unfortunate that there has been so much discrimination towards different groups of people based on a particular concept of time. Though I'm sure that if how time is interpreted was never a factor in cultural collision, other things would have still given rise to a similar state of oppression and prejudice.
The western concept of time is perhaps only several centuries old, and originated with the invention of reliable timepieces such as waterclocks. Before that, Europeans used natural cycles: day and night, the lunar cycle, and the annual cycle. If colonizing westerners felt that precise timekeeping was a mark of superiority, it was probably because they connected it deeply to the recent advancements in science and navigation that it had helped to bring about, which in turn had propelled them rapidly around the world.
What I find more disturbing, is the continued lack of respect for indigenous thought and philosphies (even indigenous european thought). Anything that isn't rooted in Judeo-Christian-Muslim thought today is considered "fringe", "cultish", or "mythology", even in the secular realm (some more hardened atheists believe it to all be mythology - which is probably more fair than picking and choosing). I think this is unfortunate. All philosphies ought to be considered as equal. This promotes an environment of openess that allows for new thoughts and ideas to emerge.
Science has yet to figure out the exact nature of time. There is an "arrow of time" that imp
Jun 18, 2006 1:43 AM
Tyson Yunkaporta
:
well, thankyou for the best reply to a post i have ever seen! i will revise my wording in the article - might just mention relativity. my source was stephen hawkings in brief history of time, although i may have misread it.
i am working on a few ideas about linking rainbow serpent dreaming to wormhole and superstring theory. if you think about the patterns of wave particles (or packets? how does the uncertainty principle work again?) and if you think about the way almost every indigenous culture on the planet (including the british "wyrm") has a serpent or dragon as a participant in creation or destruction. but still only half-thoughts as yet (so was the other article, to tell the truth!). anyway, if you have any ideas about that, then let me know.
Jun 18, 2006 5:43 AM
Katharine M. J. Osborne
:
I'm not that familiar with the concept of the serpent - other than a vague notion recalled from the short-lived sci-fi series "Millenium" that had a logo depicting a serpent eating its own tail, and I'm not entirely certain of the meaning of that particular symbol. Could you explain what rainbow serpent dreaming is?
I'm not sure how this relates to wormholes (which are still theoretical), though it is thought that wormholes can form to join two nonlocal points in space, making them as if they were near or local. We really don't know enough about the nature of space-time to say for certain if they are possible, but it is an intriguing concept; it would be a way to step around the limitations of the speed of light. Travel between distant points might become possible. The movie and TV show "Stargate" revolves around this concept (as well as many other sci-fi stories), but wormholes are still only fiction. One major possible limitation is that the act of passing through one might destroy the information in an object (a blackhole destroys the information in objects, but retains the energy of the object), but a again, we really don't have any idea. Now I feel like a big geek talking about sci-fi! :-)
