dgeake

Seems like you may have included "non-physical" in your definition just to be sure it could include time. What other non-physical "objects" exist. Is "non-physical object" an oxymoron? I don't usually think of time as an object. Maybe it's just semantics, but I think of objects as things with limits and boundaries. Is time bounded, or is it limitless? I really don't know the answer.

It probably depends on how you define a dimension. Time can certainly enter into equations just like spatial dimensions. To me time seems to be unique in only one aspect, it is incredibly difficult to travel through time except in the "preferred" direction if you have mass. And if you are massless, the best you can do is to stay in one place (in time). (In fact that might be all you can do.) At this juncture I don't think it's fair to involve tacyons because they are purely hypothetical and their use in theories usually results in inconsistencies. I'm only aware of one purported detection and it has not been reproduced. Of course if they did exist, that would mean travel in time could be bidirectional, which, I think, would support the idea of time as a dimension. Define dimension, and let the fun begin. So what is a dimension?

You mention you might be seeing the disk of Mars at opposition with the unaided eye. That is likely an illusion, but here are some things you might try. If you would like a challenge, here is a planetary observation you may be able to make with just your eyes. When Venus gets very bright it is also very close, if you view it through binoculars or any 'scope, you will easily appreciate that under these conditions it is actually a crescent. Some people with very good sight claim to actually see this cresent without aid. My eyes are not nearly good enough, but yours may be. Here's another observation which might not be possible, but then again it might. Look at Jupiter with a good pair of binoculars and you may see all 4 gallelean moons. They usually shine at close to magnitude 6 and were it not for the bright planet they orbit, they would be visible to the naked, acclimated eye on a clear dark night. Just possibly you might be able to see them without aid, but I've never heard it reported. Some folks claim to be able to see some of the craters on the moon. At just the right phase, this might also be possilbe. (Though probably not at full. It's hard enough to see them with binoculars when its full.) About the best I can do is to resolve the double stars Alcor and Mizar in the handle of the big dipper, not very challenging to most people. Anciently this was considered a test for visual acuity, but perhaps they were closer to each other then. Have fun.

I did say "is sometimes described" etc. I did not go to a single sorce, or even just to sources on the internet. I just cited a URL which I thought margot would find interesting, because I did. Unless there is such a thing as a white hole, you would never be able to exit a wormhole. There are many other things which almost certainly make wormholes unacceptable for travel even if they do exist, such as the stability of the conduit, it's dimensions, the incredible tortous warping of spacetime. They do make interesting subjects on which to speculate on however. 1. Perhaps white holes do exist, but in some other universes with different natural laws. 2. Some have theorized that a wormhole could be used as a timemachine. 3. We do not have a quantum description of gravity yet, so we know that our speculations at extremely small dimensions and high degrees of spacetime warping are actually wild guesses at present. Reliance on exotic matter is an interesting device, but just that currently, a mathematical device, as is true for almost any discussion about wormholes.

<a target=new class=ftalternatingbarlinklarge href="http://www.crystalinks.com/wormholes.html">Wormholes</a> just testing to see if I can imbed a link.

A wormhole is sometimes described at a connection between a black hole and a white hole. A black hole, of course, is an immensly dense object from which nothing, not even light can escape, once it has passed it's event horizon. Many suspected black holes have been located in the visible universe. A white hole is a mathematical prediction from the imaginary number solution of the calculation for a black holes event horizon. (One example of an imaginary number is the square root of negative one.) There are no suspected candidates for these. Apparently there are reasons to not suspect quasars might be white holes. This is an object which repells anything close to it. Nothing can enter a white hole, not even light. A workhole is the connection between these two features. Black holes almost certainly exist, white holes and wormholes probably do not exist. So the short answer to your question is: an object would be attracted gravitationally to one end of a wormhole (the black hole) and would be gravitationally repelled from the other end (the white hole.) Check this out... http://www.crystalinks.com/wormholes.html

It has been beaten: http://www.cnn.com/2000/TECH/space/07/20/speed.of.light.ap/index.html Or so someone thinks. ;-)

Fatty, The only connection I know of between Atomic Clocks and Relativity, is that these clocks are accurate enough that they can be used to observe time dilation predicted by relativity. The change in energy states which make Cesium Atomic clocks accurate actually is a consequence of quantum effects. Quantum physics is not really related to relativity in any obvious way. It must be related in some non-obvious ways, but Quantum physics was developed without much regard to Relativity. They will all come together someday in a TOE (Theory of Everything). http://science.howstuffworks.com/atomic-clock4.htm

Alternative-3, you would survive as long as the accelleration wasn't too great. You would not notice the Lorenz contraction at all. In a Newtonian universe if you accellerated at 1g (9.8 meters/sec/sec - very confortable) it would take 3*10^8 / 9.8 = 30612200 seconds to reach c. Thats about 1 year. And of course after a year you really wouldn't be going that fast because relativistic effects would prevent that. Guess what! Something does travel faster than the speed of light. (But it has no mass.) At least according to some scientists: http://www.cnn.com/2000/TECH/space/07/20/speed.of.light.ap/index.html

fatty_ashy "Erm, I was wondering if travelling at the speed of light actually means instant travel." alternative-3 "- If I were moving at the speed of light through deep space or whatever, would I get squished into a near-2D line? Would I survive?" 1. You cannot move at the speed of light as long as you have mass, because as you approach the speed of light, your mass increases and the energy requred to accelerate you faster increases. 2. As you approach the speed of light your mass approaches an infinite mass. This is how it appears to an observer outside your inertial frame (at rest). 3. Your dimension in the direction of travel also appears to contract by any measurements made by such an observer. For non-relativistic speeds this contraction is very small. The formula for the Lorenz contraction is: L = L'*sqrt(1-v2/c2) where L is the length measured by the observer and L' and v are the length measured by the subject, and the subjects velocity measured by the observer. You can see that L and L' are nearly equal unless v approaches a significant fraction of c (which is the speed of light.) 4. Time appears to slow down to an observer at rest relative to you also. The formula for time contraction is: t' = t*sqrt(1-v2/c2), where t' is the observers time, t and v are the subjects time and velocity relative to the observer. You can see that unless v approaches a significant fraction of c (the speed of light) there is very little difference between t' and t. 5. You notice none of these things until you return from your trip. On your return, we will disagree on how long you were gone. Our time measurements of your trip will differ by a certain amount, depending on how fast you traveled and how far. And both of us will be correct. 6. If you could travel at the speed of light, it would appear instantaneous to you in your inertial frame, because time (for you) would have stopped for the period which you were traveling at the speed of light. But to me, you would appear to have traveled at the speed of light, not instantaneously. This is the opposite of what sardonyx247 said, but (s)he was correct in stating that time is relevant only to the observer. Observers who are in the same inertial frame measure time identically. If the inertial frames differ, then their measures of time also differ. Lucky for us the difference is very small at speeds we are likely to travel at. 7. Fatty_ashey had a question regarding the distance of the trip as it appears to the travelers. This is interesting because their meter-stick would have contracted in the direction of their travel, but because of time dilation, they would also think they had traveled for a shorter time (and they actually did in their inertial frame); but at a higher velocity (their meter-stick has contracted). But when they multiply the time by their measured rate of travel the two effects would cancel out and they would measure the distance of the trip to be the same as an observer in a more or less stationary inertial frame. This is contrary to the conclusion drawn in the second link below. I think the difficulty is because the author is using v as measured by someone outside the inertial frame of the travelers when he should have used v as measured by the travelers. I was wrong once before, this might be the second time. ;-) (This note added later... There is something inconsistent in my explanation above, and I must admit, I am not sure what the answer is. As you travel at a constant velocity along the route, the route appears to be moving past you at some velocity in the opposite direction, and thus would appear contracted to you. I'm beginning to think that as you travel the route at a relativistic velocity it will actually seem to be a shorter route.) check these liniks: http://www.drphysics.com/syllabus/time/time.html http://www.physics.umass.edu/gemsFolder/p116f02/Lengthcontractionexample.pdf

The article states: "Dark energy will cause the universe to expanded faster and faster and eventually, over time, we will see less and less of it," Kirshner said. Over millions of years, familiar stars and nearby galaxies will disappear from view and the sky, now choked with stars, will slowly darken. "The piece of the universe that we can see will get lonelier and lonelier," he said. This may not be the final outcome of the universe. A long time ago a "steady state" theory of cosmology thought that the average density of the university is constant. The measurement of the microwave background radiation and support of the "big bang" theory left this theory in the dust. New theorys now declare that it is possible that this may still be somewhat true, if protons and electrons are spontaneously appearing in interstellar space. There is currently not much evidence for this, however, and the theory is not widely accepted. It is good to know that there are other opinion. Quasi steady state theory: http://www.iisc.ernet.in/pramana/dec1999/c3.pdf http://casswww.ucsd.edu/personal/gburbidge.html The original steady state theory: http://cosmology.berkeley.edu/Education/cosprinc.html#steadystate Awesome site with questions and answers on cosmology: http://www.astro.ucla.edu/~wright/cosmology_faq.html

If you were observing the ship from outside the event horizon, the ship would appear to approach the event horizon ever more slowly, but never actually pass through it. If you were on the ship, time would appear to pass normally and you would seem to cross the event horizon, as long as it was a very large black hole. Crossing the event horizon of smaller black holes would tear you and your ship apart due to the delta G's affecting the ship. Because of time dilation, I don't think you would ever reach the singularity. Yes the singularity has mass, it bends space and time, so it must. Ever wonder what it would look like as you crossed the event horizon? The event horizon would fill more and more of your field of view, until the universe outside appeared as a diminishing sphere in the direction you are coming from. I think to you the physics would appear as if you were being repelled by that sphere and were sailing into a vast new universe. I have never read any speculation on what that would be like and would love to be directed to speculation by someone with more knowlege than I. (That means just about anyone.)

Seems to me if an object which had passed the event horizon of one black hole was attracted to an even greater extent by the gravitational influence of a second black hole, those two black holes would be inside each others event horizons and would effectively be a single black hole. I suspect these two holes would be orbiting a common center of gravity at a furious rate and giving off gravitational waves like crazy, thus losing angular momentum and would be on the verge of merging into a new singularity. Now if only someone could detect these gravitational waves...

The measurement of velocity depends upon your inertial frame. It is not possible to be motionless with respect to all inertial frames so the question is meaningless. It would be like trying to be motionless in a car with respect to all other cars on all the streets in your town; only even more impossible. Some of the later posts seem to consider a lack of velocity with respect to the center of the universe, or something like that. Finding the center of the universe is similar to trying to find the center of an infinite saddle-shaped object, or of an infinite plane, or of the surface of a sphere; depending on what you think the shape of the universe is. (As determined by what the value of the cosmological constant ultimately turns out to be.) I use 2 dimentional objects in 3 dimentional space in the example above, becasue I my head hurts if I try to think of 3 dimentional objects in a 4 dimentional space. (Yes the SURFACE of a sphere is 2 dimentional, even though the sphere itself is 3 dimentional.)

I remember playing text-based adventure games in the late 1970's. No graphics just text descriptions. "Your are standing on a beach. To your left is a path leading to the top of a cliff. Behind you is the hull of a shipwreck." You would respond with something like "Go path". These were more like puzzles to be solved and were very linear. They did not allow much variation from the predetermined path you were to follow, but I found them very addictive. The original game which I remember appears to be available on the 'net for playing at: http://games.igateway.net/adventure/pirateadventure.html I doubt you will even get an inkling of how fun this was when computers ran at 1 mhz and had 48 k of memory (including display memory) total. The only thing close to them now, which I am aware of, are some games by Red Orb, called Myst, Riven and Myst II. I suspect the parody on these called Pyst is similar. They are not quite so linear in their play, much more intricate with their puzzles, and I find the graphics and sounds amazing. Of course I still enjoy the "if it moves, shoot it!" type of games too.

Yeast could grow in a pile of rotting food, the amount of yeast depends on the type of foods and the amount of oxygen available. Yeast are obligate aerobes ie. they need oxygen. They seem to thrive in places where there is an abundance of carbohydrates. An abundance of bacterial action tends to make the whole mess go anaerobic (low oxygen levels), which would slow down yeast growth. Baking soda and vinegar would probably not kill the yeast, but too much vinegar would lower the pH (make the environment too acidic) to a point that yeast may cease to proliferate. Too much baking soda might raise the osmotic pressure (make water hard for the yeast to get) to the point that the yeast would stop growing also. Too much of both might also raise the osmotic pressure (from sodium acetate produced) and inhibit yeast growth. This whole mess would probably decay more rapidly at a temperature closer to body temperature (37 degrees C.) or perhaps slightly higher than it would at room temperature (25 degrees C.) Such an environment might favor the growth of bacteria rather than yeast, especially if the pile was rich in proteins rather than carbohydrates. Agitation will also speed up the decay process. If the decay is produced by yeast and fungi, aeration would speed up the process also. Yeast and fungi might also prefer slightly lower temperatures. Just because yeast and bacteria are microscopic doesn't mean they are closely related. Yeasts (and humans) are eucaryotes (they have a nucleus and mitochondria), bacteria lack both of these structures (and are procaryotes). Yeasts are also much larger than bacteria. Interestingly, we are more closely related to yeast than are bacteria. Many organisms we call fungi can also look like yeasts if the conditions are right.