losfomot

I don't think both these statements can be true regarding the 'antipodal point'. If the first statement is correct (which I suspect), then the second statement should be changed to something like: 'I believe you could see yourself in focus about a mile away (if it is a mile circumference) and that would be true in any direction.' And as far as the optics... I would describe it as being like you were surrounded by one solid fun-house mirror that was all wavy... some parts stretched, some parts compressed... except in a mirror your image is facing you, in an s^3 you would be facing away from yourself. By the way, thank you Martin. I appreciate you taking your time to explain some of this stuff. And the links are great too.

By 'circumference' and 'circuit' do you just mean going in a straight line until you come back to your starting point, or would going in a straight line feel like going around a bend? Also, with a pair of binoculars, would you be able to see the back of yourself?.. if so, would it matter what direction you looked in? (These questions are pertaining to the 'mile circumference' S3)

When you say 'some people find hard to imagine living in' you do not mean that some people can actually picture this do you? Or do you just mean that some people can accept the 3-sphere analog concept.

Not limited by, but still subject to the effects of? I understand that the expansion velocities can be greater than c. But are those velocities still subject to the effects of special relativity? For example, a galaxy moving away from us at .99c (due to expansion) is subject to time dilation and length contraction by a factor of 7 relative to us? EDIT- Wait, I think I am coming to a realization... because the two galaxies are co-moving, neither one has undergone an acceleration relative to the other one (disregarding Lambda), so neither galaxy could be subject to time dilation (and length contraction, and mass increase) relative to the other. Is that sort of right?

Just so I am clear about things... a galaxy that is moving away from us due to expansion is not subject to relativistic effects (as a result of said motion)... right?

the 'infinitely large' rising raisin bread dough fits in just fine with your logic? Pick a raisin... from that raisin's point of view, what center are all the other raisins moving away from?

The problem with that is... you would find that WE are where the BB started... and anyone else, anywhere in the universe would calculate that THEY are where the BB started... and we would all be correct.

Nobody needs to offer up a defense to some misguided theory. As Martin mentions, you need to learn what current Cosmology really says before trying to come up with a different theory to debunk it. At this time, you do not understand what current cosmology is saying, so how can you say that it is wrong? Take the time to learn... ask questions... do not shove aside something that you don't understand and insist that your theory is right, and that we all have to disprove it.

The problem I have is in distinguishing between expansion velocities and peculiar velocities. If there is no (physical, material thing that we can call..) space.. that is, if space is just distance between objects... then a galaxy moving away from us FTL is still a galaxy moving away from us FTL, regardless of why it is moving away from us that fast...

They can't really both share the same present (now) until the space twin has come home and is in the same reference frame as his Earth brother. Let's say the space twin leaves Earth on his journey in the year 2001... he speeds off at close to light speed... flies around the nearest star (proxima centauri) and comes back to Earth. Once he is back on Earth, the Earth brother will say "It's good to see you, you've been gone for ten years!" To which the space brother will say "What do you mean, ten years? I've only been gone for 2 years!" The year is now 2011 on Earth, and the Earth twin is 10 years older. But only 2 years had passed for the space twin in his spaceship... so he is now (biologically) 8 years younger than his twin brother. But it is still 2011 for the space twin simply because he must conform to Earth's calendar now that he is back... It would be awful hard for him to convince everyone on Earth that, according to his spaceship calendar, it is only 2003 and they should all change their calendars to conform with his. What the twins have just experienced is something called 'time dilation'. As to why this happens... well there could always be an infinite number of 'why's. If I told you it was 'a prediction of relativity', you could ask me why is it a prediction of relativity? Then I would say it was 'a side effect of the fact (postulate) that light travels at the same speed © regardless of the motion of the light source.' You could ask me why does light act that way? Then I would probably say 'I don't know, that just seems to be the way it is' Now if you start asking more specific questions regarding the answers that myself and others have already given you, you might start understanding better... For example... you might ask "Why is 'time dilation' a side effect of the fact that the speed of light is constant in all frames?" Well, when you think intuitively about distance and speed, you can add things up easy peasy. For example If you drive North at 100 km/hr, and your friend is drives in the opposite direction (South) at 100 km/hr, you can figure out how fast you are going relative to your friend by just adding the speeds... 100 + 100 = 200 km/hr. But say you are in a spaceship and you pass your friend at 99% of c. Just after you pass him, he flashes a light after you. How fast is that light beam traveling after you? Intuitively you would think: 'Well, light travels at 100% of c and I am traveling at 99% of c, so the light must be moving toward me at 1% of c' But remember that light travels at 100% of c in all frames. So the light is approaching you at 100% of c. Now, if you think about this, you would conclude that this is impossible... How can the light leave your friend at 100% of c, you are moving away from your friend at 99% of c, and yet the light beam is still approaching you at 100% of c? The only way for this to be true is if your time is passing slower than your friend's time. Think about it... if your time was slowed down (relative to your friend's time) by about 99%, then the light beam's speed would, intuitively, be 100% of c relative to you. (Please do not put any faith in my actual numbers... Your time would not be slowed down by 99% relative to your friend. It would be less than that because time dilation is not the only effect that is taking place (and I think 99% would be wrong even if it were). The actual formula is a bit more complicated than simple addition, I am just trying to show you conceptually so I used 99%. Thedarkshade just gave you the proper formulas if you want to work it out, or there are many websites that will do it for you.. here's one http://www32.brinkster.com/snefru/space/srcalc/srcalc.htm )

I just watched a mini-documentary on 'medical myths' like the 'fact' that we only use 10% of our brain. They say that is totally untrue and we use 100% of our brain. CAT scans certainly show a lot of activity...

I especially like this part, but the whole post was great.

Yeah, right... who are you selling this stuff to? Just kidding, it all makes sense to me now. I was assuming that: when ship 1 accelerates away from ship 2 at .99c, ship 1 is now standing still relative to Earth (which is correct). But I was also assuming that, to cruise back to ship 2 at .99c, ship 1 would be again moving away from Earth at .99c. This is incorrect. Ship 1 would actually be moving at .99995c relative to Earth, in order to catch up to ship 2 at .99c (relative to ship 2). Man this stuff can get confusing!

Yes but this is a doppler effect. Who's clock really is running slower via a relativistic effect? Say ship 1 takes off in some direction at .99c (we'll pretend acceleration is nearly instantaneous just for simplicity) cruises for an hour (ship 1 time) stops (relative to ship 2), turns around and comes back toward ship 2 at .99c for another hour (ship 1 time), and then stops next to ship 2 and compares clocks. Since we are pretending the acceleration periods were instantaneous, a total of 2 hours have elapsed for ship 1... has more or less time elapsed for ship 2?

I understand that... and I don't feel like I'm mixing frames... (sigh)... my problem must be here: I thought that, as the two ships traveled together with a velocity of .99c away from Earth, they could reset their speedometers (and directionometers) to zero, and assume that they were at rest, regardless of what Earth or the rest of the universe was doing. If this was the case, then it wouldn't matter what direction Ship 1 went in when it decided to leave ship 2 at .99c. Ship 1's time would be dilated relative to ship 2, because ship 1 was the ship doing the accelerating away from ship 2. So ship 1's clock should run slower than ship 2's clock. we are only dealing with two clocks right now... ship 1's relative to ship 2's... so is the above paragraph wrong?

Yes, I understand what the actual relative velocities would be. My problem is with the no preferred frame part. I thought that, as the two ships traveled together with a velocity of .99c away from Earth, they could reset their speedometers (and directionometers) to zero, and assume that they were at rest, regardless of what Earth or the rest of the universe was doing. If this was the case, then it wouldn't matter what direction Ship 1 went in when it decided to leave ship 2. Ship 1's time would be dilated relative to ship 2, because ship 1 was the ship doing the accelerating. So ship 1's clock should run slower than ship 2's clock. But, if the direction ship 1 chose happened to be back toward Earth, then the opposite would happen... ship 2's clock would be running slower.

Every once in a while I think of a scenario that I can't figure out in my head. I'm sure the solution is simply something I missed, but here it is: 2 ships in Earth's reference frame... we'll call it 'frame 1'. So Two ships leave Frame 1 and accelerate in a given direction: (we'll call it:) North. They accelerate together until they are traveling with a velocity of .99c relative to frame 1... So they have a relativistic factor of about 7... which means that (among other things) their clocks are now running 7 times slower than frame 1 clocks. The ships are at rest relative to each other and we'll call their current reference frame 'frame 2' In the next paragraph, we'll ignore frame 1 for a moment... Ship 1 decides to accelerate away from frame 2 (leaving ship 2 in frame 2). Ship 1 accelerates away in a given direction: (we'll call it:) South. Ship 1 accelerates in that direction until it reaches a velocity of .99c relative to frame 2. According to relativity, because ship 1 accelerated away from frame 2 and is now coasting at .99c relative to frame 2, Ship 1's clock should be running 7 times slower than ship 2's clock. Now we bring frame 1 back into it... if frame 2's (ship 2's) clock is running 7 times slower than frame 1's (Earth's) clock and Ship 1's clock is running 7 times slower than frame 2's (ship 2's) clock, then Ship 1's clock should be running 49 times slower than frame 1's (Earth's) clock... But Ship 1's second acceleration was in the opposite direction of it's first acceleration, which means that Ship 1 should be back in Frame 1 (roughly the same frame of reference as Earth) What am I missing here?

--------------------------- What would the world be like without religion? Less War? Stem cell research, cloning, genetic research in general would not be stymied so much? A lot of people with nothing to look forward to after they die? More war? I think there would be both good and bad changes. The thing is, it's happening as we speak. Religion is dying. Oh it's still very much alive at the moment, but as we get smarter and figure more stuff out, the church is losing ground. I have no facts or figures to offer, but I'll bet there are more non-religious people on the planet now than EVER before (both numerically and per-capita)... maybe I'm wrong?

I concur.

I don't see anything wrong with discussions of this sort. If someone reads the discussion and disagrees with some point(s), then give us your argument. But someone coming and saying something like 'it's wrong to discuss this, you should be ashamed' Seems a little like censorship. Obviously it is a topic that interests that person or he wouldn't be reading it. I am not saying that there should be an 'anything goes' policy... obviously a poster who posts in a vulgar or hateful manner should be warned and then banned if he continues. Anyway, I am an agnostic/borderline atheist myself, and I have a Christian friend with whom I constantly have arguments about the existence of god. He is (apparently) unflinching in his faith, and it annoys me, but then I think about the strength his belief gives him and his family. It is a comfort to them to know that if any of them dies, they will be up in heaven waiting to be reunited. It allays their fears to some extent (even if some of us believe that their fears are being falsely allayed). Do I really want to be responsible for taking that away from him or anyone else? No. IF anything, I am a bit jealous... unfortunately (blind) Faith remains something that I just don't understand.

Here is a 19 minute talk that I think you should listen to. It starts a little slow, but is actually quite fascinating. The gist of it is that cancer seems to be a direct result of injury to our bodies (ie - if you smoke you are damaging your lungs and have a higher risk of lung cancer) so perhaps cancer is part of the bodies healing mechanism gone bad. My understanding of what she is saying is that cancer is the bodies way of trying to replace the damaged tissue with new tissue... but something is going wrong. Anyway, I think it relates to this discussion if not to the OP, and it really is a fascinating talk. Check it out.

I'm not sure that I understand exactly what this is... can give us a bit more info? For example, your drawing looks like a picture of the tracks on a track loader, but the description calls it a wheel... are you talking about wheels or tracks? Does this thing 'levitate' vehicles or just propel them forward magnetically? And what do you mean by the reverse of magnetic levitation? You seem to get it... want to explain it to me?

In an effort to impress Klaynos.... I thought, at first, that 'inertia phenomenon' referred simply to INERTIA... but now I think he just uses 'inertia phenomenon' to describe the expansion of space. I think he is looking for something that could be used as a universal reference frame (like the cmbr maybe?) And, I can't make out the details but, I think he's giving us his theory of gravity based on motion relative to this universal reference frame. NOVAJOE - I have to agree it is very hard to understand, as you seem determined to use unnecessarily big words to try get your idea across, and it just doesn't help. Try to cut down on the fancy sentences ( ie: How are we to modify a postulate for the functionality of the inertia phenomena could just have easily said: How can we explain the expansion of space... and if I'm not translating correctly, you still get the idea.)

Like AI just said... a magnet sitting still on the table in front of you does not create an electric field because it is not moving relative to you. Take a magnet and an electrical wire. place them beside each other on the table and there is no electric current flowing through the wire... but if you pick the wire up and sweep it past the magnet lengthwise, a current will run through the wire. This is what is meant by 'frame dependent'... The magnet has a magnetic field in one frame and an electric field in another frame (the frame that is moving relative to the magnet) (I hope this is correct, I'm no expert I'm just trying to help convey the idea in an understandable way)

The photon simply doesn't have a rest frame... so we can't talk about the photon's travel from the point of view of the photon. OK... The photon doesn't have a point of view, but for the sake of this discussion, I'll word the answer as if the photon did have a point of view: From the photon's point of view, it's entire journey is instantaneous... it doesn't travel from one point to another because, from the point of view of the photon, the two points (origin and destination) occupy the same space... there is zero distance to travel. So you cannot say 'the photons, relative to each other, are not moving' Because it implies that the photons have a rest frame.