MigL

Note that I'm not saying they don't have valid reasons, but a protestor's rights to protest, stop when they start infringing on my rights to conduct business and live free of fear. I believe Voltaire said something to that effect. Even if we consider Officer Wilson's behaviour criminal, I fail to see how more criminal behaviour solves the problem.

The universe is worse than any bank , Mike. It strictly enforces its lending rules, and will not let you borrow to cover an existing debt. If the universe can't collect on a virtual particle pair, on the edge of the event horizon of a black hole, because one of the pair has fallen in and the other had to become real, it takes its "pound of flesh" out of the black hole's mass. There's no free lunch or debt.

Tar, what if the Great Attractor is spinning ( more than likely ), and we are orbiting around it ? That means in the time it takes for one orbit, the direction "towards the Great Attractor" has changed by 360 deg. i.e. half an orbit ago, you were pointing backwards ! Any frame, no matter which you choose or how big, will always be moving with respect to another. So there cannot be an absolute one.

Ooooo, that's harsh, Ophiolite I think he's a little confused, we've all been there. Michel123456, consider a volume of space, say 100 mil LY radius around us, and note the density of galaxies as well as their make-up. Now take a look at a field of roughly the same spherical volume, but at a distance of say 4.9 to 5.1 bil LY from us, in any direction ( it doesn't matter ). Is the density of galaxies in that volume greater than the first volume, immediately surrounding us ? Are a lot of the galaxies elliptical rather than spiral with a predominance of active. black hole cores ( quasars ) ? Is the composition of these galaxies primarily younger generation stars, and a lot more gas clouds? These ( and others Mordred has listed ) are the observations which tell us the universe has expanded since 5 bil years ago. What evidence do you have to the contrary ?

Mike, the supply of energy by the vacuum, is a process that's accepted and reasonably well understood. It explains the concept of virtual particles, which are necessary for many calculations. Vacuum energy is constrained by the Heisenberg Uncertainty Principle, however. It can only be 'borrowed' from the vacuum, for minute periods of time, and must then be re-paid. Virtual particles are, therefore, elusive and short-lived. These virtual particles and the way they behave, make QM extremely useful and accurate. It wouldn't 'work' without them. We can 'see' photons from 300-400 mil years after the big bang ( the CMB ). That's over 13 bil years ago. So if photons are borrowed vacuum energy, how can they be soooooo long lived ?

Well way to go, John, Studiot and Strange. We may have lost another productive and valuable member because of your strict adherence to logic, facts and common sense. When will you guys learn !

Here is a simple experiment, Michel123456... Set up a camera to take a picture of the same location at two different times. It is very easy for you to be in both photos, is it not ? You stand in front of the camera yesterday, and there you are, yesterday, in the photo. Similarily, you stand in front of the camera today, and there you are again, today, in the photo. And I have no doubt that if you repeat your efforts tomorrow, you'll be there again, tomorrow, in the photo. And even if you look at these photos in a month or a million years, you'll still be there in the photos. The fact that time has progressed doesn't mean that you disappear from that space-time co-ordinate. Now set up two cameras, side by side, to take a picture of two different locations at the same time. Can you be in both photos ? Without Photoshop of course. Why do you think that is ? And if you can't, does that mean you need to re-examine the similarities and differences between spatial and temporal dimensions ? Maybe they don't 'work' the same way and are not as similar as you think. Maybe you should stop applying your preconceived notions about movement through the spatial dimensions, to movement in the temporal dimension

So ( because I'm still not clear ) is the uncondensed scalar field tachionic in name only, implying that it's unstable and you're heading down the wrong path ? Or does the uncondensed phase allow for tachions ( which I thought no theory is happy with as it implies something has gone wrong ) ?

I'm gonna have to say you've got it back-assward, Eise. We measure change using time. It is very convenient that the inverse also happens to work out and we can use change to measure time also. As SringJunky has stated, time proceeds ( rather the local 'now' proceeds ), and that allows us to gauge the amount of change. But at any instant in time, there is no change. A foliation of the manifold which is space-time, has no movement in the three spatial dimensions. This is, of course classical GR, where every event ( x,y,z,t co-ordinate ) is 'fixed'. AS for QM, bearing in mind that I'm not sure about this, is it accepted that electron orbital jumps are instantaneous ? Even granting that a lot of orbitals overlap, so this isn't necessarily a violation of locality, would this not allow for change without the passage of time ?

Take two harmonic oscillators, Eise. One completes one cycle and stops. The other completes 1000 cycles and stops. Neither has changed more than the other, they are both back at their original position, yet for the second oscillator 1000 times the amount of time has passed. So I really don't follow your reasoning. Time can pass without anything changing.

Yeah, maybe I put it too simply. And Mordred had already explaned the difference between the Hubble sphere and Cosmological event horizon.

Yes, to put it simply, extremely far-away galaxies will move away from us faster than c, so their light will never reach us. There is an 'outside' to what we can observe ( observable universe ) which we'll never see and can never affect us.

What are your thoughts on what was said by R. Giuliani the other day ? To paraphrase... ' African-Americans are outraged at the shooting death of a young black male by a white Police officer, yet 93 % of black Americans are killed by other black Americans. Where is the outrage for those deaths ? Why are they being ignored ? " Is the implication that this is more about the opportunity to air Black vs. White grievences ( and raise some hell ), than about Brown's death/killing ?

" It goes from here to there. It changes coordinate. Why is it so difficult conceptualize the same thing for time?" Because an object cannot be at two different places, here and there, at the same time. But that same object can certainly be in the same place at two different times. Maybe you hadn't noticed, but time is different from position, conceptually as well as how it's treated. You cannot go freely from 'here' to 'there' in the time dimension ! I do see where you get the idea of an 'extension in time' though. Since light takes a finite time to get from your head to your feet, by necessity, the local 'now' at your head must be different from the local 'now' at your feet. This is a minute amount and trivial. GR being a classical theory means it treats all particles as dimensionless points, so although the aggregate 'you' may have a fuzzy ( how long does light take to get from your head to your feet ) , local 'now', the individual particles that make 'you' up all have an explicit local 'now'.

Say a car is 100m away from you. And say that car is moving at 100m/s away from you. After one second it is no longer 100m distant, but 200m distant. The universe is 13.7 bil yrs old, but it has been expanding ( at variable rates ) since then. Do you see how it works Dima ?

How about we stop talking about unmeasurable things at the Planck scale. Lets talk about things that have to be counted, like you suggest. Pi is not a ratio any more than 100 cm is the ratio of a meter to a centimeter. 2PI is a count of how many radians add up to the circumference of a circle. The units are radians. How many are there ? Can you count them for us ? And if you can't, does that mean there cannot be radii or diameters ? Or does this just apply to cows ? Six pages of silliness and counting. I believe you've set a record. Keep it up and you'll be mentioned by name in that thread in the Lounge subforum.

So Zapatos, I watch the news here in Canada, but can you tell us what the situation is really like in Ferguson after the GJ verdict ? Airbrush, I've heard it many times that police should shoot for the legs. That is impractical, most cops are not marksmen, and are trained to shoot at the largest part of the body when a perp is charging/threatening them. That being said Brown was hit in the head, so it must have been close enough that if he had wanted to, the officer could have just wounded him. Even wearing video cams wouldn't solve the problem, as the PD could always cite that its an ongoing investigation and the video cannot be released ( that doesn't mean your suggestions wouldn't help ). I wonder if the officer involved will at least, lose his job ? Or maybe a civil suit ?

"At any instant the object is at a single point in time" Very profound Strange ! But at another instant, it is at another point in time ( +space ) If you were at location A one hour ago, the fact that you are at position B now does not mean you were no longer at position A one hour ago. Points ( events ) in space-time are fixed. GR being classical, past and future are just as 'real' as present. They just can't be accessed like spatial co-ordinates can. Is it just me, or is English ( or any other language ) unsuited for describing the 'workings' of time ?

String ( or M ) theory is a very elegant theory ( so they say, myself, I don't understand the math ) in search of a universe to describe. It provides an infinitude of models. Picking the one which describes our particular universe is a challenge. That doesn't mean it shouldn't be investigated further, as it could provide a 'framework' for a final theory, although I have a particular fascination with the competing LQG. Investigating these theories experimentally is way beyond current technology, even if they did make testable predictions. The evidence for the Higgs mechanism, the Higgs boson ( and the final proof of the Electroweak symmetry break ), has been found. It turns out it was hiding in Switzerland all along. It will keep the standard model viable, even if only a 'limit' for years to come.

I guess there are no circles in your world davidivad. The ratio of a circumference to the radius is Pi ( sorry no LaTex ). What are the units of Pi ? Is it related to h ? Yet we can measure it. Use it in calculations. and very simply disprove your assertions. The fact that certain things are quantized doesn't require that EVERYTHING is quantized. And if that is your assertion you need to provide some evidence for your thinking. Anything other than 'this apple is red, all apples must be red'. We have QM on the one hand and GR on the other. Both work extremely well in their own domains, but they only slightly overlap. Perhaps a quantum gravity theory will demand quantization of space-time, but we don't have one yet, and wishful thinking on your part is not proof. Nor is the assertion that all we calculate is in discrete numbers ( see first paragraph ).

A world population of 7 bil and rising is a problem. A cut in birth rates, however causes additional problems. You end up with an aging population ( already a problem in western nations and the reason for high immigration rates ), where too few young people support ( through taxes ) too many old, retired people ( on pensions ). People then, whether they like it or not, need to work to a much older age than 65. This is difficult because although we can keep people alive longer, the body and mind do wear down and are incapable of the same effort of a younger age. This is where cloning could help. I don't suggest a cloned person, and I'm not foolish enough to wade into the ethics of such actions with regards to religion and personal beliefs. The cloning of body parts and organs could, however, be beneficial to an an aging population. Say every person, at puberty, is required to store some genetic material ( a vial of blood ? ), to be used later on in life, when needed, for replacement organs, limbs, joints, etc. We don't have the technology for this. Yet. But we may in the near future. What are the ethical implications, if any, of this limited 'cloning' ?

The one and only theory we have which deals with time ( superficially I might add ) is GR. GR tells us all space-time events are fixed in the manifold. If a cat is at co-ordinate (x,y,z,t), then an observer in the local 'now' of this co-ordinate will see the cat. If the observer is not in the local 'now' of the co-ordinate, he may not see the cat, because it may have moved, or it may not have been born yet, etc. The only way 'your extended in time' makes sense is time has a 'granularity', such that there's a smallest unit of time and time proceeds in 'steps'. Then the local 'now' would extend across that smallest time unit. This begins to sound like a quantisation of space-time or a quantum gravity theory. Unfortunately we don't have that yet What we do have is 'classical' GR which says world lines and no extension in time for events. Who knows maybe 'quantised' GR will provide a better understanding of time and that you were right all along. Look me up when that happens and I'll gladly buy you dinner and drinks.

Pzkpfw's cat is at the BBQ at 1pm and will always be there. That point is 'fixed' in space-time. Pzkpfw's cat is at the Birdbath at 2pm and will always be there. That point is also 'fixed' in space-time. Space-time events do not move, they are fixed. There is nowhere/nowhen else for them to move to. The cat follows a world line along the time axis. Actually more of a cat shaped world 'tube'. We've had this discussion before Michel123456. This is what GR tells us. I'm guessing it wasn't to your satisfaction

I'm beginning to see an 'agenda' to Michel123456's OP.

I think John is so opposed to the idea of a Christ, because he's afraid it may be true, and he has lived a sinful, evil life, Just kidding John. Thank God I'm an atheist !