IM Egdall

ronians1, I'm gonna give this one last try. I hope it helps. Say you are sitting in your chair reading this. Right now you are at rest. Correct? Ya, you're at rest with respect to the chair you are sitting in and the Earth upon which it sits. But what about the Sun? You, the chair, and the Earth are moving at some 67000 miles an hour with respect to the Sun. Do you feel this speed? No. Why? Because you are moving in (nearly) uniform motion -- hardly any change in speed or direction. And right now you, the Earth the Sun, and the rest of our solar system is moving relative to the center of our galaxy at some 486,000 miles an hour. Yet you don't feel this motion either. Everything in our universe is moving relative to something else. And perspective or point-of-view cannot be brushed aside. It is key to understanding what is going on. From your point of view, you and the Earth are at rest (that's why you see the Sun rise and set). To you, time is running normally. But an observer say at the center of the Milky Way galaxy sees you moving relative to her at 486,000 miles an hour. So she sees you and your clock and your biology and everything else on this Earth moving slower. She measures your time as running slower than hers. There is no absolute time. You must give up this notion. (I teach lay physics courses but please find your own physics teacher who is knowledgable in relativity -- she/he will certainly confirm what we are all trying to say to you here.)

Ya, but . . . space between galaxy clusters is expanding. Space inside galaxy clusters is not expanding because spcaetime curvature (gravity) within clusters overcomes expansion forces. So if new material is formed inside galaxies, how does this produce expansion outside galaxy clusters?

In your example, if you were on that spaceship cicumnavigating the Earth, the hands on the spaceship clock would be running normally as you see it. From your perspective on the spaceship, you are at rest and the Earth is moving. From your point of view, you are not virtually frozen in time. But we on Earth see your spaceship clock running much slower than our Earth clocks and, as Swansont pointed out, your heart beating much slower. To us on the Earth, you appear to be virtually frozen in time. You on the spaceship measure the hands on the spaceship clock running at a different rate than we measure from here on Earth. As strange as this sounds and as hard as it might be to accept it, this is what relativity is telling us.

Observations indicate the observable universe is flat. But I think the entire universe -- which includes objects so far away their light has not had time to reach us yet -- may very well be curved. Inflation theory predicts the universe underwent an exponential expansion just after the big bang, making the region of the universe we see appear flat. (Sort of like blowing up a balloon to gigantic size so that an ant on the surface of the balloon sees the region it lives on as flat.) I don't think anyone knows for sure what the curvature of the entire universe is.

Here's an example. Muons are a heavier form of electrons. They are unstable particles and only exist for a small fraction of a second before transforming into lighter particles. When they are made to go at speeds near the speed of light, e.g. in particle accelerators, they last much longer than they do when at rest. What gives these muons a longer life (as seen in the laboratory reference frame)? Time dilation. This increase in lifetime matches predictions of special relativity. So here we have evidence for a subatomic particle and the relativitity of time. Since biological systems are made up of subatomic particles, this implies biological systems in uniform motion also experience slower aging as seen from a frame at rest. Muon time dilation has also been verified in our atmoshpere. See link: http://home.fnal.gov...ght_page18.html

Nah. The laws of physics are the same in any uniformly moving reference frame. Say you are in a rocket going at a constant speed of 99.9 percent the speed of light relative to me. From your point of view, you and your rocket are at rest and I am moving by you in the opposite direction at 99.9 percent the speed of light. But from my point of view, I am at rest and it is you who are moving. Since in your reference frame, you are at rest, time for you goes by "normally." You see no effects of motion on the rate of passage of your time. But you see me going at 99.9 the speed of light. So from your point of view, my time is running much slower. (By a factor of 0.045X.) What do I see? I see myself at rest, my time running normally, and your time running much slower by the same factor. Whose point of view is correct? They both are. Time is relative.

So do you mean by this to say that per Bell's theorem experiments either: 1) Local but no scientific realism - the universe is local but a particle's variable attributes are not there until you "look at them", or 2) Non-local but there is scientific realism - the universe is non-local but a particle's variable attributes are there before you "look at them"? I thought Bell's theorem experiments show the universe is non-local, period. And the interpretation using standard qm says there is no scientific realism -- a particle's variable attributes are not there until you look at them. However other interpretations like Bohm's qm are non-local but do maintain scientific realism. Do I have this right?

After conducting his own analysis, skeptic physicist Richard Muller now convinced "global warming is real and humans are causing it." http://www.scientifi...=SA_WR_20120801

Einstein's field equations of general relativity has proven to be the most accurate theory of gravity to date. And when it is applied to the universe as a whole, it predicts the universe is not static -- it must change size over time. In 1928, I think, Georges Lemaitre combined Hubble's galaxy distance measurements with known redshiift data to show that in general the further away a galaxy is the more its light is redshifted. Lemaitre proposed this as evidence for the expansion of the universe as predicted by general relativity. Observations of supernovae in 1998 and later observations show the expansion of the universe is speeding up over time. The cause of this acceleratation-- dubbed dark energy -- remains a mystery. I hope this helps.

In the expansion of space, the distance between galaxy clusters is increasing. Does this mean there is more space between the clusters as time goes on? Yes. Thinking of space as a fabric is just an analogy, not to be taken literally. I believe the NASA figure above is meant to show how the spinning of the Earth drags space around with it -- a phenomenon called frame dragging. In the Gravity Probe B satellite, a set of gyroscopes were set to point in a certain direction. Over time, they drifted ever so slightly. The average amount of drift agreed with frame dragging predictions (to about 20%, I think). Objects in "empty" space (gyros) were affected by the spinning of a distant object (the Earth). Another strange prediction of general relativity confirmed.

I think this is a bunch of baloney. It uses physics terminology to justify pseudoscience.

Light always goes at the same speed, no matter what the (uniform) speed of the source of that light or the (uniform) speed of someone observing the light. This is Einstein's light postulate -- verified in countless experiments and tests. Eisntein's light clock thought experiment shows that -- due to the light postulate -- time runs slower with relative motion. Take a look at this link: http://galileoandein.../lightclock.swf In the link, a photon (particle of light) in the left clock (Jack) goes up and down between the two mirrors of the light clock. Imagine that when the photon hits the top mirror, the clock goes tick. When it hits the bottom mirror, the clock goes tock. So we hear tick, tock, tick, tock. Now set the speed dial above to say 0.87 c and press play button. The clock on the right (Jill) is now moving relative to you. But the photon in the right clock is unaffected by this uniform motion. So it goes at the same speed as the photon in the stationary clock on the left. But because the right clock is moving, the photon has to travel a longer diagonal path between the mirrors. Longer path at same speed means longer time. So the right moving clock goes tick . . . tock . . . tick . . . tock . . . This is called time dilation. As you see it, time on the moving clock runs slower than time on the clock at rest. Numerous epxeriments and observations have verified this strange phenomenon. Time is relative!

I think the documentary was talking about speed through spacetime. This is a combination of speeds through space and through time. As I understand it, speed through spacetime is always c, the speed of light.

Thanks, ajb, for the enlightenment.

This article suggests its not the Higgs, but the top quark "super-particle" or stop squark. Seems a bit premature to announce it, but what do I know. http://physicsworld.com/blog/2012/07/the_higgs_seven_days_on_what_h.html

Deosn't string theory propose that all fundamental particles are made of one-dimensional vibrating strings? And most strings are open-ended, so their ends stick to the "brane" that is our 3-d universe. But the strings for the gravity particle are a closed loop. They are not stuck to our universe but can travel to other universes. This, I think, is the general idea. So since gravity particle strings, unlike other forces, can escape our 3-brane universe, this explains why it is such a weak force compared to all the others. And if gravity strings are free to travel from one universe to another, maybe they can be used to communicate between universes. This is all speculation. So far, there is no substantive evidence which supports a prediction of string theory. Sorry for the double post. Either I pressed submit twice, or its a post from a parallel universe.

Deosn't string theory propose that all fundamental particles are made of one-dimensional vibrating strings? And most strings are open-ended, so their ends stick to the "brane" that is our 3-d universe. But the strings for the gravity particle are a closed loop. They are not stuck to our universe but can travel to other universes. This, I think, is the general idea. So since gravity particle strings, unlike other forces, can escape our 3-brane universe, this explains why it is such a weak force compared to all the others. And if gravity strings are free to travel from one universe to another, maybe they can be used to communicate between universes. This is all speculation. So far, there is no substantive evidence which supports a prediction of string theory.

As I understand it, quantum mechanics and general relativity are based on fundamentally different views of nature: 1) General relativity assumes the universe is deterministic. For example, if you know the location of a particle and its velocity (speed and direction), you can know where it will be in the future (and where it was in the past) -- in principle to arbitrary accuracy. But according to the Uncertainty Principle of quantum mechanics, you cannot know a particle's location and velocity simultaneously to arbitrary accuracy. The lower the uncertainty in one parameter, the higher the uncertainty in the other. Quantum mechanics says all you can do is predict the probability of where a particle will be in the future or where it was in the past. But there is no Uncertainty Principle in general relativity. 2) According to general relativity, space and time (spacetime) are warped by mass/energy. There is no such warping of spacetime or spacetime curvature in quantum mechanics. These differences are big reason why the two theories are not compatable.

Thaks for the link. Really cool discussion. I'd never considered that a star could have overall zero energy.

There is an inherent logic to the universe. That is why humans can construct mathematical equations to represent physical behavior. It underlies all the so-called laws of physics. This logic, I think, represents Einstein's "God".

Do you know of a link to Jordan's idea?

I'd like to add my happy birthday wishes as well. I love this forum and have learned so much. Keep up the good work, staff and members!

I think your explanation is really good. Some writers talk about this so-called quantum consciousness, as though you need a conscious observer to collapse the wave function to get a localized particle like an electron. But its really an interaction which results in the wavefunction collapse, and that, as you say, can be with a brick wall -- so human or other consciousness is not needed. At least that's my take on the subject.

CERN says it found a new particle and it is a boson. This alone is a remarkable achievement. But they say they need more analysis to know whether it is the Higgs boson predicted by the standard model of quantum mechanics or something more exotic. My bet is that it's the standard Higgs. See link: http://physicsworld.com/cws/article/news/2012/jul/05/its-a-boson-but-what-sort