IM Egdall

Yes, but a new theory must still explain all known observations to be viable. I found my notes but can't find the link. They say that there are observable differences between black holes and other compact massive objects. Infalling matter collides with the object at relativistic speeds, leading to high-energy emissions. Thermonuclear "burning" may occur on the surface as material builds up. This produces irregular flares of X-rays and others. The lack of flare-ups is evidence the object is a black hole because there is no surface onto which matter can collect. Does Krauss's theory explain this?

To expand on Swansont's comments, say you are in a car moving along a highway and I am on the side of the road. To you inside your car, time is running normally. But to me on the side of the road, I see your time running slower. Why? Because you are moving with respect to me. At car speeds, this effect is extremely tiny. But if you were in some future rocket-car traveling at say 87% the speed of light (relative to me), then according to special relativity, I would see your time running slower by 50%. So for every second which ticks off on my watch, only a half second ticks off on yours. However, you inside your rocket-car still see your clock running perfectly normally. Why? Because your clock is not moving with respect to you. This is the wild world of relativity.

I think all the arguments with Owl could be resolved with the facts from actual experiments. But here's the problem. We have all kinds of evidence with atomic clocks on airplanes, rockets, and satellites and numerous laboratory experiments that time does indeed slow down with motion, and in the amount predicted by Einstein's special relativity formula. But the evidence for length contraction is indirect. I know of no direct measurement verifying length contaction. I'd be thrilled to learn that I am wrong.

The speed you measure depends on your perspective (more formally, your frame of reference). But per special relativity, no matter what your frame of refernce, the speed you measure for any object cannot exceed the speed of light. More precicely, no object with mass can reach the speed of light. And light itself (or any particle with zero mass) always measures as traveling at the speed of light, no matter what speed you are traveling at.

The Uncertainty Principle is fully consistent with the results of the double-slit experiment. See link: http://galileo.phys.virginia.edu/classes/252/uncertainty_principle.html

Say object A is moving to the left at 30,000 miles an hour relative to you. And say object B is moving to the right at 60,000 miles an hour relative to you. Now at what speed is object B moving away from object A? Newton would say 30,000 plus 60,000 equals 90,000 miles an hour. But this is incorrect. Per the relativistic formula given above, the true answer is 89,999.99964 miles an hour. (If you set w = 30,000 and v = 60,000 and c = 670 million and solve the equation; this is what you get.) So for small speeds relative to the speed of light, Newton's simple formula is an excellent approximation. But at speeds approaching the speed of light, the asnwers are quite different. For example, say object A is moving at 90 percent the speed of light and object B is moving at 80 percent the speed of light in the opposite direction. At what speed is B moving away from A? Newton says 0.90 plus 0.80 equals 1.7. This is 1.7 times the speed of light. But if we set w = 0.90 and v = 0.80 and c = 1 in Einstein's equation, we get the answer of 0.988. This is 0.988 times the speed of light. In fact, per Einstein's formula, no matter what the speeds of the two objects, the resultant speed is never greater than the speed of light.

There is no invariant description of distance. There is no invariant description of time. All the evidence, experiments, tests, etc. confirm this. Whether we like it or not, this is how the universe works. But there is a combination of space and time which is invariant! It's called the spacetime interval. Take two events; like a light flash here at a certain time and a light flash there at another time. The separation in space (distance) between the locations of the flashes is called the space interval. The separation in time between the two flashes is called the time interval. Both are affected by motion. So both are not invariant; they are relative. Different observers moving at different speeds with respect to each other all measure different values for the space interval and the time interval between these same two events. Now bear with me; the spacetime interval, ds is defined as: ds^2 = c^2dt^2 - dx^2 (One space dimension for simplicity) Here dt is the time interval and dx is the space interval. This so-called spacetime interval is invariant. That is, it is unaffected by the uniform motion of the observer. It is absolute. (Alll this comes from the fact that the speed of light is invariant. ) So the spacetime interval does not depend on reference frame. Say the Sun emits a single photon at its surface at some time. This is event 1. Then the photon strikes the surface of the Earth at a later time. This is event 2. Observers in motion with respect to each other will all disagree on the space interval (distance) between the two events. This means they disagree on the distance from the Sun to the Earth! And they also disagree on the time interval between the two events. That is how long it took the photon to go from the Sun to the Earth. But when they put there individual measurements of the space interval and time interval into the formula above, they all get the same value for the spacetime interval between the two events.. So the spacetime interval is the same for all observers.

A black hole and the big bang are not the same. I read somewhere that a black hole is a singularity in space extending through time. And the big bang was a singularity in time extending through all space. Think about that mind-twister! So the big bang is not just a single location in space; it is space itself which is contacted. And then space expanded, taking the particles (matter and energy fields) with it. And per special relativity, nothing can travel faster than the speed of light through space. But per general relativty, space itself can (and does) expand faster than the speed of light. And remember, the so-called singularity is really a problem. Here all known physics breaks down. So no one knows whether there really was a singularity of infinite density and infinite temperature at the big bang. I think most physicists doubt this description. So what was it really like at exactly time zero of the big bang.? Again, nobody knows. And no one knows what it is really like at the very center of a black hole. Physicists hope that by somehow combining quantum mechanics and general relativity into some new "quantum gravity" theory, it might tell us what is really going on in these instances. Let's hope so. I found a link that might help: http://www.phys.ncku...s/universe.html

You can dare all you want. This is a science forum. What you are proposing has no known scientific basis in evidence; your views are purely philosophical.

You are right. What you say is not, as far as we now know, a "fact". According to our current understanding of the physical world, a quark is a fundamental particle. This means it cannot be divided further. Will some new theory or experiment reveal a further subdivision of quarks? No one knows. So for now, any ideas on half-quarks and such is just speculation with no scientific basis.

The Twins Paradox can also be explained using special relativity. It involves time dilation and the Dopper effect. And the turn-around of the traveling twin is the key. It isn't brief, but I find it the easiest explanation for my small brain to understand. I wrote up a version on my website: Link: http://www.marksmodernphysics.com/ Click on It's Relative, Archives, Twins Paradox

The distance to the Sun you quote is for a particular frame of reference; one where the Sun and the Earth are at rest with respect to each other. But the Earth moves with respect to the Sun. Thus the numbers you quote are only an approximation, albeit an excellent one. (This is because the speed of the Earth with respect to the Sun is a small percentage of the speed of light) In our universe where pretty much everything is moving with respect to everything else, there is no absolute distance (or absolute time).

Thanks for the detailed write-up. But I still have a question. Maybe I need to ask it more clearly. Doesn't hidden variables mean that a particle is in a definite state before it is measured? I know this goes against standard QM which say that the particle is in a superposition of states before measurement. And I know that Bell's theorum testing shows that the universe is nonlocal. I get that. But what does it say or not say about nonlocal hidden variables? In other words, based on Bell testing, do particles have a definite state or not prior to measurement? I hope I have made my question more clear.

We actually time travel all the time! Into the future and into the past. And no time machine is necessary. It all comes from gravitional time dilation of general relativity. See my blog: It's Relative.

Yes. As I understand it, any local theory is excluded by the results of Bell's theorum tests. But the question remains; how about nonlocal hidden variable? Do the Bell test results tell us whether particles have attributes before they are measured or not?

Am reading How to Teach Physics to your Dog by Chad Orzel. Good book on quantum mechanics in layman's terms. It discusses a subtle point on Quantum Entanglement and Bell's Theorum. Orzel says that Bohm's version of quantum mechanics uses nonlocal hidden variables, and reproduces all the predictions of quantum theory using particles with definite positions and velocities. Then Orzel says that Bell's theorum experiments have conclusively shown that quantum mechanics is nonlocal. So far so good. Both standard QM and Bohm's QM are nonlocal. So Bell's theorum experiments show that the universe is nonlocal. But do they say anything about hidden variables? As I understand it, if hidden variables are allowed, then the attributes of a particle (e.g. postion, polarization) are there before we do a measurement. But per standard QM, these attributes are undefined until they are measured. The photon, for example, is in both polarization states until it is measured. I have seen this issue argued about in physics journals. So is there a definitive answer; what exactly does Bell's theorum tests say or not say about hidden variables?

The quantum rule is this: If, in principle, you cannot tell which path the particle takes, there is interference. If, in principle, you can tell which path the particle takes, there is no interference. All tests to date show this rule to be true. For example. in the double slit experiment, a single photon passes through both slits (like a wave). It interferes with itself and is detected in one location on the screen (like a particle). When a number of photons are put through the slits one at a time, we see an interference pattern build up. Now what if we choose some way to detect which path each photon took; that is which slit it went through. Now we find there is no interference pattern on the screen. There are many websites on this effect - just google double slit. Or go to: http://www.marksmodernphysics.com/ and click on Selected Animations, Quantum Entanglement #6 - Light through beam splitter.

Here are examples of how mass/energy warps space and time. Space: Imagine two points in outer space where there is no gravity. From your point of view here, they are one above the other (vertical). You measure a certain distance between these two points. Now assume you place the Earth just below these two points. Now there is a gravitational field where these two points are. Someone far away where there is no gravity will measure those same two points as being a longer distance from each other! This is due to the stretching (or warping) of space due to the mass/energy of the Earth. Time: Place your watch over your head. Now put it on the ground. Your watch actually runs a tiny bit slower on the ground than over your head. Why? The mass/energy of the Earth slows down (warps) time. The closer to the Earth, the stronger the gravitaional field; thus the more time slows down. Space and time warping effects are very small here because Earth has a relatively small amount of mass/energy. However, this warping of space and time due to Earth's mass/energy is what makes objects fall to the ground and man-made satelites and the Moon orbit the Earth. Space and time warp (or spacetime curvature as it is called) is gravity.

PLease give links or references to experiments which disprove the Big Bang. As far as I know, all experiments, observations, tests to date support the concept of a Big Bang and expanding universe.

Mass and energy are two aspects of the same thing. The fact that they have different conventional units is just because these units were assigned before we realized that they are linked. The same is true of space and time. The spacetime interval tells us that there is a basic link between space and time. So let's use units which more properly represent this link: A light year is a unit of distance. Speed is in units of distance per time. So we can give speed in units of light-years per year. Using these units, the speed of light is 1 light-year per year. So in these units, the famous equation E = mc^2 becomes: E = m Thus the correct statement is that mass equals energy!

Light (like all energy) has inertia. Per E= mc^2, properties of mass (like inertia) are also properties of energy. And vice versa. Another example. Mass and energy are both sources of gravity.

There is no "true speed" of 0 miles per hour. Everything is moving with respect to everything else. There is no at rest frame of reference. Consider two observers; one on Earth and an alien in outer space somewhere. (Assume neither are changing their speed or direction.) Say the Earth observer is moving at 1 million miles an hour relative to this alien observer in outer space. Earth frame of reference: The observer on the Earth feels that she is standing still and the alien is moving. To the observer on Earth, time is running normally here. But she sees time running slower for the alien due to his motion. Alien frame of reference: The alien observer feels that he is standing still and the Earth is moving. To the alien, time is running normally where he is. But he sees time for the observer on Earth running slower due to her motion. So each sees the exact opposite effect. Who is correct? They both are. Time is relative. And 1 million miles an hour is a small fraction of the speed of light (some 670 million miles an hour). So the time slowing factor involved is quite small. The formula is: square root of (1 - v ^2) where v is the speed as a fraction of the speed of light. Here v is 1 million miles an hour divided by 670 million miles an hour or 0.0015. So the slowing factor is sqrt ( 1 - (0.0015)^2) = sqrt (1 - 0.0000022) = sqrt (0.999997) = 0.9999988 The relative velocity has to be some 100's of millions of miles per hour before the slowing of time is significant. See my blog "It's Relative" for other examples.

Do you have a link to this YouTube video?

There is a connection between motion through time and motion through space. Let's choose a frame of reference, say your chair. If you are sitting in your chair, you are at rest relative to the chair. So relative to the chair, there is no time dilation, no slowing of time on your watch. Thus you are moving through time as fast as you can! Say you get up and move relative to the chair. Now from the chair's point of view, you are moving through space. So from the chair's point of view, your watch runs slower due to time dilation. And the faster you move through space, the more time dilation or the slower you move through time. Thus there is a kind of sharing between space and time, The more you move though space, the less you move through time. And vice versa.

The easiest explanation I have found for this is from S. Gibilisco, Understanding Einstein's Theory of Relativity, pp. 65-66: An Inertial Balance scale measures an object's mass. The object is placed between two springs, pulled to one side, and let go. It then oscillates back and forth between the springs. The key point is that the greater the mass, the slower the object moves back and forth between the springs. This gives us a relationship between mass and time. (For an animation, go to http://www.marksmodernphysics.com/ Selected Animations, The Inertial Balance) Now place the Inertial Balance on a rocket ship which is moving relative to you. To you, time on the moving rocket is runnings slower (time dilation). So the same object now takes longer to go back and forth between the springs (from your point of view). So to you, the object between the springs appears to be more massive. This is one explanation of the connection between increase in apparent mass due to relative motion. A better and more modern way to look at it is that the momentum of the object is what is really changing, and mass is the rest mass which does not change.