Professionals only please; fourth dimension.?

Never wise to get in the middle of a family discussion, also not the way to get "best answer" but here goes:

One point for husband: Time is a unit of measure invented by people. We see things change and we want to know how long since a thing happened. So we divided the time between a commonly agreed upon recurring event. Earth orbit (years), moon orbit (months) .. blah, blah, minutes, seconds.

The concept of bent space came from an observation during an eclipse of the sun. Some stars that were known to be behind the sun at the time of the eclipse were visible in photos. Since light exhibits both particle and wave characteristics it is not surprising that a strong gravity field like the sun could bend light as it passed. The stars were visible in the same way a periscope shows something around the corner. Theoretical physicists (read: science fiction writers) made up the bent space thing.

The 17 year old is probably only interested in what other 17 year olds are interested in, not likely other dimensions . However, 3 dimensions length, width, hight were also invented by us, to help us describe what we see. Since the most we can see at one time is front, side, and top; or front, side and bottom, we have 3 dimensions . If we could see the front, side, top, and back at the same time, we would have 4 four dimensions . Or 5 if you count time as a dimension (which it is).

Stephen Hawking , "A Brief History Of Time" the best book on the subject.

Your husband holds a common and valid understanding of time. However, this is a limited understanding. Modern physics incorporates this, but this is not all that time is.

Space and time are not exactly the same, but are certainly intertwined.

Your son has the best, in my opinion. Space and time are related. Can he grasp 3 dimensions? Then why can he not grasp the fourth? Without time, nothing can ever change. The other 3 dimensions must always be in a constant state of change, and this change is enabled by time. Time is considered to be the fourth dimension. The fifth dimension is not something that physicists typically speak of, unless they are talking about the numerous other dimensions theorized in some of their complex theories of space.

Michio Kaku, Hyperspace : Stephen Hawking , A Brief History Of Time ; The cambridge lectures ;

I'm not a "professional" but I do know a thing or two about a thing or two, and you are all right in a way. Einstein's general theory of relativity explains that time is not relative(which is probably where your husband gets his view.) But any physicist will tell you time is crucial for most physical calculations.

Check out those books and good luck proving each other right. It's refreshing to know there are families out there that actually do have stimulating intellectual conversations without anyone feeling left out in the cold. Current societal observations of the majority would make that seem almost as impossible as losing the concept of infinity.

Thanks to General relativity/special relativity. You are essentially correct.

It is hard to describe what is actually happening(ie bending of space), since if you are bent and the space is bent wouldnt it seem normal?

Without getting into an entire 10 week long lecture; essentially massive objects cause space-time to 'curve' and the factor at which is curves will alter space time.

I mainly looked at this in terms of dropping rocks into black holes, but the same holds for ships--however they are using energy to propel them rather than mass. Anyway There are two books I would like to recommend.

1. Black Holes ad Time Warmps: Einstein's Outrageous Legacy, by Kip S. Thorne

2. A Journey into Gravity and Spacetime, by John Archibald Wheeler.(Wheeler is said to be the father of black holes)

Good Luck. Its a tough subject, and even harder to explain over the internet. Look into those books, they should be available at a library or something. (The first one is about 12 buck son amazon.)

It has been difficult to understand what exactly a fourth dimension consists of.

We all know that the phenomena of time flows, not only flowing but flows in a single direction (what we call forward in time).

As a professional, researching into the fundamentals of the underlying structure of electrical energy, gravity and our cosmic motion within the heavens, I discovered that the fourth dimension is in reality cosmic energy flowing in a spiral motion.

This flowing spiral cosmic motion is the underlying energy structure for all activity that comes under the banner of phenomena, responsible for what we refer to as gravitation and also atomic electrical stability which the current quantum model of the atom cannot explain.

This answer is likely to generate controversy because what I am saying is not yet known or taught in universities. In fact it has taken a whole lifetime to come to terms with.

I have published information about this energy research on our company website shown below. For obvious reasons I have had to withhold formulas and other proofs because of technical security, government interests etc.

Please take the time to find out more below, and rest assured this fourth dimension does exist with measurable dimension.

Well your view sort of describes GR (although the bending space/time to propel ships is a little hypothetical).

A good place to start would be any introductory college (or even high school) physics text. It should have a few chapters on special relativity.

Never learn it, even though I do consider Carl Sagan's little demonstration within the sequence "Cosmos". Of direction, the relevant change among the Flatland situation and your god is, the Square and absolutely understand that SOMEthing is occurring while the Sphere passes by way of the 2-dimensional aircraft of flatland, while theists had been hemming and hawing for the final 2000+ years for even a unmarried piece of proof helping the God Hypothesis.

Read "Parallel Worlds" by Michio Kaku. He is a professor of theoretical physics and one of the co founders of String Field Theory. A fascinating book. Extremely informative.

Within Einstein's Theory of General Relativity, time is the fourth dimension - so that space and time become space-time. This fourth dimension is then incorporated into calculations of the 'metric' or measure of a small element 'ds' of (here flat or Minkowski) space, in an equation of the type: -

ds² = dx² + dy² + dz² - c²dt²

Thus, in relativistic calculations time becomes a fourth dimension. However, a more general consideration of time might proceed as follows.

As humans, we perceive time as a steady progression of a sequence of events whose progress we measure with artificial units. These artificial units are centuries, years, months, days, hours, minutes, and seconds. Although physics allows a symmetric nature to the progression or regression of time; we only observe time as progressing inexorably forward. For human perception, the progress of time may seem fast or slow depending upon what we are doing - despite the imposed units of time progress. Artificial units for time are awkward and so some writers and theorists discuss the march of time in terms of the thermodynamics quantity known as entropy. The entropy of an object is its energy content divided by its temperature: -

S= ∆Q

......__

.......T

Where 'S' is the entropy and '∆Q' the energy content and 'T' is the absolute temperature. The concept of entropy is a measure of order. The more ordered a system is then the lower its entropy. It is a rule of nature that systems such as the universe drift towards greater and greater disorder as 'time' progresses. Thus, the universe started out with a low entropy but its entropy has increased continually since the Big Bang. Although it is possible to reduce the entropy of a closed system, for example by cooling, it is only possible for the entropy of the overall universe to increase. Thus, time may be linked to the entropy of the universe - it must forever go forwards and increase.

The Special Theory of Relativity was published in 1905 and deals with (frames of reference) objects separating with constant high velocities (close to the speed of light). In this first theory, Einstein stated that the speed of light was the absolute limit for all velocities and furthermore all observers, what ever their motion, must measure the speed of light to be exactly the same. Finally, only mass-less objects may attain the speed of light. However, massive objects contract in their direction of motion, their clocks slow down relative to observer's clocks and they gain mass and thus inertia as they accelerate towards the speed of light.

Einstein's theory of General Relativity (1915) is a cause and effect theory. The theory describes the fabric of space-time as a medium that may be distorted by the presence of mass and energy. From his earlier relativity theory, Einstein had related mass and energy in the famous equation: -

E = mc²

From this concept, he described the curvature or distortion of space-time as due to the total sum of mass-energy present within the region of distorted space. It is the curvature of space-time we call gravity. Thus, our planet follows the 'straightest' path or path of least action whilst it orbits the mutually curved space around the Sun. An object falling to earth, under the pull of gravity, is following the curvature of space in the region around the surface of the Earth. Einstein described the relationship between space-time curvature and the mass-energy causing it, in the tensor field equation: -

G = 8πT

Where 'G' is the Einstein tensor representing the 'gravity' or curvature of space-time and 'T' is the total energy tensor representing the mass-energy creating the gravitational curvature of the space-time.

The theory, accurately predicts many features of the solar system, such as the peculiar motion of Mercury’s perihelion, and may be used to account for the gravitational physics of black holes and neutron stars. The extreme high pressure physics at the core of a star may be described using this theory. General relativity also predicted the Big Bang origin of the universe, although Einstein refused to accept the conclusion. He later claimed that this erroneous conclusion was his biggest blunder. Overall, after ninety-three years, General Relativity is still the best theory of gravity that we have!

I am British therefore the books avaiable to me may not be in print in your country!

There is, however, a very old but for all that readable book, which is not too 'heavy' with graduate mathematics: -

Space, Time & Gravitation - An outline of the general relativity theory, Sir Arthur Eddington, Cambridge University Press, 1920.

ISBN 0 521 33709 7