Physics

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Originally posted by systep
as far as i know their not teleporting photons either it's only in theory

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http://www.cnn.com/2002/TECH/science...eporting.reut/

Well that should satisfy all the non believers out there.

Reviewed a lot of this post, and just want to point out to the poster (al bundy I believe) who brought up the work of Cameron Y. Rebigsol.

FYI, his work appears on Crank Dot Net (http://www.crank.net/relativity.html) which speaks volumes to begin with.

Secondly, if you actually look at some of his arguments, they're remind one of the old algebra trick where you can prove 2=1 because you make the substitution a=b, and then divide by (a-b) later.

For example, the very first equation of his proof by contradiction is supposed to be a simplificatin of another equation, but he clearly makes the substitute of x=ct where explicitly stated in the main equations is that x^2 = (ct)^2. Very different (one has 2 solutions for x, a point which he dwells on a little later).
Careless? Or intentionally deceiving. Doesn't matter. Don't waste your time reading his book on the so-called Mathematical Invalidity of Relativity.

Can someone confirm this.

Mathematically speaking a straight line has one dimension. Length.
A square or any surface area has 2 dimensions, L x W. A cube or pyramid, cone, whatever have you, Has 3 dimensions L x W x H. And a tesseract is a 4D cube?!?

Therefore a dot or point in the universe has no dimensions? No length, width or depth. Can someone explain. I remember an arguement against this in Maths class. Where someone stated that it is impossible to have a 0-dimensional object.

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Originally posted by Gogita
Therefore a dot or point in the universe has no dimensions? No length, width or depth. Can someone explain. I remember an arguement against this in Maths class. Where someone stated that it is impossible to have a 0-dimensional object.

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I don't think a point is an object... a point is not supposed to have any dimensions. although i am just speaking from common sense so don't take my word for it ;)

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Originally posted by Gogita
Can someone confirm this.

Mathematically speaking a straight line has one dimension. Length.
A square or any surface area has 2 dimensions, L x W. A cube or pyramid, cone, whatever have you, Has 3 dimensions L x W x H. And a tesseract is a 4D cube?!?

Therefore a dot or point in the universe has no dimensions? No length, width or depth. Can someone explain. I remember an arguement against this in Maths class. Where someone stated that it is impossible to have a 0-dimensional object.

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Here are my thoughts (im a young guy so you might not want to read on, but i'll write on anyway):


Ok, it isnt possible to have an object with no dimensions. Everything has at least one dimension, because everything exists at that moment. A point is an object, it just doesnt have any mass to it. It still has a dimension, the dimension is its presence in time.

A 4D cube i suppose would then be a regular cube, that exists for a period of time (the 4'th D).


am i close at all? those are all ramblings straight from the anal cavity, so i could be all wrong

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Originally posted by iamsostupid

Ok, it isnt possible to have an object with no dimensions. Everything has at least one dimension, because everything exists at that moment. A point is an object, it just doesnt have any mass to it. It still has a dimension, the dimension is its presence in time.

A 4D cube i suppose would then be a regular cube, that exists for a period of time (the 4'th D).


am i close at all? those are all ramblings straight from the anal cavity, so i could be all wrong

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Pretty close. A point just a mathematical construct. Physically, nothing exists as a point. Additionally, it's a little bit odd to thing of a point as 0 dimensions, since a point is defined by it's location in some number of higher dimensions. Things get stranger when you simplify Newtonian physics and deal with point masses - but this is a good example of where it's a helpful construct even if it doesn't map to anything physically.

However, the above quote, in an attempt to make higher dimensions understandable by us lowly non-physicist humans, incorporates time whenever an additional dimension is needed. This isn't really necessary. It's an okay way to think about things, but what about a 5D hypercube?

If anyone has done datamining, there are always problems with visualizing higher dimensions there too, but clearly none of those dimensions need to be time. Just instead of a point in 3D space defined by coordinates (x1,x2,x3), you have a point in nD space defined by a larger set coordinates (x1,x2,x3,x4,..,xn-1,xn). Mathematically, it's very easy to extend things to higher dimensions. Being able to mentally get a grasp on those higher dimensions is where it gets tough.

Okay, getting rambly too....

holy ****.

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Originally posted by iamsostupid
holy ****.

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I second that

What is gravity? I know that a larger mass will attrect a smaller mass such as earth being atracted to the sun, but why does gravity work. In a perfect situation with no friction and only 2 masses one being larger why exactly does the larger mass attract the smaaler mass. Could it be that gravity is a completely different form of energy sorta like light maybe gravity can travel faster than the speed of light. If you had 2 objects in a vacum with no outside gravity( i know this is impossible ) how much time would it take for the objects gravity to effect each other? I have been wondering this for awhile now. Im only 15 so if im completely missing something please explain.

some scientists have ideas/theories concerning gravity... such as it may be quarks..."gravitons" and all these theories with quantum physics....
and the traditional view is basically of gravity as a force...
but its hard to comprehend what it is, (what is energy?) because we have limits
the best understanding we have of gravity is actually experiencing it, right??? you can go to www.sciam.com to "Ask the Experts" or something to find out more... this is all my broken, fragmented data

Our best theories say that gravity is a wave that travels at the speed of light. They have actually built a LIGO detector next to where I live. The LIGO detector sends a laser down a huge pipe and watches gravity affect it.

Planets do not "pull" each other around, gravity simply adjust space itself. It's like those quarter things at stores. You flick in a quarter and it circles and speeds up as it reaches the center hole. Gravity is made up of quantum particles, just like everything else.

There are many levels on which you can understand gravity. The simplest is according to Newton - M1*M2*k/D^2, where M1 is the mass of the first object, M2 is the second, k is the universal gravitation constant, and D^2 is the distance squared. So you see that its not that large objects pull small objects, but there is a force between the two - ie, if you weigh 150lb, that means you exert a force of 150lb on the earth and vice versa. Thats the effect, but where does it come from?

It was found that Newton's theory didn't quite fit with observations and Einstein figuerd out why - it doesn't account for the speed of light. Einstein's theory is best described by the bowling balls on a trampoline analogy: The bowling balls are objects like planets and the trampoline is space itself. Every object bends space in a way that is proportional to its mass. This is what is meant by the "curvature of space." If the objects are not moving, this explanation fits with Newton's theory, but when the objects are in motion, the changing effects of their gravity is not instantaneous, but travel at the speed of light. Gravity waves are the ripples in space caused by the motion of objects in space (which is far different than the way light works).

This theory also explains why light, which is massless, is affected by gravity. Since gravity bends space, something passing near an object of high mass need not have its own mass to be affected - light traveling past a planet or star gets bent toward that planet or star. Scientists later used this part of the theory to mathematically model black holes, long before they were ever discovered (by the Hubble telescope about 10 years ago).

These theories explain very well WHAT happens, but I'm a little fuzzy on the HOW or WHY. I'm not sure if scientists really know WHY mass affects space in the way it does.

As a caveat, it is known that just as Newton's theory was incomplete (it didn't take into account the speed of light) Einstein's theory is also incomplete in that it doesn't take into account Quantum Mechanics. Both theories still work if you take into account their limitations, but scientists continue to work on combining Relativity and Quantum Mechanics. The quantum theory of gravity would be the holy grail of physics if it is discovered.

The best layman's source for all of this is Stephen Hawking's "A Brief History of Time." It helps to have higher math and science to understand it, but high school education is enough to get a lot out of it. It takes a few reads to get most of it though.

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Originally posted by russ_watters
It was found that Newton's theory didn't quite fit with observations and Einstein figuerd out why - it doesn't account for the speed of light. Einstein's theory is best described by the bowling balls on a trampoline analogy: The bowling balls are objects like planets and the trampoline is space itself. Every object bends space in a way that is proportional to its mass. This is what is meant by the "curvature of space." If the objects are not moving, this explanation fits with Newton's theory, but when the objects are in motion, the changing effects of their gravity is not instantaneous, but travel at the speed of light. Gravity waves are the ripples in space caused by the motion of objects in space (which is far different than the way light works).

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Einstein also said that the universe isn't non-local; meaning that mass or occurances in one area do not affect mass or occurances in another area unless there is a physical/real force or object between the two. Your post is an attempt to explain this force/mass that is gravity.

Scientists today are studying quantum physics and believe they have proved that the universe IS non-local; if you are familiar with the experiment where the laser is split into two directions and differences on one side mirror differences on the other side. I think this is just a way around Einstein's theory.

My dumb brain tells me that gravity is a sort of organic/toned down magnetism. Mass affected by gravity acts a lot like magnets do. If magnetism is the transfering of ions or whatever from atom to atom, then couldn't gravity be something very similar?

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Originally posted by talldude


If you are not moving at exactly the speed of light (impossible) you will see light ahead of you from the headlights, although it will be very slow.

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It is not impossible to alter c. Just a small crazy thought but if a black hole is able to bend and attract light, would this not mean that there might be a faster element than c?

Regarding the alteration of c. A Danish physist once made a breakthrough on this subject by freezing light at ultra-low temperatures. She was able to decrease c from 3000000 km/s to 2 km/s.

Also, a German physist named Günter Nimtz from Kölns University was able to optain a very interesting result with some scientific microwave experiments. He projected 2 microwaves to the same two distances. The first microwave, moving with c and the second microwave, originally moving at c but after passing through a 17 cm 4-shaped long wave-conductor a speed increase was observed. This was the result of a so called "tunnel-effect," since the wave conductor was designed to make an opstacle for the microwave which leaded to increasing the speed of c from 1.0 c to 4.7c. Quite amazing.

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Originally posted by Positron


It is not impossible to alter c. Just a small crazy thought but if a black hole is able to bend and attract light, would this not mean that there might be a faster element than c?

Regarding the alteration of c. A Danish physist once made a breakthrough on this subject by freezing light at ultra-low temperatures. She was able to decrease c from 3000000 km/s to 2 km/s.

Also, a German physist named Günter Nimtz from Kölns University was able to optain a very interesting result with some scientific microwave experiments. He projected 2 microwaves to the same two distances. The first microwave, moving with c and the second microwave, originally moving at c but after passing through a 17 cm 4-shaped long wave-conductor a speed increase was observed. This was the result of a so called "tunnel-effect," since the wave conductor was designed to make an opstacle for the microwave which leaded to increasing c from its original 1.0 c to 4.7 c.

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You can decrease C but not increase it. Light is bent by lenses for example, because it travels at a lower speed through the lens than the air.

I think Quantum Physics in the next decade will reveal ways of communicating faster than light. Just IMO. :)

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Originally posted by russ_watters
You can decrease C but not increase it. Light is bent by lenses for example, because it travels at a lower speed through the lens than the air.

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I also thought that increasing c was impossible. However, the difference in the experiement was measured. That the light which traveled through the obstacles was traveling faster than c. Strange.

nevermind.. everything i said was already said..

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Einstein's theory is best described by the bowling balls on a trampoline analogy: The bowling balls are objects like planets and the trampoline is space itself. Every object bends space in a way that is proportional to its mass. This is what is meant by the "curvature of space."

russ_watters you hit the nail on the head with this phrase. I beleive that the bowling ball on a trampoline analogy is the best way to explain how gravity works and it helped me figure it out. Keep up the good work :)

I've been doing some light reading. My lastest has been "A Brief History of Time" by Stephen Hawking. An EXCELLENT book, I might add. Especially if you get the newest print with all the pretty pictures. Incredibly helpful.

My biggest question still remains, however...

How were "quarks" discovered? How do they know there are six different types and three different colors?

Seriously, what phenomonon was observed that could not be explained using the "electrons/protons/neutrons are the smallest division of matter" model?

And this begs a new question...are quarks really the smallest division? If we can actually produce particle accelerators about 1,000 times more powerful than today's generation...will we discover sub-quarks?

But basically....how were quarks discovered? And how do we know how many quarks makes up one proton/neutron?

George Zweig is the guy who discovered the quark in the mid 60s much the way anything is discovered on that level: ramming really fast little things into really fast slightly heavier things and watching the pieces fly.

"Keep up the good work

Thanks, pilatus, but I'm pretty sure I got that bowling ball/trampoline analogy from A Brief History of Time.

Positron, I haven't read too much about those experiments, but It was my understanding that the light wasn't traveling faster than the speed of light, but jumping around faster than it could have traveled normally. Thats not quite the same thing.

Melojo - the "colors" of quarks are just labels. They have no color since they are smaller than the wavelengths of visible light. And ABHOT is light reading? Damn....

C can not be increased but only decreased... bending of light...