Thoughts, Theories and Ponderables

awip2062 · Post by **awip2062** » Fri Dec 05, 2008 1:13 pm

Mayhaps, but then I trust very few "out there". lol

Snopes has to be careful, though, with what people say they are saying.

CygnusX1 · Post by **CygnusX1** » Fri Dec 05, 2008 1:18 pm

awip2062 wrote:Mayhaps, but then I trust very few "out there". lol

Snopes has to be careful, though, with what people say they are saying.

Wurd.

awip2062 · Post by **awip2062** » Fri Dec 05, 2008 1:45 pm

Consider the following:

And this:

Raiden · Post by **Raiden** » Tue Dec 09, 2008 3:15 am

I HATE Santa. He's a bad person. I don't want to go to Shade.

Big Blue Owl · Post by **Big Blue Owl** » Tue Dec 09, 2008 11:55 am

Looking on the bright side;

When it is lonely and miserable at home, work seems a little better.

ElfDude · Post by **ElfDude** » Tue Dec 09, 2008 12:14 pm

Big Blue Owl wrote:Looking on the bright side;

When it is lonely and miserable at home, work seems a little better.

Oh geez... I remember those days. Not wanting to go home.

awip2062 · Post by **awip2062** » Tue Dec 09, 2008 12:47 pm

*hugs BBO and Elfie*

Consider this....
If you can start the day without caffeine,

If you can get going without pep pills,

If you can always be cheerful, ignoring
aches and pains,

If you can eat the same food everyday
and be grateful for it,

If you can understand why your loved
ones are too busy to give you any time,

If you can overlook it when those you love
take it out on you, through no fault of yours
something goes wrong,

If you can take criticism and blame
without resentment,

If you can face the world without lies and deceit,

If you can conquer tension without
medical help,

If you can relax without liquor,

If you can sleep without the aid of drugs,

If you can honestly say that deep in your
heart you have no prejudice against
creed, color, religion, or politics,

then my friend...

You are ALMOST as good as your dog!

Big Blue Owl · Post by **Big Blue Owl** » Tue Dec 09, 2008 2:11 pm

Thanks t. That made me smile big

awip2062 · Post by **awip2062** » Tue Dec 09, 2008 2:14 pm

Big blue smile!

Big Blue Owl · Post by **Big Blue Owl** » Tue Dec 09, 2008 2:25 pm

awip2062 · Post by **awip2062** » Tue Dec 09, 2008 2:33 pm

Cute! LOL

awip2062 · Post by **awip2062** » Sun Dec 14, 2008 9:24 pm

How do they get deer to cross at the yellow sign?

*has a song in her head now*

awip2062 · Post by **awip2062** » Mon Dec 15, 2008 3:08 pm

One for our friendly physics fans:
If you are in a vehicle going the speed of light, what would happen if you turned on your headlights?

zepboy · Post by **zepboy** » Mon Dec 15, 2008 6:03 pm

nothing.

YYZ30 · Post by **YYZ30** » Tue Dec 16, 2008 9:56 am

awip2062 wrote:One for our friendly physics fans:
If you are in a vehicle going the speed of light, what would happen if you turned on your headlights?

(oh boy are you gonna be sorry you asked...)

Your question contradicts Einstein's Special Theory of Relativity which states that no object with mass CAN travel at, or above, the speed of light (c). As your car approaches c, its resistance to acceleration (mass) increases so that it would take an impossibly infinite force to actually reach c. Your question, then, is based on an impossible premise. It's like asking 'What would happen if I reached the North Pole and kept going north?'

As you approach the speed of light with your headlights on, however, you would still measure the light beam racing away from your car at 186,000 miles per second (c). A 'stationary' observer watching this happen, though, would not then measure the beam's speed at almost twice c. Relativity says that all observers always get the same measurement for c.

While that may not sound logical or plausible, it happens because what we normally think of as fixed concepts--length and time--are both variable at high speeds. If you observed a car travelling past you at close to c, its length in the direction of travel would appear shortened and the passage of time on board would appear slowed down.

Although these ideas sound strange to all of us not used to moving at relativistic speeds, they have all been confirmed experimentally.

Answered by: Paul Walorski, B.A. Physics, Part-time Physics Instructor

First of all, you need to realize that when you say you are traveling at the speed of light, that has to be with respect to, or relative to, something else. It is an underlying fundamental assumption of Einstein's special theory of relativity that uniform, non-accelerated motion has no meaning of and by itself. That is, there is, by assumption, no meaning to the idea of moving uniformly at the speed of light in an empty universe. That state is completely equivalent to being at rest in an empty universe..

I preface my answer with this comment because it leads immediately to the answer to the question. Imagine that you are in your car 'traveling at the speed of light' and that you turn on your headlights. That state of motion is utterly equivalent to being at rest in an empty universe. Since, when at rest, the light from your headlights would be launched forward from your car at the speed of light, relative to you, with a certain color spectrum, that is exactly what would happen if somehow you could be moving instead at the speed of light.

In other words, the presence or absence of other objects or matter in the universe relative to which, if present, you could make a determination that you were moving at the speed of light makes absolutely no difference to your own experiences and experiments. The light that you launch behaves in exactly the same way whether the other referential matter exists or not.

This leads into another interesting question, however. And that is whether the rest of the matter (mass) in the universe in some way affects your own local observations. So far this question has come up in relation to theories of gravity. If effect, the question is how does the universal gravitational constant, G, which determines how strongly gravitating masses attract each other, know what value to assume if there is no other mass in the universe. Mach proposed, essentially on philosophical grounds, that G must be determined by the sum total of all of the mass in the universe. Einstein assumed in his General Theory of Relativity that G is simply a universal constant, independent of the specific mass distribution of the universe. On the other hand, Brans and Dicke later proposed a so-called scalar-tensor theory of gravity in which the local value of G depends upon the rest of the mass in the universe through an additional scalar field that does not appear in Einstein's theory.

Answered by: Warren Davis, Ph.D., President, Davis Associates, Inc., Newton, MA USA