[luke warm]

jdonn, on May 15 2009, 12:25 PM, said:

My head feels like a slowly-aging spinning tetherball of uranium.

hahahahaha...

[Winstonm]

Can someone help me with this question?

Don't Einstein's theories suggest that nothing can move faster than light speed, yet it takes light speed squared to transform matter into energy? If so, doesn't that leaves a huge expanse of speeds faster than light speed at which matter might be able to travel without transforming into energy?

And if it is matter moving faster than the speed of light yet slower than light squared, how could its speed be known?

[mike777]

Winstonm, on May 15 2009, 07:31 PM, said:

Can someone help me with this question?

Don't Einstein's theories suggest that nothing can move faster than light speed, yet it takes light speed squared to transform matter into energy? If so, doesn't that leaves a huge expanse of speeds faster than light speed at which matter might be able to travel without transforming into energy?

And if it is matter moving faster than the speed of light yet slower than light squared, how could it's speed be known?

Winston, I always thought Einstein said we cannot cross the light speed barrier, things can move slower or faster than light just not cross the barrier.

[Winstonm]

kenrexford, on May 15 2009, 12:17 PM, said:

If a man takes of in a rocket at a very fast rate of speed, and then returns, he will have aged slower than the people at home, they say.

So, suppose he makes several shorter trips at the same speed. Same net result, right?

What if his trip went in circles? Out into the vast unknown in a circular path, returning back each time, all in circles.

What if these circles were really small, like maybe eight feet away, always returning, always fast?

What if he was just spinning around a central spot like a tetherball, going really fast in circles?

What is "he" was a block of uranium? That would seem to slow down the decay rate relative to us.

Now, the tetherball of uranium would have a larger mass than usually. But, what if the tetherball was made of something that has no mass?

What if you could spin something that had no mass in a circle? Perhaps not spin, but simple re-direct it in a circle? Like, perhaps light somehow trapped in a closed loop of fiber optic cables?

Or, what if the object, mass or no mass, just shook violently? Or, spun violently?

I'm not sure where this leads, and I cannot remember how I decided this, but somehow all of this seemed to me years ago to suggest that disk-shaped spinning devices (or tubes of trapped light) might somehow play havoc on and actually reduce the effect of gravity, or at least the felt effect of gravit, so as to create a theoretically-plausible means of elevating things or reducing the relative weight of the thing such that heavier atmospheres might "lift" the thing. Something like that.

I thought you said didn't do drugs back then.

[gwnn]

Einstein doesn't say that "it takes light speed squared to transform matter into energy". E=mc^2 just specifies the rate of exchange between mass and energy. For example if you had 100 lb of Hydrochloric acid and you somehow transformed it into ninety something pounds of Chlorine and a few pounds of Hydrogen, you'd find that the sum of the two masses exceeds 100 pounds (because the bonding energy is negative). Even though you never accelerated anywhere close to c.

The postulate that nothing with non-zero rest mass can accelerate to c is reflected in the maths of relativity - as you approach the speed of light, your mass increases beyond any finite limit, absorbing infinite energy. BTW there are hypothetical particles called 'tachyons' (featured in K-Pax for example) that were "born" with v>c, so they didn't need to be accelerated beyond the speed of light.

[Winstonm]

gwnn, on May 15 2009, 07:42 PM, said:

Einstein doesn't say that "it takes light speed squared to transform matter into energy". E=mc^2 just specifies the rate of exchange between mass and energy. For example if you had 100 lb of Hydrochloric acid and you somehow transformed it into ninety something pounds of Chlorine and a few pounds of Hydrogen, you'd find that the sum of the two masses exceeds 100 pounds (because the bonding energy is negative). Even though you never accelerated anywhere close to c.

The postulate that nothing with non-zero rest mass can accelerate to c is reflected in the maths of relativity - as you approach the speed of light, your mass increases beyond any finite limit, absorbing infinite energy. BTW there are hypothetical particles called 'tachyons' (featured in K-Pax for example) that were "born" with v>c, so they didn't need to be accelerated beyond the speed of light.

Thank you for clarifying.

Edit: Now you may understand why I hated math so when growing up. Here you give me Energy=Mass X Speed of Light Squared, and then tell me it has nothing to do with velocity.

[blackshoe]

Velocity is a vector. Speed is a scalar. What's the difference? Well, a scalar has one dimension, one value (example: 20 MPH). A vector has at least two (20 MPH, headed North).

The Mass-Energy Equivalence equation does not say that energy is simply mass moving at a velocity (or speed) of c-squared. It says that mass and energy are two aspects of the same thing, and that their equivlance is defined by multiplying the mass by a conversion factor which is the square of the speed of light (or 9x10^20 cm-squared/second-squared.

[Winstonm]

blackshoe, on May 15 2009, 10:59 PM, said:

Velocity is a vector. Speed is a scalar. What's the difference? Well, a scalar has one dimension, one value (example: 20 MPH). A vector has at least two (20 MPH, headed North).

The Mass-Energy Equivalence equation does not say that energy is simply mass moving at a velocity (or speed) of c-squared. It says that mass and energy are two aspects of the same thing, and that their equivlance is defined by multiplying the mass by a conversion factor which is the square of the speed of light (or 9x10^20 cm-squared/second-squared.

Very good. That is helpful.

[barmar]

mike777, on May 15 2009, 08:33 PM, said:

Winston, I always thought Einstein said we cannot cross the light speed barrier, things can move slower or faster than light just not cross the barrier.

This is because it would take an infinite amount of energy to do so. For particles with non-zero rest mass, momentum is inversely proportional to the difference between c and velocity. And for any particles it would take an infinite amount of time, because time slows down as you approach c, or infinite acceleration.

Photons have zero rest mass and start out at the speed of light, so they don't have to accelerate to get there.

Einstein's theory also implies that if there are any particles traveling faster than light, time would run backward for them. This is because time slows as speed approaches c, stops if you're at c (so photons don't experience a flow of time), and reverses for speeds above c.

[Winstonm]

Although ignorant about much of Einstein's work, I did know enough to realize this part:

Quote

This is because time slows as speed approaches c, stops if you're at c (so photons don't experience a flow of time), and reverses for speeds above c.

Again I wonder: if time stops for photons, doesn't that mean that time doesn't exist at the speed of light? If it doesn't exist at the speed of light, does it really ever exist at all or was it an illusion?

In other words, is it more reasonable to assume two sets of realities or is it more likely that there is a common ground that links both worlds?

If we know how fast something is moving and the direction in which it is moving, we can determine based on time where it will be. But this doesn't work for the subatomic world, I understand. Which raises my question about Heisenberg's Uncertainty Principle - is the reason we cannot know both speed and position of sub-atomic particles because time itself is actually only an illusion?

Feel free to laugh. I don't mind making a fool of myself in this department.

[helene_t]

mike777, on May 16 2009, 01:33 AM, said:

Winston, I always thought Einstein said we cannot cross the light speed barrier, things can move slower or faster than light just not cross the barrier.

This in not correct. Nothing can move faster than light (more precisely: nothing can move faster than the speed of light in vacuum. Light travels slightly slower through chicken soup than through vacuum).

winstonm said:

If we know how fast something is moving and the direction in which it is moving, we can determine based on time where it will be. But this doesn't work for the subatomic world, I understand. Which raises my question about Heisenberg's Uncertainty Principle - is the reason we cannot know both speed and position of sub-atomic particles because time itself is actually only an illusion?

No, Heisenberg's inequality is part of quantum theory which isn't dependent of the special theory of relativity. While the special theory of relativity only comes into play at high speeds, Heisenberg's inequality is equally important at low speeds (or for particles at rest for that matter).

[Winstonm]

As a non-scientific, fairly uneducated doofus, I am utterly fascinated with this Heisenberg proposition - it's kind of like Rod Serling telling us that the closer we get to the signpost up ahead, the blurrier will be the letters, but no matter what it's still the twilight zone.

[gwnn]

I don't like Helene's dogmatic approach. http://en.wikipedia.org/wiki/Tachyon

Of course I should mention that I am quite clueless in this area.

[mike777]

helene_t, on May 16 2009, 07:25 PM, said:

mike777, on May 16 2009, 01:33 AM, said:

Winston, I always thought Einstein said we cannot cross the light speed barrier, things can move slower or faster than light just not cross the barrier.

This in not correct. Nothing can move faster than light (more precisely: nothing can move faster than the speed of light in vacuum. Light travels slightly slower through chicken soup than through vacuum).

winstonm said:

If we know how fast something is moving and the direction in which it is moving, we can determine based on time where it will be. But this doesn't work for the subatomic world, I understand. Which raises my question about Heisenberg's Uncertainty Principle - is the reason we cannot know both speed and position of sub-atomic particles because time itself is actually only an illusion?

No, Heisenberg's inequality is part of quantum theory which isn't dependent of the special theory of relativity. While the special theory of relativity only comes into play at high speeds, Heisenberg's inequality is equally important at low speeds (or for particles at rest for that matter).

See cats. See Germans...see two photon expertments with two hole expertments.

[Gerben42]

Quote

Which raises my question about Heisenberg's Uncertainty Principle - is the reason we cannot know both speed and position of sub-atomic particles because time itself is actually only an illusion?

Heisenberg's uncertainty principle is very simple: A husband goes on a business trip. At this point, his wife knows exactly where he is, but not what he is doing. Weeks later, she finds lipstick on his shirt. Now she knows what he was doing, but not where

Really, quantum mechanics is a weird mathematical construct that can be used to describe the observations. I could point out that the reason for not being able to measure mass and energy is because their corresponding operators do not commute, but that's not really the reason, is it? The model works fine for predicting things, but it's just too weird to have any realistic basis.

[gwnn]

mass and energy? You mean momentum and position? Or time and energy?