15 Dec 2012, 5:02 am
BlueMax wrote:
NASA divides by zero, folds space. Spacing guild navigators wanted!
Seriously - I can't see how it's even possible... can ANYTHING go faster than the speed of light? There was that recent particle accelerator that came awfully close and some people SAID it did but there was serious debate as to if it was juuuust over or under the barrier.
I thought the very idea is that of something were to go faster than light its physical properties would become irreversably changed, possibly to that of pure energy (since almost unlimited energy would be required to achieve it, according to Einstein. Right?
Seriously - I can't see how it's even possible... can ANYTHING go faster than the speed of light? There was that recent particle accelerator that came awfully close and some people SAID it did but there was serious debate as to if it was juuuust over or under the barrier.
I thought the very idea is that of something were to go faster than light its physical properties would become irreversably changed, possibly to that of pure energy (since almost unlimited energy would be required to achieve it, according to Einstein. Right?
Things can -- mathematically -- go faster than light and still possess non-zero mass. Things with some kind of mass cannot reach the speed of light, because as you approach the speed of light mass reaches infinity. What would characterise superluminal or tachyonic matter is that they have a mass that is imaginary (the same imaginary number property that we use to define the square root of minus one). As for how that would turn out in reality... I only know that there are seriously weird things happening to causality and that the whole thing is a theoretical construction with (AFAIK) no experimental evidence as of yet. But the math, as I understand it, checks out.
So how do we visualize it? Well, we don't, not easily. Our primarily visual frame of reference is far removed from such conditions -- heck, our very frame of reference is going to be called into question.
(attempted physics joke, check)
So what does that mean for anyone wanting to go faster than light? Well, it means that the FTL barrier still exists, and that trying to go faster and faster in order to go FTL is definitionally impossible. If you could somehow change your own mass at will so that it became complex (i.e. had an imaginary component) then that would work. It is how astrophysicist Curtis Saxton rationalized the Star Wars hyperdrive on his homepage.
So, tl;dr, three kinds of mass-speeds:
- Bradyonic - our ordinary matter, with mass and at speeds always below the speed of light (c). As speeds approach c, mass approaches infinite.
- Massless - particles without mass, that is photons and mesons. A massless particle always travels at the speed of light within its given medium (3E8 m/s in vacuum, 2.2E8 m/s in water, etc).
- Tachyonic - theoretical not-so-ordinary matter, with mass (though imaginary) and at speeds always above the speed of light (c). As speeds approach c, mass approaches infinite -- and yes, that means it goes faster if you remove more of its kinetic energy. How that would work in real life is an exercise best left to physics savants and/or contortionists.
15 Dec 2012, 8:48 am
Eleas wrote:
BlueMax wrote:
NASA divides by zero, folds space. Spacing guild navigators wanted!
Seriously - I can't see how it's even possible... can ANYTHING go faster than the speed of light? There was that recent particle accelerator that came awfully close and some people SAID it did but there was serious debate as to if it was juuuust over or under the barrier.
I thought the very idea is that of something were to go faster than light its physical properties would become irreversably changed, possibly to that of pure energy (since almost unlimited energy would be required to achieve it, according to Einstein. Right?
Seriously - I can't see how it's even possible... can ANYTHING go faster than the speed of light? There was that recent particle accelerator that came awfully close and some people SAID it did but there was serious debate as to if it was juuuust over or under the barrier.
I thought the very idea is that of something were to go faster than light its physical properties would become irreversably changed, possibly to that of pure energy (since almost unlimited energy would be required to achieve it, according to Einstein. Right?
Things can -- mathematically -- go faster than light and still possess non-zero mass. Things with some kind of mass cannot reach the speed of light, because as you approach the speed of light mass reaches infinity. What would characterise superluminal or tachyonic matter is that they have a mass that is imaginary (the same imaginary number property that we use to define the square root of minus one). As for how that would turn out in reality... I only know that there are seriously weird things happening to causality and that the whole thing is a theoretical construction with (AFAIK) no experimental evidence as of yet. But the math, as I understand it, checks out.
So how do we visualize it? Well, we don't, not easily. Our primarily visual frame of reference is far removed from such conditions -- heck, our very frame of reference is going to be called into question.
(attempted physics joke, check)So what does that mean for anyone wanting to go faster than light? Well, it means that the FTL barrier still exists, and that trying to go faster and faster in order to go FTL is definitionally impossible. If you could somehow change your own mass at will so that it became complex (i.e. had an imaginary component) then that would work. It is how astrophysicist Curtis Saxton rationalized the Star Wars hyperdrive on his homepage.
So, tl;dr, three kinds of mass-speeds:
- Bradyonic - our ordinary matter, with mass and at speeds always below the speed of light (c). As speeds approach c, mass approaches infinite.
- Massless - particles without mass, that is photons and mesons. A massless particle always travels at the speed of light within its given medium (3E8 m/s in vacuum, 2.2E8 m/s in water, etc).
- Tachyonic - theoretical not-so-ordinary matter, with mass (though imaginary) and at speeds always above the speed of light (c). As speeds approach c, mass approaches infinite -- and yes, that means it goes faster if you remove more of its kinetic energy. How that would work in real life is an exercise best left to physics savants and/or contortionists.
The lesson to take away from all this is: Just because something is mathematically possible does not mean it is physically realizable. Sometimes the math turns out to be right. For example by purely mathematical means, Dirac, deduced that anti-matter must exist. He lucked out on that one. It so happens that anti-matter does exist. Maxwell deduced that a current through space exist even in an incomplete circuit. Imagine a battery, a resistance and a capacitor are in series. When the capacitor charges up a kind of current flows in it even if it is not a closed circuit element. Maxwell deduced this current purely on mathematical grounds.
See: http://en.wikipedia.org/wiki/Displacement_current
Sometimes the mathematics is physically correct and sometimes it isn't.
ruveyn
15 Dec 2012, 1:30 pm
15 Dec 2012, 2:04 pm
16 Dec 2012, 12:00 am
16 Dec 2012, 1:03 am
"...which runs on a particle accelerator fueled by dump trucks filled with flaming grant money."
