Q & A: Relativity
Here are some answers to reader questions. Please send any more to eagle@eaglegamma.com.
Q. Why can't matter go to the velocity of light?
A. Matter cannot go the speed of light, according to modern understanding, because matter is basically light that is also busy doing other work, which costs some of its speed.
As light (electromagnetic energy) travels through the universe, it flows freely. However, light that interacts with other particles in intricate ways takes on the property of matter. This work takes energy, and it also takes energy to move. So, the light that we perceive as matter moves more slowly than the light that we perceive as color.
By the way, Einstein discovered this limit in 1905 with the "special theory of relativity," the first part of his revolutionary theory of relativity. After making various technically motivated changes to connect space with time, his mathematical description revealed that matter must travel slower than the speed of light. Observations have thoroughly confirmed the superiority of this theory over classical mechanics.
The speed of light in a vacuum is 299,792,458 meters per second. And you thought Olympic sprinters ran fast! If you're wondering about going really far from Earth, traveling faster than the speed of light doesn't seem like a plausible scenario. A few people have speculated about alternatives like creating wormholes, to move matter across huge distances without traveling faster than the speed of light. However, for now those dreams remain more in the realm of the imagination than engineering.
More info: https://en.wikipedia.org/wiki/Faster-than-light
Q. Can you explain to me the concept of time deformation?
A. Time runs slower when measuring an object moving by you than when measuring an object moving with you. This comes about because of how light moves in relativity theory, which connects with space instead of going against an abstract background. With matter moving so much more slowly than light, we hardly notice the effect in our everyday lives. It affects astronauts moving very fast on spaceships, although only enough to measure it.
This also comes from Einstein's special theory of relativity, and has lots of evidence in its support. There are time dilation effects in general relativity as well. Because time and space are connected in relativity, these time changes also apply in space, so mass and velocity also experience deformation.
Also, psychologically we experience time at different rates, as our mental gears shift according to our conditions. Certain drugs can help with this process.
More info: https://en.wikipedia.org/wiki/Time_dilation
Q. What is holding all those atoms?
A. Matter, in the form of atoms and other particles, moves about in a sea of space and time. However, the joint spacetime isn't so much a "container" holding the atoms. It's more like a complete system, like a chess board: do the white squares hold the black squares, or do the black squares hold the white squares?
This came from the other part of Einstein's relativity theory, the "general theory of relativity" in 1915. Einstein extended his thinking to pretty much everything in the world, and realized that the "background" of matter actually interacts with all the "contents". Again, plenty of observations verify that this theory reflects physical reality better than an independent background container.
Space, that great enormous expanse where we live, "holds" all the people and atoms and light. Although we can describe how space acts, it still holds plenty of deep mystery. All that matter and energy moving through all that space and time evolves to produce the designs that we find in our lives. The world includes the atoms, the empty places, and the spatial relationships among them, in this ever-changing system. And we can at least make a little sense of it.
More info: https://en.wikipedia.org/wiki/Space
A general principle arising from these three questions is that the world operates mechanically very differently than humans intuitively believe, and we can find more accurate descriptions by a careful effort at thinking and checking. Also, we continue to have ignorance and learn new things, so bear in mind that these are provisional answers that work extremely well yet continue to develop.
Again, please send any questions to eagle@eaglegamma.com
Thank you!