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By Marcus Aurelius
Let me attempt to blow your mind: “Now” travels at the speed of light.
When the light turns green, I don't concern myself with the fact that the light actually turned green a nanosecond earlier than I saw it. As far as the distances we're used to, “now” might just as well be universal.
On interstellar distances, you might expect that the lag start mattering. Except it really doesn't. Maybe Sirius isn't there anymore. Maybe it went supernova five years ago, and the shockwave is riding towards us as you read, and it will hit us in another three years. There's no way we'd know. We look up and see the old faithful Sirius sitting right where it's always been. And we can measure its gravitational influence on us and neighboring stars. There is no knowing it's actually gone, and that's because it actually isn't. To someone in the neighborhood of Sirius, the star is no more, but, to us, it still exist. “Existence” travels at the speed of light.
If the sun was spirited away by a species of prankster kardashev 3 aliens, it would keep “being there” for 8 minutes as far as we'd be concerned.
And those 10 billion light years away stars we see through our telescopes, they are there. Because we can see them.
- Julien Boyer
By Bible Speaks
Origin of the Universe:
Gen. 1:1: “In the beginning God created the heavens and the earth.”
Astronomer Robert Jastrow wrote: “Now we see how the astronomical evidence leads to a biblical view of the origin of the world. The details differ, but the essential elements in the astronomical and biblical accounts of Genesis are the same: the chain of events leading to man commenced suddenly and sharply at a definite moment in time, in a flash of light and energy.”—God and the Astronomers (New York, 1978), p. 14.
By Bible Speaks
“Send out your light and your truth. May these themselves lead me.” Psalm 43:3. JEHOVAH is very considerate in the way he makes his purposes known to his servants. Instead of revealing the truth all at once in one blinding flash of light, he enlightens us progressively. Our trek along life’s pathway might be compared to a walk that a hiker takes down a long trail. He starts out early in the morning and sees little. As the sun begins to rise slowly over the horizon, the hiker is able to distinguish a few features of his surroundings. The rest he sees in hazy outline. But as the sun continues its ascent, he can see farther and farther into the distance. So it is with the spiritual light that God provides. He allows us to discern a few things at a time. God’s Son, Jesus Christ, provided spiritual enlightenment in a similar manner. Let us learn how Jehovah enlightened his people in ancient times and how he does so today.
Time gets slow for an object when the object moves nearly with the speed of light. Does time slow down even for light?By admin
Remarkably, the question cannot be answered. Einstein's theory of relativity gives the rate of time in any "inertial frame" relative to that in any other inertial frame. (Inertial frames are traditionally called Lorentz frames, after the person who first introduced the transformation.)
According to relativity theory, there is no inertial frame that travels at the speed of light. Therefore, according to our current theory, the question is fundamentally unanswerable.
What we can say is this: compared to an Earth-bound clock, the clock in a frame moving at velocity v progresses at a slower rate. In the limit as the frame velocity approaches the speed of light, that rate approaches zero.
But that does not mean that the value at c is zero. To do that, mathematically, you must first show that the limiting situation exists. According to relativity theory, it does not. Some future theory might give a different answer, but in the present day, no alternative to relativity theory has made predictions that show it to be correct.
- Richard Muller, Prof Physics, UCBerkeley, author of "Now-Physics of Time" (2016)
When you turn a light on, does the light instantly travel at the speed of light (186,000 miles a second), or does it start at 0 and increase its speed until it reaches its top speed?By SciTechPress
Light always travels at the speed of light. It never increases or decreases its speed. (Technically, this is only true when the light is in vacuum, but the air in a room where the light is turned on is sufficiently close to a vacuum.)
You're thinking about light as a classical particle, which indeed has to start from rest if it wants to move. Instead, think of light as a vibration of the electromagnetic field.
There is a simple analogy for this - without any quantum mechanics or relativity, just classical mechanics.
Consider a string attached to a wall on one side and held by you on the other side. If you vibrate the string on your side, the vibration will propagate to the other side at a fixed speed that depends on the material from which the string is made and on the tension of the string.
The propagation speed of the vibration of the string does not start from zero, nor does it increase or decrease at any time. It is always constant.
Similarly, light is a "vibration" of the electromagnetic field. This vibration always propagates at a constant speed c.
- Barak Shoshany, Graduate Student at Perimeter Institute for Theoretical Physics
Listen to my commentary on this
If I run with a speed of 15 km/hr towards the source of light, nothing can be faster than light, what phenomenon will be taking place?By SciTechPress
This is a tough one to answer since in an earlier post we debunked the infinite mass old theory.
A common misconception is that light travels at different speeds through different mediums. People say that the speed of light in a vacuum is cc, and then say that the speed of light through glass is slower than cc. This simply is not true.
The speed of light is always cc. Then why does it take longer for it to travel through glass? Experiments show that light "moves about 200000 km/s through glass" (as opposed to 300,000 km/s through a vacuum), so how could the speed of light be constant?
Because of this little thing called interaction.
Imagine you are receiving a prize, maybe for writing a great paper about physics. As you walk from point A to point B, you take 2 steps every second. The walkway, being 60 steps long, takes you 30 seconds to get from A to B. Your pathway looks like this.
Pretty simple right? I would think so.
But let's say you didn't win the prize just by yourself. Some people also helped. In this case, you might want to thank your contributors as you walk to the prize. If you walk at a speed of 2 steps a second, it takes you 120 seconds now to get from the same point A, to the same point B. How is this possible? Both times you were walking at 2 steps a second, yet it took twice as much time as before? Well, let's take a step back and look at the picture.
Well that explains it. You were moving both times at 2 steps a second, but you interacted with other external things.
Now, let's substitute you for light, the walkway for glass, and the contributors for glass molecules.
No matter what, light is always moving at cc. The speed of light does not change in a vacuum, but the time from point A to point B does change, depending on what interacts with the light.
So in short, no, light does not change speeds depending on the medium it travels through. The speed of light is always cc.
- Ignacio Cabero
"The notion of mass "increasing" with velocity is an outdated one. Under current definitions of "mass", mass doesn't increase at all with velocity; instead, it is an intrinsic property of the object in question, which is the same in all reference frames.
... If you're inside your rocket ship traveling at 99.99% of the speed of light relative to Earth, you wouldn't be able to tell you were moving at all without looking out the windows (or at your instruments, etc.) Specifically, you would not somehow have more trouble moving because of your increased inertia, and you would not see time slow down for yourself. It's only observers on Earth who would see your time slow down and your inertia increase."
The magnitudes of most of the famous effects of special relativity (time dilation, length contraction, increase in inertia) are determined by the "gamma factor",
This is where Allan Steinhardt's answer comes from. It's the factor by which inertia increases, and it's the factor by which we used to say your mass increased, before "mass" was redefined. (Again, this is all according to an observer who sees you moving at 99.99% of the speed of light relative to them; according to you, everything about you is "normal".)" Source
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