The 'Sonic Boom' of Light

[Dryson]

Camera catches the sonic boom of light.

I mentioned this in an thread on the old Star Trek website several years ago. It seems I was proven correct.

Just like an object moving faster than the speed of sound something is traveling faster than the speed of light to create the photonic boom.

If not an object then perhaps light itself has found a medium that increases its velocity to FTL speed. Much the same way that glass reduces the velocity of light speed something must be magnifying the velocity of light past the speed of light if no known object is able to travel faster than the speed of light.


http://www.livescience.com/57572-ul...c-booms-of-light.html?utm_source=notification

Just as aircraft flying at supersonic speeds create cone-shaped sonic booms, pulses of light can leave behind cone-shaped wakes of light. Now, a superfast camera has captured the first-ever video of these events.

 

[PurpleBuddha]

Just like an object moving faster than the speed of sound something is traveling faster than the speed of light to create the photonic boom.

The article you linked is clear that there is no faster than light travel here, at least not faster than 300,000 kilometers a second. They produced the 'sonic boom' by making the light travel through different mediums and slowing it down.

The description of this starts with paragraph six of your article:

Light travels at a speed of about 186,000 miles per second (300,000 kilometers per second) when moving through vacuum. According to Einstein's theory of relativity, nothing can travel faster than the speed of light in a vacuum. However, light can travel more slowly than its top speed — for instance, light moves through glass at speeds of about 60 percent of its maximum. Indeed, prior experiments have slowed light down more than a million-fold.

The fact that light can travel faster in one material than in another helped scientists to generate photonic Mach cones. First,study lead author Jinyang Liang, an optical engineer at Washington University in St. Louis, and his colleagues designed a narrow tunnel filled with dry ice fog. This tunnel was sandwiched between plates made of a mixture of silicone rubber and aluminum oxide powder.

Then, the researchers fired pulses of green laser light — each lasting only 7 picoseconds (trillionths of a second) — down the tunnel. These pulses could scatter off the specks of dry ice within the tunnel, generating light waves that could enter the surrounding plates.

The green light that the scientists used traveled faster inside the tunnel than it did in the plates. As such, as a laser pulse moved down the tunnel, it left a cone of slower-moving overlapping light waves behind it within the plates.

 

[Asbo Zaprudder]

^^OP There are theories that the speed of light might have been greater in the very early Universe (variable speed of light or VSL), if the vacuum energy is lowered (Scharnhorst effect), or by using evanescent modes (quantum tunnelling). However, the linked article relates to none of these effects and the light does not travel faster than c in vacuo (per @PurpleBuddha's comment).

 

[Dryson]

VSL - A variable speed of light (VSL) is a feature of a family of hypotheses stating that the speed of light in vacuum, usually denoted by c, may in some way not be constant, e.g. varying in space or time, or depending on frequency.

The Width of the Universe - It is estimated that the diameter of the observable universe is about 28.5 gigaparsecs (93 billion light-years)

Age of the Universe - This information helps astronomers determine the age of the universe. Age may only be a number, but when it comes to the age of the universe, it's a pretty important one. According to research, the universe is approximately 13.8 billion years old.

The estimated diameter of the observable Universe is 93 billion light years. The age of the Universe is approx. 13.8 billion years old.

Therefore based on the speed of light's velocity, the Universe should be 93 billion years old. But since the Universe is only 13.8 billion years old then the speed of light was much faster after the Big Bang.

If I have done the math correctly.

The velocity of the speed of light would had to have been 715.38 times greater, after the Big Bang, until roughly 13.8 billion years ago when it encountered a force that slowed the speed of light to its current velocity.

If it takes light one year to travel a light year then the velocity of light was much greater after the Big Bang.


What the Hell - WTH

Lt. Madison - "Computer...did he just post What the Hell - WTH"

Computer - "No...I believe he posted that it was rather nipplely in here and that the temperature needed to be increased as the environment would send the Thermians into an uncontrolled breeding frenzy."

Taggart - " No, I didn't."

Computer - "Yes, you did."

Madison - "Computer, replay what Commander Taggart recently said."

Computer - "No."

Madison - "NOW!"

Computer -"In Taggart's voice....Lt. Madison's *&^ has gotten so big I wonder if we will have to add more stabilizing struts to the hull at our next port of visit."


The fact that light can travel faster in one material than in another helped scientists to generate photonic Mach cones. First,study lead author Jinyang Liang, an optical engineer at Washington University in St. Louis, and his colleagues designed a narrow tunnel filled with dry ice fog. This tunnel was sandwiched between plates made of a mixture of silicone rubber and aluminum oxide powder.

Then, the researchers fired pulses of green laser light — each lasting only 7 picoseconds (trillionths of a second) — down the tunnel. These pulses could scatter off the specks of dry ice within the tunnel, generating light waves that could enter the surrounding plates.

The green light that the scientists used traveled faster inside the tunnel than it did in the plates. As such, as a laser pulse moved down the tunnel, it left a cone of slower-moving overlapping light waves behind it within the plates.

 

[Nebusj]

The estimated diameter of the observable Universe is 93 billion light years. The age of the Universe is approx. 13.8 billion years old.

Therefore based on the speed of light's velocity, the Universe should be 93 billion years old. But since the Universe is only 13.8 billion years old then the speed of light was much faster after the Big Bang.

If I have done the math correctly.

The velocity of the speed of light would had to have been 715.38 times greater, after the Big Bang, until roughly 13.8 billion years ago when it encountered a force that slowed the speed of light to its current velocity.

If it takes light one year to travel a light year then the velocity of light was much greater after the Big Bang.


What the Hell - WTH

Relax a bit. You're going to sprain something going off like that.

The 'observable universe' is the set of things that we, from here, could conceivably have gotten a signal from. That could be light, could be gravity, could be whatever. It's not going to be anything traveling faster than light, so for the sake of convenience, suppose that it's light.

There's stuff from about 46 billion light-years away that we could, conceivably, have got light from. That isn't because light's been traveling for 46 billion years. That's because there's things that (could have) sent us signals which are now 46 billion light-years away. The light from them hasn't been traveling more than about 14 billion years.

They got that far because the space between them and us got bigger. Think of it as the difference in a game of Marco Polo between hearing someone cry out ``Polo'' and where they actually are by the time you could get them. (This is not what's going on, but it may help you understand the difference between how far something in the observable universe is and how long a signal from it has been traveling to get to us.)

Here's a paper that tries to explain some of the subtleties, although I'm not sure how much it will help without even more background material. Still:

https://arxiv.org/abs/astro-ph/0310808

 

[Asbo Zaprudder]

The diameter of the observable universe being bigger than its age is because space-time has been expanding ever since the big bang.

https://www.quora.com/How-can-it-be...-across-and-yet-only-13-8-billion-years-old-1

 

[Haggis and tatties]

Always amazing to think that the universe is so vast that even light seems to slow for it. Ha

 

[Asbo Zaprudder]

Not slow, red shift of course.