If it is compact (the mathematical term for “non-infinite space”), then it is still possible for the photons to travel forever because depending on the topology (the mathematical term for “shape and symmetry”) of the universe, it may be possible for the photons to wrap around to the “other side” of the universe and ...
Do photons last forever?
Now, by studying ancient light radiated shortly after the big bang, a physicist has calculated the minimum lifetime of photons, showing that they must live for at least one billion billion years, if not forever .
Do light particles travel forever?
Light just keeps going and going until it bumps into something . Then it can either be reflected or absorbed. Astronomers have detected some light that has been traveling for more that 12 billion years, close to the age of the universe.
How far does a photon travel in a year?
A light-year is the distance that light can travel in one year — about 6 trillion miles (10 trillion kilometers) . It’s one way that astronomers and physicists measure immense distances across our universe. Light travels from the moon to our eyes in about 1 second, which means the moon is about 1 light-second away.
How fast do neutrinos travel?
Neutrinos are subatomic particles that have almost no mass and can zip through entire planets as if they are not there. Being nearly massless, neutrinos should travel at nearly the speed of light, which is approximately 186,000 miles (299,338 kilometers) a second .
Do all photons travel at the same speed?
The highest-energy photon and the lowest-energy photon ever observed both travel at exactly the same speed . All massless particles travel at the speed of light, including the photon, gluon and gravitational... [+] But if you’re willing to step outside of a vacuum and into a material, it is possible to slow light down.
Can you freeze a photon?
For some time now it has been possible to freeze photons and re-emit them on command . However, whilst they are stopped, the photons do not exist as such. They are swallowed by an atomic cloud, which then assumes a so-called excited state and stores the photon as information.
What happens if a photon stops?
When photons of that energy meet an atom, they can scatter and excite it to a higher level, thus the photon is absorbed and “dies” .
Can photons break down?
If a photon did have a non-zero rest mass, that means that it can decay into lighter elements , so the photon would breakdown into either some known elementary particles that are lighter, such as a neutrino and antineutrino, or an as-yet-undiscovered-particle.
Can light be destroyed?
6. Photons are easily created and destroyed . Unlike matter, all sorts of things can make or destroy photons. If you’re reading this on a computer screen, the backlight is making photons that travel to your eye, where they are absorbed—and destroyed.
Why is speed of light not infinite?
That something, the universal conversion factor, is the speed of light. The reason that it is limited is simply the fact that a finite amount of space is equivalent to a finite amount of time .
Does sound ever stop traveling?
Due to that friction, the wave’s amplitude, or height, get smaller and smaller until it eventually dissipates. That is slowly fades out, due to friction in the air. Therefore, to answer the question, sound waves only have a limited amount of time to travel, but yes, in fact they do travel after being emitted .
How long it takes a photon to escape the Sun?
The path that photons take is called the “random walk”. Instead of going in a straight beam of light, they travel in a zigzag direction, eventually reaching the surface of the Sun. In fact, it can take a single photon upwards of 200,000 years to make the journey through the radiative zone of the Sun.
Why do photons not experience time?
Yet despite this incredible journey, the photon itself experiences none of what we know as time: it simply is emitted and then instantaneously is absorbed, experiencing the entirety of its travels through space in literally no time . Given everything that we know, a photon never ages in any way at all.
How long does it take light to escape from the core of the sun?
So, if you think photons only travel 0.1 millimeters between crashes, it will take more than half a million years for the photon to escape the sun. If you think it’s about a centimeter, then it will take about 5,000 years for the photon to get outside the sun.
Can neutrinos be slowed?
In theory, because neutrinos have a non-zero rest mass, it should be possible for them to slow down to non-relativistic speeds .
Can neutrinos escape a black hole?
They cannot pass through a black hole just as light cannot pass through a black hole. Photons are even lighter (no mass is as light as can be!) than neutrinos, and photons are certainly at “subatomic scales” (they are fundamental particles!) and so if photons cannot escape black holes, neutrinos can’t either.
Do neutrinos travel back in time?
Päs: In their own frame the particles always travel forward in time. But for an observer — or a neutrino detector — traveling with a relative speed as compared to the frame where the particle was sent off — the particle travels back in time .
Does red light travel faster than blue light?
We call this effect dispersion, since it disperses the colors in different directions. Blue light travels slightly slower in glass than red light , so it bends a sharper angle when it enters the glass from air.
Why do photons move?
Since photons are massless, they travel at c, which is called the speed of light because the photon was the first known example of a massless particle. So the short answer to the question is that a photon knows to travel at the speed of light because it is massless .
Can all light be seen?
Not all light is in the visible spectrum , which is the light you can see. There are many kinds of electromagnetic waves that you can’t see. Just look at the spectrum below.
Can photons from a Bose Einstein condensate?
By irradiating the dye solution with a laser, the physicists increase the number of photons between the mirrors. The strong concentration of the light particles combined with simultaneous cooling causes the individual photons to fuse to form a “super photon,” also known as Bose-Einstein condensate.
Can photons be collected?
Both traces show well-behaved emission patterns that allow easy collection and manipulation. The solid red and blue curves show the collection efficiency as a function of the collection angle. We find the remarkable result that 99% of the total emitted photons can be captured within an angle of 55 ̊ .
Do photons freeze at absolute zero?
The particles in a system do not “freeze” at absolute zero . A system at absolute zero should be defined to be in its quantum mechanical ground state.
Do photons experience space?
Yet despite this incredible journey, the photon itself experiences none of what we know as time: it simply is emitted and then instantaneously is absorbed, experiencing the entirety of its travels through space in literally no time . Given everything that we know, a photon never ages in any way at all.
How can you destroy photons?
The simplest answer is that when a photon is absorbed by an electron , it is completely destroyed. All its energy is imparted to the electron, which instantly jumps to a new energy level. The photon itself ceases to be.
Has anyone stopped light?
Scientists at the University of Darmstadt in Germany have stopped light for one minute . For one whole minute, light, which is usually the fastest thing in the known universe and travels at 300 million meters per second, was stopped dead still inside a crystal.
