The simple answer is, anything moving through space at c, equal to the speed of light in a vacuum, experiences zero time flow. If you were to travel at the speed of light, you would experience no time.
Five years on a ship traveling at 99 percent the speed of light (2.5 years out and 2.5 years back) corresponds to roughly 36 years on Earth. When the spaceship returned to Earth, the people onboard would come back 31 years in their future--but they would be only five years older than when they left.
One light year is the distance light travels in one year; so if you look at a star ten light years from Earth, the light you see from it left ten years ago and is therefore ten years old.
The difference isn't noticeable though — after spending six months on the ISS, astronauts have aged about 0.005 seconds less than the rest of us.
Previous research has shown that spending time in space causes bone density loss, immune dysfunction, cardiovascular issues such as stiffening of arteries, and loss of skeletal muscle mass and strength in both humans and rodent models. These changes resemble aging in people age on Earth, but happen more quickly.
The time dilation on that planet—one hour equals 7 Earth years—seems extreme. To get that, you'd apparently need to be at the event horizon of a black hole. Yes. You can calculate where you must be to have that level of time dilation, and it's extreme.
Scientists have recently observed for the first time that, on an epigenetic level, astronauts age more slowly during long-term simulated space travel than they would have if their feet had been planted on Planet Earth.
Can you Age less if you live in an environment with more Gravity? No, definitely not. Clocks tick slower in more gravity, but the time on clocks has nothing to do with aging. The force of gravity is the cause of motion and stress that causes physical age.
It turns out that while most systems in the human body are heavily affected during spaceflight, the female menstrual cycle doesn't seem to change at all. “It can happen normally in space, and if women choose to do that, they can,” Jain said.
The age calculator will tell you that on New Year's Day 2050, you'll be 44 years 9 months, 28 days old.
To play this video you need to enable JavaScript in your browser. Astronomers have a new candidate in their search for the nearest black hole to Earth. It's about 1,000 light-years away, or roughly 9.5 thousand, million, million km, in the Constellation Telescopium.
One of the most distant exoplanets is 3,000 light-years (17.6 quadrillion miles) away from us in the Milky Way. If you were to travel at 60 miles an hour, you would not reach this exoplanet for 28 billion years.
Amazing Fact : If you leave Earth at the age of 15 in a spaceship at the speed of light and spend 5 Years in space, when you get back on Earth you will be 20 years old and all your friends who were 15 when you left will be 65 years old. This phenomenon is known as "Time Dilation" in Physics.
This form of time dilation is also real, and it's because in Einstein's theory of general relativity, gravity can bend spacetime, and therefore time itself. The closer the clock is to the source of gravitation, the slower time passes; the farther away the clock is from gravity, the faster time will pass.
If you travelled at the speed of light, how would you experience time? Travelling in space for three years at close to the speed of light would equal five years on Earth.
What's happening. With age, bones tend to shrink in size and density, weakening them and making them more susceptible to fracture. You might even become a bit shorter. Muscles generally lose strength, endurance and flexibility — factors that can affect your coordination, stability and balance.
Astronauts age a bit slower than those of us on Earth due to something called "time dilation" described by Einstein's theory of relativity.
Time as a proportionate to memory
So, why does time go so fast as you age? Put in the simplest terms, one of the most prevalent explanations is that our perception of time is inherently linked to how much time we have already lived – ie the older you get the more memories and experiences you have to draw on.
Time Travel
Special relativity states that nothing can go faster than the speed of light. If something were to exceed this limit, it would move backward in time, according to the theory.
If an object ever did reach the speed of light, its mass would become infinite. And as a result, the energy required to move the object would also become infinite: an impossibility.
A succession of astronauts have described the smell as '… a rather pleasant metallic sensation ... [like] ... sweet-smelling welding fumes', 'burning metal', 'a distinct odour of ozone, an acrid smell', 'walnuts and brake pads', 'gunpowder' and even 'burnt almond cookie'.
One hour on Earth is 0.0026 seconds in space.
Thus, upon calculation we find that one hour on Earth is equivalent to seven years in space. Einstein's theory of Special Relativity stands as a explanation to this calculation.
The ISS orbits the earth at speeds of approximately 17,000 miles per hour, which is considerably faster than the earth rotates on its axis. Therefore the solar day on the ISS is considerably shorter than the earth day at just over 90 minutes in duration.