Astrophysics time travel

How fast do we travel in time?

We all travel in time! We travel one year in time between birthdays, for example

And we are all traveling in time at approximately the same speed: 1 second per second

We typically experience time at one second per second

Credit: NASA/JPL-Caltech NASA's space telescopes also give us a way to look back in time

How fast does a telescope travel?

It takes a long time for the light from faraway galaxies to reach us

So, when we look into the sky with a telescope, we are seeing what those stars and galaxies looked like a very long time ago

However, when we think of the phrase "time travel," we are usually thinking of traveling faster than 1 second per second

Is time travel possible?

And, as physicist Stephen Hawking pointed out in his book " Black Holes and Baby Universes" (Bantam, 1994), "The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future

," Science does support some amount of time-bending, though

More than 100 years ago, a famous scientist named Albert Einstein came up with an idea about how time works. He called it relativity. …

Hypothetical travel between stars or planetary systems

Interstellar travel is the hypothetical travel of spacecraft from one star system

Solitary star

Or planetary system to another.Interstellar travel is expected to prove much more difficult than interplanetary spaceflight due to the vast difference in the scale of the involved distances.Whereas the distance between any two planets in the Solar System is less than 55 astronomical units (AU)

Stars are typically separated by hundreds of thousands of AU

Causing these distances to typically be expressed instead in light-years.Because of the vastness of these distances

Non-generational interstellar travel based on known physics would need to occur at a high percentage of the speed of light; even so

Travel times would be long

At least decades and perhaps millennia or longer.

Measurement of time

Jiffy can be an informal term for any unspecified short period

As in I will be back in a jiffy.From this

It has acquired a number of more precise applications as the name of multiple units of measurement

Each used to express or measure very brief durations of time.First attested in 1780

The word's origin is unclear

Though one suggestion is that it was thieves' cant for lightning.\nIt was common in a number of Scots English dialects and in John Jamieson's Etymological Dictionary of the Scottish Language (1808) it is suggested that it is a corruption of 'extiw>gliff' (glimpse) or 'gliffin' (glance)\n and may ultimately derive from Gothic or Teutonic words for 'shine'.

Synchronization of clocks within a geographical region

Standard time is the synchronization of clocks within a geographical region to a single time standard

Rather than a local mean time standard.Generally

Standard time agrees with the local mean time at some meridian that passes through the region

Often near the centre of the region.Historically

Standard time was established during the 19th century to aid weather forecasting and train travel.Applied globally in the 20th century

The geographical regions became time zones.The standard time in each time zone has come to be defined as an offset from Universal Time.A further offset is applied for part of the year in regions with daylight saving time.

Astrophysics time travel

How fast do we travel in time?

How fast does a telescope travel?

Is time travel possible?

Standard time is the synchronization of clocks within