Can blackholes and wormholes be used to time travel?
FIRST - There are " BLACK HOLES or WORMHOLES ".
SECOND - TIME and EXISTENCE
" TIME " is just a measurement. It is constant wherever you are. The accuracy of the instrument you use will be influenced by gravity, centrifugal force, heat, and a few other variables. There is no " TIME " dimension. There is no possibility of " TIME TRAVEL ". There is no " SPACE/TIME " effect - plane old gravity works just fine. All that exists, does so in the present " INDIVISIBLE " moment.
THIRD - BLACK HOLES
There are " NO " black holes as they are conventionally thought of...
What the common term " BLACK HOLE " is referring to is a " HOLE " at the center of a Galaxy which has a gravitation intensity so strong that nothing can escape. That is wrong. At the center of Galaxies the " CORE STAR (S) " do not emit enough light to be seen against the brightness of it's surroundings. I prefer to call them " GALACTIC CORE STARS ". They are not " BLACK " at any time of their existence. There may also be circumstances where the galactic core is a formation with no firm boundaries, just a jumble of gravity, energy, and matter be pulled in all directions by the gravitational forces surrounding it.
Some people have related the look and formation of Galaxies to " TORNADO'S, HURRICANES, CYCLONES " with a " CALM EYE " at their center. They conclude that the " CALM EYE " they think lies at the core of Galaxies to be a " BLACK HOLE ". However, Galaxies are based on gravitation, and there is " NO " calm eye at their core.
Carbon and some metals like iron comprise a portion of a star's surface after it has used up all or most of it's available fuel whether it is a galactic core star or by itself. " MOST " of the electromagnetic spectrum would be absorbed, and not be reflected or radiated from most of the surface. However, every type of energy known and matter has been detected being ejected from the poles.
The " HOTTER " something gets, the greater is the intensity of energy. Like a carbon filament in a light bulb - ( i.e. It glows. ) - taking into account the entire electromagnetic spectrum.
The gravitational intensity at the core of galaxy's would
" NOT " be strong enough to retain all of the energy types being generated - keep in mind gravity is the weakest of the forces. The energies surrounding a " CORE STAR (S) " at the center of galaxies would have an energy buildup extending millions of miles. That is far beyond gravity's ability to retain it - ( i.e. The energy escapes. ). Back to the color of a " Galaxy Core Star (s) " - the color would be bright depending on it's composition and stage of development, but not black.
http://www.creationoftheuniverse... For more info.
Yes they have been used many time, as have Deloreans (Back to the Future), Phone Boxes (Bill and Ted), Police Boxes (Dr Who). I'm sure you can think of many more! Of course all of them examples of science fiction.
The only way to time travel is through film and video games. There is no such thing as a worm hole, time can not be folded back on itself and the nearest black holes are many light years away, not that they would be any use anyway.
Can you imagine the chaos if anyone could pop back and alter the past. It doesn't bear thinking about. I love time travel films and games but you must come to terms with the fact that it is just fantasy.
Best regards Bob
Time travel is not possible, by any physical means.
Blake holes appear to be black dots in the sky, what they really are is still a mystery. Although we do have a lot of speculations as to what they are.
As for wormholes, there appears to be no evidence to support their existence. They are at present only fictional concepts, anyway the primary idea for them was to send you to another part of the universe, not a different time period.
Kerr ring singularities may allow time travel.
If the ER=EPR conjecture is correct, wormholes and entangled particles are the same thing. And, yes, in that case wormholes allow time travel.