The e-mails we receive
on time travel usually fall into the following categories: about 8% contain serious scientific
discussions, 12% are people claiming to have built their own time machines in
their bedrooms using magnets, 40% are from students requiring further
information for project work and finally 40% are just plain weird. Here are the most common questions we are asked. If you
have a question which has not been addressed here please feel free to contact us.
Question - I am 14 years old and really
interested in time travel but have found your site a little difficult to
understand. Please can you explain some of the fundamental concepts in a little
more detail for somebody of my age?
Answer - Time has fascinated people throughout
our history, we have constantly come up with every increasingly more complex and
accurate ways to measure the passing of this thing which we call time. However,
I wonder how many people realise that time itself is not exactly the same
wherever you are. Albert Einstein was the first to show in his Theory of
Relativity that time was not, in fact, a smooth river, constant in its flow, but
something that could be affected by motion and by gravity - an effect known as
time dilation. Einstein did not consider time and the three spatial dimensions
as being separate, but as being linked to form a four-dimensional quantity known
as space-time. Einstein's theories of relativity have
been proved by numerous experiments, including one in 1971 in which highly
accurate atomic clocks were placed aboard two high-speed aircraft, with another
one at an airbase. Despite staying in the same location, the ground clock was
not stationary, since it was travelling at the same rate as the Earth spins.
One aircraft flew eastwards from the base, travelling in the rotational
direction of the earth and so moving faster than the ground clock, while the
other flew westwards and so moved relatively slower. After the flight, the
eastbound aircraft's clock had lost time relative to a ground-based atomic
clock, while the opposite was true of the westbound aircraft's timepiece.
Amazing eh? The only constant in the theory of Special Relativity is that the
relative speed between any observer – regardless of their own motion and any ray
of light is always 300,000 kilometres per second (186,000 miles per second). The
consequence of this theory, once the equation has been balanced, is that not
only is time different for a faster observer, but also lengths and mass change. In 1915, Einstein developed his ideas to
form the General Theory of Relativity, in which he considered objects that were
being accelerated with respect to one another. He compared the forces of
acceleration and gravity and found them to be indistinguishable. For example,
an astronaut standing in a rocket on a launch pad would feel himself pressed
against the floor because of gravity. If the same rocket was in outer space and
not affected by gravity, but with its engines turned on so that it was
accelerating, the astronaut would again be pressed against the floor. If the
acceleration due to the engines were the same as the acceleration due to
gravity, the astronaut would have no way of telling whether the rocket was at
rest on the earth or accelerating in outer space unless the looked out of the
window. Einstein stated that the attraction to the Earth of a rocket that is
resting on a launch pad is equivalent to the acceleration of the rocket. So
although in three-dimensional space, the rocket remains stationary, in
four-dimensional space-time the rocket is in motion along its world line. The
upshot of this motion in space-time is that gravity also makes time run slower. This notion becomes more relevant when
considering the greatest gravitational fields known: those within a black hole.
A black hole is a dying star that has collapsed under the weight of its own
spent fuel, with the result that its gravity field is so strong, not even light
can escape its pull. The edge of a black hole is called an event horizon, since
that is where light cannot escape. Compared to such forces, the Earth's escape
velocity is paltry in comparison. A spacecraft needs a mere 11.2 kilometres per
second to break free of our planet's grip. As the edge of a black hole - known
as the event horizon - is neared, time slows down relative to areas, which are
distant from the hole. Some scientists believe that within the event horizon,
all matter collapses into a dimensionless object of infinite density known as a
singularity. However, others argue that no such collapse occurs and that
space-time forms a closed surface without a boundary. In effect a black hole
would then not be a rip in space-time, but would be more like the hole of a
doughnut. This second theory opens the possibility of using black holes to link
to other parts of the universe through tunnels in space-time known as wormholes.
By entering one end of a wormhole a traveller might be able to take a short cut
through space-time to another part of the universe. In a similar way, the
shortest route between one side of a donut to the other is through the hole in
the centre, rather than around the rim. Einstein's General relativity equations
do not rule out the possibility that these wormholes might not only provide a
tunnel through space, but also a tunnel through time.In principle, Einstein's General Theory
of Relativity allows the possibility that a practical time machine might be
built. Such a machine would need to be able to create and manipulate black
holes, and the technology needed for it is far more advanced than anything
humanity might devise for hundreds or even thousands of years.We believe from a personal viewpoint
that time is not simply linear - flowing in one direction but cyclic. Eastern
concepts about the universe have often interpreted it as a series of cycles of
birth and death. By analysing some complex equations, we believe that the
universe runs in cycles, with time running backwards as well as forwards. In
other words, we will all live again and again.
Question - How do I build a Flux Capacitor?
Answer -We assume you are referring to the film “Back to the
Future”. Unfortunately we get used to receiving
e-mails like this and it deeply saddens us. You see, the world’s
scientists are working really hard to push our knowledge forward but it seems
that every step forward that the scientific community make Hollywood pushes us
back two steps. The aim of our website is to try and separate fact from fiction,
such as "Back to the Future".
Question - Time doesn’t exist. It is man made
and totally artificial. Do you agree?
Answer - No. Are you saying that before
man evolved there was no time? I agree that the measurement of time is man-made,
but as for the actual existence of time, that is undeniable.
Question - I built a time machine in my garage
using some magnets and a quartz crystal.
Answer -We have found that after extensive scientific study
that the power required is a little greater than can be achieved with a magnet
and/or a crystal. There is some truth in the statement that a crystal has some
lattice energy but it is only very small indeed and not enough to light a candle
let alone propel a machine and its user at trans-light velocities. Seriously we
have received a surprisingly large number of e-mails on this subject, including
a guy from the USA who was positive that by taping a magnet to his head he was
able to see the future. We were in regular contact with this individual until we
received an e-mail from him saying that he needed more power and was going to
wire his copper head magnets to the main electricity supply. We never heard from
him again, either his experiment worked or, as we suspect, he didn ’t achieve the
results he had hoped for.
Question - If I could go back in time and shoot
my grandmother surely I would then never have been born so I couldn’t then shoot
Answer -This paradox is discussed in detail in the website and
so we must assume that you were unable to follow the argument contained therein
and require a more basic explanation. The truthful answer to this is that nobody
knows the right answer. Professor Hawking from the University of Cambridge in
the UK prefers the idea of a “Cosmic Censor”, i.e. something will always happen
that stops you from changing history, e.g. the gun will misfire etc. Other ideas
are that you can kill your grandmother and by doing so you generate a new
universe where you are not born. Finally, there is another school of thought
that suggests there are an infinite number of universes and so everything that
is possible has already happened.
Question - Are there any countries which are
developing time machines?
Answer - What is being worked on
in area 51? On a serious note, in a way yes, but not in the way that you think.
There are several countries looking at accelerating particles to high velocities
and smashing them together to create all sorts of exotic matter. In these
experiments the high velocities result in significant time dilation effects,
which can be observed and measured.
Question - I have enjoyed your website and have
found it most informative. I would like to investigate the topic further, what
do you suggest I do?
Answer - Thank you for your kind e-mail.
We would recommend that you have a look at the recommended books section.
Question - I regularly have dreams where I visit
ancient Egypt and watch the building of the pyramids. Is this time travel?
Answer -No, this is dreaming. The human
mind is an amazingly complex entity and is able to produce many experiences
which could be interpreted incorrectly as time travel. We also receive many
e-mails from people claiming that after taking LSD and other mind altering drugs
they have “Time Travel” experiences – draw your own conclusions.
Question - When do you think man
will have a fully functional time machine like the TARDIS?
Answer -It will be a very long time before technology is available to build a time
machine. We guess that you’re looking at hundreds probably thousands of years if
at all. We think it much more likely that man will not survive long enough to
develop the technology, being killed off either by bacteria and viruses (our
only true predator) and annihilation by war.
Question - Where does God fit into this?
Answer - Would it surprise you to learn that one of the financial backers of this type of
research is the church as the church recognises that It is no good trying to pretend that scientific
advancement is detrimental to religion. We believe that one day Science will
either prove the existence of God or totally disprove it