你地覺得第時有冇時光機?

本人覺得會有
只係因為現在冇人識發明時光機
即時未來有人識發明時光機
都唔會阻止事情發生
因為阻止了事情發生之後
好可能會影響未來已發展事情

In my opinion, a time machine is workable theorically.

The theory towards travelling through time is not complicated.

I assumed that you know time and space are compatible units.

It might be little bit too complicated for you to understand without a graph,

so please take a white paper and a pen out, and plot a graph with x and y axis.

Let's assume the vertical axis to be TIME and the horizontal one be SPACE.

Now take a step forward. The action you have just done is an example of

space-time advance. For the universe, you are constantly advancing in

space-time as the Earth, the Sun, the Milky Way and the Galaxy are

always moving and that the time always goes by whatever you are doing.

However, in space, our action is not limited by the rotation of the Earth.

Therefore, we can advance only in time, not space. To represent our action

now, we draw a diagonal line away from the x and y axis.

To time travel( going back to the past), in theory, we need to

draw a curve on the line back to the vertical axis. It seems easy enough to

do. The action of drawing a curve on the graph is to bend time.

To do this practically, we need energy. A LARGE amount of energy.

A source of energy large enough to form a blackhole. Well, it is easy.

Make the Sun collapse and press it into a ball 10 km in radius.

The sphere will become a dense superstar called Blackhole.

Its mass is so big that even time and space is distorted.

That is what Einstein said in the Theory of Relativity.

When a spaceship goes near the blackhole,

in our eyes( if we can even see it), the spaceship is not moving,

although all things are natural to the astronauts inside.

We can still contact with the spaceship through microwave,

but the astronauts' speech is distorted. All of those are because of the

bend of time and space by such a huge mass.

2008-06-13 17:37:48 補充：
In this way, we produce a ' thing' with similar structures with

the blackhole, though this one is in a shape of tornado and is called

a WORMHOLE.

2008-06-13 17:38:28 補充：
A wormhole is a extended blackhole,

only with one difference: a blackhole bends, a wormhole fastens.

It fastens the passed time and space, digging a hole through the time barrier.

2008-06-13 17:39:00 補充：
In this way, we can travel back to the past if we can have enough energy

to produce a wormhole, and that we can survive passing through one.

2008-06-13 17:39:29 補充：
We can also travel ro the future by a simpler way. Just leap over the

bended time and space by a blackhole. It is the fastest way to

travel to the future but just remember not to be sucked into the blackhole.

2008-06-13 17:39:39 補充：
In theory, a time machine is workable. However,

in the coming 100 years, can human beings invent such a machine

requiring such high technology and large energy consumption?

This is a really interesting question!
我認為無。
假設,我而家20歲,發明左時光機,咁我係咪可以返到20年前,阻止自己出世??
如果人人都有時光機,咁歷史會點?
時間係一去不返,正如我地無可能阻止地球自轉

本人覺得會有
因為在某一日,
我在明報看到有一名科學家話:「
就算只是一粒塵也可以製造時光道路,
although還未製造出來。」