 |
Getting
there faster |
|
|
 How
slowing down can reduce journey time
|
|
 |
|
|
|
|
|
|
How
can reducing speed increase flow?
|
|
|
|
|
|
Dr Ben Heydecker
says that speed restrictions can be a good thing. He argues
that at high speed cars need to spread out for safety and this
reduces the number of cars you can have on the road at any one
time. |
|
|
|
|
| |
Reducing
the speed allows cars to travel more closely, increasing the
number of cars that the road can carry at any one time. |
|
|
|
|
|
The
benefits of road closures |
|
|
|
|
|
|
|
|
When
is a road closure a good thing? |
|
|
|
|
|
When
it improves the movement of traffic. But why doesn't closing
roads cause more traffic jams? Dr
Ben Heydecker argues that restricting choice can actually
make travel easier. He says that in their resourcefulness
road users will find a better way to travel. |
|
|
|
|
| |
The
origination of zero goes back to some completely unknown Indian
in the 8th century who realised the empty column on the abacus
could be represented by some sort of symbol, a zero. This gave
you a different representation for numbers, what we call a place-holding
method. For example One hundred is one, zero, zero. |
|
|
|
|
| |
Without
the zero we would be in a world of roman numerals where 100
men can go off to fight or a man can own 50 ships but where
calculations are very complex and would require specialists
to do them. With the introduction of zero it is possible for
every man to do his own calculations. |
|
|
|
|
|
The
travelling salesman problem |
|
|
|
|
|
|
|
| |
This
is a classic mathematical problem. A salesman has to visit Madrid,
Paris, Rome, Amsterdam, Budapest and Prague. He can visit these
in any order. What is the shortest route that he can take? |
|
|
|
|
| |
Now
add Barcelona and Berlin to the cities he must visit and the
calculation becomes more complex. |
|
|
|
|
| |
The
more destinations that you have, the more rapidly the number
of possible routes grows and the more difficult the problem
becomes to solve. |
|
|
|
|
| |
It
becomes what mathematicians term a 'hard problem', a problem
where if you just try to list all the possibilities it won't
work. You have to look at different strategies for calculating
all the different possible routes and identifying the shortest. |
|
|
|
|
| |
Ian
Stewart says that what really interests mathematicians about
the travelling salesman problem is not solving it each time
but the theoretical problem of just how bad can it be. What
is a really nasty travelling salesman problem? |
|
|
|
|
| |
"...because
that tells you about the limitations of your mathematical technique
and it's always worth knowing what your limits are." |
|
|
|
|
