Invergowrie, October 1979: Five killed and 52 hurt when two trains
collide after one passes through warning signal.
Looking through the brochure for
Collide WM 05, what strikes you about the 12 specially-commissioned projects is how wide-ranging they are in style and medium.
Within auroral ovals, some 100 to 1,000 km (62 to 620 mi) over our heads, high-energy electrons from solar plasma
collide with air molecules in Earth's upper atmosphere.
If dark matter particles can
collide with each other, for example, then they might avoid getting crowded together near the centers of galaxies, despite gravitational attraction.
Gamma rays that
collide with lower-energy radiation sometimes vanish, leaving pairs of electrons and positrons in their wake.
In one scenario, if energetic quarks
collide at a fireball's edge, the quark heading away from the collision's center might get away while its partner bogs down in the soup of still agitated, colliding particles--the quark-gluon plasma.
The region in which it sits--a giant void some 30 million light-years in length--is so sparsely populated that it took nearly the entire 14-billion-year history of the universe for the few galactic building blocks that reside there to
collide. Likewise, other dwarf galaxies in the cosmic web's voids may also have just popped into existence.
In deep space, black holes may sometimes swirl together and then
collide, sending out staggering bursts of gravitational waves.
As the galaxies
collide and pass through each other, their dense clouds create a magnetic bridge, stretching out their magnetic field lines much as a taffy machine pulls taffy, Condon says.
A similar fate may befall our own galaxy, which is expected to
collide with Andromeda, its nearest spiral neighbor, several billion years from now.
When high-energy protons
collide with atoms and molecules in space, they create a short-lived subatomic particle called a neutral pion.
In the absence of sunlight, atmospheric gases freeze onto the moon's surface and electrons have fewer particles with which to
collide, Geissler's team explains.
In one scenario, material falling toward the black hole generates high-energy photons, which
collide to produce pairs of electrons and positrons.