Are there other dimensions?

• We’re used to the three dimensions we live in

• Scientists count time as a dimension as well, which makes four dimensions

• At the scale of fundamental particles things are very different

• There might well be extra dimensions that we can’t sense

• Scientists think that everything - including protons, neutrons and electrons - is made of families of fundamental particles that take up no space at all

• They’re called quarks and leptons

• But is something that has no volume really a “particle”?

• Are they something completely different?

• Like one-dimensional strands of vibrating loops and strings?

• This is the idea behind string theory, and if it’s true it will really shake up our view of what the universe is made of on the smallest scale

• String theory could sort some big problems with our present theory of what stuff is made of

• In particular, it allows gravity to fit nicely into the equations that describe all the particles and their interactions

• But extra dimensions must exist for string theory to work

• 10, 11 or even 26 extra dimensions!

• From a distance, an ant crawling along a string is moving in just one dimension

• But the ant is aware of three dimensions in its tiny world

• Could the extra dimensions proposed by string theories be the same?

• Compacted down to an invisibly small size that we just don’t sense?

• The experiments at the LHC might just provide the missing evidence for other dimensions

• We won’t “see” them, but we might catch freshly-created particles slipping away into them…

• …And that will change our whole concept of what the universe is made of