### Guardian has cool ‘Cern’ feature… still can’t figure out capital letters

07Jul08

The good folks at the Guardian have put together a nice interactive presentation about the LHC. Unfortunately, they continue to deny that ‘CERN’ is an acronym by spelling it as ‘Cern.’ [edit:see comments.] If you’re willing to forgive their editor, the presentation is a really nice introduction for non-physicists.

#### 6 Responses to “Guardian has cool ‘Cern’ feature… still can’t figure out capital letters”

1. 1 Lake

Nice blog. A pedantic point, though: several newspapers (I can’t remember if the Guardian is one) cap down acronyms that are pronounced as single words – such as Nato, or Peta. Full caps are reserved for the likes of IRS and GCHQ.

2. Aaah — that explains it. Thanks. Why do certain organizations get capital letters while others don’t?

3. 3 Matt

Maybe the acronyms which are pronounced as words are ‘cap’ed down’ and the acronyms which are spelled-out when spoken are a string of all-caps. Just a guess…

4. 4 ND

Although they seem to think the protons will collide “at nearly twice the speed of light”!

5. 5 just a student

Well, aren’t they?

Riding a random proton in proton bundle A, what is the speed that protons of bundle B ”seem” to have?

6. 6 rpenner

If Speeds added like Newton thought ( v_AB = v_A + v_B ) then we would have plenty of evidence of particle moving faster than light. Experimentally, this is not so. So in 1905, Einstein proposed to preserve most of physics and have it be compatible with Maxwell’s equations, that the relationship should be: v_AB = (v_A + v_B)/(1 + v_A v_B/c^2)

Speed of proton A in the lab frame: v_A = c – d_A (a small bit less than c, the speed of light)
Speed of proton B in the lab frame: v_B = c – d_B

Speed of proton A as seen by B for a head-on collision: v_AB = (v_A + v_B)/(1 + v_A v_B/c^2) = c(2 – d_A/c – d_B/c)/(2 – d_A/c – d_B/c + d_A d_B/c^2) which is approximately c – d_A d_B/(2 c) when d_A/c and d_B/c are small.