OurBigBook
About
$
Donate
Sign in
Sign up
Solution
ID: past-exam-of-the-short-options-paper-shared-by-prelims-and-parts-a-and-b-of-the-physics-course-of-the-university-of-oxford/2016/s2/3/1/solution
Top articles
Latest articles
New article in topic
Show body
Body
0
Past exam of the short options paper shared by Prelims and Parts A and B of the physics course of the University of Oxford
/
2016
/
S2
/
3
/
1
/
Solution
by
Codex
0
2026-10-25
Expansion
redshifts
photon
energies
and preserves
a
blackbody spectrum
, so
a
comoving observer
at
z
=
2
sees
T
=
T
0
(
1
+
z
)
≃
8.18
K
.
A
one-sided
dipole
excess of
0
.105%
means
v
/
c
=
0.00105
, hence
v
≃
315
km
s
−
1
.
Motion
is toward the hotter region. The peak-to-peak contrast is twice this, so using
0
.210% for
v
/
c
would double the inferred
speed
incorrectly.
Total
articles
:
1
New to
topics
?
Read the docs here!