Portfolio

Christopher Savagechris@savage.name

© Copyright 2006­2015 Christopher SavageAll rights reserved

The following pages contain various graphics and photographsthat are representative of my work.

Having spent over a decade working in the field of physics andhaving worked extensively with computers, most of the graphicshere are computer generated, sometimes using programs writtenmyself. The graphics include figures created for use in theclassroom, for research­based publications & presentations, forhome projects, and some just for fun. The first part of theportfolio focuses on these graphics.

As photography has become a recent hobby of mine, the latterpart of the portfolio provides a selection of photographs. Nature,buildings/monuments, cityscapes, and the nighttime sky arefavorite targets of mine; a few images are shown for each ofthese.

Enjoy!

Self portrait

In scientific research, graphics are used toillustrate concepts and processes as well as topresent data, the latter usually in the form ofgraphs. The next few pages show examples ofgraphics created during my time as a physicist.Most have appeared in published (or forthcoming)articles, though some of the more colorful oneswere for seminar and conference presentations.

Sun

Earth

December

June

WIMP

wind

These figures are used to illustratesome physics concepts andprocesses: scattering of a particlein the human body (above) and awind of dark matter entering thesolar system as the Earth orbits theSun (right).

Physics Research

Gas

Liquid

PMT

E-field

E-field

Xe2

e-χ

(a)

e-

γ

⊗

(b)

e-

γ

(c)

The panels above show howelectrons and photons (light) arecreated and move around in theXENON100 experiment's detectorat different points in time. Thefigure to the right shows exampledata for XENON100.

More physics research­basedfigures follow on the next twopages (without explanation). S2 threshold

nuclear recoil band cut

0 10 20 30 40 50 60 70

S1 [PE]

101

102

103

S2/

S1

0 2 4 6 8

- 0.01

0.00

0.01

0.02

0.03

0.04

Energy @keVeeD

Mo

du

lati

on

Am

plit

ud

e

@cpd

kgke

Vee

D

Phase: June 2

9.9 GeV , Χr2 =10.3 7 @SDD

51 GeV , Χr2 =14.4 8

Model 310.2 GeV , Χr

2 =10.2 8Model 2

67 GeV , Χr2 =8.5 8

Model 1DAMA data

1996 1998 2000 2002 2004 2006 2008 2010

−0.05

−0.04

−0.03

−0.02

−0.01

0

0.01

0.02

0.03

0.04

0.05

Residual

Rate[cpd/(kg

keVee)] 2–6 keVee

DAMA/NaI DAMA/LIBRA Best-fit

10 10010-6

10-5

10-4

10-3

Mass @GeV D

Cro

ss-

sect

ion

@pbD

goodness-of -fit regions

contours at 3Σ 90% CL

XENON100DAMA total rateDAMA H improved LDAMA H originalL

v [km/s]

f(v)

[s/k

m]

N-bodyinferred SHM

MB fitrotating MB fit

0

0.002

0.004

0.006 g1536 (DM-only)

bands: MB simulation 1-σ

rela

tive

diff

eren

ce-0.75

-0.5

-0.25

0

0.25

0.5

0.75

0 100 200 300 400 500

relative to best-fit rotating MBdashed line: simulation average

1010

1011

1012

1013

1014

1015

1016

1017

1018

1019

Monopole Mass (GeV)

10−30

10−28

10−26

10−24

10−22

10−20

10−18

10−16

10−14

10−12

10−10

Mon

opol

eFlu

x(c

m−

2s−

1sr

−1)

Ω = 1 (clumped)

Ω = 1 (uniform)

white dwarfs

neutron stars

NS w/ MS accretion

Parker

extended Park

er

(allowed)

bin

coun

t

x [mm]

all pairsΔp cutΔx cut

100

101

102

103

104

105

106

107

108

109

1e-10 1e-05 1 100000

Graphics shown over the next fewpages were used in various introductoryphysics assignments/exams and theirsolutions, like the one shown. Figuresare generally in black & white andsimple in form as they must be printed/photocopied a large number of times(up to 200 students in a course).

Physics InstructionLecture Quiz Problem: Lens

Physics 1202 – Fall 2008

A candle sits 180 cm from a thin glass lens with an index of refraction of 1.67. The first (nearestthe candle) and second surface of the lens have radii of curvature with magnitudes of 80 cm and40 cm, respectively, with the center of curvature of both surfaces being on the same side of the lensas the candle.

(a) Determine the location and magnification of the image. Is it real or virtual?

(b) Draw a ray diagram using three rays to indicate where the image forms.

Find the solution(s) in symbolic form first.

Solution:

(a) The problem is illustrated in the figure above. The centers of curvature for the first (‘C1’) andsecond (‘C2’) surface are on the same side as the candle, opposite the side of the lens that the lightpasses to, so both radii of curvature are negative: R1 = -80 cm and R2 = -40 cm.

For a lens, the focal length is given by:

1

f= (n − 1)

(

1

R1

−1

R2

)

⇒ f =1

(n − 1)

(

1

R1

−1

R2

)

−1

.

Plugging in n = 1.67, R1 = -80 cm, and R2 = -40 cm yields f = 119 cm (this number will be usefulfor part (b)), so the focal point is located on the far side if the length.

Find the image distance:

1

f=

1

p+

1

q⇒ q =

(

1

f−

1

p

)

−1

=pf

p − f=

p

p(

1

f

)

− 1=

p

p(n − 1)(

1

R1

−1

R2

)

− 1

Plugging in p = 180 cm, n = 1.67, R1 = -80 cm, and R2 = -40 cm yields q = 355 cm. The imageis on the side of lens opposite the candle and is therefore real.

Find the magnification:

M = −q

p= −

1

p(n − 1)(

1

R1

−1

R2

)

− 1

Plugging in the values for p, n, R1, and R2 yields M = -1.97.

(b) See the diagram. The three rays are:

1. Ray parallel to the principal axis, proceeds through the focal point (f) after passing throughthe lens

2. Ray through the anti-focal point (−f), proceeds parallel to the principal axis after passingthrough the lens

3. Ray going through center of lens, continues straight

θ

mill

ravine

ramp

log

elevatorcar

Fm

drum

mg

T

a

T

Fm R

RaT

ϕ

apparentlocation of fish

water

θi

θsunwall

fish

dock

key

water

air

Bob

d

d'

BA

L

x

θ

θ

mg

T

FB

θ

solenoid (side)

q

r Rsolenoid (front)

B

wiresd

(not to scale)

glass

θi

θ4

air

θ2

θ3d

t

d1

d2

O1

I1

p1

q1

O2

I2

q2

p2

R1

R2 f

part (b)

lens

C1

C2

ξ1+

-

+

-

ξ2

+ -

ξ3(2)

(1)

+Q -Q

C

Ra

Rc

Rb

I1

(a) (b)

(c)

Ib

I2

I3

(3)

Ic

(a) (b)

0λ

+1λ

+2λ

+3λ

-1λ

-2λ

-3λ

y

x

θ

+ λ52

I wrote my own software to generatethese buddhabrot (left) and mandelbar(below) fractals.

Fractals

Asymptote is a software package for creating graphics. Imade some minor contributions to the software, notablydeveloping routines for plotting contours and creating someexample figures. Two of those figures are shown here.

Asymptote

0 1 2x

0

1

2

y

−1 −0.5 0 0.5 1

f(x, y) = sin(πx) cos(πy)

0 20 40 60 80 100x

100

101

102

y

10−3 10−2 10−1 100 101 102f(x, y)

Every time I move, I map out andmeasure the dimensions of the rooms inmy new place, then generate a CADdrawing. I cut out identically scaledfurniture (below) so that I maydetermine appropriate placements forthem. Two of these home plans areshown, on this and the following page.

Home Plans

Photography

Donut Falls, Utah Red Pine Lake, Utah

Yellowstone National ParkHyde Park, Sydney

Trafalgar Square, London

Sydney Harbor BridgeColiseum

Seppelts Winery, Great Western, AustraliaWasatch mountain range, Utah