50th Anniversary Special Feature the Discovery of Cosmic Microwave Background

5/21/2018 50th Anniversary Special Feature the Discovery of Cosmic Microwave Backgroun...

http:///reader/full/50th-anniversary-special-feature-the-discovery-of-cosmic-micro

50TH ANNIVERSARY SPECIAL FEATURE:

THE DISCOVERY OF

COSMICMICROWAVE

BACKGROUND

........................................

Charles Bahr,

Marcus Weldon, and

Robert W. Wilson

The world is becoming more closely connected every day. In 2014, the total

number of mobile phone subscriptions will have exceeded the world's popula-

tion. As a result, access to voice, Internet (data) and television (video) services

are now ubiquitous for over half the world's population. The global telecom-

munications industry generates about 5 trillion USD in annual revenue and this has

been shown to strongly correlate with GDP growth [1]. Furthermore, broadband con-

nectivity demands are expected to accelerate in all practical metrics, which will re-

quire the industry to innovate in areas such as signal transmission, coding, materials,

applications and sustainability.

In the midst of this communications technology explosion, we look back 50 years

to a discovery that provided important insights into an explosion of another sort: the

Big Bang. We show that this seminal discovery was the result of investigations into

solving a practical problem (radio communications) and it has connections to a multi-tude of other subsequent innovations and discoveries. As a result, this legacy con-

tinues to inspire innovators to come together to invent technologies and methods that

push the boundaries of information and communications technology and that will

transform the way humans and machines connect and collaborate.

Cosmic Microwave Background RadiationThe 20th century brought an astonishing series of scientific discoveries and technical

achievements. When the century began, radio waves and radioactivity had just been

discovered. There were few automobiles and no aircraft. By little more than halfway

through the century, however, humans had built general-purpose mainframe com-

puters, launched artificial satellites, and orbited the Earth.Not long after the first manned space flights, an experiment by Robert Wilson and

Arno Penzias opened up an unexpected new area of discovery. Their work with a

Horn-reflector antenna and maser (microwave amplification by stimulated emission of

radiation) amplifier revealed the existence of cosmic microwave background radiation,

the first direct experimental evidence of the origin and evolution of the universe.

Serendipity played a key role in the discovery. It united two people with a com-

mon interest in mapping and measuring intergalactic radio signals. It brought all the

necessary technologies together and put Bell Labs at the forefront of improving com-

munications technology within the Bell System. It also created the changing political

environment that handed the right tools to Bell Labs researchers to continue to invent

a wealth of pivotal communications technologies.

1538-7305/142014ALCATEL-LUCENT V O L U M E 1 9 Bell Labs Technical Journal



Wilson and Penzias did not set out to measure the

remnant radiation from an expanding universe. They were

taking part in a long tradition of Bell Labs: pushing state

of the art communications technologies and discovering

new science as a result. The Horn antenna and maser

were both new technologies that, when combined togetherby the right people, paved the way for a breakthrough in

human understanding and technology. In order to under-

stand this, we have to delve a bit deeper into Bell Labs

history and look at a sequence of important developments

in communications that made the Big Bang discovery

possible at Bell Labs in 1964.

From Transatlantic Phone Calls to Interstellar NoiseFounded in 1877, the Bell System grew to become a

regulated monopoly that provided phone service for

virtually all of the United States and Canada. It was led

initially by the American Bell Telephone Company.American Telephone and Telegraph (AT&T) acquired its

assets in 1899.

Bell Laboratories was created from the combined re-

search and engineering departments of Western Electric

and AT&T in 1925 to solve the technical challenges

AT&T faced in its quest to provide universal service. At

that time, good quality voice calls were already possible

across much of the U.S., but few people could afford ac-

cess to a telephone [2, p. 3]. Technologies like carrier

modulation, radio telephony, echo suppression and reli-

able vacuum tubesVall either invented or refined at Bell

LabsV

made these phone calls possible.But connections that spanned continents were still a

thing of the future in 1925. These connections would re-

quire radio, a technology that was not yet sufficiently de-

veloped. Limitations in electronics had confined radio

transmission to frequencies in the sub-MHz region, in the

..............................................

Taking part in a long tradition of

pushing state of the art communications

technologies and discovering newscience as a result.

range of 100 KHz. By the mid 1920s, higher-frequency

radio experiments by Guglielmo Marconi and re-

searchers at Western Electric had shown the potential of

transmission at 5 MHz and beyond. Bell Labs began to

focus research on radio transmission theory, transoce-

anic radio, and broadcast radio.

The decade from 1919 to 1929 saw dramatic improve-ments in radio technology. In 1919, the cutting edge in

long distance wireless communications had been described

by Swedish-American electrical engineer Ernst Alexan-

derson, who listed five transmitters in the world capable

of long-range broadcast. These transmitters operated

between 18 and 25 KHz, each one delivering up to 100

words per minute. According to Alexanderson, their col-

lective capabilities offered the potential to achieve a trans-mission capacity 175 times higher [3]. Long distance

radio communication existed but it was highly impractical

for everyday two-way communications.

The earliest transoceanic radiotelephone circuit was

noisy and took a circuitouspath [3]. A phone conversa-

tion from the United States to the United Kingdom trav-

eled to New York City, then to Rocky Point, on Long

Island. It was then transmitted by long wave radio to

Cupar, Scotland, then by wire to London, and finally to

the subscriber. The return signal traveled through London

to Rugby, England, then over long wave transmission to

Houlton, Maine, and then back by wire through NewYork City. The 60 KHz transmitting system in Rocky

Point used six antennae 400 feet high. Receivers were

also massive: the receiving antennas in Scotland were dis-

tributed over three miles [4, p. 178].

Transmission at higher frequencies would require

much more advanced antennas. AT&T engineer George

Campbell developed the theory of multi-element antenna

arrays in 1919, but it would take nearly a decade for

Edmund Bruce, another Bell Labs researcher, to develop

and implement a practical approach to highly directional

antenna systems [2, p. 27]. His directional Grecian-Key

antenna had about 16 dB gain. Higher-frequency trans-mission was important at the time because low-frequency

(60 KHz) transmissions were susceptible to interference

caused by thunderstorms. High-frequency transmissions

(several MHz) were immune to thunderstorms but suscep-

tible to ionospheric disturbances. AT&T addressed these

challenges by building a transoceanic system that could

support diverse frequencies, and by adapting the live car-

rier frequencies to the weather.

In 1928, Bell Labs hired Karl Jansky to solve noise

problems in the transoceanic links. The signals were then

being transmitted at both the 5000 meter wavelength

band (

60 KHz) and the 16

33 meter wavelength band(510 MHz) [5]. Jansky aimed for even higher fre-

quencies, and by 1931, he had a working 14.6-meter

(20.5 MHz) receiver with a rotatable, directional antenna

(Figure 1). After over a year of measurement, he was able

to characterize noise sources, local thunderstorms, distant

thunderstorms, and a steady hiss that appeared to be

coming from outer space. Jansky realized the signal was

both extraterrestrial and extrasolar because its direction

varied with the time of year. He pinpointed the origin as

the center of the Milky Way galaxy.

Jansky reported this discovery at the International

Scientific Radio Union in Washington D.C. in 1932, andradio astronomy was born. Although Jansky was trans-

ferred to other assignments, his work inspired another

Bell Labs Technical Journal V O L U M E 1 9

2



young scientist, Grote Reber. Reber applied to work atBell Labs but was not hired. Undaunted, he became an

amateur radio astronomer, building his own 9.6-meter pa-

raboloid reflector. He eventually reproduced Jansky's

measurement, and went far beyond into areas that re-

vealed various cosmic processes. His pioneering work

marks him as the real father of radio astronomy, although

Jansky made the first measurements [6].

The Right Combination of People and TechnologyRadio provided the only practical transoceanic telephone

link in the 1920s and 1930s, but AT&T had a broader vi-

sion to further develop wired communications. One of themost important developments in long-distance signal

transmission was a negative feedback amplifier invented

by Harold Black, a Bell Labs electrical engineer. Bell

Labs president Mervin Kelly offered this assessment of

Black's amplifier in 1957: Although many of Harold

Black's inventions have made great impact, that of the

negative feedback amplifier is indeed the most out-

standing. . . without the stable, distortionless amplification

through Black's invention, modern multichannel transcon-

tinental and transoceanic communications systems would

not be possible[2, p. 61].

Black's achievement is considered by many to be oneof the most important advancements of the 20th century

in applied electronics. He had been working on amplifier

distortion for years, with a goal of reducing distortion

sufficiently to enable communications systems to employ

thousands of repeaters. In a moment of inspiration, he fed

a portion of the output signal in opposite polarity back

into the input. This reduced the gain slightly but dropped

the distortion by about 50 dB or a factor of 100,000. The

idea was so revolutionary that it took 10 years for his pat-

ent to be accepted.

In anticipation of future needs, Bell Labs embarked on

an effort to replace vacuum tubes with components ofboth lower cost and improved reliability. This led to the

development of the transistor by Shockley, Bardeen, and

Brattain at Bell Labs in 1947. Continuing efforts to im-

prove the signal-to-noise ratio of communications links

resulted in an understanding of the theoretical underpin-

nings of information theory, which were first described in

a two-partBell System Technical Journalpaper by Claude

Shannon in 1948 [7, 8]. Even today, we strive to achievethe Shannon Limit in any communication system.

To further illustrate the connections between inven-

tions and ideas, as post-transistor semiconductor work

continued, Bell Labs scientists Gerald Pearson, Calvin

Fuller, and Daryl Chapin created an array of silicon

strips, placed them in sunlight, captured the electrons

freed by the light and turned them into electrical current.

In 1954, they used the results of this work to create the

first solar battery.

The increasing demand for more cost-effective and

longer range wireless telephone links fostered a need for

better antenna systems. The 1941 invention of a horn-reflector antenna by Bell Labs scientists Alfred Beck and

Harald Friis provided a key enabling technology. Com-

posed of a parabolic section with shielded sides that taper

.........................................

The idea was so revolutionary it took

10 years for the patent to be accepted.

to a waveguide, the antenna combined the high direc-tionality of a dish reflector with the low noise properties

of a horn. The horn reflector design was successful and

eventually overtook competing designs for wireless

communications applications. Within 10 years of the

horn-reflector's invention, AT&T had built a network of

microwave relay towers across the U.S. and extended

long-distance voice and television signals across all

types of terrain. Horn-reflector antennas were installed

on many of these towers.

Around the same time, another breakthrough technol-

ogy was being developed in the Soviet Union. In 1952,

Nicolay Basov and Aleksandr Prokhorov developed thetheory of the maser. The first working model was built by

Charles Townes, James Gordon, and Herbert Zieger at

Columbia University in 1953. Townes helped bring the

maser to Bell Labs, a development that helped inspire

Arthur Schawlow to invent its optical analog (the laser).

The maser had several applications, for example as a pre-

cision frequency standard or a very sensitive radio ampli-

fer. Its superior performance as a low noise radio signal

amplifier made it a key technology in the early days of

satellite communications.

Meanwhile, in wired communications, AT&T installed

the first transatlantic telephone cable, TAT-1, which wentinto service in 1956. TAT-1 carried 36 two-way channels

at a cost of over $1 million per channel [2, p. 341]. The

FIGURE 1. Karl Jansky with his 100-foot rotatable antenna.

V O L U M E 1 9 Bell Labs Technical Journal

3



cable used 51 vacuum tube-based repeaters over its 1950

nautical-mile link. Transistors were still too new at that

time to be relied on for the cable. Transatlantic voice

communications were greatly improved, but the improve-

ments came at a high cost.

The Horn Antenna and the Dawn ofSatellite CommunicationsIn 1957, the Soviet Union kicked the Space Race into

high gear by launching Sputnik, a beach-ball-sized radio

transmitting sphere. This satellite crossed the U.S. several

times a day, and led to a political uproar that prompted

the U.S. to step up its efforts to compete with the Soviet

Union. Space investment increased, and within a few

months, the U.S. had launched a similar, but smaller, sa-

tellite called Explorer. Explorer, like Sputnik, was only

capable of transmitting measurements of the space

environment.As the space race began to unfold, the Bell System re-

cognized that it was in an ideal situation to exploit space

for communications. Millions of people were connected

by telephone wires, microwave relays or radiotelephones.

Yet there were gaps across the world that could only be

filled by space-based communications. Satellites were en-

visioned as a way to greatly extend the reach of voice

and video. Most of the required technologies existed, but

had not yet been integrated into such a radical new sys-

tem, and the proposal for satellite communications be-

came another important challenge for Bell Labs.

In 1960, NASA launched Echo 1A, a 30-meter Mylarballoon coated with aluminum. Its aim was to develop

and test communications relaying between widely sepa-

rated points on earth. Data from Echo 1A would be used

to adjust the design of subsequent satellite systems so that

a working satellite communications network could be de-

ployed. Bell Labs designed and built the powerful trans-

mitters and sensitive receivers needed for Project Echo. It

also developed the Echo tracking and rocket guidance

systems.

For a receiver, Bell Labs constructed a horn-reflector

antenna in Holmdel, New Jersey, and used a maser as the

low-noise amplifier that was essential for voice signal re-covery. The Holmdel horn-reflector, shown in Figure 2,

was built with a gain of 43 dB and a beam-width of

1.5 degrees. Voice communications were successful, and

as the balloon circled the Earth, it was possible to bounce

the signals off the satellite from Goldstone, California to

Holmdel and back for a few minutes during each orbit.

The requirements for the receiver were demanding.

Because the satellite was passive (i.e., merely reflected

radio waves without amplifying them), the signal incurred

a loss of about 180 dB from source to destination (for

example, from Holmdel to Goldstone). To track the satel-

lite as it sped across the sky, the antenna had to rotate at1.5 degrees per second and achieve an aiming accuracy

of 0.02 degrees [9]. The Echo experiment was successful,

and AT&T (and Bell Labs) immediately began work on

the Telstar satellite project.

Telstar was driven and funded entirely by AT&T. The

company built and installed a 340 ton horn-reflector on a

new site outside Andover, Maine, and protected it with

the largest inflated structure (radome) ever built. The newsite was conceived, designed, built and made operational

in about two yearsVan extraordinary achievement.

AT&T hired NASA to launch Telstar, which turned out to

be a technical masterpiece.

Telstar, shown in Figure 3, was powered by solar cells,

and boasted receivers and transmitters with sufficient sig-

nal-to-noise ratio to relay television signals. AT&T envi-

sioned a globe-circling constellation of Telstar satellites

that would provide continuous video and voice communi-

cations around the world.

Shifting Gears: From the Space Race to the Big BangU.S. President Eisenhower had been in favor of allowingAT&T to extend its monopoly, but in 1962, President

Kennedy decided with Congress to assign the satellite

monopoly to a new corporation, Comsat, thereby exclud-

ing AT&T from the satellite business. AT&T had invested

several million dollars into the Telstar project, but its fu-

ture work would be relegated to more routine activities.

The company decided to complete its initial Telstar exper-

iment and exit the satellite business.

However, for Arno Penzias and Robert Wilson, the

decisions that brought AT&T into and out of the space

communications business were fortunate. Had AT&T notinvested in the horn-reflector and maser amplifier and

then been compelled to stop using it for satellite projects,

FIGURE 2. Robert Wilson and Arno Penzias with the Holmdelhorn-reflector antenna.


4



the two scientists may not have had the opportunity to

pursue their research into radio astronomy with the same

focus.

Before coming to Bell Labs, Robert Wilson had

mapped part of the Milky Way during his graduate work

at Caltech, but he was still looking for a halo around the

galaxy that he might have missed. Because the Owens

Valley radio telescope dish he was using at Caltechpicked up terrestrial noise, he had to point at a fixed posi-

tion and wait for the earth to scan across the Milky Way,

so he was looking forward to the use of the horn antenna,

with its better rejection of terrestrial noise, when he ar-

rived in New Jersey. Arno Penzias was interested in emis-

sion from neutral hydrogen atoms in clusters of galaxies.

Together they wanted to use the 20-foot horn for tests at

4 GHz, and then move to 1.42 GHz, or 21 cm, where the

hydrogen emission line was a practical radiation source to

map galaxies. As Wilson tells the story, the two were

hired by Bell Labs to work on communication technol-

ogy, but with permission to pursue radio astronomy intheir spare time. Because of this dual mission, they were

given access to the best radio communications equipment

in the worldVnamely the Holmdel horn reflector and ma-

ser amplifierVwith which to conduct their measurements.

In a short time, they perfected their equipment and experi-

ment, and rapidly exceeded the state of the art in micro-

wave receiver sensitivity. Then they found a noise floor

they could not explain (Figure 4).

Penzias was told by his friend Bernard Burke, an MIT

physics professor, about a preprint from Robert Dicke,

Jim Peebles, Peter Roll, and David Wilkinson, which

described a theory predicting detectable remnant radiationfrom the Big Bang. Dicke's theory predicted that the

young, hot universe would have eventually cooled to the

point where the hydrogen plasma could condense into a

gas and become transparent. The universal expansion

would then red-shift thermal radiation, dropping its tem-

perature to a few degrees Kelvin at the present day. The

presence of remnant radiation was a critical test of the

theory. Penzias spoke to Dicke, got a copy of his preprint,

and the extended team collaborated to interpret the data.

In 1965, they published their contributions separately in

.........................................

They found a noise floor they could

not explain.

Astrophysical Journal Letters [10]. In 1978, Penzias

and Wilson were awarded half of the Nobel Prize in

physics for their discovery of cosmic microwave back-

ground radiation.

Bell Labs continued to support astronomy through the

1990s. Bell Labs alumnus and University of California

Davis professor Anthony Tyson pursued studies of mass

distribution and nonuniformity in the universe. Later, he

used gravitational lensingVthe bending of distant light

by massive objects such as galaxiesVto create a map of

dark matter distribution. His measurement of faint (and

distant) galaxies required him to collect light using highly

sensitive charged coupled devices (CCDs). Once again,

the coupling between Bell Labs inventions and discov-

eries came into playVCCDs were a Bell Labs invention

spawned from research into bubble memory data storage,and their inventors, William Boyle and George Smith,

were awarded the Nobel Prize in physics in 2009.

FIGURE 4. Raw data illustrating unexplained noise measured withthe horn antenna system.

FIGURE 3. The Telstar satellite, showing solar cells and arrays ofantennae.


5



Opening New Chapters in CommunicationsAs the 1960s unfolded, AT&T was faced with continually

increasing voice traffic as well as a new demand for

data networks. To address future communications needs,

AT&T conceived a plan to crisscross the U.S. with

60 mm diameter waveguides, transmitting 274 Mb/s in theform of 475,000 two-way voice circuits at frequencies be-

tween 40 and 110 GHz [11]. Repeaters would be spaced

every 50 to 60 km apart. The project required further

R&D into waveguides but also included a significant civil

engineering component laying these waveguide pipes

underground across North America. The project actually

reached the trial stage, but before its deployment, optical

fiber emerged as a superior technology. Optical fibers are

today the dominant technology for wired communications.

The first demonstration of mobile telephony punctu-

ated wireless communications development in 1946, and

in 1947 Bell Labs developed the cellular concept. Thefirst practical trials of the concept of cellular mobile

communications were conducted by AT&T in Chicago,

Illinois and Newark, New Jersey in 1978.

Bell Labs also pioneered the concept and implementa-

tion of combining multiple input multiple output (MIMO)

antenna systems with spatial division multiplexing to im-

prove wireless throughput and achieve data rates higher

than the single channel Shannon limit. It is an extension

of earlier multiple-antenna systems that exploit high-

speed digital signal processing to obtain the benefits of

multiple signal path transmission. The MIMO innovation

became practical in the early 2000s. It has been incorpo-

rated into WiFi as 802.11n, and is also part of 4G cellularcommunications.

The telecommunications industry was dominated by

AT&T for most of the 20th century. It is clear from the

preceding that many of the most important innovations in

communications during the century can be traced back to

Bell Labs. Figure 5 offers a timeline that shows how Bell

Labs has contributed to the evolution of communications

technology over the last nine decades.

The Horn Antenna and HistoryWith its central role developing, supporting, and enhanc-

ing the technologies used by AT&T, Bell Labs had the re-sponsibility for being at the forefront of communications

technology. This role gave Bell Labs the ability to attract

the best scientists with challenging problems and sub-

stantial resources. Sometimes, as in the case of radio as-

tronomy and the discovery of Big Bang radiation, new

understanding of physics came about through serendipity,

collaboration between parties with different perspectives,

FIGURE 5. Timeline of selected Bell Labs innovations in telecommunications and related fields.


6



the existence of a real practical problem, and a touch of

genius.

The horn-reflector antenna was invented at Bell Labs

as a means to make long-distance phone calls. It subse-

quently became a key element of the first satellite-based

voice and video transmission systems. It was not expectedto play a role in providing direct experimental evidence

of our universal origin, and yet the important discovery

by Arno Penzias and Robert Wilson may not have been

made without it.

This culture of innovation continues to drive Bell Labs

researchers to expand the boundaries of communications.

Today, Bell Labs is using the same approach of hiring the

brightest minds from diverse disciplines and applying

them to practical problems in information and commu-

nications technology and networking. We stand on the

verge of another revolution in information and communi-

cations networking as we seek to deliver another massiveleap in capacity and ubiquity using virtualization and

software-defined networking, smaller access nodes and

cells, and other related technologies, and it is reasonable to

conjecture that Bell Labs will once again play a profound

role in enabling this new reality.

References[1] B. Rooney, Broadband Penetration and Economic Growth, Jul. 19,

2013. Ghttp://blogs.wsj.com/tech-europe/2013/07/19/broadband-penetration-

and-economic-growth/9

[2] E. F. O'Neill (ed.), A History of Engineering and Science in the Bell

System: Transmission Technology (19251975), Indianapolis, IN, USA:

AT&T Bell Laboratories, 1985.[3] E. F. W. Alexanderson, Transatlantic Radio Communication, Proc.

Amer. Inst. Electr. Eng., 38:10, 10771093, Oct. 1919.

[4] O. B. Blackwell, Transatlantic TelephonyVThe Technical Problem,

Bell Syst. Tech. J., 7:2, 168186, Apr. 1928.

[5] C. M. Jansky, Jr., The Discovery and Identification by Karl Guthe

Jansky of Electromagnetic Radiation of Extraterrestrial Origin in the Radio

Spectrum,Proc. IRE, 46:1, 1315, Jan. 1958.

[6] J. A. Tyson, Grote Reber, Phys. Today, 56:8, 6364, 2003.

Ghttp://scitation.aip.org/content/aip/magazine/physicstoday/article/56/8/

10.1063/1.16113609

[7] C. E. Shannon, A Mathematical Theory of Communication, Bell

Syst. Tech. J., 27:3, 379423, Jul. 1948.

[8] C. E. Shannon, A Mathematical Theory of Communication, Bell

Syst. Tech. J., 27:4, 623656, Oct. 1948.

[9] Telstar Project Internal File, 1962, Bell Laboratories.

[10] A. A. Penzias and R. W. Wilson, A Measurement of Excess An-

tenna Temperature at 4080 Mc/s,Astrophys. J., 142, 419421, Jul. 1965.

[11] D. A. Alsberg, J. C. Bankert, and P. T. Hutchison, WT4 Milli-

meter Waveguide System: The WT4/WT4A Millimeter-Wave Transmis-

sion System,Bell Syst. Tech. J., 56:10, 18291848.

(Manuscript approved May 2014)

AcknowledgementsThe authors gratefully acknowledge the assistance of

Edward Eckert, Corporate Archivist, Alcatel-Lucent.

AuthorsCharles Bahr is Director of Integrated Information Solu-

tions at Alcatel-Lucent. His broad experience includes

manufacturing information systems, fundamental research

in molecular surface dynamics, manufacturing R&D in

sol-gel for optical fiber, as well as work in the corporate

marketing division to promote digital video, ad insertion,

and quality of service. His current responsibilities include

managing the corporate library system, and developing

publication channels such as Bell Labs News and the Bell

Labs website. He received a B.S. degree in chemistry

from Texas A&M University, College Station, and a Ph.D.

in physical chemistry from the University of California,

Berkeley.

Marcus Weldon is President of Bell Labs and Chief Tech-

nology Officer for Alcatel-Lucent. He is responsible for

harnessing the power of Bell Labs to address the biggest

technical challenges in information and communications

technology, for coordinating technical strategy across the

company, and for driving technological and architectural

innovations into the portfolio. He was named CTO of

Alcatel-Lucents Fixed Access Division and Wireline Net-

works Product Division following the merger of the two

companies in 2006. Prior to that, he was CTO of the

Lucent Technologies Broadband Solutions business

group. Dr. Weldon began his career at AT&T Bell Labs

as a postdoctoral member of technical staff, winning sev-

eral scientific and engineering awards for his work on

electronics and optical materials. He received a B.Sc. in

chemistry from Kings College, London, and a Ph.D. in

physical chemistry from Harvard University, Cambridge,

Massachusetts.

Robert W. Wilson is a Senior Scientist at the Smithsonian

Astrophysical Observatory (SAO) of the Harvard

Smithsonian Center for Astrophysics in Cambridge,

Massachusetts. Until his recent partial retirement, he was

the technical leader of the Sub-Millimeter Array, an

8-element synthesis radio telescope near the summit of

Mauna Kea, Hawaii built by SAO in conjunction with the

Academia Sinica Institute of Astronomy and Astrophysics

(ASIAA). He studied as an undergraduate at Rice Univ-

ersity, Houston, Texas and did his graduate work at the

California Institute of Technology. Dr. Wilson is best

known for his part in the discovery of the 3 degrees K

cosmic black body radiation thought to have originated in

the early stages of the Big Bang. He won a Nobel Prize

in 1978 for that discovery. t


7

Documents

50th Anniversary Special Feature the Discovery of Cosmic Microwave Background