Nobel Prize in Astronomy? Nonsense, you will say, there is no such thing! And you will be right! Today I would like to talk about the Nobel Prizes in Physics awarded for the discoveries directly related to Astronomy. Of course, many scientific advances contributed to the modern understanding of Space. But let’s look at those few that achieved the highest scientific recognition.

1. Nobel Prize in Astronomy. Part 1.

2. 1936
Victor Franz Hess received the Nobel Prize “for the
discovery of cosmic radiation”.
Hess, an Austrian-American scientist, studied the
phenomenon of the charged Earth’s atmosphere. The
ionization of the atmosphere was well known before Hess,
but physicists didn’t know what caused it. The original
idea, that the radiation comes from the ground, was
contradicted by Hess’s famous balloon experiments. The
scientist himself flew the balloon to the altitude of over
5000 kilometers and showed that the ionization of the
atmosphere increases with the distance from the ground.
Therefore the radiation comes from Space, not Earth!
Now we know that the Supernova explosions are the main
source of the cosmic radiation. Although our Sun also
contributes to the stream of the high-energy particles.

3. 1967
Hans Bethe received the Nobel Prize “for the contribution
to the theory of nuclear reactions, especially his
discoveries concerning the energy production in stars”
Bethe was a German -American nuclear physicist. Many
people know him as one of the Manhattan project
scientist. Bethe was the first to come up with the
explanation how the Sun-like stars (proton-proton
reaction) and stars, heavier than the Sun (CNO cycle)
produce their energy.

4. 1974
Martin Ryle and Antony Hewish received the Nobel Prize “for the pioneering
research in radio astrophysics”.
Martin Ryle
Ask any astronomer what comes to their mind when they hear the name of
Martin Ryle and they will say two things: interferometry and aperture
synthesis. (Is it even English?)
The problem with astronomical telescopes is that the resolution of a single
telescope is limited by the size of the telescope itself. But what is we use a
cluster of telescopes working together as one giant telescope? In theory,
such instrument’s “mirror” (or dish if it’s a radio telescope) will be as big as
the distance between the separate telescopes. Therefore we will achieve a
much higher resolution! This is called astronomical interferometry. Ryle and
his colleagues constructed the first two- component radio interferometer
(two radio telescopes on rails placed about a mile apart). They used the
new instrument to observe the farthest radio sources to date. Ryle also
developed the method , known as aperture synthesis. In the simplest two-
telescopes version of this method, the telescopes scan the source as the
Earth spins around (that gives the telescopes a different angle of view).
Then the high-resolution image of the object is restored from the combined
signals using a special mathematical technique.

5. Antony Hewish
Another English Astronomer received the Nobel Prize for the discovery
of the first pulsar. Pulsars are fast rotating compact objects, usually
neutron stars, that emit two beams of radiation in the opposite
directions. The axis of the radiation beam is not in line with the axis of
rotation. This produces the strange observational effect of “pulsing”.
Imagine spinning the flashlight on the horizontal surface in front of you.
The light beam will only be shining in your direction for a short period
but at regular intervals. Now if you are far enough from the flashlight,
you will not be able to see the source, only the light. Coming in pulses!
Back in 1967 Hewish and his team designed and built a radio telescope
to look for a very interesting space objects called quasars. One of his
graduate students, Jocelyn Bell, was in charge of operating the
telescope and proceeding the data. She was the first to notice the
strange signal, that kept appearing at regular intervals once every 1.3
seconds. First, the team ruled out all the possible terrestrial sources,
then they thought it could be a signal from an alien civilization! Later
Bell spotted a similar signal from a different area of the sky. That meant
the sources were some new objects, not aliens. A few years later
scientists finally explained the nature of pulsars. Hewish received an
award in recognition of his initial discovery. Many scientists agree, that
Bell should have shared the award too!

6. 1978
Arno Penzias and Robert Woodrow Wilson received a Prize “for the discovery of cosmic microwave background radiation
(CMB)”
This is one of my favourite examples of how what looked like an observational mistake became one of the greatest
discoveries in the history of Astronomy.
It all started with the Holmdel Horn Antenna owned by Bell Labs. This radio telescope was built to support NASA’s satellite
project Echo. When it was no longer needed, the two Bell Lab scientists, Penzias and Wilson, jumped at the opportunity to
use the antenna for the astronomical observations. They were planning to use it to study the interstellar gas in the Milky Way
Galaxy.
Unexpected signal
But as they started to test the equipment, they noticed the funny background noise on the wavelength of 7.35 cm. The noise
was coming from all directions and had an effective temperature of about 3K.
Penzias and Wilson worked really hard to get rid of the noise. First they made sure the source of the signal was not man-
made. Then they checked all the sources in the Solar System and even in the Galaxy they could think of. Nothing could
explain the it! They had two option: either the signal came from outside the Galaxy or it was a mistake, something to do with
the telescope itself. The pigeons lived in the horn and the antenna was covered in the pigeon’s droppings. Could they be
responsible for that 3K signal? Penzias and Wilson cleared the antenna and covered it with a net. The signal still remained.
Around the same time a group of astronomers from Princeton University was about to publish the theoretical paper about the
Big Bang and its leftover radiation. They expected to find it in microwaves (radio waves about a few cm long).
The two groups of astronomers met to discuss their theories and findings. Soon they published two papers. One was about
the theoretical prediction of the CMB, and another, by Wilson and Penzias, about the discovery of the 3K background
radiation. Wilson and Penzias offered CMB as a possible explanation to their discovery.
Why was it so important? Back then, there were two rival theories about the origin of the Universe: Big Bang Theory and
Steady-State Theory. The discovery of the CMB was the prove that everything started with the Big Bang!
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