Examples of topics

This page is for those who want to practise their speaking skills by talking on scientific and technological topics.

You can select one of the recommended topics here or suggest your own topic, and then prepare it and present it to the society. The presenter and the topic will be announced in advance. Everyone else should become familiar with the topic and its vocabulary before its presentation in order to be able to actively participate in the discussion. Again, participation in discussions is in your own interest.

Please select topics not yet presented at meetings during the current semester. Topics may be repeated, but not by the same person and not more than once in a semester (or still better, not more than once in an academic year).

1. Physics

1.1. Mechanical motion.

What causes it? What do Newton’s laws have to do with it? What kinds of motion do physicists distinguish? How do we describe motion?

1.2. Units of measurement.

How did they develop? What units do we use now? Which units are fundamental, and which are derived? How do we name them correctly? What units are used in other countries?

1.3. Electricity and magnetism.

Electric charge and electric field. Current and voltage. Resistance. Direct and alternating current. Active and reactive load. Laws of electric circuits. Nature of magnetism. Ferromagnetic, diamagnetic and paramagnetic substances. Electromagnets.

1.4. Conductivity

Conductors, insulators and semiconductors. Doping of semiconductors, electron and hole conductivity. Superconductivity.

1.5. Laws of conservation.

What are they? What are the limitations of some of them?

1.6. Optics.

Propagation of light. Wave and particle properties of light. Visible spectrum and light beyond it. Refraction and reflection. Prisms, lenses and mirrors.

1.7. The Doppler effect.

The nature of the Doppler effect. The sound of a train passing by. The red shift of distant galaxies. Practical use in science and technologies. If you drive towards a traffic light at the speed of around 110,000 km/s, you may see the red light turning green .

1.8. The theory of relativity.

Pre-Einstein understanding of relativity. Special and general theory of relativity.

1.9. Elementary particles.

They may be strange. They may have charm. Their mass and their energy are measured in the same units. When they collide at very high speeds, they do not fall apart, they produce other particles.

1.10. Plasma.

The fourth aggregate state of matter. Cold plasma can scorch you. Hot plasma is really hot, from hundreds of thousands to tens of millions kelvins. We can see hot plasma on a sunny day, if we look towards the Sun – its corona is over a million kelvins hot. What is plasma? What kinds of plasma are there? What are its properties? How do we produce and use it?

1.11. Reference systems.

They may be inertial and non-inertial. What are their properties? What kinds of accelerations exist in non-inertial systems?

2. Mathematics

2.1. Number systems.

How do we write numbers? Positional and nonpositional numerical systems.

2.2. Kinds of numbers.

Natural, integer, rational, irrational, real numbers. Fractions, numerators and denominators, fraction separators. Prime numbers, Fibonacci numbers, names of large numbers (the short and long scales). Complex numbers and quaternions.

2.3. Mathematical expressions.

Constants, variables, their notation, arithmetic and algebraic operations, priorities of operations and how to change the order of their calculation. Frequently used functions. Equations and inequations, difference between inequations and inequalities,

2.4. Calculus.

Division by zero, but not quite. Infinitesimals, limits, derivatives, differential equations, integrals.

2.5. Geometry.

Points, lines, planes, surfaces. Reference systems. Zero, one, two, three, four and n-dimensional systems. Euclidean and non-Euclidean geometries. Geometrical figures and solids, and their elements.

2.6. The probability theory.

What is probability? Is it possible to calculate it? How is probability distributed over the range of possible values or outcomes of observations or experiments? How are the probability distribution functions determined in the cases of discrete and continuous stochastic variables? Moments of stochastic values as general characteristics of random values. Fundamental theorems.

2.7. Statistics.

When probabilities cannot be measured or calculated, they can be evaluated. How are probabilities and other characteristics of random values evaluated? What pitfalls can we encounter while guessing about our chances using statistics? Is it possible to lie with statistics and how can this be done?

3. Astronomy, astrophysics

3.1. Structure of the Solar System.

There used to be 9 planets in the Solar System. Now only 8 left. Why is that? Where is the asteroid belt and what may be the reason of its existence? And what are asteroids, by the way? What material is the Kuiper belt made from? Where does the Solar System end and the interstellar space begin? What is the Oort cloud beyond the heliosphere?

3.2. Barycentre.

We assume by default that the Moon orbits the Earth, and the Earth orbits the Sun. But this is not exactly so. For instance, the Moon and the Earth both rotate around a point, which is their common centre of mass. Where is that point? What is about rotation of the Earth and other planets around the Sun? How do we distinguish a planet with a natural satellite from a binary planet consisting of two planets?

3.3. We are made of dust of dead stars.

The first atoms in our Universe began to form millions of years after the Big Bang, and they were atoms of hydrogen. Even now hydrogen makes up around 96% of the visible matter of the Universe. Another 2% is helium, and the remaining 2% include all other chemical elements. But initially there were no atoms of carbon, oxygen, nitrogen, calcium, potassium, sodium, phosphorus, iron, magnesium and other elements, which are present in our bodies. And of course, there were no other elements, which compose landscapes we see around us, the air we breathe, the food we eat and things we make for our convenience. Where have those atoms come from?

3.4. The Big Band

There was nothing before it, because it started time, and thus, there was no any “before”. It did not happen anywhere, because it started space too, and at the very first moments the whole space of our universe was tiny. What happened next? How did the first atoms form? How did the first stars form?

3.5. Origin of the Moon.

There have been several hypotheses about its origin, which generally boiled down to the idea that the Moon formed independently from the Earth, and then it was hooked by the gravity of our planet. However, with the samples of lunar soil (rock and dust) delivered by spaceships, scientists concluded that its chemical composition is the same as that of the Earth. Is the Moon a part of the Earth? What theories of its origin are widely accepted now?

3.6. Dark matter and dark energy.

They are invisible, they cannot be registered with any instruments currently available to scientists. And yet, they make over 80% of the mass of our universe. What made scientists believe that they are out there? What are they? Do we have them around or are they far away?

3.7. Exoplanets.

Even the stars they orbit are seen as just dots of light even in the most powerful telescopes. How do we know that they exist? What methods are used for detecting them? Are there any of them in the circumstellar habitable zone? And why is that zone called the Goldilocks zone?

3.8. Evolution of stars.

How are stars born? For how long do they live? Why are they of different colours? How do they die? What happens to them after death? White dwarfs, pulsars, neutron stars, black holes – what are they?

4. Geophysics, geology, geography, geophysics.

If you design an orbital mission, you need to know quite a lot about the celestial body your satellite will be orbiting.

4.1. Free fall acceleration.

People tend to believe that free-fall acceleration is created by the gravitational force alone. This is, however, not so in the non-inertial reference systems. What causes the free-fall acceleration on the surface of the Earth? How does it depend on the latitude? What should people designing space flights know about the free-fall acceleration?

4.2. The sea level.

The level of water in seas and oceans changes. Waves, tides, winds change the sea level all the time and rather frequently. Plate tectonics and climate change also influence it slowly, but surely. Sea levels in the UK and France are substantially different, which made it necessary to agree on a common sea level when the tunnel under the British Channel was built. So, what is the sea level? How is it measured? What is it used for?

4.3. The structure of our planet.

The crust, two mantles, liquid outer core and metallic inner core. How big are they? What are they made from? In what conditions do they exist? How do we know all this? Why is it so hot down there? What is plate tectonics and do other planets have it?

4.4. Tides.

We usually believe that sea tides are caused by the gravitational force of the Moon acting on big masses of water on the Earth. But this is not exactly so. The gravitational force acting between the Sun and the Earth is hundreds of times stronger than that acting between the Earth and the Moon, but tides caused by the Sun are much weaker. Why is that? What does actually cause tides? How do tides influence rotation of the Earth around its axis and rotation of the Moon around the Earth? Are there (or were there) tides on the Moon? Is the fact that the Moon is turned to us by its one side related to tides somehow?

4.5. Map projections

We draw maps of the Earth on flat paper. But the Earth is spherical. Well, not exactly spherical. It is even not an ellipsoid, it is a geoid. But still we draw it on a flat sheet of paper. And, by doing this, we introduce distortions in our drawing. How do we do this? What methods of projections are used? What distortions do they introduce?

4.6. Atmosphere

It is clear where it begins, but where does it end? What layers is it made of? How do pressure and temperature change with the height?

4.7. Zodiac and ecliptic.

What are they? Why do we see planets only within the zodiac belt What are zodiacal constellations?

4.8. Equinox.

The vernal equinox for us is the autumnal equinox for those living in the Southern Hemisphere. What is the equinox? Why do we have equinoxes and solstices? When do they occur? We use the point of the March equinox as the reference point for orbital navigation, and it is in the constellation Pisces. Why do we call this point ‘the First Point of Aries’? Aries is another constellation, neighboring Pisces.

5. Exploration of space

5.1. Tsiolkovsky and the ideal rocket equation.

How is it derived? To what conclusions does it lead as for designing space rockets? What is the specific impulse?

5.2. Launch vehicles.

Evolution and variations of design. Boost path. Separation of stages. Typical subsystems.

5.3. Rocket engines and thrusters.

Solid and liquid propellants. Fuel components and specific impulse. Propellant injection. Combustion chamber. Nozzle of bell-shaped engines and their expansion section. Effect of the external pressure on the efficiency of rocket engines. Alternative designs: plug nozzles and aerospikes. Thrust vector control. Thrusters for attitude control, orbital maneuvers and station-keeping. Electric thrusters. Why have the single-stage-to-orbit vehicles been so rarely considered? Are there any perspectives for them now?

5.4. Inertial navigation.

Instruments and methods. Gyro-stabilized platform and strap-down navigation systems. MEMS sensors.

5.5. The first space missions.

The first artificial satellite was launched in 1957, but there were earlier attempts to reach space. The first manned space flight was accomplished in 1961. But there were earlier attempts to launch animals and people into space. What were they? What did they achieve? What lessons were learned from them?

5.6. Satellites and orbits.

Kinds of satellites. Missions of satellites. Kinds of orbits and their specific features. Constellations of satellites.

5.7. Earth remote sensing.

Satellite imaging of the Earth. Spectral bands and their application. Imaging sensors and methods of imaging. Optics, spatial resolution, orbits. Image processing. Synthesized aperture radars. Lidars. 3D imaging of the Earth. Practical applications of satellite imagery and image processing (use cases).

5.8. Nanosatellites.

Definition, typical cubesat dimensions, applications, advantages and limitations, orbits, methods of orbital injection, methods of building groups and constellations.

5.9. Missions to the Moon.

The first fly-bys. Images of the reverse side of the Moon. Lunar orbiters, landers and rovers. Manned missions. Lunar atmosphere (yes, it exists) – what do we know about it?

5.10. Missions to the inner planets and the Sun.

Missions to Mercury – too close to the Sun, too hot on the day side and too cold on the night side. A small planet with a disproportionately big core. Its orbit is highly eccentric in comparison with those of other planets. Venus – it is about twice as far from the Sun than Mercury, but it is hotter. Why is that? It is always veiled in dense clouds. What did missions to Venus find under those clouds? How to come close to the Sun and orbit the Sun at a close distance?

5.11. Missions to the outer planets and beyond the Solar System.

Mars, gas giants, ice giants, Pluto demoted into dwarf planets, numerous satellites of Jupiter and Saturn. What have robotic missions revealed about them? Voyager 1 launched in 1977 has been travelling in the interstellar space since 2012, And Voyager 2 launched same year crossed the boundary of the Solar System in 2016. Built with technologies of that time, they keep sending valuable scientific information. What have they told us about our Solar System?

5.12. Space debris.

We have spoiled our environment, polluted soil, water and air. And also we have polluted the near-Earth space. Defunct satellites, pieces of broken satellites – they remain in their orbits for years and represent a serious danger. Occasionally they collide and create thousands of pieces of debris. How dangerous are they? What can we do about this situation?

6. Materials.

6.1. Steel.

One of the most widely used construction materials. It is strong and elastic, it can be cast, lathed, milled, welded, and this made it suitable for almost any application. But what is it? How is it obtained? What are its limitations? What is the purpose of alloying it?

6.2. Aluminium alloys.

They are metals of silvery colour, the can be light and strong at the same time - an ideal combination for designing flying vehicles. How are they obtained? What properties are given to them by the alloying metals? How are they processed? What are they used for?

6.3. Polymers.

Around 60% of parts of the International Space Station are made of different kinds of plastics. What are polymers? What kinds of them are used? How are they obtained and processed?

6.4. Composite materials.

They combine advantages of materials, which compose them, and reduce their disadvantages. What composite materials and for what purposes are used? How are they produced and processed?

7. Manufacturing technologies

7.1. Cutting.

Lathing, milling, drilling, punching. Machine tools and cutting tools for these operations. Accuracy and quality of processing.

7.2. Casting.

Ways of casting. Kinds of moulds. Problems with casting and their solutions.

7.3. Welding.

Methods of welding. Materials that can and cannot be welded. Problems with welded seams.

7.4. Printed circuit board manufacturing.

Methods of obtaining conductors on printed circuit boards. Multilayer printed circuit boards. Processing of openings and connections between layers. Methods of soldering.

7.5. Manufacturing of integrated circuits.

Growing extremely pure monocrystals, doping them in order to obtain transistors with required properties, covering them with insulating layers and conductors, adding terminals and packing them into airtight cases. How is that done? How do we have microchips with the size of transistors of around 20 nanometers or less, when the wavelength of the shortest visible light is around 400 nanometers?

7.6. Additive technologies.

3D printing, current and perspective applications, sintering of metal powders.