Episodes
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Welcome back, Spherical Cow Moonions!
This week unfortunately marks the final episode of Spherical Cow. Thank you so much for supporting our podcast - we hope you have enjoyed the episodes!
In this episode we are finishing off our discussion about the history of the universe. We will be talking about the Epoch of Reionization, how scientists actually learn about this era and saying goodbye!
Please see an amendment to our discussion below:
1:35 - Sorry I slipped up here! I meant to say that when high energy radiation was emitted by the first starts and, then later, by quasars, the neutral hydrogen was broken apart into positive nuclei and electrons not positive nuclei and ions (the positive nuclei are the ions)!
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. Parts of this episode were recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This week we are continuing our journey through the history of the universe and discussing Cosmic Dawn. We will be talking about what Cosmic Dawn is, the properties and formation of the first stars and why they are so interesting!
Please see some additions/amendments to our discussion below:
04:45 - To explain this a little further, ATLAS is one of the four detectors located around the Large Hadron Collider ring at CERN. Two protons beams, travelling in opposite directions, collide inside the ATLAS detector. Before this collision, the momentum in a direction perpendicular to the proton beams is 0. Therefore, after the collision, the momentum in a direction perpendicular to the proton beams must also be 0 since momentum is always conserved in collisions. So, if ATLAS detects any particles travelling in a direction perpendicular to the original proton beams there must be other invisible particles (possibly dark matter) travelling in a different direction so that overall the momentum in a direction perpendicular to the original proton beams adds up to 0.
12:32 - Just to clarify, these Population II stars are not just found in the Milky Way but all over the universe! They are often found in 'globular clusters' (spherical groups of stars found within many galaxies). The age of these stars is similar to the age of the Milky Way so Population II stars were formed around 13.6 billion years ago.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal. -
Missing episodes?
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Welcome back, Spherical Cow Moonions!
This week we are continuing our discussion about the history of the universe and once again talking about 380,000 years after the Big Bang. We will be discussing the formation of sound waves in the early universe and how studying the imprint of these acoustic oscillations of the Cosmic Microwave Background map can tell us lots of fascinating information about our universe!
Please see some additions/amendments to our discussion below:
13:42 - Sorry! I meant to say that you can do some calculations and see if they agree with your observations (i.e your measurements of the size of the ‘spots’ on the cosmic microwave background map).
https://www.esa.int/ESA_Multimedia/Images/2013/03/Planck_Power_Spectrum - This is a link to the CMB Power Spectrum graph we discussed in our episode - the measurements were taken by the Planck Satellite
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal and we are sorry about the noisy background in some places!
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Welcome back, Spherical Cow Moonions!
This week we are discussing the surface of last scattering and cosmic microwave background radiation (CMBR).
We will be talking about what CMBR is, how it was discovered and how measurements of CMBR agree with observations of our universe.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This week we are continuing our journey through the history of the universe and discussing the beginnings of matter! We will be talking about the quark-gluon plasma era and big bang nucleosynthesis.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal. -
Welcome back, Spherical Cow Moonions!
This week we are continuing our journey through the history of the universe and discussing inflation and reheating. We will be talking about what inflation is, what are the motivations behind inflationary theory and what happened to the universe immediately after inflation.
Please see some additions/amendments to our discussion below:
3.30 - I misspoke here! The fluctuations are actually at a level of one part in 100,000 so they are even tinier than I suggested (but still very important which we will discuss next episode).
5.55 - I have found some contradictory values to how close the density of the universe was to the critical density in the early universe- some websites say it departed from the value by one part in 10^62 whilst others say the density right after the big bang must have been equal to the critical density to 50 decimal places! The main idea is that the initial density of the universe would have been incredibly fine-tuned to the critical density which is why physicists question how the density came so close to this 'special value'. Inflation suggests one solution to this 'fine-tuning' problem.
09.30 - According to inflation, because our whole observable universe was once a tiny part of the early universe, this tiny part was small enough for light to be able to propagate from one side to other, allowing the small section to reach the same temperature. You can say that this region is 'causally connected'.
11.45 - Once again I meant to say the the fluctuations are at a level of one part in 100,000 not 10,000!
To view our sources please see our website - https://www.podpage.com/spherical-cow/
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Welcome back, Spherical Cow Moonions!
This week we are venturing all the way back to the birth of the universe! We will be discussing the big bang, the Planck epoch and the GUT era.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B We are sorry about the noisy background!
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Welcome back, Spherical Cow Moonions!
This week we will be discussing dark energy! We will be exploring the evidence for dark energy, how scientists determined the expansion of the universe is accelerating and what dark energy might be.
Please see an addition to our discussion below:
3:22 - To expand on this further, if the universe is closed (has positive curvature) and the shape of space is spherical, this would mean that initially parallel beams of light would converge (like how, when you follow two lines which are parallel at the equator on a globe, they meet up at the north pole). If the universe is flat (has zero curvature) and the shape of space is flat, then parallel beams of light would remain parallel. Finally, if the universe is open (has negative curvature) and the shape of space is hyperbolic (like a saddle) then initially parallel beams of light would diverge (spread apart).
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. Parts of this episode were recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This week, we are talking about Dark Matter! We will be discussing why the notion of dark matter was first introduced, what evidence there is for the existence of dark matter and what dark matter could be.
Please see an addition to our discussion below:
21:58 - After looking into this more, we are still not sure if we were talking about the same neutrino! If you would like to learn more about neutrinos, please see our podpage for some links to resources.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. Parts of this episode were recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This episode is all about the exciting Particle Physics News from CERN and Fermilab which came out around March-April time. We will be discussing the results published by both organisations and what they mean for the future of physics! If you stay to the end you will also hear an interesting link between muons and special relativity!
Please see some additions/amendments to our discussion below:
2:00 - The charm quark is similar to the up quark because of its +2/3 electric charge and the strange quark is like the the down quark because of its -1/3 electric charge.
17:13 - Just to clarify this analogy further, hold the pen vertically in front of you with the tip pointing up. Imagine an axis running through the pen from the tip to the bottom and spin the pen around this axis by holding it straight with one hand and twisting the bottom of the pen with the other. Now, still twisting the pen in this manner, hold the bottom of the pen still and trace out a horizontal circle in the air. By twisting the pen as before but also rotating the tip, the spin axis is now precessing or wobbling. This is analogous to the precession of the muon's spin.
17:52 - If you would like a link to a video which demonstrates how a spinning top wobbles, please go to our podpage.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
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Welcome back, Spherical Cow Moonions!
This week we are discussing the topic of antimatter! What is antimatter? How was antimatter first discovered? Why is there such an imbalance between matter and antimatter in the universe? Listen to this episode to find out more!
Please see some amendments/additions to our discussion:
Around 10:50 - I misspoke here! The weak force only governs beta decay. Alpha decay is essentially caused by a quantum mechanical phenomena called quantum tunneling!
Around 25:06 - To add to what I mentioned here about kaons, kaons are a type of composite particle known as mesons. Mesons are composed of equal numbers of quarks and antiquarks, commonly one quark and one antiquark. In the case of kaons there are four different possibilities:
one strange quark and one up antiquark (a negatively charged kaon) one strange antiquark and one up quark (a positively charged kaon and the antiparticle of the negatively charged kaon) one strange antiquark and one down quark (a neutral kaon) one strange quark and one down antiquark (a neutral antikaon)Around 28:30 - I got a little muddled with the names here! The six quarks are actually called 'up', 'down', 'charm', 'strange', 'top' and 'bottom'. 'Beauty' is just another name for the bottom quark. The top quark is also known as the truth quark.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. Parts of this episode were recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This episode is the last installment in our series of q&a episodes. We will be discussing some of the fascinating quantum mechanics questions you have sent in including the notorious thought experiment, ‘Schrödinger's Cat’ and the notion of parallel universes!
Please see an amendment to our discussion below:
3:40 - To be more precise, we should say that the radioactive substance has a 50:50 chance of decaying within a certain time period. This time period, which is characteristic to each radioactive substance, is called 'the half-life'.
To view our sources please see our website - https://www.podpage.com/spherical-cow
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Welcome back, Spherical Cow Moonions!
This week we are continuing to answer all the great questions you have sent in! We will be discussing how we know the universe is expanding, where the universe will end and lots more!
Please see an amendment to our discussion below:
10:34 - We were quite far off! Dinosaurs actually roamed the earth in a period of time known as the Mesozoic Era (between about 245 - 66 million years ago) but the same logic of our discussion applies!
To view our sources please see our website - https://www.podpage.com/spherical-cow/
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Welcome back, Spherical Moonions!
To celebrate the tenth episode of our podcast, this week we will be answering interesting physics questions sent in by you! Thank you very much for all your great questions! We will be discussing the physics of rainbows, what actually is touch and lots more!
We would also like to say a big thank you to all the physics teachers at our school for supporting our podcast. We really appreciate it!
To view our sources please see our website - https://www.podpage.com/spherical-cow/
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Welcome back, Spherical Cow Moonions!
This week we are bringing our miniseries about the history of light, the birth of quantum mechanics and particle-wave duality to a close. In this episode we are revisiting the Double-slit Experiment but looking at it from a slightly different angle. By doing so, we will finally reach the 'particle-wave duality' stage of our journey and discuss some of the crazy ideas quantum mechanics has to offer!
Please see a slight amendment to our discussion below:
06:49 - Olivia accidentally said 'proton' instead of 'photon' !
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This week we are continuing our journey through the history of light, the birth of quantum mechanics and particle-wave duality! In this episode we are carrying on with our discussion about the birth of quantum mechanics by talking about the Photoelectric Effect and the Compton Effect.
Please see an addition to our discussion below:
15:07 - Poor Robert Millikan! We forgot to mention that he also won a Nobel Prize in 1923 for his work on the Photoelectric Effect and for determining the charge on the electron.
To view our sources please see our website - https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This week we are continuing our miniseries about the history of light, the birth of quantum mechanics and particle-wave duality! In this episode we will be discussing the Ultraviolet Catastrophe, the work of Max Planck and the birth of quantum mechanics.
To view our sources please see our website -https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This week marks the beginning of our miniseries about the history of light, the birth of quantum mechanics and particle-wave duality! This episode is all about the wave theory of light. We will be discussing some of the key figures involved in the development of this theory, exploring some of the central ideas behind wave theory and looking at the evidence which supports a wave theory of light.
Please see a slight amendment to our discussion below:
09:30 - Whilst diffraction is one of reasons there are fuzzy edges around shadows, the main reason is because the light source involved in creating the shadow is not a point source. For example, a lamp is not a point source because it has a shape and size. The part of the shadow which is 'fuzzy' therefore is the part which is partially illuminated by the light from one section of the lamp but the rest of the light from the other areas of the lamp are blocked by the object. Hence the 'fuzzy' area isn't as dark as the main shadow because some light from a particular area of the lamp is still able to fall on it.
To view our sources please see our website -https://www.podpage.com/spherical-cow/
N.B. This episode was recorded virtually so the audio quality might be different to normal.
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Welcome back, Spherical Cow Moonions!
This week's episode is the second part of our double episode about Pressure! We will be discussing why it is important for divers to slowly ascend after being underwater, what prevents stars from collapsing inwards, how aeroplanes are designed to keep you conscious when flying and lots more!
To view our sources please see our website -https://www.podpage.com/spherical-cow/
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Welcome back, Spherical Cow Moonions and Merry Christmas and a Happy New Year!
This week's episode is the first part of a double episode all about Pressure! In this week's episode we will be discussing how pressure cookers work, why competitive cyclists travel directly behind each other, how to break the bottom of a bottle by hitting the top and lots more!
To view our sources please see our website -https://www.podpage.com/spherical-cow/
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