The Modern Face of Popular Science

Cosmos: A Personal Voyage – a 13-part TV series co-written and presented by the US astronomer Carl Sagan -- was a huge success when first broadcast in 1980. At the time, the show was the most widely watched series in the history of US TV – a record it held until the 1990s. Described by critics as a “watershed moment” for science on TV, it helped to inspire the public to learn more about the universe. With TV science and nature documentaries attracting millions of viewers, it was inevitable that in the age of the Internet, using video to present science to the public would prosper online.

And indeed it has. Due to the ease of accessibility of the free content on YouTube, science channels on the website have been incredibly successful in reaching huge audiences. For example, Veritasium – featuring experiments, interviews and discussions about science – has over 3.5 million subscribers, while Vsauce that has videos about science as well as gaming, technology and culture has a whopping 10 million subscribers. Their output has even reached classrooms with teachers using these videos as a way of engaging students with a certain topic, making it more appealing and presenting it in a more in-depth fashion.

Crucial to the success of an educational YouTube channel is the personality behind it. People enjoy watching Michael Stevens behind Vsauce, and it is clear to see the passion that astronomer Phil Plait displays when presenting Crash Course Astronomy, which recently finished earlier this year. Indeed, when astronomers proposed the existence of a ninth planet in our solar system earlier this year (see Physics World July pp28-31) people flooded the comment section with requests for Plait to continue the series.

There is a great variety of science videos on YouTube. MinutePhysics presents physics topics through time-lapsed drawings that are approximately one-minute long, Crash Course has a more traditional classroom feel -- with the teacher sitting at the front with a desk – while SciShow uses a news format to discuss the latest science developments. The scientific YouTube community is also diverse. Mitchell Moffit and Gregory Brown, who present ASAPScience are in an openly gay relationship, which could encourage those that are lesbian, gay, bisexual and transgender to see themselves as scientists. Likewise, Dianna Cowern of Physics Girl encourages more women to get involved with science. 

Since 2011, Physics World has also launched its own YouTube channel that features interviews with leading physicists and reports from major international research facilities. The channel includes the 100 second series in which a scientific question – such as ‘What is a black hole?’ or ‘Why do neutrinos change flavour?’ -- is answered by a specialist in less than 100 seconds.

The success of science YouTube channels have even resulted in the White House getting involved. Rocket engineer Destin Sandlin of Smarter Every Day and Hank Green of SciShow and Crash Course, interviewed US President Barack Obama as part of a ‘YouTube Asks Obama’ event. Their audiences had the chance to submit questions to Obama, giving them the opportunity to ask him tough questions on US science policy and research funding in the US.

Creating an educational platform

Science on YouTube does have its critics. Physicist Philip Moriarty of the University of Nottingham, who presents YouTube episodes of Brady Haran’s project Sixty Symbols, says that real science is much more than understanding a concept and that watching a YouTube video should only be the first step in actively learning something.

Although there are clear limitations as to how much of the education process can be done online, it has a lot of potential. However, more could be more done to address criticisms. One solution is provided by the show PBS Space Time, which regularly has “challenge” videos that give the audience a question to answer. The audience emails their answer, and if that answer is correct, the submissions have a chance to win a prize. These challenge videos encourage the audience to be more active in their learning, and they show that YouTube can be a platform for a more interactive learning experience.

But while the audience for such channels is built of many casual watchers, I believe that even physics students can use them as a learning aid. While they may not have fully understood a topic at school, watching a video about it online can aid them in taking better notes. I, and probably many more students, have been partly inspired by YouTube educators to follow a scientific career having chosen to study physics at university after just completing my A-levels. Watching these videos for the past few years has played an important part in providing me with a new-found interest in physics that I then pursued by reading more around the areas that I held a great interest in. With many hundreds of hours of science videos being uploaded to the website weekly, it seems more and more likely that online science content will play a part in inspiring the next generation of scientists.

Physics World article - The Modern Face of Popular Science

Hey everyone!

You can find the Physics World September 2016 press release here.

As well as the article I wrote over here.

I will post a text version of the article soon on this blog, stay tuned!

- Blaze

Life Update

So I got into Imperial College London for MSci Physics. I got my A Level results of A*A*A*A in Maths, Physics, Computer Science and Chemistry (in that order) with an A in AS Further Maths and an A* in the EPQ (Extended Project Qualification).

I move in on the 1st October. Kinda excited and scared about this. Hopefully physics isn't too hard.

I will be posting my EPQ later this month on this blog, as well as an article that is being published in the September edition of Physics World (that's tomorrow!)

Also I'm learning basic animation atm to step up the quality of my videos so that's why I've been on a long hiatus.

Thanks for reading, non-existent people!

- Blaze

New video!

Made a new video about Heat Death.

New Channel and New Video

Just started a random science and maths channel.

May do videos every week.

Depending on how busy I am.

(so don't be surprised if I don't ever upload again :P)

Check out: A very quick intro to Calculus! Will upload a blog post later, expanding on the example given in the video.

Faster than Light Travel - September 2015

Can we ever travel faster than the speed of light?

It is a dream of the greatest physicists of our time as well as the average Joe; space exploration. The incomprehensibly vast distances involved in the universe, ever increasing due to accelerated expansion of spacetime because of dark energy, means that our planet is simply ‘a mote of dust suspended on a sunbeam’, as Carl Sagan put it. The Milky Way galaxy is 100,000 light years in diameter; meaning light would take 100,000 years to travel from one side to another. The fastest space probe so far, the NASA craft Juno, clocks in at 0.0013% the speed of light. Space colonisation seems to be an impossible feat for mankind to achieve.

But why is it impossible? Why can’t we power a spaceship to travel faster than the speed of light in a vacuum? This can actually be explained and proven geometrically using Einstein’s equation:   

E² = (mc² )² + (pc)²

Photons travel at c (the speed of light in a vacuum) as they have virtually no mass and exist as a form of energy (light energy). Therefore, the momentum term of a photon would be theoretically equal to the energy, as mass would be 0, E = pc. As the structure of the equation is like that of Pythagoras’ Theorem, we can draw a triangle with E as the hypotenuse as shown in Figure 1.

As the hypotenuse of a right angled triangle is always greater than the other sides, we can see that as long as there is mass, E cannot equal pc. With no mass the equation collapses to E = pc, as with the photon, and for static objects with no momentum in that reference frame, E = mc², the famous equation we know today.

Even if theoretically a spaceship were to travel at c, it would have adverse effects on time itself. As the laws of physics are supposed to hold true in all reference frames, logical thinking makes you assume nothing would be visible inside the spaceship as light cannot travel fast enough to catch up with your eyes as you recede from it in the spaceship at the speed of light. Einstein deduced that physics should work as normal inside the spaceship; doesn’t that mean the photons inside the ship are travelling at 2c, which violates the laws of physics? Only if space and time are absolutes. The distance between the spaceship walls and your eyes actually shortens (meaning c can remain as a constant as we are considering a smaller distance here, therefore we don’t need to cover the same amount of distance in that time) and you experience ‘time dilation’. The time perceived slows down with your speed, compared to a static observer. At small speeds like <0.1c this effect is too small to notice. However, at high speeds you would age less than your hypothetical twin who decided to not take this superluminal journey. If you perceive 2 minutes passing in a light speed spaceship, for the static observer it could’ve actually been 10 minutes. You could return to Earth and realise centuries have passed, but you haven’t aged much at all. Time dilation poses a serious logistical problem to light speed travel, and we have shown that as long as Einstein’s theories hold true to experiment and testing, an object with mass cannot travel faster than c through spacetime anyway.

Hold on; didn’t we just cover the accelerating expansion of the universe? Even in the Planck era with a second of the Big Bang the universe had expanded to astounding sizes. If this expansion has been accelerating (an observed phenomenon due to red shifts) for 13.8 billion years isn’t spacetime expanding faster than c? Doesn’t this violate the theory of general relativity? Apparently not; spacetime itself can move faster than the speed of light as it isn’t a ‘thing’ in the traditional sense. An apt analogy would be of ants, crawling around a balloon with a speed limit. They move slow, and nothing on the balloon is allowed to travel faster than the ants (the balloon symbolising spacetime), however the balloon itself can inflate very fast increasing the distances between the ants. To an ant on the balloon they would observe other ants receding at ‘faster than ant’ speeds. This concept is important to the question on ‘faster than light’ travel.

A spaceship has mass, and therefore cannot travel through spacetime faster than light as just shown. However, if we could manipulate spacetime, can we get to (for example) Alpha Centauri, the nearest star system at about 4 light years away, within the span of a human lifetime? Two theories currently exist that can help with space exploration and that do not violate the laws of physics.

Wormholes (also known more formally as Einstein-Rosen Bridges) are shortcuts through spacetime. They can connect two places across spacetime so that distances are reduced. Theoretically you could go through a wormhole and get to a place faster than light could get their if it takes the longer, ‘normal’ way. Light travelling with you through a wormhole will obviously reach the end faster as the laws of physics hold true in all reference frames. Figure 2 shows a visualisation of a wormhole.

As space and time are intrinsically connected it is thought that wormholes could allow for time travel as well. Exotic matter with negative energy density is needed to stabilise a wormhole large enough for a spaceship to get through, and this is possible under quantum field theory, however no such mechanism has been found in nature to create wormholes. The quantum foam hypothesis (a candidate for ‘fabric of the universe’) is used to theorise that miniscule, Planck scale (on the orders of magnitude many times smaller than even an electron) wormholes pop into existence and disappear spontaneously. These wormholes are not traversable and are not candidates for ‘faster than light’ travel. It is important to reiterate that none of the methods discussed are truly faster than light, as they involve manipulating spacetime, which can expand faster than light.

The Alcubierre drive, also known colloquially as a theoretical warp drive works on the principle of negative mass and energies, just like wormholes. If we had a lot of power, we could use this drive to expand the space behind a spacecraft and contract the space in front. This constant deformation of spacetime can allow an object to reach a destination faster than light would by travelling through normal space. This is entirely theoretical but it is mathematically consistent; however, it assumes that exotic matter with the correct properties exist. As we have not directly interacted with exotic matter (dark matter, negative mass etc) this theory cannot be confirmed as of yet.

The spaceship would travel in an area of ‘flat’ spacetime known as a warp bubble. The expansion behind and contraction in front is shown in Figure 3.

To change the nature of spacetime with a human invention is incomprehensible for our minds; we use 2D grids to represent the 4D nature of spacetime as we cannot comprehend more than three dimensions. The fourth dimension, time is not understood as readily as the three spatial dimensions. It is hard and counter-intuitive to think that general relativity could allow for time itself to be an observed effect and not a universal constant, that time depends on the speed you’re going at. The Alcubierre drive is such an invention that would require a huge amount of energy as well as a better understanding of exotic matter; scientific milestones that we have yet to attain.

Our understanding of dark matter and dark energy is depressingly poor; current estimates suggest that normal matter and energy, everything we perceive and see in the universe only make up 4 or 5% of the universe. There is hope however as Ray Kurzweil put it, ‘The Law of Accelerating Returns’. As our understanding grows, our capacity for learning even more increases as well, leading to an exponential cycle of understanding, and then discovery. We have seen this in action in recent times; it took only 66 years from the invention of heavier than air flight to get mankind to the moon. Mankind increases knowledge exponentially. The brightest minds of our generation have come up with mathematical frameworks and consistent theories that do not violate any laws of physics, and NASA has already begun exploration and research of Miguel Alcubierre’s theory. Colonisation of the distant stars and galaxies we see twinkling in the night sky may not be such an impossible feat after all.

New Blog

New blog from a perpetually bored Physics student, who finds a bit of pleasure in writing about science to an audience of precisely zero people.

Plenty more to come in a few years when I actually get a degree in Physics...

- Blaze