Your Questions 2020

You asked questions to our WISDOM contributors. This section contains the answers to your questions.

The Skeleton of Our Universe

Your questions answered by Cora in 2020.

Thank you for your interest and the great questions. Asking questions is really what science is all about! Many of your questions have only been answered recently or are still an active area of research."

"Do you think we will we ever be able to develop telescopes powerful enough to record videos that are practically in real-time?“ (anonymous)

We already have very powerful telescopes that can track individual objects and events with a good time resolution. Many of the telescopes used to map the large-scale structure are simultaneously being used to study rare and variable objects. Observing the cosmic web as a whole in real time wouldn’t look all that interesting, because it takes quite a while for large structures to form. When observing the cosmic web with telescopes, we actually do something extraordinary, we simultaneously record different times at once. But then scanning a large area of the sky is the part that really takes time. The challenge for large galaxy surveys is to find the right balance between finding many distant and dim galaxies (a deep survey) and covering a large area (a wide survey) to get a good idea of the large-scale structure.

"If the galaxy continued to expand, would it ever expand so extensively that it collided with another galaxy? If so, what happens then?“ (anonymous)

The galaxies themselves actually do not expand, just the distance between them. This is because galaxies, like our Milky Way, are bound objects, so the gravitational forces hold them together and effectively shield them from the expansion. So a very extensive expansion of the universe would mean that most galaxies get further and further apart from each other. But the gravitational pull in bound systems can cause galaxies to collide with each other. This is a common process in galaxy evolution and can lead to a merger of two galaxies into one. We actually expect one of those mergers to occur in our our local group of galaxies. (see the answer below)

"Thank you for giving up your time to do that talk - it was so interesting! I was curious to ask about the cosmic web. I'd like to know a bit more about what it is that causes some galaxies to move away from us and some to move towards us." (Cora A)

This is question connects very well to the previous one. Broadly speaking, most distant galaxies move away from each other as the universe expands. But galaxies that are gravitationally bound within a larger system do not behave like this, instead they are being pulled by gravitational forces that are much stronger than the overall expansion. Our Milky Way and Andromeda are part of the local group of galaxies, which is part of the even larger Virgo supercluster of galaxies. Within the local group, the Andromeda galaxy is slowly approaching the Milky Way and a collision is expected to happen in about 4 billion years. (See this nice NASA article with a video: https://www.nasa.gov/mission_pages/hubble/science/milky-way-collide.html) And our whole local group is being pulled towards the centre of the Virgo supercluster.

"Also, do we have records of other planets experiencing this kind of shift with other stars.etc and if not, do we aspire to investigate this deeper in the future?" (Cora A)

Stars can also collide and merge, and those events can be of great interest for cosmology. One example is a certain kind of supernova that occurs when a white dwarf and another star orbit each other closely, which can set off a large stellar explosion. Those so-called Type Ia supernovae are extremely bright and have a very characteristic profile of light, such that we can use them as „standard candles“ to measure distances. In 1998, scientists analysed observations of distant Type Ia supernovae and found that the universe was expanding at an accelerated rate. This observation caused a real paradigm shift and multiple upcoming large galaxy surveys are aimed at finding out what drives this accelerated expansion.

The Reality of Imaginary Numbers

Your questions answered by Matina in 2020.

”Please could you explain in more detail how complex numbers are used in circuits?” (anonymous)

An AC circuit can be described by the voltage \(V\) (Volts), the current \(I\) (Amps) and the impedance \(Z\) (Ohms). Voltage measures the energy that a charge gets when it moves between two points, an electric current is the rate of flow of charge past a point and impedance measures the opposition of an electrical circuit to the flow of electricity when voltage is applied. We represent the impedance as a complex number and Ohm’s Law becomes \[V = IZ.\]

For example, if the circuit has a current \(I = 4 + 2i\) and an impedance \(Z = 1 - i\), then \[\begin{align}V & = (4 + 2i)(1 - i) \\ & = 4 - 4i + 2i - 2i^2 \\ & = 4 - 4i + 2i + 2 \\ & = 6 − 2i.\end{align}\]

Further notes: In a series circuit, the impedance is the sum of the impedances for the individual circuit components. In a parallel circuit, there are several paths through which the current can flow. If we have two impedances \(Z_1\) and \(Z_2\) connected in parallel, then the total impedance is given by \[Z_t = \frac{Z_1Z_2}{Z_1 + Z_2}.\]

We also note that complex numbers are used to analyse DC circuits.

Sarah Rogers

Mechanical Engineer, Babcock

You questions answered by Sarah in 2020.

"Where did you get your degree?" (Selby M)

Coventry University

"How did you decide to study mechanical engineering?" (Selby M)

I had always really enjoyed Physics and Design Technology, and Engineering was a combination of the two. There were several variations of Engineering such as Aerospace, Automotive etc. but I decided to do Mechanical as it is a broad subject and wouldn’t limit my future decisions on a career.

"What would you say would be an average day in Babcock?" (Evie P)

This is actually a very difficult question to answer as the graduate scheme is so varied it can change from day to day.

Over the past year my days have been completely different depending on what placement I was on.

One day I was specifying new compressors required for a project and the next day I was on AutoCAD designing the layout that the room would need to be to include all necessary equipment and pipe runs.

Another day I would be head to toe in PPE walking through flooded underground subways sketching the route for a new LP air system.

One day I could be calibrating radiation sensors using gamma rays (the radiation was locked away behind thick concrete walls of course!) and another day I would be taking them apart to replace any broken parts.

Every day starts the same however… A cup of tea and checking of emails!

Megan Reeve

Therapy Radiographer, NHS

You questions answered by Megan in 2020.

What are the most important qualities of a Radiographer? (Emma H)

I would say that the most important quality is to be able to care, you have to really want to be there every day and make a difference to people’s lives. You also need good empathy and listening skills for this job because we mainly deal with cancer patients and whilst the job is very positive because we are aiming to cure most of our patients, it is still a very scary journey for patients with lots of emotions involved.

This does need to be balanced with a range of other qualities though, I would say it is very important to be quick thinking, have good attention to detail, have good mental maths and a technical mind. We often have a lot of patients in a day, so it is good to be a fast worker and be able to problem solve under pressure.

What are the most challenging parts? (Emma H)

Running to time! Radiotherapy is an outpatient’s department and due to the number of patients we have and complexity of treatment we often run behind schedule, which can make the job challenging at times. However, I often enjoy having to think and work quickly but it can just be tiring on some days.

The other challenging aspect can sometimes be making decisions on your feet about how to give a patient’s treatment. Some days we just can’t get our patients in the right position and when we take an image it just doesn’t line up with what we want – these situations are challenging because you want to give a patient their treatment accurately and especially as we use such high doses of radiation. You just need good problem-solving skills and also team work because you always work in pairs so you never have to make these decisions alone.

Finally, working with cancer patients, whilst the majority of our job is extremely positive and on a day to day basis you wouldn’t necessarily even notice some of our patients even had cancer, there are of course some cases that really tug on your heartstrings. Sometimes it can be really challenging as you naturally become attached to certain patients that you have more of a rapport with and who might be very ill with their disease but that is why I do the job because the treatment we give will be helping them and also just being there for them can sometimes provide comfort in tough times.

What advice would you give to someone who wanted to go into a career in medicine or medicinal science? (Molly BT)

Be prepared to work hard! Studying for anything medicine or healthcare at university is tough; you will be expected to manage both a heavy academic workload and also clinical placements which will also have academic components attached. You need to be organised, have good time management skills and be dedicated to the profession. This is something that will carry on even when you are qualified as you are expected to carry out continuous professional development and take on research as you progress through your career. If it’s what you want to do it’s well worth it though, I personally find my job very personally rewarding and love what I do.

Also, I would say visit departments! Whatever you are interested in, see if you can arrange a visit even if it’s just for an afternoon to get a taster of what the job is like and then visit somewhere else to contrast and compare. It’s a big commitment so definitely try and pick something that suits your personality – there is so many careers to choose from across medicine and healthcare so find something you will enjoy! Have a good chat with people who work in the departments – ask them what they enjoy, what they don’t and get a feel for the day to day.

Katie Hopkinson

MMath (hons) Stage 2

Your questions answered by Katie in 2020.

"How did you teach yourself further maths?" (S A)

Fortunately my Sixth Form were very supportive of me, they got me the right textbooks and registered for me to sit the exams. I mainly used the textbooks to work through the course, doing any practice questions there were along the way. For topics I was unsure on I found Youtube videos explaining the concepts, which helped a lot.

The hardest part for me was timetabling it all, in normal lessons it is set out what you will achieve each week, but since I was teaching myself I had to do this myself. Before I started I looked at all the chapters in the textbooks and set out a rough timetable of what I wanted to accomplish and when by, this helped a lot. Finally, I did all of the past papers out there that I could find, this helped with finding appropriate questions to answers.

Sarah Gascoigne

BSc Mathematics and Psychology (hons) Stage 3

Your questions answered by Sarah in 2020.

"What would you like to do with these degrees?"

"What kind of job would you prefer and which subjects would you recommend to someone who would like to do medicine?"

Clarissa Barratt

Physics PhD at Newcastle

Your questions answered by Clarissa in 2020.

“Well, I have no idea what i want to do once I leave high school. I’m getting decent grades at the moment (especially in maths I’m at a grade 8 in year 10) but I don’t know what path to take once I get to college. Any advice?” (Jessica B)

Congratulations on the amazing grades! Sounds like you’ve definitely got your options open for you. If maths is something you enjoy as well as something you’re good at, I think my advice would definitely be to try to have that as something you study. It’s so transferrable, if you can do maths you can do anything from finance to engineering to game design.

The main thing is that you’re doing something that you enjoy. Don’t feel like you have to bow to any external pressures saying that you have to study a certain thing, or that you shouldn’t study a certain thing, do what makes you happy, and everything else will follow.

If it helps, I’m coming to the end of my PhD now at 27, and honestly, still don’t know exactly what I want to do! But as you saw in my video, you can change your mind a fair amount and flit between options, you don’t have to pin yourself down just yet. So, do what makes you happy, keep your options open, and ignore people telling you that you should or shouldn’t study anything, you do you! I hope that that helps.