Guest Blog by Dr Steve Cross: The Science of Space

By Steve Cross

Do you know what everyone in space is scared of? It’s not lasers (we’ve got shields) or fire (we’ll just get a droid to put it out) or even fifth-dimensional beings (they can be defeated by being witty or saying their name backwards). No. It’s torpedoes. Well, in Star Wars and Star Trek it is. I don’t know about Battlestar Galactus or Paddington 5 or Expansys or whatever it is that you like. I only know the classics.

Photo by Craig Adderley on

Torpedoes come in two types. Star Wars has proton torpedoes (if you fire one into a sewer it ignites all the old poop and makes it destroy the whole base) and Star Trek has photon torpedoes (these are often fired as a “full spread” which implies there are roasties, Yorkshire puddings and possibly pigs in blankets on the side).

But how scary are they?

Science can tell us.

A proton, as anyone who listened for 5 seconds in GCSE science knows, is a hydrogen ion. Basic boring old hydrogen is a single proton with a single electron floating around it. Take the electron away and you’ve got protons. Do you know what’s really rich in protons? Acid. Even a really weak acid has trillions* of spare protons in it.

Canonically we don’t know whether Star Wars torpedoes have a warhead of lemon juice, vinegar or possibly even Viakal. Sadly there are no scenes of brave flight technicians precisely measuring teaspoonfuls of Diet Coke into primed torpedoes. What we do know is that the torpedoes would definitely get the limescale off their targets with their rich proton loads. Star Destroyers probably shine like chrome after a good old space battle.

We can only speculate about how the first Death Star was destroyed. Did it have a core made of millions of tons of sodium, just waiting to recreate the most exciting moment of A-Level chemistry but at grand scale? Only Darth Vader knows. And he can’t tell us because he isn’t real.

Over in the Star Trek universe we’re all wearing our uniforms that are apparently solely designed to make cosplaying unsexy, and we’ve tried shooting the enemies with phasers (the first time I used the guitar pedal of the same name I was sorely disappointed). It didn’t work. It usually doesn’t. Phasers only exist to provide a moment of tension by not working. So it’s time to up the stakes. We will unleash the fearsome photon torpedoes!

In tedious-science-explanation land, a photon is the smallest possible unit of electromagnetic energy. It is the basic unit of light. Photons move pretty fast, in fact they move at the speed of light. That’s why it’s called that. Physicists are pretty literal. That’s how they came up with units like “Light-year (ly)f” and “Earth mass (M⊕)”.

It’s easy to blast your enemy with literally trillions* of photons; Just point a torch at them. Is this the payload of the fearsome photon torpedo? We know they’re big enough to fit a dead Vulcan in, ears and all (from the second movie) so they could hold some serious lighting. “Priming photon torpedoes” presumably means turning on all of the torches in each one by hand. Although, if all those torches had poorly-made lithium batteries and it got a bit warm, the photon torpedo might make a perfect incendiary bomb.

Is anyone else not scared? I’m not scared.

*It might be more. I refuse to do the maths.


A dismissal of the other forms of Star Trek torpedo, most of which only appear in one episode of Voyager when the writers were desperate because, against all the odds, Deep Space Nine was eating their lunch. It turns out we just wanted to see someone drink silently at a bar while Worf seduced every female character on a space station. Who knew?

fusion torpedo – This is what is known in normal human history as a thermonuclear or H Bomb. This is scary shit. It was also invented in the 1950s which suggests other cultures should have come up with a way of blocking it by now.

photonic torpedo – A more-sciencey-sounding version of a photon torpedo, presumably.

plasma torpedo – I’m assuming this is full of ionised superheated gas, not human blood with the cells removed. I’m not sure how scary that would be to anyone except a vegetarian. Less threatening than a fusion torpedo either way.

quantum torpedo – the smallest possible unit of torpedo

spatial torpedo – a torpedo that is used in outer space? Or that occupies some physical space? It doesn’t seem that scary. Or well named.

transphasic torpedo – I’m not sure why anyone would want to add phasers (which don’t work, ever) to a torpedo?

gravimetric torpedo – Uh oh look out this torpedo has mass!

NB from Girlymicro. If you’d like to submit a guest book review or guest blog drop me a line on the links on the right of the page

All opinions on this blog are my own

Guest Blog by Dr Claire Walker: A clinical immunologist’s thoughts on lateral flow antibody testing for SARS CoV2

By Dr Claire Walker

Paid-up member of the Dream Team since 2013 (as discussed in a previous post, in her personal life most people call her Girlymicro Dream), token immunologist and occasional defector from the Immunology Mafia. Registered Clinical Scientist in Immunology with a background in genetics (PhD), microbiology and immunology (MSc), biological sciences (mBiolSci) and indecisiveness (everything else). Now a Senior Lecturer in Immunology at University of Lincoln.

A clinical immunologist’s thoughts on lateral flow antibody testing – this post follows on from Dr Dream’s awesome post on testing for the virus – concerns my thoughts on COVID-19 antibody testing by lateral flow technologies.

‘The LEDs on the top of the box turned on, one red, one green, beginning to flash in an alternating patter. The flashing slowed and finally stopped as the red light went out, leaving the green. Still clean.’

‘Feed’ by Mira Grant 2010 (see Newsflesh book review for some more on the series)

Whilst some days it might feel like the end of the world during the COVID19 Pandemic, we aren’t quite living through the zombie dystopian vision of the future described in Mira Grant’s Feedback trilogy. However, much like in the world envisioned in Feed, point of care testing has become part of many people’s lives. A friend recently received a lateral flow anti-SARS CoV-2 antibody test and sent me his result saying, “turns out I never had it, 80-90% confident”. It sounds like quite good odds, doesn’t it? If you happen to like gambling, and someone told you to bet on a horse with an 80-90% chance of winning, it’d be tempting to have a flutter. But when it comes to clinical testing, a 1 in 5 chance that that result is inaccurate is far less appealing.

What are the tests?

Antibody tests, unlike testing for the virus itself, detect the antibodies produced by our immune systems in response to infection. To envisage a lateral flow test, think about a pregnancy test. Instead of urine, a few drops of blood from a finger prick are mixed with a solution and applied to the device.

You then wait 10-15 minutes and the results can be read in the result window (image 2). There are many different versions of these tests out there, but the underlying principle is much the same. If you have the antibodies in your blood sample, they bind to viral proteins attached to gold particles. This forms an antibody-antigen-gold-particle complex which can be seen as the positive test line.

How good are the tests?

‘Confident’ isn’t a term we like to use in clinical science: we like the terms ‘sensitive’ and ‘specific’. We also like to use statistics to describe the sensitivity and specificity of a test. In the case of COVID-19, the sensitivity of the test is the proportion of people with COVID-19 that have a positive blood test. A test which is 100% sensitive means that all individuals with COVID-19 are correctly identified as having the disease. Conversely, specificity is the proportion of individuals without COVID that have a negative blood test. A test that is 100% specific means that all healthy individuals are correctly identified as not having COVID-19. It’s pretty hard for any clinical test to be this wonderful, but we are trying to get as close to this ideal as possible. The MHRA recommends these tests have a sensitivity of >98% and specificity of >98% (1). To date, none of the lateral flow assays to detect antibodies have met these criteria.

What are we using them for?

Testing for antibodies isn’t the same as testing for virus. A positive result means you were likely infected with COVID-19 in the past. This result should not be used to diagnose a current COVID-19 infection because it can take 1-3 weeks after infection for your body to make antibodies. We aren’t sure how long these antibodies are going to stick around either. Some viruses are very memorable to the immune system. Unfortunately, coronaviruses are pretty forgettable, and the ‘immunological memory’ – the antibodies against the SARS CoV-2 virus – may disappear in a matter of months. In the case of my friend, who took his antibody test in October to find out if he had COVID-19 in February, that negative result doesn’t mean very much.

This test only tells you that you’ve made antibodies to the virus, not how many are there and if they can stop reinfection. We don’t know if these antibodies are protective or if that makes you immune to the virus. You can also test positive for the virus and positive for antibodies at the same time, meaning you are still infectious. Best not to use the result to decide whether or not to visit Grandma.

The Bottom Line

Whilst I don’t love these tests for individual use, they are useful. By monitoring the prevalence of antibodies against SARS CoV-2 at a population level, we get a snapshot of what is happening in the country in the moment the test is taken. It tells us something about the antibody status of a community of individuals, helping to monitor the COVID-19 pandemic at a population level and more data will hopefully help immunologists better understand what on earth is going on with the immune response to this virus.

TLDR. Lateral flow tests for antibodies are best left for community studies and aren’t going to let you know if you had COVID-19 in January. You’ll just have to keep wondering.


  1. MHRA. Target product profile antibody tests to help determine if people have immunity to SARS-CoV-2, 2020. Available:

NB from Girlymicro. If you’d like to submit a guest book review or guest blog, drop me a line on the links on the right of the page

All opinions on this blog are my own