Space movies scientific goofs

Written on 24 October 2019, 11:39am

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I recently watched a number of space movies. Apollo 11, Apollo 13 and First Man looked more like a documentary – following the real events that happened 50 years ago. But then I also watched (or re-watched in the first 3 cases) Gravity, The Martian, Interstellar and Ad Astra – where the directors left their imagination free. But how scientifically-accurate are these 4 movies? Here is some insight.

Warning – spoilers ahead. You have been warned!

Ad Astra (2019)

I should probably start by saying that I didn’t like Ad Astra. Partially because of the story (which I found silly), partially because the whole masculinity idea was ridiculous, but more importantly, because it was full of science goofs. I really liked the idea of the regular service to the Moon and beyond, but, as soon as Brad Pitt climbed into a firing rocket, the movie started to feel bad. And then it didn’t get any better.

So here is a non-exhaustive list of science goofs from Ad Astra:

  • Climbing up inside a rocket while the engines are running? Wow. Just wow.
  • Using a piece of metal to travel through Neptune’s rings? Sure, in Tom&Jerry, but in reality, the relative velocities would be so big that shooting with bullets would feel like a water pistol…
  • Using the blast from a nuclear explosion in space to thrust you back to Earth? There is no atmosphere in space, so a shock wave is out of question. The only thing that the explosion would create is debris.
  • How would the main character jump into a years-old trip knowing that the life support supply is limited? Either he planned to kill somebody or never thought about that. Neither of this fits the character.
  • Using a rotating radar to slingshot you through space? Sure. But with that extraordinary precision? Unlikely.

The guys behind Ad Astra simply don’t get how space works. Almost everything related to the space travel is wrong. There are scenes like the rocket hijacking one when people who know a bit of physics feel insulted. What’s even worse, there was no need for such inaccuracies:

There could have been solid science reasons to motivate nearly all of the film’s more far-fetched plot points.


Read more:, USA Today

Gravity (2013)

Gravity is the kind of movie that grows on you. I didn’t really enjoy it first time I saw it, but after watching it again several years later, I liked the main idea of the movie: our fragility and helplessness in space. The director admitted from the beginning that “Gravity is not a documentary; it is a piece of fiction“. Consequently there are a number of space goofs as well:

  • The ISS and the Hubble space telescope are orbiting Earth at different altitudes (420km vs 560km). They are both in low-Earth orbit, but could never be so close to each other. The Chinese space station was not in space when the last space shuttle was retired from service.
  • The communication satellites are much, much higher: 22240 miles (geostationary orbit). So there was no way the debris of the communication satellites would have any impact on the Shuttle/Hubble telescope.
  • Communication with the world would continue through ground stations even if the communication satellites were off
  • The space walk is not so easy at it seems in the movie. You cannot simply put on your space suit and jump off to space. Decompression sickness is a real problem, as is the exhaustion. At the end of a space walk, the astronauts are exhausted and must gradually re-accommodate to breathing air (during the space walk they are breathing pure oxygen at lower pressure). Plus, in the movie, there is no sign that the astronauts were wearing any thermal / cooling / ventilation system, nor a space diaper. Just some sexy panties 🙂
  • Finally, the thing with the fire extinguisher: in theory, it’s doable. But in practice, you are much more likely to go into a spin, unless you manage to point the jet really close to your center of gravity.
  • As in ‘Ad Astra’, the mechanics of moving in space are not very accurate:

It is hard for most people to understand the difficulty in being in orbit trying to reach another object in orbit. Accelerating an object in the direction of travel will actually not move you forward. Instead the energy is used up raising the object’s altitude, where it will have a slower orbital speed and therefore actually move “backwards” in orbit.

Overall, Gravity manages to give a good idea on the look and feel of the space. The science goofs rarely distract you from watching the movie. And the message in the end is brilliant. The entire landing scene is like the evolution of life, in one shot.

Read more:,, wikipedia.

The Martian (2015)

The movies does a really good job in following the story from the novel of Andy Weir. This means that it also inherits the artistic licenses from the book. The science goofs are small and far apart, here is the list:

  • Due to the low atmospheric pressure on Mars, the wind would not be strong enough to tip a space ship. Plus, how come the second ship (Ares IV) can wait on Mars for years without any stability problem?
  • Figuring out an emergency escape route from Mars would be trivial for NASA and would not require a space nerd to figure it out. Also, using the Ares IV would be the obvious solution to get out of Mars
  • The Ironman scene has the same problems with the fire extinguisher scene from Gravity. See above.
  • Getting in and out of the space suit would not be so trivial. There are different pressures in the space suit compared to the hab. Stepping into the space suit and going out of the hab would require similar preparations as for a space walk, just as in Gravity:

Dropping from 14 PSI to 4.7 PSI pressure requires a progressive decompression sequence each time, which takes over two hours by the NASA protocol. The astronaut must pre-breathe pure oxygen to purge nitrogen from the body for this time, plus a period of “vigorous exercise” at the start of each pre-breathing and decompression sequence. Without this, the astronaut will get “the bends” due to nitrogen in the body tissues forming bubbles.

Once you accept the idea that people have a small base on Mars, things go smoothly from a scientific point of view. Brilliant movie; I highly recommend reading the book before watching the movie.

Read more: The Guardian,

Interstellar (2014)

I might be subjective on this, because it’s one of my favorite movies. Or because the film director hired a scientific consultant who later on wrote a book and then won a Nobel price in physics for the detection of the gravitational waves. Or the fact that you need a degree in astrophysics to understand the science goofs of Interstellar:

No one can survive the g-force necessary to produce 7 years of time dilation per hour.


What’s amazing for me is how Nolan manages to mix scientific facts with a great story. He even gets the time travel right; I cannot recall any other movie where the time relativity is presented in a better way.

Theoretical physicist Michio Kaku praised the film for its scientific accuracy and has said Interstellar “could set the gold standard for science fiction movies for years to come.” 

— Wikipedia
2014: A black hole as described in ‘The science of Interstellar’ book
2019: NASA Visualization of a Black Hole’s Warped World

10 things that I liked in 2018

Written on 31 December 2018, 12:50pm

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In the last day of the year, it’s time to look back at the year and highlight the things that enjoyed in 2018. For reference, here is the list from the last year.

1. Two books: Daemon and Freedom, by Daniel Suarez. Absolutely brilliant, I don’t know how I missed them for so many years. Here’s an excerpt:

The Code book from Simon Singh was probably the runner-up – a few months ago I ordered the printed version and read it again after 5 years.

2. My new notebook: Huawei Matebook x Pro. Say what you want about Huawei, but they came up with a brilliant device. Miles ahead of the premium-priced Macbooks, it fundamentally changed my workflow. Never been a tablet guy and probably never be, so the combination of an iPhone + an ultrabook like the Matebook works best for me.

3. WorkFlowy: an exponent of the makers (*) culture, WorkFlowy is a dead-simple, cross-platform note-taking app. The hierarchical structure of the notes makes it compatible with mind-mapping and I found myself using it in a variety of ways. For instance, I drafted the outline of this post in WorkFlowy. Others wrote books with it:

(*) the makers culture: Peter Levels

4. A place: the Austrian Alps in the summer time. I had the chance to spend about a week in the mountains. The combination of mountains, clean air, outdoor activities and clear blue sky is amazing. Just have a look:

5. Security. There were plenty of security things that I learned in 2018. Went to a few classroom training sessions (CISM, CISSP, TLS), passed some challenging certification exams, and realized that (IT) security is a fascinating domain with a lot of brilliant people.

The IT industry rocks (as one of the security guys that I follow said today), and on top of that, the security aspects make things much more interesting to watch.

6. Simona Halep: not only for finally winning her Grand Slam, but also for having the capacity to remain competitive for a long time: never dropped out of the top 10 for over 5 years and currently number 1 for more than a year (with a brief 4-weeks interruption). Well deserved and very inspirational.

Simona Halep, Roland Garros 2018, Simple Dames, Finale, Photo : Nicolas Gouhier / FFT

7. Two series: Breaking Bad and Better Call Saul. I enjoyed watching Breaking Bad when it was released on Netflix, and found the Better Call Saul a very good continuation of the series. Now that Better Call Saul is over, I went back to re-watch Breaking Bad – it’s amazing how a few years and another prequel change the perspective.

8. Jurgen Klopp. He joined Liverpool 3 years ago and built an amazing team around him. One can learn a lot about leadership just by listening to his interviews. Humble and determined, he’s a perfect fit for Liverpool and you can sense how everybody around the club loves him.

9. The iPhone X – because the dimensions are finally right, and, more importantly, because its camera allowed me to take some amazing photos throughout the year:

10. Tesla Model S. Finally, I left this at the end because it offered me some very mixed feelings. As I said in a recent post, the car is really amazing and it offers an experience that you will not find anywhere else. But the quality of the support services is disappointing here in Belgium. I hope that things will improve, even though I’m not holding my breath.

Here’s for a brilliant 2019 and remember, in the end it’s all about getting better.

10 things that I liked in 2017

Written on 24 December 2017, 12:01am

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Time to look back at 2017 and put together a few things that I enjoyed.
You can read the rest of this post while playing the song below, one of the things that will remind of 2017:

1. A book: Sapiens: A brief history of humankind, by Yuval Harari.
If you want to explain to an alien who we are and what’s our story on Earth, this is probably your handbook. A lot of insightful ideas and explanations, but one that stuck in my mind was how evolution doesn’t care about the individual:

The Agricultural Revolution left farmers with lives generally more difficult and less satisfying than those of foragers. Hunter-gatherers spent their time in more stimulating and varied ways, and were less in danger of starvation and disease. The Agricultural Revolution certainly enlarged the sum total of food at the disposal of humankind, but the extra food did not translate into a better diet or more leisure. The average farmer worked harder than the average forager, and got a worse diet in return. The Agricultural Revolution was history’s biggest fraud.
The evolutionary success of a species is measured by the number of copies of its DNA. If a species boasts many DNA copies, it is a success, and the species flourishes. From such a perspective, 1000 copies are always better than a hundred copies. This is the essence of the Agricultural Revolution: the ability to keep more people alive under worse conditions.
Quote from the book on

2. A photo editing tool: Photolemur. It promises to edit all your photos in one click, with the help of artificial intelligence. I like taking pictures, but I was never really into photo editing. So I am happy to leave this part to AI 🙂
And the results are not bad:

Click the image for the entire Flickr album

3. A place: Tuscany. One of the most amazing places in Italy, which is in turn one of the most amazing places in Europe. I spent there a full week last summer and I enjoyed every day of it!

Click the image for the entire Flickr album

4. A game: Really Bad Chess One of the very few games I play; really smart and so addictive that I’m playing it daily. The classic rules of chess apply, but you play with random pieces (ex. you can start with 3 queens and 4 towers).

5. A movie. I did not watch too many movies in 2017. But I watched again (after 8 years) Inglorious Basterds, and I believe that the way Christoph Waltz is playing the German detective is a masterpiece. I could watch it over and over again:

6. A learning tool. I am trying to constantly learn new things. Learning how to learn is one of them. Brainscape helps me create flash cards on my laptop and study them on my phone, whenever I have a few minutes free. Highly motivating.

7. A blog: Even if I know it for a couple of years, it’s in 2017 when I spent lots of time reading it. The series of posts about Elon Musk are really entertaining, but you have to see them as small novels instead of blog posts. Tim Urban (the author) has a funny way of zooming out and showing you things from a higher perspective.

8. An event: In 2017 I was lucky to attend a number of interesting sports events. I went for the first time on Anfield to watch Liverpool play in Champions League, I saw Ronnie O’Sullivan winning the Snooker Masters in London, and was present to the amazing comeback of Simona Halep in the quarter finals of Roland Garros.
But the live event that I enjoyed the most was no doubt the summer Coldplay concert in Brussels. The sport events have their own way of making you feel the moment, but once it’s over there’s not too much left. But a music concert is different. The way the songs make their way into your mind turns the entire experience into something close to magic and create long-lasting memories.

9. Writing In line with one of the resolutions for 2017, I tried to write a bit more. I had a few guest posts about snooker, football and analytics on and doubled the number of posts on this blog. Turns out, writing is one of the experiences that I enjoy 🙂

10. A picture: Romanian protests in Bucharest, February 2017. To be continued in 2018…