In old versions of Windows, such as 3.1, there was this screensaver called "Starfield". It looked like this:

However, in movies and TV series, it usually looks like this when they travel through space:

What I'm asking is, regardless of whether the stars would appear like little "dust particles" or like smeared "lines" when traveling in a space ship at the extreme speed necessary for this to possibly happen, would it ever look like that?

Let's ignore optics for a moment, and focus on the original video/screensaver. Would the stars, being so far away, really ever appear to be "within your view" and "fly past"? Would they not originally, appear like a star sky when the space craft is standing still, and then sort of just "disappear from view" to the sides very slowly as our space ship moves forward at this extreme speed which, to me, looks like it's many, many times the speed of light?

I've always been annoyed by how that screensaver makes it look like space is full of little "dust particles" the size of grapes, rather than distant, huge collections of gas (or whatever stars really are made of), and I've always thought to myself that the objects would never travel like that from our perspective, no matter how fast our space ship goes.

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    $\begingroup$ I'm pretty sure there'd be a pretty big blue shift if you were moving at a high enough relativistic speed that time dilation was making you seem to move multiple light years every second of apparent time. $\endgroup$
    – nick012000
    Commented May 22, 2020 at 6:30
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    $\begingroup$ The difference between a moving dot and a streak is entirely due to persistence, be it phosphor lifetime, retinal retension, or digital history-filtering. $\endgroup$ Commented May 22, 2020 at 13:16
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    $\begingroup$ Those aren't stars. Those are microscopic space dust particles hitting your navigational deflector. They're a few atoms wide at most, they're bright like that because of the considerable amount of energy required to deflect them at translight speeds. That energy comes from your own auxiliary generators to power the nav deflector, and the energy comes from the fuel you overpaid for at Outpost 419. So might as well enjoy the light show! $\endgroup$ Commented May 22, 2020 at 14:57
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    $\begingroup$ You could get such a "video" if you make a timelapse of flying at moderate cosmic speeds with a frame shot every megayear or so. $\endgroup$
    – Ruslan
    Commented May 23, 2020 at 7:46
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    $\begingroup$ @nick012000: You wouldn't notice the blueshift, because the wavelengths that get shifted out to the ultraviolet are compensated for by the wavelengths that get shifted in from the infrared. Blueshift is detected by a shift in the spectral lines of a star, not by a bluer appearance. $\endgroup$
    – TonyK
    Commented May 23, 2020 at 18:34

3 Answers 3


I do disagree with the other answers, not on the result, but on the reason.

You don't need to go faster than the speed of light to pass through multiple stars in a few seconds. Putting aside the problems of accelerating to a high enough speed in a human lifetime without being crushed by G forces, storing enough fuel for that (what would you use as fuel? antimater? microblackholes exploding hawking radiation? whatever it is, must store a LOT of energy), and shielding from external radiation, (at that speed, radio waves looks like metal evaporating gamma lasers) if you get close enough to the speed of light, you suffer a phenomenon called length contraction. The closer to the speed of light, the smaller interstellar distances are for you, in the direction you are traveling.

I don't actually know the average mean distance between stars, but assuming you have to cross 5 light years per second so that much stars blaze past you, you would have to travel at 0.99999999999999998 of the light speed (yep, 16 nines). I plugged the formula from Wikipedia with the numbers into Wolfram Alpha to get this result.

Besides being a completely unrealistic number at a totally crazy energy level (which will probably be impossible to achieve, ever), at this speed, stars in front of you will be blueshifted into far gamma ray spectrum, and stars behind, redshifted into extremely low frequency radio waves, neither which are visible on naked eye (and one of them is quite lethal).

But the real problem is that the space will be so severely distorted that, for you, all star field will be clumped into a single point in front of you in a phenomenon called light aberration, and even if you have the optical precision to distinguish individual stars, it will look absolutely nothing like the screensaver, as they will not zip past you.

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    $\begingroup$ I wouldn't say you suffer length contraction—not more suffering than due to getting a shorter shadow as the Sun goes up. The object undergoing length contraction won't even notice the changed lengths. $\endgroup$
    – Ruslan
    Commented May 23, 2020 at 7:43
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    $\begingroup$ I agree that suffer is a worse term than experience in this case. But it is clear from the following phrase that what contracts is not the traveler itself, but the distance between stars. In fact, in traveler's frame, it is the only thing that explains how she is able to cross 1 ly in less than 1 year: the length must be sorter, because she certainly isn't faster than light. $\endgroup$
    – lvella
    Commented May 23, 2020 at 16:21
  • $\begingroup$ Whilst television, movies, and computer screensavers haven't tried for verisimilitude, written science fiction sometimes has. c.f. the descriptions of the uncorrected relativistic starfield in Niven's A World Out of Time for just one example. $\endgroup$
    – JdeBP
    Commented May 23, 2020 at 18:12
  • $\begingroup$ All this physics mumbo jumbo is great and all, but I call for an animation how it would really look like. Maybe only blueshifted, I think my monitor can't do gamma $\endgroup$
    – Christian
    Commented May 23, 2020 at 22:18
  • $\begingroup$ In the "light aberration" link, if you get to Part 4, there is a series of rendered pictures showing the sky viewed from someone passing through the solar system at different fractions of speed of light: 0, 0.5, 0.8, 0.95 and 0.999. No animation, sorry. But even at 0.999, you would have to stare to the screen for too much time to see something change. $\endgroup$
    – lvella
    Commented May 23, 2020 at 22:24

It helps to suppose that you're flying your ship somewhere closer to a galactic nucleus than we are. Sure, the nearest star to us (after the Sun) is several light years away, but if you get within a few light-years of the center of the Milky Way, the average distance between stars is less than 0.02 light year (1/250th of what other answers are taking as the typical value). Of course, that still means that at non-relativistic speeds, you should be passing a few stars per week, not per second. But we must be going pretty fast for the old red stars in the galactic center to be blue-shifted enough to appear white anyway. Any remaining discrepancy can be accounted for by the fact that this is time-lapse footage from the spaceship dashcam, and not a live view out the window.

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    $\begingroup$ Oh yes, those dashcam videos from Russian star ships ... $\endgroup$ Commented May 23, 2020 at 16:33

Yes, via a light-speed U-turn

When traveling at speeds close to the speed of light, stars appear to conglomerate into a single blurb in front of a spacecraft (artistic example). When slowing down, those stars will appear to move back to their 'normal' rest positions, and diminish in spectrum (i.e. they will appear to undergo redshift). This means that stars will appear to move from the blurb across the field of vision to the rear of the craft. As the craft continues accelerating opposite its original motion, even stars which would appear at rest velocity with respect to the starfield to be mostly in line with its original motion will end up appearing mostly in line with its new, opposite, direction of travel.

Maintaining a more-or-less stable apparent velocity of the stars flying past will require some wonky acceleration, and you'd want to be coming head-on at the center of a spiral galaxy so that that wonky acceleration can maximize the number of stars that appear to fly past rather than bubble past (if you accelerate at a constant amount of energy, the stars will move slowly near the center of the field and quicker near the sides, which will create a visual bubble effect, rather than the nice linear progression in the screensaver), but assuming you are okay with near infinite g-forces and near infinite energy expenditures it should be possible. You will want to go from approximately c to approximately -c over the course of your desired viewing, and you will want to perceive the stars' light far into the gamma radiation part of the spectrum.


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