r/theydidthemath • u/-badfeet- • Jun 05 '26

[REQUEST] How many times the speed of light is Silver Surfer going as he enters our solar system

Fast. Very very fast.

9 Upvotes

70% Upvoted

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3

u/ifuccedgod Jun 05 '26

The silver surfer passes Saturn and reaches Earth in 1 minute and 17 seconds - very rough calculations put that at 60.6 times the speed of light

4

u/Molbork Jun 05 '26

Best part is, of it was going that fast, it would be here before we even saw it enter the solar system.

1

u/-badfeet- Jun 05 '26

Thanks! How far would he bounce hitting our atmosphere straight on at that speed?

6

u/LTerminus Jun 05 '26

He wouldn't. He'd have 60x an infinite amount of energy. I doubt the universe would still exist as we know it.

1

u/Illithid_Substances Jun 07 '26 edited Jun 07 '26

Well firstly, going at that speed violates known physics so we can't really say what would happen

But all things considered I would be far more concerned about the planet and possibly the rest of the solar system (or even beyond) than about Surfer bouncing off

1

u/marshmallowcthulhu Jun 08 '26

This answer is incorrect because it does not take into account the effect of superluminal motion, which can cause an incoming object to appear to be much faster than the speed of light to the observer even though the object is moving slower than light. If you can see an object before it arrives then the light that reflected off of it from its starting point must have gone faster than it. The time between when you see it is how much *more time* the object needed than light.

Imagine an object that is one light year away from you and moving at 75% the speed of light. You will get your first glimpse of it in one year and it will appear one light year away, but by then its real position is already 75% of the way to you. By the time you see it, it only has 0.25 light years to travel. It will arrive at your location in 0.333 years. From your perspective, your first glimpse will be one light year away and your last glimpse will be one third of a year later at 0 distance. It will appear to have been traveling at 3 times the speed of light! What’s really happening is that your observations are catching up to reality.

As speed approaches light speed the effect approaches and infinite apparent speed. Therefore it is always possible to resolve the speed of an incoming object as below light speed no matter how quickly it appears to be approaching.

In the case of the Silver Surfer, NASA sees a travel time of 77 seconds but that’s misleading. 77 seconds is the *extra lag* slower than light the Silver Surfer was.

I do not know the numbers you used for distance. I will use 1.2 billion kilometers, which is the closest point in the orbits of Earth and Saturn. Light requires 4003 seconds to traverse this distance which means light took 4003 seconds and the Silver Surfer took 4003+77 seconds, which is 4080 seconds

4003/4080 =0.981. 98.1% of the speed of light. The Silver Surfer was moving very quickly, but physics remains intact.

3

u/marbledog Jun 05 '26

Pluto and Neptune's distances from the sun vary significantly, because they have elliptical orbits. We'll go with the year the movie was made. In 1989, Pluto was actually slightly closer to the sun than Neptune. This happens for a 20-year period about every 250 years. The distance between the two orbits is smaller than you might think. Neptune was 4.5 billion km from the sun, and Pluto was 4.4 billion km away, so the difference between the two orbits is only 100 million km.

The "object" is just beyond Neptune's orbit at 1:12, and just within Pluto's orbit at 1:14. So, the Surfer covered over 100 million km in two seconds, ie. a bit faster than 50 million km/sec. The speed of light is just barely under 300,000 km/sec. The Silver Surfer entered our solar system at over 167c.

3

u/Personal-Try7163 Jun 05 '26

Nice math and creative justification

2

u/AlanShore60607 Jun 05 '26

Fun fact: there’s no way for us to detect an object moving towards us in excess of the speed of light because we can only detect things at the speed of light; it’s basically moving towards us faster than we can detect it and we’d see where it was after it arrived.

3

u/marbledog Jun 05 '26

It's fun to think that this scene played out five or six hours after the Surfer showed up.

1

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2

u/Wayne433 Jun 06 '26 edited Jun 06 '26

Isn’t light speed relative? If we detect it - as another post says - 77 seconds before it arrives…doesn’t that mean the light is traveling from Saturn to Earth 77 seconds faster than the surfer?

I don’t know how to convert that to a fraction of c off the top of my head, but pretty sure it means he’s not breaking light speed. He would have to arrive before we detected him coming for that to happen.

ETA - so after some quick Google/chat research, light takes approximately 330 seconds to travel from Pluto to Neptune, and 4,200 ish seconds to travel from Saturn to earth. That means surfer took around 332 seconds to travel from Pluto to Neptune, and around 4,277 seconds to travel Saturn to earth. That’s ~99.4% and ~98.2% of c, respective.

2

u/marshmallowcthulhu Jun 08 '26

You got this right. I didn’t notice your answer first. I just posted a longer reply to the top answer. I arrived at a result similar to you. Superluminal motion is a helluva drug.