zlacker

It's about 3.5 trillion NFL football fields away. 15km/s is about 33,000 mph - more than 10x the speed of sound, and faster than a bullet. Does that help?

We are talking about distances that are so big, there is no comparison that makes sense. Nothing else IS that big. The numbers are literally "astronomical". If you're struggling to wrap your head around it, you're doing it right.

"Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space." -- Douglas Adams

>>ohtheh+(OP)
> 15km/s is about 33,000 mph - more than 10x the speed of sound

Well, technically, 15km/s IS "more than 10x the speed of sound". An average car, is, TECHNICALLY, more than twice the size of a bicycle.

>>ohtheh+(OP)
Good description.. reminds me of Vernor Vince’s description in his novels.

We are truly lost in a “The Deep” … as in absolute nothingness

>>onetim+Y
honestly I was just shooting for easy round numbers. "More than 43x the speed of sound" doesn't have the same ring to it. And besides, as we all know "technically correct is the best kind of correct!" :)

>>ohtheh+(OP)
When you start getting beyond the "thousands of football fields" it starts becoming difficult to conceptualize. In this case, even though GP was asking for football fields, it may be easier to visualize it as flying nearly 800 thousand times around the entire equator of earth. And voyager is going around the equator roughly once every 45 minutes or so.

So to catch up, you would have to be faster. Let's say you were able to travel around the equator in 15 minutes, so you're gaining 30 minutes per equator. If my napkin math is right, it would take you roughly 45 years to catch up to voyager.

>>ohtheh+B2
So what was wrong about "40 times the speed of sound"?

Also, I don't particularly like the speed of sound for this comparison. Most people think of speed of sound as speed of sound at about sea level pressure, in gas composed of around 78% nitrogen and 21% oxygen and at roughly 25C temperatures. But the speed of sound is highly dependant on the medium and its temperature and pressure. There actually can be sound waves in space (pressure waves in interstellar gas resulting from various astronomic phenomena) and they propagate at very wide range of speeds, typically somewhere between 10 and 100km/s.

The main reason to use "speed of sound" is because important things change when objects travel at little below or above speed of sound in the medium they are in. But this is only useful in relation to the actual medium the object travels through.

One place where it trips people up is when they are talking high altitude airplanes or rocketry. They are talking about something traveling at "X Mach", or "X times the speed of sound" and then I try to figure out if they mean X in relation to the speed of sound up there or the speed of sound at sea level. Just a nightmare trying to use it to convey speeds even within confines of our atmosphere.

>>onetim+A9
A nice feature of using the speed-of-sound as a measurement unit is that people know how difficult it is for aircraft to achieve it. So it makes it clear how much faster these things are going. We don’t have anything comparable between the speed-of-sound and the speed-of-light, do we? I suppose you could use escape-velocity, that isn’t something as many people know, but does I guess get you closer to the speeds in question.

>>ohtheh+(OP)
It’s crazy when you consider that the sun is 8 LIGHT MINUTES away from earth. Light can go around the entire planet hundreds, no, thousands of times in that same period. Space is huge. Incredibly huge.

>>chesch+Y2
> When you start getting beyond the "thousands of football fields" i

I feel like that line is somewhere between 5 and 15 for americans, and not "thousands". And probably at around "oh the handegg one, no, I have no idea how big one is in the first place" for rest of the world

>>blueje+eg
> A nice feature of using the speed-of-sound as a measurement unit is that people know how difficult it is for aircraft to achieve it.

But it's not aircraft ? It's trivial for spacecraft to achieve it

>>ilyt+pk
There is nothing trivial about it. The only reason Voyagers are traveling so fast is we were very lucky at the time and got gravity boost from pretty much everything we could get gravity boost from.

But yeah, it is not comparable as the challenges for spacecraft and planes are completely different.

>>chesch+Y2
Your parent was not suggesting to catch it, but rather to launch a transmitter to intercept Voyager's radio beam as a relay. Unnecessary, but creative.

>>onetim+A9
I think Mach numbers are always given for the situation the aircraft is in at the time

>>ilyt+1k
As an American, I've never seen more than maybe 2-3 football fields next to each other. They're usually stand alone items so that is even rare. Imagining them in plural at all is something people likely do with a large degree of error is my guess, even for us American's that are familiar with the size of a single field. It's a awfully small unit for anything related to space. Even a kilometer which is ~11x as long as an American football field is a small unit for space.

>>ilyt+pk
Trivial seems the wrong word here. Picking your nose is trivial. Space travel is exceptional.

>>chesch+Y2
> 800 thousand times around the entire equator of earth

This probably wasn't your intention, but putting it in terms like this, for me anyway, actually drives home just how short a distance the Voyager probes have travelled.

>>messe+wv1
I just wanted to make the distance something that could be understood and processed. Sounds like it worked!

>>ip26+zu
My math also didn't account for the fact that voyager would continue traveling in those 45 years you'd be trying to catch up, so it would actually take longer to catch up to it anyways.

>>FredPr+Xx
That's the idea. But quick survey of people in my vicinity confirmed most people think about Mach numbers as just another unit for speed of sound.

>>chesch+4x1
You definitely did a good job. I'm an avid sci-fi reader, write it as a hobby, spend a not-insignificant amount of my free time reading up on space news, and even have a degree in mathematical physics; this is the first time in a long time that an analogical choice of units has had an impact on my perception like that. Well done!

>>ilyt+1k
For order of magnitude descriptions, American and Association Football fields can be treated as approximately equivalent lengths. (The former is slightly larger counting the endzones as part of the size, slightly smaller if not counting them.)

>>onetim+Y
> Well, technically, 15km/s IS "more than 10x the speed of sound".

Technically, the speed of sound depends on the medium, and 15km/s is much slower than the speed of sound in interstellar space. (Which the sources I can find give at ~100km/s.)

>>onetim+Ko
> The only reason Voyagers are traveling so fast is we were very lucky at the time

“Lucky”, only in the sense that (1) completing a large government project on time, and (2) not having some kind of disaster (particularly, at launch) screw up the mission require a certain degree of luck of luck on top of planning and execution (though, not relying completely on that luck is also why there were two Voyagers): we got all the gravity boosts because the mission was planned around an alignment that enabled it to do that and visiting each of the outer planets (which was really the main goal; the beyond the solar system part was gravy.)

>>burnis+Rs1
Well, getting to space is the hardest part, once you're there breaking speed of sound is trivial

>>ohtheh+(OP)
... and it's not even close to being that far away from the solar system.

>>dragon+7V1
"Lucky" because the planets LITERALLY aligned for this to work. This kind of alignment only happens very, very rarely.

The New Horizons probe was launched at much faster speed than Voyagers, actually beating the record of the absolute fastest launch in history, but because of not getting those gravity assists it will never overtake Voyagers.