Distances in the Honorverse

One item that continues to be discussed (or is related to discussions) about the Honorverse is distances. Many can't seen to grasp the immense distances being discussed - or just don;t have an internal measure large enough to put the distances in scale.

Unfortunately, Sci-Fi shows (like Star Trek) provide an unrealistic representation of space distances for dramatic effect – a space battle where 3-5 vessels are distinguishable on screen at the same time is normal. Even shows that attempted to show the distances, like the 2005 BSG series and The Expanse series still don’t do the sheer distance justice.

The other day I noticed a jetliner passing overhead – and ran some numbers through the rusty Physicist part of my brain and a decent analogy appeared.

Imagine that plane cruising at ~10 km altitude (which is about as high as airliners normally go – but still a plausible height - and let’s keep our numbers round), and it’s flying directly above you. If your eyes are good, you can still make out the plane’s details on a clear, sunny day, and see the wings and tail – if your eyes are really good, you can see the engines, identify the model and make out the colors of the plane.

Now, imagine I’m on that plane, I’m 6’-3”, but for this discussion call me 2m in height. I’ve gotten up to visit the lavatory and tripped in the aisle and am thus lying flat on the floor of the plane looking down at you. Now imagine that plane is invisible, and you on the ground can see me lying flat on the floor cursing the errant purse strap I tripped over...

My sprawling form is what a Dreadnaught would look like in parking orbit (or in travel formation) from another ship in close parking orbit – (separation is at least 5000KM). A Dreadnaught (a little more than 1KM in length), is 500x my height, so that 10KM distance gives roughly the correct ratio between my height and the length of the DN.

Now my dropped, cracked 10” ipad laying on the floor in front of me is a perfect representation of the size of the DN’s front profile – i.e., an IPad seen at 10km is what someone would see when a Dreadnaught is in formation directly behind them.

And this is for ships “flying” in a standard, safe formation.

Graser burn through range is 100x this distance - so imagine the 2 cm wide nickel in my pocket (still viewed from 10km)- that's the length of a DN at Graser range.

SDM range is ~15x that, so we're gonna picture the 1.35mm thickness of a dime. ... again from 10KM away.

Put down those Binoculars - and don't reach for a telescope - that's cheating. I know, everything i just mentioned, including me lying on the floor, is impossible for the human eye to see. At best, my form would be a spec or 2, able to be covered by that dime's thickness held at arm's length... but that's the point.

Space (as Douglas Adams so eloquently put it)....is Big.

Really big. You just won't believe how vastly, hugely, mindbogglingly 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.

Some other "Rough" distance analogies...
An SD’s wedge is slightly smaller than the size of the State of Ohio.
A BC’s Length is a little less than the Width of NY’s Central Park (And ~2 blocks wide)
The Moon is in Laser and Graser range from Earth’s surface (Grasers have over 2.5x the range of the Earth to the Moon distance against unprotected targets.)
A 3 drive MDM can hit Venus’ orbital path from Earth (in <9 minutes) with power to spare, and no coast stages.
Honor’s Demo attack on Tourville in AAC was the equivalent of firing missiles from Earth’s orbit, and hitting targets in Mars’s orbital path (OR targeting the Sun).

(Updated from Feedback)

Theemile wrote:Some other "Rough" distance analogies...
An SD’s wedge is roughly the size of the State of Connecticut.
A BC’s Length is a little less than the Width of NY’s Central Park (And ~2 blocks wide)
The Moon is in Laser and Graser range from Earth’s surface (Grasers have nearly 3x the range of the Earth to the Moon distance.)
A 3 drive MDM can hit Venus’ orbital path from Earth (in <9 minutes) with power to spare, and no coast stages.
Honor’s Demo attack on Tourville in AAC was the equivalent of firing missiles from Earth’s orbit, and hitting targets in Mars’s orbital path (OR targeting the Sun).

Actually an SD's wedge is quite a bit bigger than Connecticut.
From the infodump on wedge geometry (and some details dropped by, IIRC, Maxxq back in the day) an SD's wedge is roughly 300 km x 300 km [1]. While Connecticut is roughly 145 km wide and generally no more than about 90 km tall -- though it right near its western edge it finally angles down and picks up some extra height)

Also, for grasers, even against an unprotected target 3x the distance of the earth to the moon is rounding up pretty generously. As I recall, against a target unprotected by any sidewall, a graser has an effective range of about a million km, only 2.6x the ~384,000 km between Earth and moon. (And against a protected target cut that range basically in half)

Still, these quibbles aside, you're right that space is unimaginably vast and Honorverse ships or even stations are tiny small specks in comparison.

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[1] Though a wedge is moderately inclined (15 degrees), and I don't know if that 300 km length is the length of the plane of the wedge, or how far it would appear if seen from directly above. So there's about a +/- 10 km possible variation in there.

Theemile wrote:My sprawling form is what a Dreadnaught would look like in parking orbit (or in travel formation) from another ship in close parking orbit – (separation is at least 5000KM). A Dreadnaught (a little more than 1KM in length), is 500x my height, so that 10KM distance gives roughly the correct ratio between my height and the length of the DN.

Now my dropped, cracked 10” ipad laying on the floor in front of me is a perfect representation of the size of the DN’s front profile – i.e., an IPad seen at 10km is what someone would see when a Dreadnaught is in formation directly behind them.

Like you, sometimes I find myself walking and looking up. I've wondered about if looking at a ship from a porthole in another would be similar to, bigger, or smaller than an aeroplane passing overhead. Or, in one case, thinking about the Moon.

People seem to have trouble with is why the Hubble couldn't see the flag left by Apollo 11's landing on the Moon from Low Earth Orbit, but can see galaxies that are 2.5 * 10^17 times further away (that's because the landing site is something like 10^19 smaller than a 10,000-light-year early Universe galaxy). Intuitively, people think the Moon is so close because it's so visible, even in daylight and so big. It's weird to think that if you shone a laser at it -- specifically, at the retroreflectors left by the Apollo crews -- and had the equipment to detect their return, it would take over two seconds to get see anything.

ThinksMarkedly wrote:

Theemile wrote:My sprawling form is what a Dreadnaught would look like in parking orbit (or in travel formation) from another ship in close parking orbit – (separation is at least 5000KM). A Dreadnaught (a little more than 1KM in length), is 500x my height, so that 10KM distance gives roughly the correct ratio between my height and the length of the DN.

Now my dropped, cracked 10” ipad laying on the floor in front of me is a perfect representation of the size of the DN’s front profile – i.e., an IPad seen at 10km is what someone would see when a Dreadnaught is in formation directly behind them.

Like you, sometimes I find myself walking and looking up. I've wondered about if looking at a ship from a porthole in another would be similar to, bigger, or smaller than an aeroplane passing overhead. Or, in one case, thinking about the Moon.

People seem to have trouble with is why the Hubble couldn't see the flag left by Apollo 11's landing on the Moon from Low Earth Orbit, but can see galaxies that are 2.5 * 10^17 times further away (that's because the landing site is something like 10^19 smaller than a 10,000-light-year early Universe galaxy). Intuitively, people think the Moon is so close because it's so visible, even in daylight and so big. It's weird to think that if you shone a laser at it -- specifically, at the retroreflectors left by the Apollo crews -- and had the equipment to detect their return, it would take over two seconds to get see anything.

Interesting thread. I think it also has something to do with the minimum focal length of the Hubble telescope which is probably calibrated to infinity.

I think I first became somewhat aware of great distances when a teacher of mine challenged us to stand outside in the cold one morning before the sun arises to measure the time it takes to feel the sun’s warmth on your body when it rises. At 186,000 miles per second . That was an eye-opener for me.

As the thread says, I think all of us have an inherent problem with such vast distances. We are limited by the range of our senses. Even on Earth we don’t have a good perception of distances or sizes. Nobody could explain to me how Grand the Grand Canyon really is until I visited. Nobody could prepare me for the scale of Niagara Falls! Or how vast the oceans are until you travel by plane across 13 hrs of nothing but ocean just to get to the other side. As a species, we probably have more information on the space around us than we do about our own oceans.

The immensity of space is what makes me question the ability of GA sensors trying to make out totally stealthed infrastructure from the hyper limit. And GR drones whizzing by at breakneck speed with such a limited field of view is not going to detect an LD even if it flies 100 meters from it if it is looking in the opposite direction. The author explained that a missile’s field of view is akin to looking at the world thru the eye of a needle.

penny wrote:The immensity of space is what makes me question the ability of GA sensors trying to make out totally stealthed infrastructure from the hyper limit. And GR drones whizzing by at breakneck speed with such a limited field of view is not going to detect an LD even if it flies 100 meters from it if it is looking in the opposite direction. The author explained a missile’s field of view is akin to looking at the world thru the eye of a needle.

But wasn't the author talking about missiles with warheads there? Would a recon drone be of any use if its field of view was so small? We know that recon drones have discovered stealthed shoals of pods from further away than the distance you mention. Also a recon drone is not forced to stay outside the hyper limit. Isn't it likely that the drone might be rotating about its axis to view more directions?

tlb wrote:

penny wrote:The immensity of space is what makes me question the ability of GA sensors trying to make out totally stealthed infrastructure from the hyper limit. And GR drones whizzing by at breakneck speed with such a limited field of view is not going to detect an LD even if it flies 100 meters from it if it is looking in the opposite direction. The author explained a missile’s field of view is akin to looking at the world thru the eye of a needle.

But wasn't the author talking about missiles with warheads there? Would a recon drone be of any use if its field of view was so small? We know that recon drones have discovered stealthed shoals of pods from further away than the distance you mention. Also a recon drone is not forced to stay outside the hyper limit. Isn't it likely that the drone might be rotating about its axis to view more directions?

That's a good question. Beats me. Anybody?

I assumed it is the same for missile and drone. If installing a needle-eye view of the world in one particular spot on a missile is possible, it should not prove too difficult to do so several more times about the circumference of the missile body. But what do I know. My guess would be that it is the limitations of the sensor system as a whole and not the sensor's "eyes". Bigger eyes do not increase the throughput of the system as a whole. Even on bigger warships, sensors have to be directed at a specific area. Scanning a much bigger area would probably involve lots more power.

As a kid in school I was in awe over the speed of light. I just could not fathom 186,000 miles per hour, let alone per second. And it still takes 8 minutes and 20 seconds for us to feel the Sun's warmth? The sun looks like it is so close to us.

tlb wrote:

penny wrote:The immensity of space is what makes me question the ability of GA sensors trying to make out totally stealthed infrastructure from the hyper limit. And GR drones whizzing by at breakneck speed with such a limited field of view is not going to detect an LD even if it flies 100 meters from it if it is looking in the opposite direction. The author explained a missile’s field of view is akin to looking at the world thru the eye of a needle.

But wasn't the author talking about missiles with warheads there? Would a recon drone be of any use if its field of view was so small? We know that recon drones have discovered stealthed shoals of pods from further away than the distance you mention. Also a recon drone is not forced to stay outside the hyper limit. Isn't it likely that the drone might be rotating about its axis to view more directions?

penny wrote:That's a good question. Beats me. Anybody?

I assumed it is the same for missile and drone. If installing a needle-eye view of the world in one particular spot on a missile is possible, it should not prove too difficult to do so several more times about the circumference of the missile body. But what do I know. My guess would be that it is the limitations of the sensor system as a whole and not the sensor's "eyes". Bigger eyes do not increase the throughput of the system as a whole. Even on bigger warships, sensors have to be directed at a specific area. Scanning a much bigger area would probably involve lots more power.

It could also have to do with the cost as well as the complexity. After watching the movie Greyhound I looked up the cost of a radar system for warships. Mostly interested in our new destroyer. I am shocked at the cost:

The cost of a radar system on a warship can vary greatly, ranging from hundreds of thousands to hundreds of millions of dollars, depending on the type of radar, its capabilities, and the size and complexity of the vessel.
Here's a more detailed breakdown:

Simple Navigation Radars:
A basic navigation radar system like the Furuno 2120 might cost around $421,000, according to a Navy fact sheet.

Surveillance Radars:
New naval surveillance radar systems can average around $12.7 million, according to Armada International.

Advanced AESA Radars:
The AN/SPY-6, an advanced active electronically scanned array radar, can cost $300 million per unit in serial production, according to Wikipedia.

Radar for a Class of Ships:
The radar requirement for a class of ships like the FFG(X) frigates could be worth up to $25.5 million.

Radar Cost in Relation to Ship Cost:
While the radar itself is a significant cost, it's also a small fraction of the total cost of a warship. For example, the FFG(X) frigate class, estimated at $870 million per ship, is considered a relatively inexpensive surface combatant program.

penny wrote:As a kid in school I was in awe over the speed of light. I just could not fathom 186,000 miles per hour, let alone per second. And it still takes 8 minutes and 20 seconds for us to feel the Sun's warmth? The sun looks like it is so close to us.

Aren't there other factors involved in feeling the Sun's warmth? After all, as soon as you can see the Sun, its rays can be hitting your body; you should not have to wait over 8 minutes from first sight. But you are wearing clothes and in the cooler morning air and the Sun's rays have already been traveling though miles of atmosphere before it came to you (which diminishes its intensity). How much warmth does the Sun have to supply to the skin on your face before it is noticeable over the coolness of the air (particularly if there is a breeze)?

I think your teacher was messing with you or possibly your teacher was also fooled.

penny wrote:I assumed it is the same for missile and drone. If installing a needle-eye view of the world in one particular spot on a missile is possible, it should not prove too difficult to do so several more times about the circumference of the missile body. But what do I know. My guess would be that it is the limitations of the sensor system as a whole and not the sensor's "eyes". Bigger eyes do not increase the throughput of the system as a whole. Even on bigger warships, sensors have to be directed at a specific area. Scanning a much bigger area would probably involve lots more power.

That seems like asking why if it's possible to install a 'needle-eye' radar in the nose of a fighter it shouldn't prove too difficult to do so several more times around it's body.

The long range radar on a fighter is not a trivially small sensor package. you're talking about something that's almost as large around as the fuselage on a single seat fighter and takes up almost 1% of its length. It's just too big (and too power hungry) to install multiple of around the rest of the aircraft.

I'm assuming the same is true for a missile's nose-mounted sensor. It's going to be as big as you can squeeze in without compromising the rest of the functionality of the missile -- and so far too large to squeeze in multiple copies to give a wider view.

OTOH a recon drone is much larger than a missile, and can devote more of its increased volume to larger, more, and better sensors. So it's not at all surprising that it'd have a wider and better view.