Focus – Does the short focal length of the eyes enlarge the moon?

Does the short focal length of the eyes enlarge the moon?

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The real cause of the moon illusion?

As shown in the figure, the blue line is the lens, w is the height of the object, x is the height of the image, v is the image distance, u is the object distance and f is the focal length. The red line is the light path.
The relationship between u, v, f is

1 / u + 1 / v = 1 / f

and so

f = uv / (v + u) (1)

The observer's eyes are constant, so v is fixed. The distance between the observer and the object is constant, so u is also fixed. As soon as v and u are fixed, it can be known from equation (1) that f is also fixed. If v is fixed and u decreases, f also decreases.

Knowledge from similar triangles:

x / w = (v-f) / f = v / f-1

and so

x = w (v / f-1) (2)

According to formula (2), x increases when v and w are fixed, when f decreases.

If the observer observes the moon on the horizon due to the influence of mountains and trees, f is smaller than when observing the moon at the zenith. According to formula (2) we can know that x increases as f decreases. The viewer will feel that the moon is larger and closer on the horizon than the moon at the zenith.

I think that's the reason for the moon illusion.

Simple calculation

If you look at nearby trees with your eyes:

u = 200 m (assuming 200 m from the tree)

v = 0.024 m (eyeball diameter, assumed image length)

w = 10 m (provided the tree is 10 m high)

f = uv / (v + u)
= 0.0239971 m

x = w (v / f-1)
= 0.0012 m = 1.2 mm (height of the tree picture)

When you look at the zenith moon (without the influence of trees on the ground) with your eyes:

u = 380000000 m (distance from the observer to the moon)

v = 0.024 m

w = 3476000 meters (diameter of the moon)

f = uv / (v + u) = A (we set this focal length to A)

x = w (v / f-1)
= 0.000219537 m = 0.219537 mm

If you observe the moon towards the horizon with the focal length of the observation tree:

f = 0.0239971 m

x = w (v / f-1)
= 420.067 m

The observation of the moon image on the zenith is 0.219537 mm, and the observation of the moon image on the horizon is 420.067 m, which shows a big difference between the two. So if you use a focal length less than A, the moon will be "enlarged".

Of course, the eyes do not generally observe the moon with a focal length of 0.0239971 m. Because the picture may not be clear. If the image of the moon is not clear at this focal length, the eyes adjust the focal length. Set a focal length that is clear for imaging. This focal length is less than A, but it is the focal length for clear imaging. Since the moon is far away, the depth of field of the moon imaging is very large. Therefore, there is a focal length that is smaller than A and can reproduce clearly. The moon illusion is therefore caused by a relatively short focal length. I think that's why the moon illusion.

Does the short focal length of the eyes enlarge the moon?


Network – How to connect to an IPSec VPN with a short (

I am trying to connect to a working VPN that uses IPSec and a pre-installed key. The recommended client is NCP Secure Entry ( it no Linux version is available.

I have an INI file that appears to contain all of the configurations I need to set up the connection. I use strongswan with the Gnome Network Manager plugin (network-manager-strongswan).

My problem is that strongswan (the UI plugin and the backend) enforces a PSK with at least 20 characters, but my work VPN uses a 12 character PSK. I have no way to change that. This is (rightly) an open bug –; The client is a stupid place to enforce server configuration.

Is there any way to convince Strongswan to accept a short PSK? If not, is there another package I could use instead?

I am so frustrated that I consider forking Strongswan just to remove this limitation …

mg.metric geometry – compatibility of the Hausdorff dimension with short, exact sequences in standardized rooms

To let $ (E, |. |) $ be a finite dimensional normalized space and take $ F subset E $ a
Subspace so that we have the canonical short exact sequence
$ 0 rightarrow F rightarrow ^ iota E rightarrow ^ pi E / F rightarrow 0 $ of standardized rooms ($ F $
be endowed by the restriction of $ |. | $ and $ E / F $ according to the quotient standard
$ | v + F | = inf_ {f in F} | v-f | $). Write $ n = dim E $ and $ k = dim F $.

We can define the Hausdorff dimension for each of these rooms (let's say $ mu_F, mu_E $ and $ mu_ {E / F} $), Deriving from
each of their norms.
Is this definition compatible with the short exact order?
in the sense that for a $ k $-Vector $ mathfrak {f} = f_1 wedge cdots wedge f_k in bigwedge ^ k E $, and $ mathfrak {e} = e_ {k + 1} wedge cdots wedge e_n in bigwedge ^ {n-k} E $, we have:
mu_E ( mathfrak {f} wedge mathfrak {e}) = mu_F ( mathfrak {f}) mu_ {E / F} ( pi ( mathfrak {e} wedge mathfrak {f}) ).

Note that this is the case if $ |. | $ is Euclidean, as a direct result of the definition of the norm in external algebra.

Another view of the question is whether the pleasure induced by the Hausdorff measure coincides with the measure induced by the quotient standard.

How do you calculate the full uncompressed public key from a short 02/03 pubkey in PHP?

How do I create the full public key from a compressed in PHP?

My test key is

and the uncompressed one is

can this be done via openssl?

Thank you for any helpful answer!

SQL Server 2017 – The linked MS Access table shows short text instead of the decimal data type

I linked tables in MS Access databases (various versions, 2007-2019) that are connected to SQL Server 2017 via SQL Server 2017 drivers (e.g. msodbcsql_17.2.0.1_x64). Fields of the Decimal (38.20) data type in SQL Server are displayed as short text in the linked tables.

According to the documentation, the data types are directly comparable.

Why could this come through as a different data type?

dnd 3.5e – What are the official abbreviations or short forms of the 3rd edition of the D&D books?

The consolidated lists published by WotC contain an extensive list of officially defined abbreviations in one place:

Product Key
AE      Arms and Equipment Guide
BFK     Barrow of the Forgotten King
BB      Bastion of Broken Souls
BC      Book of Challenges: Dungeon Rooms, Puzzles, and Traps
BE      Book of Exalted Deeds
BV      Book of Vile Darkness
CR      Champions of Ruin
CV      Champions of Valor
CiP     City of Peril
CSW     City of Splendors: Waterdeep
CSQ     City of the Spider Queen
Ci      Cityscape
CAd     Complete Adventurer
CAr     Complete Arcane
CC      Complete Champion
CD      Complete Divine
CM      Complete Mage
CP      Complete Psionic
CS      Complete Scoundrel
CW      Complete Warrior
Co      Cormyr: The Tearing of the Weave
DG      D&D Gazetteer
DH      Deep Horizon
DF      Defenders of the Faith: A Guidebook to Clerics and Paladins
DD      Deities and Demigods
Dr      Draconomicon
DM      Dragon Magic
Dra     Dragonmarked
DCS     Dragonlance Campaign Setting
DrF     Dragons of Faerûn
DrU     Drow of the Underdark
DMG     Dungeon Master's Guide v.3.5
DMG2    Dungeon Master's Guide II
Du      Dungeonscape
ECS     Eberron Campaign Setting
EA      Enemies and Allies
EL      Epic Level Handbook
EE      Exemplars of Evil
XPH     Expanded Psionics Handbook
Rav     Expedition to Castle Ravenloft
EDP     Expedition to the Demonweb Pits
ERG     Expedition to the Ruins of Greyhawk
EU      Expedition to Undermountain
EH      Explorer's Handbook
ELQ     Eyes of the Lich Queen
FP      Faiths & Pantheons
FE      Faiths of Eberron
FLFD    Fantastic Locations: Fane of the Drow
FLFR    Fantastic Locations: Fields of Ruin
FLHP    Fantastic Locations: Hellspike Prison
FF      Fiend Folio
FCI     Fiendish Codex I: Hordes of the Abyss
FCI     Fiendish Codex II: Tyrants of the Nine Hells
Fo      Forge of Fury, The
FW      Forge of War, The
FRCS    Forgotten Realms Campaign Setting
FY      Fortress of the Yuan-Ti
Fr      Frostburn
Gh      Ghostwalk
GHR     Grand History of the Realms
GC      Grasp of the Emerald Claw
HN      Heart of Nightfang Spire
HBG     Hero Builder's Guidebook
HB      Heroes of Battle
HH      Heroes of Horror
LM      Libris Mortis: The Book of the Dead
LG      Living Greyhawk Gazetteer
LF      Lord of the Iron Fortress
LD      Lords of Darkness
LoM     Lords of Madness
LE      Lost Empires of Faerûn
MIC     Magic Item Compendium
MoE     Magic of Eberron
Mag     Magic of Faerûn
MoI     Magic of Incarnum
MP      Manual of the Planes
MW      Masters of the Wild: A Guidebook to Barbarians, Druids, and Rangers
MH      Miniatures Handbook
Mon     Monster Compendium: Monsters of Faerûn
MM5     Monster Manual V
MM4     Monster Manual IV
MM3     Monster Manual III
MM2     Monster Manual II
MM      Monster Manual v.3.5
Mys     Mysteries of the Moonsea
OA      Oriental Adventures
PlH     Planar Handbook
PE      Player's Guide to Eberron
PG      Player's Guide to Faerûn
PH      Player's Handbook v.3.5
PH2     Player's Handbook II
PF      Power of Faerûn
RD      Races of Destiny
RE      Races of Eberron
Rac     Races of Faerûn
RS      Races of Stone
RDr     Races of the Dragon
RW      Races of the Wild
RH      Red Hand of Doom
RT      Return to the Temple of Elemental Evil
Sa      Sandstorm
SS      Savage Species
SoS     Secrets of Sarlona
SX      Secrets of Xen'drik
SK      Serpent Kingdoms
SSL     Shadowdale: The Scouring of the Land
SL      Shadows of the Last War
Sh      Sharn: City of Towers
ShG     The Shattered Gates of Slaughtergarde
ShS     Shining South
SM      Silver Marches
SiS     Sinister Spire, The
SaS     Song and Silence: A Guidebook to Bards and Rogues
SG      Sons of Gruumsh
SD      Speaker in Dreams, The
StS     Standing Stone, The
Sto     Stormwrack
SB      Stronghold Builder's Guidebook
SC      Sunless Citadel, The
SpC     Spell Compendium
SF      Sword and Fist: A Guidebook to Monks and Fighters
TB      Tome and Blood: A Guidebook to Wizards and Sorcerers
ToB     Tome of Battle: The Book of Nine Swords
TM      Tome of Magic
Una     Unapproachable East
Und     Underdark
UA      Unearthed Arcana
VGD     Voyage of the Golden Dragon
WB      Whispers of the Vampire's Blade

Not all communities or websites use the correct official names because they have developed their own short forms. Please note this fact in your communications.

Bluetooth speakers and buds: delay in playback, cuts off short sounds

Current Android phone.

I initially only saw this problem with Boom and Megaboom Bluetooth speakers, but now I have Jabra buds and see the same problem:

The first 100-500 milliseconds of audio are not played.

This is a problem if it's a voice app (that says a word) or a training app (that says “start” and then says “stop” 30 seconds later) because all or most of it Sounds do not play at all.

What is the resolution?

I was forced to use wired buds for language learning (which is NOT fun!)

When I used Apple Airpods, I did NOT have this problem. (I no longer use Airpods because they cannot be repaired or replaced with a battery.)

What is a sitemap? Do you really need it? This short introduction should help you make the decision! | Proxies-free

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Exchanges – To open a short position at Kraken, does BTC have to?

Suppose I have dollars on octopuses and no BTC. Assuming I expect Bitcoin's price to drop a bit (which I don't but assume), I would speculate and take a short position.

Is that even possible or do I have to have BTC in my account to sell it?

It feels counterintuitive to buy BTC first and then sell (sell) it immediately.

Suppose I don't want a higher leverage, i. H. I just want to short-circuit "1x", so to speak. A price drop of 7% would mean a profit of 7% (minus trading fees). Am I right when I think I should buy BTC first and then sell it with 2x leverage?

And similarly, if I want to short-circuit with 3x leverage. But I don't have a BTC yet. Should I then buy BTC first (via a normal order, no margin) and then sell margin with 4x leverage?