How could the Marauder's Map detect something which Death could not?

Question

According to this article on the Marauder's Map, and from the general knowledge acquired through the books and movies, it is quite clear that nothing is hidden from the map. This includes even the invisibility cloak, as this quote from a related question here on SF&F says-

"The number of times I saw James disappearing under it…" said Lupin, waving an impatient hand again. "The point is, even if you're wearing an Invisibility Cloak, you still show up on the Marauder's Map. I watched you cross the grounds and enter Hagrid's hut. Twenty minutes later, you left Hagrid, and set off back toward the castle. But you were now accompanied by somebody else."

My question is- How can a map created by four 15/16 year olds be able to detect the invisibility cloak, when Death wasn't able to detect the third brother hiding under it?

Have I missed a hint somewhere on any indication of some specific magic being used to create the Map, such that it is this special?

UPDATE:

Thank you all for posting such good answers. From what I can sum up there seem to be two main points brought to light in the answers:

1. The Invisibility Cloak was not your average cloak, and the Marauder's Map was an even powerful magical object. It just knows when something is there, regardless of cloak or not.

2. The Tale of the Three Brothers as told by Beedle the Bard are merely tales. Everything about Death, it's role and presence is probably a complete fabrication.

In light of the above points, my question is: If we agree that Death and it's role in the movie is a complete fabrication, then so is the fact that the Deathly Hallows were given to the three brothers by Death himself(or itself).

Then, who really created the Three Deathly Hallows?

I can recall a quote from Dumbledore in this Harry Potter Wikia link, where he speculates:

"...I think it more likely that the Peverell brothers were simply gifted, dangerous wizards who succeeded in creating those powerful objects" — Albus Dumbledore's speculation

Somehow, I am not fully convinced by Dumbledore's speculation. Besides, he himself thinks it's just "more likely". I also cannot recall any other hint/suggestion elsewhere in the books/movies indicating that the brothers created the Hallows.

Am I missing something (again)?

Answer 1

To begin with, the Tales of Beedle the Bard are just those-- tales. Even though it referred to actual powerful magic objects and actual wizards, the story is a morality play written for small children. The power of the Cloak of Invisibility is exaggerated, and the role of Death in the story is probably a complete fabrication.

According to Pottermore, the Marauder's Map uses something called the Homonculous Charm. Presumably, the Homonculous Charm is identical or related to Homenum revelio, an incantation which reveals if there are people nearby. JK Rowling said in a web chat that the spell was used by Dumbledore during the moments throughout the series where he seemed to know Harry was present beneath his cloak:

Why is it that albus dumbledore can see harry under his invisibility cloak at certain moments? (during the series is the cloak only infallible to those who do not own a deathly hallow).

J.K. Rowling: Dumbledore, who could perform magic without needing to say the incantation aloud, was using ‘homenum revelio’ -the human-presence-revealing spell Hermione makes use of in Deathly Hallows.

The only real indications we get that the Cloak of Invisibility was better than the average Invisibility Cloak are that:

• Snatchers were unable to summon the cloak when Harry apparated into Hogsmeade
• The cloak has never lost its abilities, while normal cloaks degrade in a few years
• The cloak granted true invisibility while most cloaks just have a Disillusionment Charm
• The cloak never tore in hundreds of years

In addition to the map and homonem revelio, Mad-Eye Moody's eye and animals can also see through the cloak. Quite simply, the legendary reputation of the Cloak to give "constant and impenetrable concealment, no matter what spells are cast at it," is simply untrue. The Cloak of Invisibility is a remarkable magical artifact, but it isn't perfect. In many ways, it's similar to the "unbeatable" reputation of the Elder Wand, whose owners are constantly beaten throughout history.

Answer 2

Well this is my theory, the cloak doesn't cover the person's feet and it's the persons feet that show up on the map. So maybe the magic that's in the Marauder's Map can somehow identify someone through their footprints. Obviously that's nerdy Lupin stuff I don't understand but I believe it could be something to do with that.

Answer 3

Simply because in the story with the Hallows, Death himself gave the 3rd brother a cloak whose purpose was to hide him from Death. Technically that cloak didn't have to be an invisibility cloak, because all the brother wanted was to hide from Death himself. Then we can get into the fact that it was a parable, but the above argument covers all bases.

Also, invisibility is only an illusion, the person is still standing there. Hiding in an illusion is no different than hiding while taking the poly-juice potion. You're still you, you're still there. The map obviously doesn't physically see anyone, it just knows you're there.

Answer 4

As others have said, it's just a fable. The truth behind the fable isn't that "Death" actually gave the three brothers these objects, the truth is that there were once three extremely talented wizards, Ignotus, Antioch, and Cadmus Peverell, who created and possessed three extremely powerful magical items which have never been equalled. The truthfulness of the owner of all three being "master of death" is not clear or whether or not Harry being "master" all three actually had an effect. Although, having all three would make the owner extremely powerful and that having "3" of anything probably has worth in a numerological/ magical sense.

Answer 5

Theory

Death is only a person and not a tracker or a sensor. Saying death should have been able to detect certain things is like saying that we know all of his attributes. Death can make certain powerful things ("unbeatable" wands, invisibility cloaks, and resurrection stones), but that is only his talent you are assuming he has special powers other don't have. Ollivander, for example, is very talented but we never assume he has special abilities.

The map, on the other hand, was like a very powerful sensor/tracker thing. Unless Death was a superhero/supervillain or a dog, I would assume that he did not have the same power as the map. Do human eyes have the same power as binoculars?

And just because 15/16 year old made it, does not mean that it was lesser in anyway. There are a lot of capable teenagers that make a lot of useful things and do useful things. Just because they weren't very school-oriented does not mean that they were not smart.

We do not know Death's capabilities. He could be like a vampire (from Twilight), having a couple of "talents" and living forever. We should not assume that he is genetically enhanced.

Also you could say it was "just a fairy tale":

The Tale of the Three Brothers is a fairy tale told to wizard children. Supposedly written by Beedle the Bard, it is published as part of a series of works that collectively are called The Tales of Beedle the Bard. While most wizards view this story as one that teaches children morals (e.g., humility, wisdom), some believe that the story refers to the Deathly Hallows, three highly powerful magical artefacts coveted by generations of wizards.

Harry: "Death had an Invisibility Cloak?" Ron: "Sometimes he gets tired of running at people flapping his arms and shrieking — sorry Hermione." — Death's Cloak of Invisibility

And this:

The map was very well made.

"The magic used in the map's creation is advanced and impressive; it includes the Homonculous Charm, enabling the possessor of the map to track the movements of every person in the castle, and it was also enchanted to forever repel (as insultingly as possible) the curiosity of their nemesis, Severus Snape."

— Description of the magic involved in the map's creation

Answer 6

James Potter, owner of the cloak, makes the map so it make sense that he knew the weakness of the cloak.

The Deathly Hallows are strong magical items but man made items not items made by death itself.

The wand is probable just a wand of elder and a thestral tail hair. Harry´s wand in the battle of seven potters can make a spell that Harry doesn´t learn so it is possible of a similar phenomenon.

The stone, well in a prior incantato a shadow of the people killed could be returned, and a horcrux could turn the fragment into a semisolid appearance, so a mix of these two phenomenons is not really weird.

Finally the cloak, based on the protection power but weakness the invisible cloak is probably based on a fidelius, we know that you could be next to a hidden house that you couldn´t see the house but if you know the location you could attack the house.

The cloak is similar but in a smaller sense, if you put the cloak you become invisible, but not only transparent but more like that people are incapable of perceive you, they could detect a person but the could not summon your cloak and probably unable to attack you. But this is not infallible, attacking people could risk the protection, and if they knew you are here the cloak are useless.

Answer 7

There's an easier explanation here that has equal chance of being true - Lupin is being figurative.

He didn't actually see them make any sort of tracks across school grounds. What he saw was Harry suddenly disappear from the Marauder's map, then appear again at Hagrid's hut. And once there, he saw him disappear, along with someone else, then reappear at the castle.

While he didn't actually see the path Harry took, it was heavily implied by where he appeared/disappeared.