Page 134 - How It Works - Book of Amazing Answers To Curious Questions, 12

� AMAZIG ANSWERS TO CURIOUS QUESTIONS -------------------

Whatmal<es How do metal

Paypal secure? detectors worl<?

The technology behind these Find out how to locate buried
protected online payments treasure using magnetism

ayPal works by utilising The process is best shown he most common metal from the object underground in
thousands of separate through a step-by-step detector uses a Very Low response, and alertthe user of
P servers running the Linux transaction. When a product is T Frequency (VLF) the metal detector via a beep or
operating system, literal 'blocks' bought, the buyer-who has technology to search for hidden on screen.
of servers that can be supplied PayPal with their objects. It employs one of the By cleverly employing a process
redistributed to perform different bank details-authorises a basic laws of electromagnetism, known as phase shifting, the VLF
tasks in tandem with one another. transaction via credit card or that an object in an alternating detector can deduce what sort of
These thousands of servers cheque to debit their account for magnetic field (switching from object is beneath the surface. This
connect with an offline database the purchase price. north to south polarity) will method works by calculating the
of customer information to This transaction is handled create an oscillating field of its time difference between the
transfer data back and forth directly by PayPat who contact own in opposition. frequency of the transmitter's field
between payee and recipient. the seller's bank, credit card A transmitter coil emits this and the corresponding response
However, the servers don't share association and card issuer, field, switching at a frequency of from underground. This all
information with each other, so paying the various interchange thousands of times per second. A depends on how easily the object
anyone trying to break into the fees necessary to process it. The device known as a magnetometer conducts electricity, and once this
system would have to scour the seller's money is then deposited within a receiver coil can detect is known its composition can then
heavily encrypted servers one by into a dedicated Pay Pal account. magnetic pulses pushed upwards be approximated.
one to piece together the relevant This process is mirrored for the
data. This separation of the merchant, but is processed on a
servers allows PayPal to remain completely separate server for
secure while quickly processing security reasons.
the millions of payments it Finally, after a set period of
receives, as it would be almost time, the money is transferred to
impossible to obtain access to the the buyer's account in another
different servers simultaneously completely separate transaction
to gather data. across another server. 0

Your payment PayPal sends Recipient receives
options the money the money

People
Credit card
- Bank account

Online
stores
Pay Pal balance
�00� PayPalplus �
credit card
g Pay Pal buyer eBay
credit

1. Method 2. 1nterest 3. Exchange
PayPal accepts many different PayPal makes money PayPal payments are not object's magnetic field.
types of payment method, from by accruing interest on restricted just to online stores The stronger the field
cheque to credit card. The type of banked payments, as and auction houses, with received, the closer the
payment affects the amount of well as direct fees people able to directly wire object is to the surface,
interchange fees that are paid and charged according to funds to any other person
processing time. an item's value. with an email address.

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