convection requires a medium is not the main difference, it is simply the most obvious aspect of what is a fundamentally different mechanism for transfering energy. Convection is the transfer of energy by movement of a medium, whereas radiation is the transfer of energy by, well, thermal radiation. Conduction also requires a medium, but, again, it is a fundamentally different mechanism than either convection or radiation; in this case it is the transfer of energy through a medium.
Unfortunately, analogies are hard but if you can visualize the particles involved, it would help. Picture the red hot iron you mentioned. On a molecular level, the material is emitting lots and lots of photons (hence why it is glowing red). The creation of these photons takes energy; energy from the heat of the iron. These photons leave the iron, pass through the environment, and eventually collide with some other object where they are absorbed and deposit their energy. This is radiative heat transfer. If that energy is deposited on your retina or a CCD (like in a digital camera), an image forms over time. This is how infrared goggles work and they would work equally well in high vacuum as here on earth.
In conduction, the next simplest example, there is no generation of photons (physics nerds forgive me for the sake of simplicity). The individual atoms in the object are vibrating with heat energy. As each atom gains energy from it's more energetic neighbors, so it gives up energy to its less energetic ones. Over time, the heat "travels" through the object.
In convection, the molecules of gas near the object gain energy, like in the conduction case, but those same molecules that gained energy then travel through the environment to some other location where they then give off their heat energy.
In summary:
radiation = generated and absorbed photonsconduction = molecules exciting their neighbors succesivelyconvection = molecules heated like in conduction, but then move to another location
When admitting digital evidence at trial, the issue of <u>Authenticity</u> comes up when the evidence involves computer-generated records.
Explanation:
The digital evidence such as video, audio or some pictures have been presented before court as evidence. The first question that may arise is related to "authenticity of the material". To authenticate that evidence court may order the forensic audit of that particular evidence.
<em>So, the issue of authenticity of evidence will arise, in case of digital evidence.</em>
RSA encryption is performed by calculating C=M^e(mod n).
However, if n is much larger than e (as is the case here), and if the message is not too long (i.e. small M), then M^e(mod n) == M^e and therefore M can be found by calculating the e-th root of C.
A web browser is a software program that allows a user to locate, access, and display web pages. Browsers are used primarily for displaying and accessing websites on the internet, as well as other content created using languages such as Hypertext Markup Language (HTML) and Extensible Markup Language (XML).
it acts like an interface between a user and a world wide web
