By qualifying the question "Is a vacuum tube a modern technology" to represent the application of vacuum tube technology in modern, even leading edge audio technologies of today we have a much better approach to answering the first part of this question.
The application of vacuum tube technology in high-fidelity, or high end audio amplification technologies can be very modern indeed. Separating the industry into two halves is required to further define what is modern about vacuum tube audio. The vast majority of applications currently being manufactured for the sole purpose of providing a more realistic sonic experience, is by and large not a novel approach. Those who actually "reinvent" or who discover a novel approach and apply new methods, thereby furthering the art and science of listening are in fact on the leading edge of modern application of vacuum tubes. Some company's and namely Singlepower Audio, reinvented the approach to using the vacuum tubes from WWII era 1940's, and invented new amplification methods to drive the listening experience into a new realm, are in fact leading the way to further the art and science of vacuum tube technology applied to amplification.
This question is most likely the result of someone either seeing, reading about, or actually listening to tube audio amplification. The general discussion that ensues is one of provoking the bias towards what is actually better. Are vacuum tubes better than transistors, or vise-versa? The common myth is that transistors are by default better since they are "modern technology" and by default all things modern are somehow better. It is the disbelief that what is heard actually is better (well maybe not for all, but many of us).
All opinion side, by the very definition, or rather qualification of this question, we can easily reach the conclusion that is it both Modern in it's application as it occurs in the audio industry (high-end), and it is one of the most basic forms of amplification device that is over 100 years old (more like 104).
Every microwave cooker contains one vacuum tube called a cavity magnetron that generates the microwaves to cook your food. These tubes are the least expensive power microwave oscillators there are, thus their use for cooking.
cAre vacuum tubes in modern TVs?
The last vacuum tube needed in TVs was the CRT, aka picture tube, which has now been universally replaced with various flat panel display types. So, your answer is no.
A vacuum tube is simply a tube with no oxygen nor carbon dioxide in it (aka no air).
Kilobytes and vacuum tubes are not in the same category. At best, a twin triode vacuum tube is a single flip-flop and can hold 1 bit of information, making a vacuum tube about 0.000122 of a kilobyte.
an electron tube containing a near-vacuum that allows the free passage of electric current.
The following stores sell a vacuum tube. Walmart, Home Hardware, Rona, Totems, and much more. Some of the stores listed might not sell a vacuum tube depending where they are located. These stores are located in Canada.
There were obvious differences between the trasisitor and the vacum tube. The transistor was faster, more reliable, smaller, and much cheaper to build than a vacuum tube. One transmisor was the equivalent 40 vacuum tubes. They also didn't produce heat compare it to a vacuum tubes. Conduct electricity faster and better than vacuum tubes.
the vacuum tube
Vacuum tubes are neither useful nor advantageous in modern computers. These were replaced decades ago by the integrated circuit.
A vacuum tube does not contain any gases. All the gases are evacuated from the tube and only vacuum is left.
Computer tubes, also known as vacuum tube computers are programmable computers that uses vacuum tube logic circuitry. They were used to solve computational problems much like modern day computers.
Because they have qualities that make them attractive. In audio technology, a vacuum tube amplifier sounds softer and richer than transistor amplifiers to many listeners.
A vacuum tube is simply a tube with no oxygen nor carbon dioxide in it (aka no air).
Millman's theorem
Alcatel Vacuum Technology was created in 1952.
Alcatel Vacuum Technology's population is 2,007.
who made the vacuum tubes
The transistor replaced the vacuum tube, allowing radios to get much smaller and portable.
Kilobytes and vacuum tubes are not in the same category. At best, a twin triode vacuum tube is a single flip-flop and can hold 1 bit of information, making a vacuum tube about 0.000122 of a kilobyte.