Questions tagged [computer]
96 questions
95
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1 answer
If we had a "perfectly efficient" computer and all the energy in the Milky-way available, what number could it count to?
The idea for this question comes from an example in cryptography, where supposedly 256-bit symmetric keys will be enough for all time to come (brute-forcing a 256-bit key is sort-of equivalent to counting to $2^{255}$, with some constant in front of…
cooky451
- 1,069
63
votes
9 answers
Why is it said that without quantum mechanics we would not have modern computers?
I've heard this in many quantum mechanics talks and lectures, nevertheless I don't seem to grasp the idea behind it.
What I mean is, at which point is that our modern understanding of quantum mechanics led to a technological development so…
harogaston
- 895
34
votes
4 answers
Why do computers generate heat?
Computers generate heat when they work. Is it a result of information processing or friction (resistance)? Are these just different ways to describe the same thing? Or does some definite part of the heat "come from each explanation"?
I often read…
isarandi
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34
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8 answers
Since cables carry electricity moving at the speed of light, why aren't computer networks much faster?
Why can't cables used for computer networking transfer data really fast, say at the speed of light?
I ask this because electricity travels at the speed of light. Take Ethernet cables for example, I looked them up on wikipedia.
Propagation speed …
Celeritas
- 451
30
votes
4 answers
Upper bounding the Kolmogorov Complexity of the Standard Model
The Kolmogorov complexity of a hypothesis/theory/model is the shortest computer program that simulates it, regardless of how inefficient executing that program may be in terms of memory and time. I'm interested in how complex the standard model is,…
Craig Gidney
- 7,172
21
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6 answers
Could a hard drive actually have been erased as described in Cryptonomicon?
In chapter 80, The Primary, Neal Stephenson has one of his character describe how the drives of a computer carried through a door (by the police, who where raiding the facility) will have been erased.
Basically, there's an enormous electromagnet…
SQB
- 321
15
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3 answers
How are physics and computer science getting united?
How is theoretical computer science getting united with physics? Phenomena like Quantum Computing uses Quantum Mechanics to be able to compute things, how are computers helping not just to model our equations but actually predict new equations,…
Isomorphic
- 1,616
10
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0 answers
Using a time-like boundary as a computer?
Question and Summary
Using classical calculations and the Robin boundary condition I show that one calculates the anti-derivative of a function within time $2X$ (I can compute an integral below)
$$\frac{2 \alpha}{\beta} e^{ \frac{\alpha}{\beta}X}…
More Anonymous
- 1,421
5
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1 answer
What makes a Quantum Computer Faster for solving specific problems?
I have an undergraduate understanding of Quantum Mechanics (or at least of whatever is covered in Griffith's) and the idea of a Quantum Computer sounds really interesting but I am having some trouble seeing where its effectiveness comes from.
I…
d128
- 183
5
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2 answers
How can the universe be a computation?
A few physicists (or computer scientists) take it for granted that the universe is a computation. However, I am not able to understand how the universe CAN be a computation in the first place.
I come from Classical Mechanics background, and I have…
shivams
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5
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Could we build a supercomputer out of wires and switches instead of a microchip?
I thought of this question; would too much wiring make a computer burn down? Or can you build an actual full-speed supercomputer computer using switches and wires?
In other words, could simply adding wires and switches into a computer already…
Victor
- 790
4
votes
1 answer
Computers, quantum information and computational complexity in Kerr-AdS black hole backgrounds
A Kerr-AdS black hole is eternal, never evaporates and has a Malament-Hogarth metric. Bob, a universally programmable reversible classical computer with a fixed maximum memory who only outputs one bit, orbits around the black hole for a…
QGR
- 2,377
4
votes
3 answers
Are quantum computers able to simulate every physical process that a classical one can simulate?
I edited the question since this comment was (rightly) made:
There are few things that are more annoying than questions where the question text is not self-contained.
So:
Quantum supremacy has been reached quite recently.
It is said that a quantum…
Deschele Schilder
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4
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1 answer
Does "computation" increase entropy?
My computer is blowing heat, and all it's supposed to be doing is sending pulses of voltage through tiny circuits to flip and check the condition of FETs.
Ignoring the source of the electricity, I know that all of the conductive paths have some…
feetwet
- 932
4
votes
2 answers
Optical Drive Physics
I have been recently wondering how is data stored on and retrieved from optical devices like CDs, DVDs, and Bluray. What makes these different storage types different from each other?
Singh
- 41