The Ultimate Parallel Processor: Quantum BitsShe implied that Microsoft would be solving these problems for the public in its cloud services in 5 or 10 years.
Certain calculations could take even the most advanced supercomputers billions of years to solve. But quantum computers, says Microsoft researcher Krysta Svore, might be able to dispatch what she calls “lifetime-of-the-universe” problems in a matter of hours or days.
I have repeatedly posted skepticism about the achievability of quantum computers, and how the supposed progress on problems like 3x5=15 is no progress at all.
But even if Microsoft succdessfully builds a quantum computer, it would have no practical value to the public. The main theoretical advantage is factoring large numbers and breaking secure internet connections.
That would not be good for society. It would be a disaster. All of the billions of computers in the world would have to be re-engineered to use different cryptographic methods that are slower, more expensive, less reliable, and are of more dubious security. Only thieves and criminals would be buying those Microsoft cloud services.
Microsoft is essentially promising to offer hacker tools to criminals to destroy everyone's security.
Some quantum computer advocates will argue that a quantum computer has other uses, such as doing unindexed database searches, and similating chemical reactions. While there is some theoretical complexity advantage in artificial scenarios, there is no practical advantage for any real world problem that anyone has found. Databases would still be better searched by indexing them and using conventional computers. Likewise, there are methods for simulating chemical reactions that are far better than using a quantum computer.
She explained quantum computers as the ultimate parallel processor because it can process qubits as being 0 and 1 at the same time, thereby giving an exponential speedup. Scott Aaronson posts that this view is inaccurate, and leads to an inflated view of what quantum computers are all about. He is writing a whole book on this subject, but I doubt that it will slow down the quantum computer hype machine.
Science Friday also had this, in celebration of Pi Day, 3-14 (yesterday):
Mathematician James Grime of the YouTube channel Numberphile has determined that 39 digits of pi—3.14159265358979323846264338327950288420 — would suffice to calculate the circumference of the known universe to the width of a hydrogen atom.No, this is nonsense, and Grime gives mathematicians a bad name.
The radium of the known universe is only known to about 1 signficant figure, so using Pi=3 is sufficient for any such calculation. Furthermore, the universe is not Euclidean on that scale, so Pi is not the circumference/diameter ratio.
I do not know any physical situation where more than about 6 decimal places are needed. I would be very surprised if more than 10 were ever needed.