Ask quick science questions here

Science!
21

There needs to be something to speculate from when discussing Science!

22

https://cplusplus.com/reference/random/random_device/

So it is possible to actually generate true random numbers? Why does this page speak out as if it’s barely even possible such as in this sentence :

A random number generator that produces non-deterministic random numbers, if supported.

Or this one :

Although, certain library implementations may lack the ability to produce such numbers and employ a random number engine to generate pseudo-random values instead.

Or even this one :

Notice that random devices may not always be available to produce random numbers (and in some systems, they may even never be available).

Why does it speak out as if it was inconvenient to use random devices instead of pseudo-random number generators? Does it require specific hardware or performance?

23

Yes Yes----------------Yes ----------Yes
Yes — Yes------------Yes ------Yes----Yes
Yes ------- Yes--------Yes —Yes----------Yes
Yes ------------Yes----Yes ------Yes-----Yes
Yes----------------Yes Yes ----------Yes

1 Like
24

Computers are deterministic, meaning that the same algorithm given the same inputs always results in the same numbers. This means that you cannot write an algorithm to generate random numbers. Modern CPUs contain a special feature to generate random numbers from thermal noise (based on a hardware switch that constantly reconfigures itself based on thermal noise to have about 50/50 chance to read a 0 or 1 bit). Thanks to the feature being pretty basic and entirely proprietary many people do not consider that to be truly random either as it can’t be proven.

Yes. Even if that random number generator in the CPU is available, it is extremely slow. It is hundreds of thousands of times slower than pseudorandom number generators because there is a physical limit to how fast you can sample enough thermal noise to get multiple bytes worth of randomness.

True hardware number generators are PCI-e cards that have a dedicated quantum uncertainty measuring device that is really guaranteed to make totally random sequence of bits. So it costs money and that is also slower because it takes again time to measure things over time to come up with enough randomness to generate a sequence of bytes.

5 Likes
25

“Is the cat alive?”

1 Like
26

How do white blood cells burst cell membranes? Do they have a pilus?

2 Likes
27

Would it be possible to make an electromagnet produce over 1 Tesla with standard DC current?

28

1st Newton’s law and FTL spaceships:
Wouldn’t I just get smashed into my chair if I were onboard a spaceship accelerating to FTL speeds in reasonable time? (Does Alcubierre Drive prevent this in some way?)

29

alcubeierre drive uses space to move you.

3 Likes
30

Doesn’t it require some sort of anti-gravity to work?

2 Likes
31

Quick question, how do magnets/magnitism work and can they be used as a replacement for electricity.
Also what technology 100% without a doubt needs electricity to function, because all I can think of is instant communication and perhaps radio (I don’t know how that works either I really need to look this stuff up) everything else I can think of can use hand cranks, pumps,switchs and gears, it would be much slower but still.

1 Like
32

I don’t know if I remember correctly, but it is basically overload of electrons (in regular atom number of electrons is equal to number of protons), on minue pole (electrons have negative charge) trying to get as close to the place, where there is lack of electrons (more protons than electrons, protons have positive charge, so that would be positive pole).

Electricity is faster in some aspects, I suppose, but who knows, maybe you’ll invent some cool magnet thing some day?

I’d say electromagnets.

Now my question: If I were to use Alcubierre’s drive while being on orbit, would I be able to just move faster on that orbit, or would I completely change it just like regular propulsion (and basically acceleration) does?

1 Like
33

an alcubierre drive slopes space around you so you get pulled forwards, so your orbit would act like there’s something really heavy right in front of you in the direction the alcubierre drive is pointed, unless i’m getting my propulsion drives mixed up, which means, if i’m not, you’d have your orbit get further and further out until you have reached the escape velocity of the body you’re orbiting, so you’d completely change it. that said they’d make it possible to escape the first event horizon of a black hole, but if you get past the one that your ship sees when below event horizon 1, ya’ screwed, but ya could use 6 of ‘em to make your space craft physically impossible ta hit without a warp drive on or as a projectile, but then ya got a black hole in the center. i’d use it for storin’ things ya’ wanna keep from havin’ time pass through ‘em, and the ‘bottom’ o’ tha gravity well is basically a constant level o’ bending of space an’ time, maybe a little hill in the center, so ya’ could build a computer in it, but you’d need to shield it first.

1 Like
34

However, Alcubierre Drives require negative gravity which, to this point, has never been achieved, atleast in a form that would be usable for AD ships.

1 Like
35

If you cut a stem off a plant that has multiple stems, like a dandelion, does the plant clot at the site of dismemberment or does it just stay open?