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If you guess randomly (CBADBA or whatever), it's possible to be unlucky enough to get every guess wrong.

If you guess AAAAA, you basically guarantee that about 20% of them are correct.

If you stand still on earth and 1 second = 1 second, is there any significant difference in time dilation relative to an astronaut floating in space who is completely still? (ie, not pulled in any direction due to orbits of any kind? Is there any frame of reference in the universe that would allow an object floating in space to be completely at rest? (factoring in planetary, stellar, galactical orbits and the expansion of the universe?)

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I was coming here to mention WRH

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I had no idea what it meant.

You're asking about relativity, which isn't exactly a subject that can easily be explained in simple terms. But I will try my best.

To understand why time slows down with increased velocity, you must first accept that the universe conspires so as to keep the speed of light the same for ALL observers, regardless of their frame of reference. This axiom of the constancy of the speed of light is directly responsible for time passing at different rates for different observers. Let's see how.

Suppose that you have a friend who is stationary (with respect to, say, the Earth). Suppose also that you're in a spaceship travelling at, say, 0.5c with respect to your friend's frame of reference. In other words, if your friend measures your speed, they will see that you're moving at 0.5c. (c = speed of light, so 0.5c means "half the speed of light").

Now, let's perform a physics experiment. Actually, let's perform two experiments -- you perform one experiment, and your friend performs the other experiment.

Inside your spaceship, you try to measure the speed of light. How do you do that? Well, c = d/t and so you measure the distance that light travels in a certain time period. Suppose that you measure how long it takes light to reach from one end of your spaceship to the other end. You know what d is because you can easily measure the length of your spaceship. It is important to note that your clock and your measuring stick retain their length. 1 meter is exactly equal to 1 meter, and 1 second is exactly equal to 1 second in your frame of reference. This sounds like a really dumb (and obvious) thing to say, but keep it in mind. So, you measure what t must be. Then, when you perform the calculations, you get that c = 299,792,458 m/s.

Likewise, your friend, who is not in your frame of reference, also performs the same experiment. He also notes that 1 meter is exactly equal to 1 meter, and that 1 second is exactly equal to 1 second in HIS frame of reference (again, a seemingly dumb observation). He measures the speed of light by measuring how long it takes light to reach from one end of your spaceship to the other end. When he does the calculations, he too gets that c = 299,792,458 m/s.

How is this possible?

It's because when your friend measures distances, he finds that your spaceship is actually SHORTER than what YOU measured. Even though 1 meter = 1 meter for him in HIS reference frame, and 1 meter = 1 meter for you in YOUR reference frame, when you compare the length of a meter from one reference frame to another, 1 meter in one frame of reference is no longer equal to 1 meter in the other frame of reference: your friend has just discovered the phenomenon of length contraction.

Now, c = d/t, and your friend measured d to be shorter than what YOU measured it to be. Yet, c must always equal 299,792,458 m/s for both you and your friend. How is this possible? Well, if d is different for your friend, then t must ALSO be different. However, the RATIO, d/t MUST equal the same: c. Hence, if d is smaller, then t must be bigger so as to keep the ratio, the speed of light, the same: your friend has just discovered time dilation.

This makes sense -- the word "contraction" in "length contraction" means to shorten. The word "dilation" in "time dilation" means to lengthen. So, if length contracts (i.e. d is shorter) then time must dilate (i.e. t is bigger) so as to exactly compensate.

Now I hope you can appreciate "relativ"ity. In your reference frame, time and space act the same -- 1 meter = 1 meter, and 1 second = 1 second. Likewise, in your friend's frame of reference, 1 meter = 1 meter and 1 second = 1 second. However, 1 meter in your friend's frame of reference, WITH RESPECT TO (i.e. RELATIVE TO) your frame of reference is no longer 1 meter. Similarly, 1 second in your friend's frame of reference RELATIVE TO your frame of reference is no longer 1 second.

Weird stuff starts happening only when we start measuring things RELATIVE TO other frames of references. Otherwise, in their own individual frames of references, everything appears to be normal.

Once you have understood the above, then the next natural question to ask is "why does the universe force the speed of light to remain constant for all observers?" And unfortunately, physics doesn't have the answer to this question. It's just how the universe seems to work. Perhaps a deeper theory will answer this question.

>Me went to the movies

Yarp

> Imperial is easy to eyeball and is in human sized chunks of understanding. Metric is precise and easy to do math with.

This is just what Americans think because they use imperial units for everyday stuff and metric for science. In countries that use metric for everything, people find metric units "easy to eyeball" and are confused by imperial units. In the UK we use a mixture of both to some extent. For some quantities (e.g. people's weights) I'm much more familiar with imperial units and they seem "easier to eyeball", for others (e.g. temperatures) I'm the opposite, and for others (e.g. short distances) I'm pretty much equally comfortable with both.

Anyway, an important part of the design of metric units is that they try to minimize the use of conversion factors. For example, take the equation "power = force x velocity". In SI, the standard unit for force is the newton, the standard unit for velocity is the metre per second, and if you multiply a force in newtons by a velocity in metres per second, you get the power in watts, which is the standard unit. To do the equivalent in imperial units, you multiply the force in "pounds force" by the velocity in feet per second, and then you have to multiply by the conversion factor of 550 to get the force in horsepower. You inevitably need some conversion factors in some places, but metric units are designed so that you generally don't need them in the most common kinds of calculations, while in imperial units they're virtually everywhere. This is the main thing that makes imperial units inconvenient for scientific purposes (along with the fact that there are often multiple competing definitions of the same unit, leading to frequent confusion). As a general rule, they are just as "precise" as metric units.

That was William Randolph Hurst. Citizen Kane was based on him.

No clue. It's a very small effect, that's why we only just noticed it recently.

I think he means e's-mail :P

What if you already don't feel emotions for others (to a certain degree). Does it exacerbate it?

In science, a hypothesis is a proposed explanation for a phenomenon. That would be what you in everyday language likely call a theory.

A Scientific theory is to quote the beginning of https://en.wikipedia.org/wiki/Scientific_theory

>A scientific theory is an explanation of an aspect of the natural world and universe that has been repeatedly tested and corroborated in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results.

So in the 19th century, what caused diseases was not really known. That bacteria is what causes infection was not known, So you might have the hypothesis that bacteria is what caused the infection. After expiration and test like what https://en.wikipedia.org/wiki/Robert_Koch did that shows that bacteria it the cause of many diseases.

The result is what is called https://en.wikipedia.org/wiki/Germ_theory_of_disease that germs can cause diseases. It is not just bacteria and another living thing like fungi( for example mold), protists (for example amoebas) etc. It can alos be no loving thing like viruses, prions, viroids etc.

So everything about how germs cause disease is a theory. The hypothesis was the idea before it was tested and shown to match reality.

That do not mean that all diseases are because of germ, it can be your own cells that do not work as they should. Autoimmune disease is for example your own immune system attaching your own tissue.

Before that https://en.wikipedia.org/wiki/Miasma_theory obsolete medical theory, that bad air causes disease, so it was the smell that could cause it. It was proposed as early as 4th century BC by Hippocrates. If you look at https://en.wikipedia.org/wiki/Plague_doctor with masks with beaks that contain dried flowers, herbs, and other things to keep the smells away. It likely helped because it keep droplets with bacteria away just like the facemask that is used today but the smell was not the cause.

The name malaria if from Italia where "mal" is bad and "aria" is air, so the literary means bad air. It was believed that the smell in for example wetlands caused it, the real explanation is that is a parasite that is transferred by mosquitos. So it did not smell but the existence of mosquitos in some areas caused it.

So both are explanations of a phenomenon Miasma theory was believed in for centuries even if it was not correct. But getting rid of smells can also reduce exposure to germs, so in a way it worked but why it works was not correct.

> In short there is no large difference between GPU and CPU besides the GPU uses what is called SIMD (single instruction, multiple data) architecture which is what this analogy was trying to convey.

The GPU is heavily geared towards floating point operations, while the CPU is less so. CPUs used to have to use a separate FPU chip. Transistors got small enough where they could fit the FPU on the CPU. Then the need for dedicated floating point performance skyrocketed with the rise of 3D games, which ultimately required a separate dedicated chip that could do absurd numbers of floating point operations in parallel, resulting in the GPU.

This floating point performance is why GPUs are a great tool for AI/ML and why Nvidia came to dominate hardware dedicated to AI/ML applications.

1. It may be thousands of cores in the GPU, but probably not.

2. The GPU is almost its own complete computer system that comes with everything else needed to run, where the CPU is only the CPU and maybe an OK heat sink and fan. The GPU unit comes with its own cooling solution, its own RAM, essentially its own motherboard to control the chips and interface with the actual motherboard, etc.

So to take the analogy way too far: the CPU is just the PhD mathematician but you still have to pay for pay for his office and air conditioning and all the paper he needs to do the work and the whole campus full of TAs and whatnot.

The GPU is like paying for the entire elementary school complete with teachers, cafeteria, and supplies, and you drop that entire school onto your campus next to the PhD's office.

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Libraries still have to pay licenses per copy, because that's how ebooks work. Even if publishers offered unlimited licenses, the costs would likely be out of reach for a local library to pay vs. a per unit license.

True, SIMD is absolutely abysmal at branches since it needs to take both true and false cases for the entire wave (usually). There are optimizations that GPUs do so it's not always terrible though.

It sounds like you're discussing vector processing instruction set with 512 bits which are very much specialized for certain tasks such as memcpy and not much else? That's just an example of a small SIMD on the CPU.

You’re right, I totally pulled that out of my ass with no thought and didn’t really check. That was stupid of me to act like I knew