I bet you didn't know that this thread would have a part 2

Fourier

VW 1 wrote: »

Please do expand, I'm intrigued

As mentioned it's basically that you can't comb a hairy sphere flat without a cow lick.

For such a simple fact it's quite difficult to prove and there isn't really an explanation compressible into English. Understanding it visually (the images on Wikipedia are good for this) is better than a written explanation. Versions of it pop up all over the place, but the most interesting is probably where you can't make a wormhole/portal without it emitting radiation. Wormhole mouths end up roughly ball shape, the hairs are lines of radiation, so the cowlick is a beam of radiation coming off.

If you've ever watched Stargate, the team should really have their faces melted off. Not that that would make a good show.

368100

Capt'n Midnight wrote: »

7,713,468,100 +/- because 7.2 billion was a few years ago

Population has tripled since 1950 give or take.

projections are that it will level off at 11 Bn by 2100

Is there a reason for it levelling off?

Noo

368100 wrote: »

Is there a reason for it levelling off?

https://www.sbs.com.au/topics/science/article/2016/07/13/four-reasons-global-population-will-level-soon

Paddy Cow

Buford T. Justice VI wrote: »

A rare spotted Zebra was seen (or spotted) in the Masai Mara in the last few days.

https://www.wtap.com/content/news/Rare-spotted-zebra-photographed-in-Africa-560788231.html

It looks like a horse Bambi

Say my name

The Philistines of the bible fame, were the people that 20th century British archaeologist Sir Arthur Evans called the Minoans after the Greek legend about King Minos who is said to have ruled Crete.

https://www.nationalgeographic.com/culture/2019/07/ancient-dna-reveal-philistine-origins/

King Minos is said to have been the son of Zeus and Europa. He was in competition with his brothers for the throne. So prayed to Poseidon the God of the Sea to send him a snow white bull as a sign of support. The bull arrived but only so that Minos would return the favour and sacrifice the bull back in Poseidon's honour. However Minos felt chuffed with his new bull and forgot the sacrifice and sacrificed one of his own plain oul bulls instead.
Poseidon wasn't having any of this and to punish Minos made his wife, Pasiphae fall in love with this new white bull.
Pasiphae could only think about this white bull. So she got the local handyman to build a bronze cow. She climbed inside the cow, made a moo sound and the bull jumped on the cow.
Nine months later she gave birth to the Minotaur, a beast with the body of a human and head of bull.

King Minos in the Greek sagas is credited with being the first ruler of a substantial navy.

Minoan frying pan with decorative spirals.

Fourier

Google claims to have achieved Quantum Supremacy. From academics who've been reviewing the results so far it seems their claim is valid.

Achieving Quantum Supremacy means for the first time a quantum computer has performed a calculation in a short amount time that just isn't practical at all for a normal computer. Namely it did a calculation in around 190 seconds that would take a super computer 10,000 years to do.

The actual calculation they performed is useless in a certain sense. Producing 60 digit long lists of zeros and ones e.g.
0010101000110....
but with certain types of lists being generated more frequently.

Since there's been a bit of hype about quantum computers I should say that although they do some calculations way faster than a regular computer, most calculations progress at about the same speed. There's also an unfortunate tendency where the more useful a calculation is for real world applications the less likely it is a quantum computer will speed it up. There was news years ago about quantum computers being able to crack any security system in the world in seconds. However companies are moving to new encryption algorithms that even quantum computers can't crack.

However one thing they will make a big difference in is the discovery of new chemicals and protein folding. Both of which have enormous medical applications. This is basically because they can very quickly run through millions of different ways of arranging the atoms in a molecule to find the arrangement best suited for some biochemical problem. They're way faster than normal computers at this since they do in minutes a calculation that would take a thousand years normally.

They'll also speed up machine learning algorithms, although I should say they're only a good bit better than normal computers at this. As in something taking a year might only take two months. It's not a seconds vs thousands of years thing.

The next step is scaling, i.e. getting them to work with enough memory to handle real world problems. The main issue here is error correction. This is basically when a 0 accidentally flips to a 1 and how to spot and correct that.

Ipso

A lot of people have probably heard of this but this thread is a good a place as any, especially since it was 36 years ago today.
https://en.m.wikipedia.org/wiki/Stanislav_Petrov

Carry

Fourier wrote: »

(...) However one thing they will make a big difference in is the discovery of new chemicals and protein folding. Both of which have enormous medical applications. This is basically because they can very quickly run through millions of different ways of arranging the atoms in a molecule to find the arrangement best suited for some biochemical problem. They're way faster than normal computers at this since they do in minutes a calculation that would take a thousand years normally.

This is actually something I would like to know more about. Though then I would need to know more about biochemistry in the first place. It's an area I find highly interesting. But it's probably a too specialised area for our humble thread.

Fourier wrote: »

They'll also speed up machine learning algorithms, although I should say they're only a good bit better than normal computers at this. As in something taking a year might only take two months. It's not a seconds vs thousands of years thing

That would be very helpful for my procrastinating way of tackling my tax returns... :rolleyes: :pac:

Fourier

Carry wrote: »

This is actually something I would like to know more about. Though then I would need to know more about biochemistry in the first place. It's an area I find highly interesting. But it's probably a too specialised area for our humble thread.

Give me a while to think about it, hopefully I can come up with something decent.

It'll be a handy way also to say why Quantum Computers are faster than regular computers which the media often gives an incorrect description of by saying they "check every combination at once" or something similar which isn't true. (Although that's not really their fault, but a lazy explanation given to them by physicists)

Realt Dearg Sec

They are notoriously lazy.

Buford T. Justice XIX

The Twitter thread below explains the distance between railroad tracks and their connections to the Roman Empire. It's been done here before, iirc, but worth reading for those joining lately.
https://twitter.com/BillHolohanSolr/status/1177631604186996737?s=19

Capt'n Midnight

On the continent they mostly use imperial gauge while here 1600mm* has been standard since 1843.

Because the Romans didn't settle here#

*Its 5' 3" in old money.

#Maybe they did, for a while. People called Romanes, they go, the house.

Fourier

Carry wrote: »

This is actually something I would like to know more about. Though then I would need to know more about biochemistry in the first place. It's an area I find highly interesting. But it's probably a too specialised area for our humble thread.

Just to set things up (I'll do this in stages rather than one big post) I'll need entanglement.

Entanglement can be illustrated with a pair of "magic" coins. You take one and your friend takes one.

When you flip the coin you first pick which way up it is before you flip it. Your friend does likewise.

1. If you and your friend put the coins heads up first, then they'll always land the same way up. Either both land heads up or both land tails up.
   
2. If you pick different faces initially, they still always land the same way up.
   
3. However if you both put the coins tails up, then after the flip they'll always disagree, i.e. one will be tails up and the other heads up

The coins will do this no matter how far apart they are and no more what is in the way between them. So they're not sending each other a signal to make sure they line up. As always QM doesn't tell you how they agree so precisely all the time*, but it does tell you how to use these connections to speed up computing. Which I'll deal with in the next post, by getting the coins to compute something.

*And as I've said before, we'll probably never know how

In a real set up the coins are photons. Picking heads or tails at first is picking one of two polarizer optical filters. Landing heads or tails corresponds to the photons going through the polarizer or not.

jonski

Fourier wrote: »

Just to set things up (I'll do this in stages rather than one big post)

I'm looking forward to this , I have the ice packs in the freezer ready to strap onto my head .

mzungu

The average cumulus cloud (pictured below) weighs 500,000 kg (or 1.1 million pounds!). They have a water density of half a gram per cubic meter and a volume of one billion cubic meters. When you calculate the cloud's total water content, you end up with 500,000,000 grams of water, or about 1.1 million pounds.

mikhail

mzungu wrote: »

The average cumulus cloud (pictured below) weighs 500,000 kg (or 1.1 million pounds!). They have a water density of half a gram per cubic meter and a volume of one billion cubic meters. When you calculate the cloud's total water content, you end up with 500,000,000 grams of water, or about 1.1 million pounds.

...

"What weighs 500 (metric) tons and floats?" sounds like a bad one-liner. Possibly about your mother's hot air balloon.

Though technically, the term here is masses, not weighs. You stick that cloud on a scale, and it doesn't exert 500 tons of force on it.

BaZmO*

mikhail wrote: »

"What weighs 500 (metric) tons and floats?" sounds like a bad one-liner. Possibly about your mother's hot air balloon.

Though technically, the term here is masses, not weighs. You stick that cloud on a scale, and it doesn't exert 500 tons of force on it.

But it's the water that makes up the cloud that would have a weight?

mikhail

BaZmO* wrote: »

But it's the water that makes up the cloud that would have a weight?

Why is the cloud floating so?

Tacitus Kilgore

mikhail wrote: »

Why is the cloud floating so?

What do you think they are made of if they aren't made of water?

Skylinehead

mikhail wrote: »

Why is the cloud floating so?

Because water vapour is less dense than air. Water isn't, which is why we have rain.

Ineedaname

The reason clouds stay aloft is because the water droplets are extremely small, usually around 10 micrometers (a single raindrop contains over 15 million droplets).

On this scale they have so little weight that the rising hot air current is able to lift them upwards. It's only when they join together to form raindrops that gravity wins and they start to fall as rain.

The dust you see floating in the air follows roughly the same principle.

mikhail

Ineedaname wrote: »

The dust you see floating in the air follows roughly the same principle.

And how much does dusty air weigh?

Capt'n Midnight

mikhail wrote: »

And how much does dusty air weigh?

About 10.3 tonnes per square meter.

Fourier

jonski wrote: »

I'm looking forward to this , I have the ice packs in the freezer ready to strap onto my head .

Well if you want a head melter that's quick to check:

Once you know the coins aren't signalling each other, the other thing you could try is that they were set up in advance to land correctly to obey the rules above.

So say the first coin was set in advance to always land heads. The second coin was set in advance to land heads if you flipped it from heads up and tails if you flipped it from tails up.

Well you can see that this would obey my rules 1 and 3. When both start heads they land the same (rule 1) and when both are tails they land differently (rule 3).

However if the first is flipped from heads and the second is flipped from tails, then they land on different faces. However from rule 2 they should land the same way up in that case.

No matter what way you try to set up the coins in advance at least one of the rules will always be broken. The connections between things in our world are too strong to be deterministic.

mikhail

mikhail wrote: »

And how much does dusty air weigh?

It depends if you ask my dad or my ma 😂

New Home

Capt'n Midnight

The planet Saturn has the most moons.


Excluding planets and moons we can't see.

maudgonner

Capt'n Midnight wrote: »

The planet Saturn has the most moons.


Excluding planets and moons we can't see.

The planet Saturn also moons the most. It's always got its ring on show.




Sorry...I'm very sorry

Ipso

There’s another joke about a planet name, but I can’t put my finger on it.

mzungu

Cheetahs can't roar. They can only meow like domestic house cats.

The four "big cats" can roar: lions, tigers, leopards, and jaguars. These species, all of which belong to the Panthera genus, have a ligament in their voice box that can be stretched to create a "larger sound-producing passage and thus a wider range of pitch."

In "small cats" like cheetahs, the "fixed structure" of their voice box limits the range of sounds they can produce. While they can purr continuously, they cannot roar.