Things you always wanted to know the answer to [Vol. 5]

[bodhi]

h0b0 said:

v9 said:

stemll said:

The head forms from dissolved CO2 by a process called nucleation. To do that they need somewhere to do it. In a clean glass the only nucleation sites are either dirty bits of glass or irregularities in the surface. In a used glass there will be residue left from earlier beer so there are more nucleation sites and hence more head.

This is the right answer, though I will add that some beer glasses (I acquired some recently like this) have nucleation sites built into the inside of the glass, often on the inside of the base, maybe try one of these and report back.

If you notice scratches on the bottom of a beer glass it is to form the head.


Oddly, many people are familiar with the opposite with champagne. The first glass poured into a dry glass often bubbles over. It’s because the soap used make the glass have that “sticky” clean feel where your fingers don’t run smoothly over the glass. To avoid this, wet the inside of the glass and the water fills the nucleation sites and your champagne doesn’t bubble over. However, at events people think they are being served flat champagne if you do this.


My final year of Chemical Engineering was spent doing all the work for Frank’s phd on “foam”. Wow, that was exciting. Also, Frank lost his st when I proved an industry accepted model was completely wrong when scaled. Apparently, he wanted to prove the model and not push the boundaries of what was known. Frank tried to falsify data until he finally caved. That prick now has his name in some fancy publications that changed an industry. He omitted mine.

Not much to add other than Amstel glasses have the nucleation site at the bottoms of the glass - so if you ever get a flat pint, it's probably a dodgy glass.

[Fastchas]

Rusty Old-Banger said:

Fastchas said:

captain_cynic said:

Is there a reason we can't have "small" big engines. Why does a V8 need to be a massive 5L monster. We can make a decent 1.6L I4 that is better than a 2L 4.pot from 20 years ago... Why don't manufacturers make a 3.2L V8?

Is it just lack of demand or are there technological limitations?

This may not 'answer' your Q, but it's a good video to watch and very explanatory.

Yeh...sorry about that!

https://www.youtube.com/watch?v=8alrpieveDg

Edited by Fastchas on Friday 3rd May 14:43

[v9]

bodhi said:

Not much to add other than Amstel glasses have the nucleation site at the bottoms of the glass - so if you ever get a flat pint, it's probably a dodgy glass.

On a slight tangent, I think this principle is also the basis of the ‘coke and Mentos’ experiment where the surface of the sweets provides the nucleation sites for the super saturated carbon dioxide to return to gas phase rather rapidly. There’s also a bit of other stuff going on too involving equilibria, but that’s the main cause I think.

What happened in hObO’s PhD sucks and is a type of behaviour surprisingly common in academia.

[StevieBee]

Train noises.

I'm editing a video that requires the addition of generic train noises; train passing by, train pulling into station, etc. This should be a simple process of selecting said clips from any stock library. However, there is a very distinct difference in sound between UK rolling stock and that from elsewhere.

Found what should have been a spot-on clip of a train passing a level crossing but didn't sound 'right'. Sure enough, it was recorded in Spain. Another one of a station that was clearly not British...(German).

How can something so fundamentally the same sound so different when in a different geographic context.

[borcy]

Why do vehicles like, diggers, telehandlers etc now have a green strobe light as well as orange?

[Kuwahara]

captain_cynic said:

Is there a reason we can't have "small" big engines. Why does a V8 need to be a massive 5L monster. We can make a decent 1.6L I4 that is better than a 2L 4.pot from 20 years ago... Why don't manufacturers make a 3.2L V8?

Is it just lack of demand or are there technological limitations?

Honda have done it on bikes in the 60’s, I’m sure they did a 6 cylinder 250/350 or something might have done a 50cc twin as well but only for racing .

CBX 1000 was a six and Z1300 was also.

[48k]

borcy said:

Why do vehicles like, diggers, telehandlers etc now have a green strobe light as well as orange?

When flashing it shows that the operator has their seatbelt fastened.

[borcy]

48k said:

borcy said:

Why do vehicles like, diggers, telehandlers etc now have a green strobe light as well as orange?

When flashing it shows that the operator has their seatbelt fastened.

Thanks.

[Clockwork Cupcake]

Kuwahara said:

captain_cynic said:

Is there a reason we can't have "small" big engines. Why does a V8 need to be a massive 5L monster. We can make a decent 1.6L I4 that is better than a 2L 4.pot from 20 years ago... Why don't manufacturers make a 3.2L V8?

Is it just lack of demand or are there technological limitations?

Honda have done it on bikes in the 60’s, I’m sure they did a 6 cylinder 250/350 or something might have done a 50cc twin as well but only for racing .

CBX 1000 was a six and Z1300 was also.

Yamaha (or was it Honda?) made an experimental one-off 1.6L V12 as a proof-of-concept one time. But the thermal and frictional losses on 12 tiny cylinders made it non-viable. Cool concept though.

I tried to google it but came up empty, but did find a link to the 1.5L Ferrari V12
https://www.carthrottle.com/news/ferrari-once-made...

[Nethybridge]

StevieBee said:

Train noises.

How can something so fundamentally
the same sound so different when in a different geographic context.

Your ear is obviously attuned to subtle nuances, metal wheels on metal rails should sound
the same anywhere, but maybe the use of CWR , metal sleepers, superior build quality
on points and crossings can make a difference, also the trains' speed, the AVE service in Spain can achieve
193 Mph, something UK trains can only dream of.

[csd19]

Jader1973 said:

captain_cynic said:

Is there a reason we can't have "small" big engines. Why does a V8 need to be a massive 5L monster. We can make a decent 1.6L I4 that is better than a 2L 4.pot from 20 years ago... Why don't manufacturers make a 3.2L V8?

Is it just lack of demand or are there technological limitations?

Because there is no replacement for displacement.


Actually Buick had a 3.5 litre V8 - the story is that a Rover executive was visiting them and saw a prototype. Rover bought the design and that is why the first cars to use it became known as the P5B and P6B - B for Buick.

And Jaguar made a 3.2 V8 in the X308 XJ, alongside the 4.0 and 4.0 S/C versions.

[Sway]

csd19 said:

Jader1973 said:

captain_cynic said:

Is there a reason we can't have "small" big engines. Why does a V8 need to be a massive 5L monster. We can make a decent 1.6L I4 that is better than a 2L 4.pot from 20 years ago... Why don't manufacturers make a 3.2L V8?

Is it just lack of demand or are there technological limitations?

Because there is no replacement for displacement.


Actually Buick had a 3.5 litre V8 - the story is that a Rover executive was visiting them and saw a prototype. Rover bought the design and that is why the first cars to use it became known as the P5B and P6B - B for Buick.

And Jaguar made a 3.2 V8 in the X308 XJ, alongside the 4.0 and 4.0 S/C versions.

Modern engine 'equivalents' in terms of smaller than typical cylinder sizes have to be the Cosworth V12s for GMA and Aston. 333ml cylinder volume.

[Clockwork Cupcake]

Jader1973 said:

Because there is no replacement for displacement.

The phrase comes from a time when it may have been true, but it no longer is. Modern turbo-charging in conjunction with modern clever ECUs is very much a replacement for displacement. That's why large capacity engines with more than 4 cylinders are a dying breed.

Jader1973 said:

Actually Buick had a 3.5 litre V8 - the story is that a Rover executive was visiting them and saw a prototype. Rover bought the design and that is why the first cars to use it became known as the P5B and P6B - B for Buick.

Not quite. It was a production engine, but GM did not consider it a success due to various issues with it, and ceased production after only a couple of years, and so leapt at the offer when Rover wanted to buy the rights to it as it was a way of recouping some of their costs. Rover then went on to fix those issues and make the Rover V8 the success story that it was.

TVR Power further evolved it, with the final evolution being the 5L used in the Chimaera 500 and Griffith 500.

Edited by Clockwork Cupcake on Friday 3rd May 22:20

[eldar]

Clockwork Cupcake said:

Yamaha (or was it Honda?) made an experimental one-off 1.6L V12 as a proof-of-concept one time. But the thermal and frictional losses on 12 tiny cylinders made it non-viable. Cool concept though.

I tried to google it but came up empty, but did find a link to the 1.5L Ferrari V12
https://www.carthrottle.com/news/ferrari-once-made...

The Honda NR was a V4 that tried to be be a V8 - 8 valves per oval or elliptical cylinder.

https://en.wikipedia.org/wiki/Honda_NR

[Clockwork Cupcake]

eldar said:

The Honda NR was a V4 that tried to be be a V8 - 8 valves per oval or elliptical cylinder.

https://en.wikipedia.org/wiki/Honda_NR

Yes, the aforementioned d4a did an entire video on it.

https://youtu.be/uC9yKXI2A-Q

The video also makes passing reference to Honda developing a 250cc inline 6 cylinder engine that revved to 20k rpm

Edited by Clockwork Cupcake on Friday 3rd May 23:38

[Jader1973]

Clockwork Cupcake said:

Jader1973 said:

Because there is no replacement for displacement.

The phrase comes from a time when it may have been true, but it no longer is. Modern turbo-charging in conjunction with modern clever ECUs is very much a replacement for displacement. That's why large capacity engines with more than 4 cylinders are a dying breed.

Nah, fuel prices and the rise of eco loons killed off large V8s. Although in Oz they are making a comeback in the form of things like RAM, Silverado, F150 etc.

I drive 4 cars regularly:
A 1.5 I4 turbo
A 2.0 I4 turbo
A 5.7 V8 na
A 6.0 V8 na

I can assure you that there is no replacement for displacement

[captain_cynic]

Jader1973 said:

Clockwork Cupcake said:

Jader1973 said:

Because there is no replacement for displacement.

The phrase comes from a time when it may have been true, but it no longer is. Modern turbo-charging in conjunction with modern clever ECUs is very much a replacement for displacement. That's why large capacity engines with more than 4 cylinders are a dying breed.

Nah, fuel prices and the rise of eco loons killed off large V8s. Although in Oz they are making a comeback in the form of things like RAM, Silverado, F150 etc.

I drive 4 cars regularly:
A 1.5 I4 turbo
A 2.0 I4 turbo
A 5.7 V8 na
A 6.0 V8 na

I can assure you that there is no replacement for displacement

that 5.7L V8

Is that a Holden...

270 W from a 5.7L V8? Less

Really?

[Jader1973]

captain_cynic said:

that 5.7L V8

Is that a Holden...

270 W from a 5.7L V8? Less

Really?

No, more than 270 W. It has to move a car.

[V41LEY]

borcy said:

Thanks.

The reality is that most equipment comes with a lap belt, so you clunk click it and sit on the strap !

[V41LEY]

Are any bookmakers offering odds on the number of migrants who get picked up by the coastguard daily ?
Imagine a spread betting range would be most attractive ?