h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I'm sure this has been asked before, but I don't know if it was ever answered. Either way, it is a matter of grave import, and it's keeping me awake at night.

Apparently if you put a blob of Marmite on a plate and whack it with a spoon it turns white (the Marmite). Which is kind of .

Does anybody know why?

A subsidiary question may be who found out that Marmite does this and what they thought they were doing, but I don't really care about that.

hmmmmmmmmm.........

http://www.bbc.co.uk/radio4/hometruths/marmitebeating.shtml

See what I mean?

Man... that's crazy.

Marmite is almost certainly a non-Newtonian fluid. This means it has properties that at times can appear to be liquid and other times solid without a normal change of state/phase. Shock (engineering not psychological!) is one of the things known to trigger this behaviour. Normally marmite flows slowly but, if struck suddenly, it might flip into brittle solid mode and fracture. A myriad of fine fracture lines usually looks white (light scattered off all the boundaries).

Now, I'm not saying the marmite anecdote is true (and I don't have the urge to get a pot right now), but it is theoretically possible for this phenomenon to have occurred as described.

I'm not sure which is stranger - the question or the fact that someone can come up with a plausible scientific explanation...

SEF

What's marmite?

What's Marmite? Youdon't know what you're missing (well obviously, because you asked) - A184097.

I just tried it out - it worked!

I like your explanation, SEF - it doesn't seem to change in consistency and taste - it just goes lighter - so I don't know if it's solidifying. It splats satisfyingly - it doesn't go thick like custard does when you hit that (I've tried that, too).

down with marmite! Long live Vegemite

Does Vegemite go white? Not that it matters, because I've tried it on toast and I'll stick to my Marmite, thank you!

I've never tried to find out. It just tastes better and has a better consistency

Well, I think you should. Or somebody Australian should (I trust you are Australian - there's no other excuse for preferring Vegemite to Marmite ).

They're both yeast extracts - it could be relevant. I'd try it myself, but I'd have to buy a whole jar of Vegemite and I don't like it!

"I trust you are Australian" them there is fighting words

I'll wait for someone else to try it as vegemite is too precious to waste on beating

Doesn't seem to work with vegemite - though I tried it on a chopping board not a plate, because I didn't want to break the plate. All I got was very small bits of vegemite over the kitchen.

B

I'm not going to hazard any more guesses!

None of which explains the white-going phenomenon. Unless SEF's explanation is the right one - it sounds pretty good, except the Marmite doesn't seem to do anything resembling going solid.

When you beat custard - the strong mixture (a couple of spoonfuls of custard powder to about the same amount of milk) before you add the bulk of the milk - it goes all stiff for a moment, which is quite . I gather this is because it's thixotropic, although all I know about thixotropic fluids is that they act like this. I recommend you to try it out - it's quite interesting. Well, it's a bit interesting.

Simulpost!

It sounds like you may have hit it rather too hard, Ben. I used a plate for the Marmite - I just tapped it fairly lightly with a teaspoon. Hard enough to splat a little on the worksurface, but not so hard as to spray it all over me and the kitchen (and the who is following the experiments with interest).

marmite goes hard when exposed to air for a period. It goes green and fury rather quickly. You could use it instead of agar in highschool biology.

Well I beat it soft and I beat it hard! I am almost but not quite curious enough to go out and buy some marmite now.

You are right, custard powder is wierd, and how can a pink powder make a yellow liquid?

B

well it's half an hour till lunchtime here in NZ. I may try it