Ketchup is a non-Newtonian fluid

No, ketchup is shear-thinning, meaning it’s less solid when under stress.

Just because it's non-Newtonian doesn't mean it's identical to oobleck. All it means is that it's not Newtonian.

Besides, you can run on water (or at least, some lizards can) at high enough speeds, though I'm not sure if water still behaves Newtonian in those situations.

Braniac is back? I miss that show

Unlikely - a spoon sinks in it.

Yeah, I kept doing that for my copper pots once a month with different things: ketchup, bar keepers friend, etc. It was never an easy wipe away experience like I imagined.

Cornstarch water is shear thickening, wheras ketchup is, I assume, shear thinning.

I don't have any copper pots, but vinegar is my go-to cleaner around the house. Try adding about 5 to 10 percent by volume to a fully flooded pot and let it soak for an hour or two, bring to a boil of you are impatient. This works wonders for my pots, shower, sink, etc.

Bar Keepers Friend is great for most copper/metal cookware and other things around the house like sinks as well.

As someone who can use almost an entire bottle of Heinz 57 on an order of French fries, this made me laugh. Whenever I ask for ketchup at a restaurant and they bring me “only” 4 packets, I do my best not to roll my eyes in disappointment because I know how ridiculous I am.

My Grandma said:

Silly silly ketchup bottle

First a little

Then a lottle

Same meaning :)

I find this with some brands but not with others, so assumed it was a solved problem and some manufacturers are just cutting corners on bottle design. Is this not the case?

I thought the article's reminiscing a bygone era now that the plastic bottle have sort of won?

I find them perfectly adequate to be honest, the full on red ones, or the upside down supermarket types...

Perhaps it's because the vinegars can settle out, so you want to shake the bottle? You can't do that with a tube.

It's probably a sizing issue, given how much ketchup gets used, you'd need a lot of toothpaste tubes, and making them huge would lead the the same issues as you get with other containers.

There's no need to change the packaging, it's a solved problem that hasn't been implemented for monetary reasons.

https://news.mit.edu/2015/liquiglide-condiments-0630

Hold the bottle in one hand as normal and instead of hitting the back of it, hit the underside of your wrist instead ie hitting upwards not downwards.

The bottle and the liquid are two "things" which are loosely connected together via "fluidy" friction etc. When you hit the back of the bottle, you are effectively trying to force the bottle around the ketchup that is trying to dribble out downwards. Gravity is trying to drag the ketchup out. The impact will make the ketchup a bit more liquid. Some ketchup will flow. We know it does because it does!

When you make an impact upwards, then you are making the bottle try to leave the ketchup behind (inertia). Combine that with gravity and the impact liquidising the ketchup and more of the stuff comes out.

There are other considerations such as the shape of the bottle. If you want the fastest deposition then probably something like a conical bottle with 45deg at the apex or whatever minimises internal surface area for a given contained volume. However that will dump an entire bottle in one go and you will impale your hand if you tap the back of it. It's quite a tough problem. The squeezy jobbies seem like a bit of a cop out somehow!

Assume a spherical, infinite ketchup bottle. Be careful with your aim.

I've always heard this is by design.

Don't hit the bottle. Keep the lid on, invert, and shake vigorously, until flow. Then remove the lid and shake gently to apply.

> it should have occured to me that combining ketchup with thickeners might be a well-researched topic in food science already.

There were articles during the Gulf War about armed forces being unhappy with thin ketchup, so they brought in standards for flow rate. (I'm struggling to find those for some reason).

Here's the FDA spec for consumer ketchup.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFR...

> (b) Quality. (1) The standard of quality for catsup is as follows: The consistency of the finished food is such that its flow is not more than 14 centimeters in 30 seconds at 20 deg.C when tested in a Bostwick Consistometer in the following manner: Check temperature of mixture and adjust to 20+/-1 deg.C. The trough must also be at a temperature close to 20 deg.C. Adjust end-to-end level of Bostwick Consistometer by means of the spirit level placed in trough of instrument. Side-to-side level may be adjusted by means of the built-in spirit level. Transfer sample to the dry sample chamber of the Bostwick Consistometer. Fill the chamber slightly more than level full, avoiding air bubbles as far as possible. Pass a straight edge across top of chamber starting from the gate end to remove excess product. Release gate of instrument by gradual pressure on lever, holding the instrument down at the same time to prevent its movement as the gate is released. Immediately start the stop watch or interval timer, and after 30 seconds read the maximum distance of flow to the nearest 0.1 centimeter. Clean and dry the instrument and repeat the reading on another portion of sample. Do not wash instrument with hot water if it is to be used immediately for the next determination, as this may result in an increase in temperature of the sample. For highest accuracy, the instrument should be maintained at a temperature of 20+/-1 deg.C. If readings vary more than 0.2 centimeter, repeat a third time or until satisfactory agreement is obtained. Report the average of two or more readings, excluding any that appear to be abnormal.

Would make a magnificent youtube video.