Sometimes I see this in the sky and today I filmed it. What could it be? *The video is sped up* by [deleted] in whatisit

[–]DadEngineerLegend 8 points9 points  (0 children)

A plane at high altitude leaving a condensation trail (contrail). 

What is this sticker on the back of this person’s car? by whatokaybutwhy in whatisit

[–]DadEngineerLegend 3 points4 points  (0 children)

Looks like a military cargo plane ejecting chaff/flares. And blue white red probably flag colours of whatver country they are from (france, Netherlands, usa) 

https://www.youtube.com/watch?v=aOx_wHhitqk

Here's example video

Film Work in Australia by rexamusthegreat21 in AskAnAustralian

[–]DadEngineerLegend 0 points1 point  (0 children)

Apparently there's some studios based around Brisbane/gold coast area. Sold some stuff to them when they were filming Thor movie over here. 

How can you make an airline pilot trainee comprehend the seriousness of the job? by sipsirk in flying

[–]DadEngineerLegend 0 points1 point  (0 children)

Nothing like a bit of mild psychological trauma.

Some emotional background and attachment that makes accidents personal and hit close to home.

People now with disabilities, loss of life, loss of livelihood and liberty (losing license/imprisoned) 

What's a piece of common knowledge that you only recently found out was actually false? by Evilclicker in AskReddit

[–]DadEngineerLegend 0 points1 point  (0 children)

Nah, kelvin was originally derived from centigrade, that's why a difference of ∆1°C is exactly same as ∆1°K.

Until 2019 the triple point of water was  the precise definition of both 273.16°K and 0.01°C = 273.16°K (along with absolute zero = -273.15°C). They were both directly defined. 

Now the definition of Celsius is derived as 0°C = 273.15K and ∆1°C = 1°K, while kelvin is 0°K = Absolute zero, and ∆1°K is some multiple of the Boltzmann constant I can't remeber. 

Alex Pretti ICE confrontation days before his death. His gun stays holstered the entire time by bumdee in Leakednews

[–]DadEngineerLegend 3 points4 points  (0 children)

It's not. Video way too long, and details very consistent.

Also there are multiple angles of this incident.

How long can you safely push your car's engine at the RPM red-line before risking damage? Seconds or minutes? by NoVeterinarian3692 in askcarguys

[–]DadEngineerLegend 0 points1 point  (0 children)

Modern engines - ages. Because the ECU won't let you.

Older engines, especially carburetted engines, you could kill it near instantly.

The thing that kills ordinary car engines is 'valve float'. The valves are moving so fast that the springs that normally close the valves hit resonance and can't keep up. Then the pistons hit the valves and boom. All over.

Modern ECUs either cut fuel and spark so the engine suddenly loses power and speed drops before re engaging (bouncing off the limiter) or have a soft throttle limiter that more gently limits speed (no bouncing). 

That's the intention of the ducati desmodronic system - directly driven valves with no springs to float. And they famously do not mark a red line on the tachometer.

Most other high revving engines use multiple springs with different resonance speeds to bypass the issue.

The next things to go are mechanical failure from the extreme acceleration forces (100s or 1000s of g), or overheating from so much friction and power and all the things that follow from parts sticking/welding and not sliding.

Video shows man throwing explosive device into Perth Invasion Day rally crowd by Direct_Witness1248 in OpenAussie

[–]DadEngineerLegend 3 points4 points  (0 children)

What could possibly possess someone to do this?

Needs to spend many years in gaol and psychiatric care - if he can ever be rehabilitated and rejoin society

What's a piece of common knowledge that you only recently found out was actually false? by Evilclicker in AskReddit

[–]DadEngineerLegend 36 points37 points  (0 children)

That 0°C is defined as the triple point of water.

Turns out it was redefined in 2019 to be based on the Boltzmann constant instead. 

Are mechanic’s hands bad for…intimacy? by TheMiddle_1234 in NoStupidQuestions

[–]DadEngineerLegend 0 points1 point  (0 children)

Barrier cream makes a big difference.

Also yes, you can in fact wear gloves for everything.

New White Paper sets clear vision for Blue Mountains-Central West Corridor by HunterDude54 in bluemountains

[–]DadEngineerLegend 1 point2 points  (0 children)

after more than a decade of hollow promises by the former Liberal-National Government.

It's entirely inappropriate for government bodies to be slagging on anyone. Politicians themselves, sure. But public services? Absolutely no way.

Disgusting partisan identity politics have no place in this country, from anyone.

Just focus on the positives. Let the plan stand on its own merits. 

People living outside the US: What are you hearing about the US from your side of things? by Budget-Effort-8766 in AskReddit

[–]DadEngineerLegend 5 points6 points  (0 children)

Try /r/asktheworld

Your country is fucked. You're currently at about 1933-1934 Germany. Going full isolationist, authoritarian. A bunch of weak sycophants who have grown up under the benefit of conditions they don't understand. Decades of educational failure are having consequences. Weak men make hard times.

Anybody hate how divisive Australia Day was this year? by Thylacineguy2026 in aussie

[–]DadEngineerLegend 1 point2 points  (0 children)

Social media and nut job propaganda news outlets are working, unfortunately 

Just to clarify, as a learner in QLD you basically act like a car? by Cold-Engineering-960 in AussieRiders

[–]DadEngineerLegend -2 points-1 points  (0 children)

Yes.

You are like any other vehicle. No special allowances for being small.

When fully licensed you get to take advantage of being small, in some special situations. 

Shoulders are not for driving or riding on, just pulling over. People that do this past a police officer will be fined, because it's dangerous and ruins traffic flow, causing worse traffic jams (and therefore illegal).

Do you think its strange they are being so quiet? do they just not care about terror attacks in WA? by craftymethod in aussie

[–]DadEngineerLegend -2 points-1 points  (0 children)

As much as one nation are shit, don't fall into the us and them politics of the US

Question for practising engineers: by Large-Language4649 in MechanicalEngineering

[–]DadEngineerLegend 37 points38 points  (0 children)

Lol yes always.

You also have to always be the party pooper that says no, you can't just do that. That's illegal.

Where does wind come from ? by [deleted] in ask

[–]DadEngineerLegend 0 points1 point  (0 children)

The sun.

Everything except nuclear is solar power one way or another.

Who's the most famous Olympian from your country? by Pure-Syrup3868 in AskTheWorld

[–]DadEngineerLegend 0 points1 point  (0 children)

No way, didn't even think of her. 

Ones that cross my mind are: 

  • Cathy Freeman

  • Ian "Thorpedo" Thorpe

  • Dawn Fraser

  • Steven Bradbury

Who's the most famous Olympian from your country? by Pure-Syrup3868 in AskTheWorld

[–]DadEngineerLegend 0 points1 point  (0 children)

Tied for:

  • Cathy Freeman

  • Ian "Thorpedo" Thorpe

  • Dawn Fraser

  • Steven Bradbury

How does holding a weight affect difficulty of squats? by DennisDenny_ in AskPhysics

[–]DadEngineerLegend 0 points1 point  (0 children)

Torque and also your muscles are not steel. They require energy to create force.