Reel Physics: The Rock - Trolley Car Launch

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Techno Squidgy:
It would make no sense to teach potential future scientists in a format that the scientific community at whole doesn't use. It just makes sense to me to have a show about physics (and a rather in-depth show about physics) in the units of physics.

I wouldn't put too much faith in the American school system if I were you..

I'll just leave this right here for you:

http://now.msn.com/zack-kopplin-fights-louisiana-creationism

Draconalis:

Techno Squidgy:
It would make no sense to teach potential future scientists in a format that the scientific community at whole doesn't use. It just makes sense to me to have a show about physics (and a rather in-depth show about physics) in the units of physics.

I wouldn't put too much faith in the American school system if I were you..

I'll just leave this right here for you:

http://now.msn.com/zack-kopplin-fights-louisiana-creationism

What.

Creationism isn't science! The only time creationism should be taught is in church or a religious/social studies class.

Federico Goldzweig:
Ok guys just linked my account just to comment, and ask you to do this scene from TORQUE
http://www.youtube.com/watch?v=mxoVMuWkluA

you've probably been asked this before

I would like to see this covered just for the amount of heating and G-forces that would occur at such a high speed. And the G-forces by going from that high speed back to zero in about a second...

Federico Goldzweig:
Ok guys just linked my account just to comment, and ask you to do this scene from TORQUE
http://www.youtube.com/watch?v=mxoVMuWkluA

you've probably been asked this before

WHAT IN THE HOLY HELL DID I JUST WATCH???????????

Jason Dean
REEL PHYSICS

I'd accuse them of going after low hanging fruit with this one, but not nearly hanging so low as that trolley at it's apex.

Federico Goldzweig:
Ok guys just linked my account just to comment, and ask you to do this scene from TORQUE
http://www.youtube.com/watch?v=mxoVMuWkluA

you've probably been asked this before

lol. what a crazy scene. pretty much everything is way off reality. i think i have to get this movie just to see these crazy action moments.

@ reel physics
as someone has mentioned, you will have lots of scenes from the movie "shoot em up". just everything is is off reality. maybe you should do the scene were clives shoots everyone in midair and all the bodies just end up in a radius of 10m.

Metalrocks:

Federico Goldzweig:
Ok guys just linked my account just to comment, and ask you to do this scene from TORQUE
http://www.youtube.com/watch?v=mxoVMuWkluA

you've probably been asked this before

lol. what a crazy scene. pretty much everything is way off reality. i think i have to get this movie just to see these crazy action moments.

@ reel physics
as someone has mentioned, you will have lots of scenes from the movie "shoot em up". just everything is is off reality. maybe you should do the scene were clives shoots everyone in midair and all the bodies just end up in a radius of 10m.

Thing is Shoot em up is suposed to be highly unrealistic physics, its supposed to be wacky like a looney tunes cartoon, TORQUE came about witha straight face, they just wanted to overdo 4FAST 4FURIOUS FAST FURIOUSER

here is another one http://www.youtube.com/watch?v=vBCeFJ66oRM

Techno Squidgy:

Draconalis:
Meters and Celsius? Where did my feet and Fahrenheit go?

IMPERIAL HAS NO PLACE IN SCIENCE, DAMN IT!
But seriously, Imperial isn't really suitable for this show in my opinion. Considering this is regarding physics I think it's best to keep it in SI units. We use both Imperial and Metric in the UK and the general rule is imperial for guesswork and big scale stuff, metric for precision and science.
That and pretty much nowhere outside of the US uses Imperial any more.

EDIT: A pint will always be a pint however!

Well, unless if you are counting in some fundamental units like based on the diameter of a hydrogen atom, SI are just as arbitrary as Imperial.

I mean an alien physicist would be just as flummoxed by someone working in feet as someone working in meters.

Yes, SI units may fit with each other in changes in powers of 10 but that is only useful because we count from 0-9. If we used a dozenal system (as was almost adopted in the French Revolution instead of what would become SI units) then we'd count 1-2-3-4-5-6-7-8-9-X-E-10.

Then things like 12 inches to the foot fit just fine as do the minutes and hours of the day.

The important thing is consistency and knowing what units you ARE working in.

I'd personally have been much happier if Imperial units like the Foot were decimalised or even better if the clock had been wound back if we'd switched over to dozenal back in 18th century. Then a 1000foot in Dozenal would be

Draconalis:

And I have literally no idea how hot 900 C is... which is my biggest complaint.

My weather reports all come in Celsius but I too don't have any idea how hot 900 Celsius is either.

See once you get much beyond temperatures you work with it's meaningless. I mean I'd recognise 200C as that's the temperature of my oven, I've been near that heat and seen what happens to things put into that heat. I mean what does quadrupling that temperature mean?

It's like banal facts that the surface of the sun is so many millions of degrees hot, it's meaningless, it's not in any immediately relatable terms and I think most lack the education to know auto-ignition temperatures.

I think any time you quite extreme temperateness you need to put onto a scale of "this temperature will do this thing" as in "auto-ignition of wood" or "Vaporisation of aluminium" which is 2500 C which is quite an image, seeing your sturdy bike get vaporised into a CLOUD OF METAL is a good indication of how damn hot something it. Also the colour it will glow at.

For example 900 C is about the temperature things begin to glow red hot and most rocks will melt. So Lava, that would be 900 degrees. I think that's relatable, we've all likely seen footage of lava from volcanoes, how it's heat affects things.

My favourite property of Lava is that it's still really rock. It looks and moves like treacle but treacle is pretty low density and never sets very hard. Lava is not only hot it's very dense for most fluids we know, it's not just going to burn everything it rolls over it's going to crush it and seal it under thick thick igneous rock. And also, because of it's density, things that won't melt or burn will float on Lava.

Treblaine:
Well, unless if you are counting in some fundamental units like based on the diameter of a hydrogen atom, SI are just as arbitrary as Imperial.

I mean an alien physicist would be just as flummoxed by someone working in feet as someone working in meters.

Yes, SI units may fit with each other in changes in powers of 10 but that is only useful because we count from 0-9. If we used a dozenal system (as was almost adopted in the French Revolution instead of what would become SI units) then we'd count 1-2-3-4-5-6-7-8-9-X-E-10.

Then things like 12 inches to the foot fit just fine as do the minutes and hours of the day.

The important thing is consistency and knowing what units you ARE working in.

I'd personally have been much happier if Imperial units like the Foot were decimalised or even better if the clock had been wound back if we'd switched over to dozenal back in 18th century. Then a 1000foot in Dozenal would be

Interesting points, but in a further reply to Draconalis I said

It just makes sense to me to have a show about physics (and a rather in-depth show about physics) in the units of physics.

so I'm not entirely certain what point you're trying to make here. Whether or not the units are arbitrary is irrelevant (though I believe all the units are tied to physical constants if not directly then through the other units), it's an international system with the purpose of unifying the scientific world.

I'm gonna suggest something that I doubt anyone else has...

There are 2 particular scenes in The Jackal (1997) - starring Bruce Willis and Richard Gere - that I want to know if it could possibly happen...some spoilers ahead

Ryoma_Nagare:

Metalrocks:

Federico Goldzweig:
Ok guys just linked my account just to comment, and ask you to do this scene from TORQUE
http://www.youtube.com/watch?v=mxoVMuWkluA

you've probably been asked this before

lol. what a crazy scene. pretty much everything is way off reality. i think i have to get this movie just to see these crazy action moments.

@ reel physics
as someone has mentioned, you will have lots of scenes from the movie "shoot em up". just everything is is off reality. maybe you should do the scene were clives shoots everyone in midair and all the bodies just end up in a radius of 10m.

Thing is Shoot em up is suposed to be highly unrealistic physics, its supposed to be wacky like a looney tunes cartoon, TORQUE came about witha straight face, they just wanted to overdo 4FAST 4FURIOUS FAST FURIOUSER

here is another one http://www.youtube.com/watch?v=vBCeFJ66oRM

lol, yeah, i have noticed it when i watched it. i really had a glorious time watching it. i was laughing all the time at every crazy action scene.

thanks for the link. again really crazy. amazing how you can break the rules of reality in a movie.

Techno Squidgy:

Treblaine:
Well, unless if you are counting in some fundamental units like based on the diameter of a hydrogen atom, SI are just as arbitrary as Imperial.

I mean an alien physicist would be just as flummoxed by someone working in feet as someone working in meters.

Yes, SI units may fit with each other in changes in powers of 10 but that is only useful because we count from 0-9. If we used a dozenal system (as was almost adopted in the French Revolution instead of what would become SI units) then we'd count 1-2-3-4-5-6-7-8-9-X-E-10.

Then things like 12 inches to the foot fit just fine as do the minutes and hours of the day.

The important thing is consistency and knowing what units you ARE working in.

I'd personally have been much happier if Imperial units like the Foot were decimalised or even better if the clock had been wound back if we'd switched over to dozenal back in 18th century. Then a 1000foot in Dozenal would be

Interesting points, but in a further reply to Draconalis I said

It just makes sense to me to have a show about physics (and a rather in-depth show about physics) in the units of physics.

so I'm not entirely certain what point you're trying to make here. Whether or not the units are arbitrary is irrelevant (though I believe all the units are tied to physical constants if not directly then through the other units), it's an international system with the purpose of unifying the scientific world.

My point is it's good to see units for what they are: arbitrary.

Okay, the meter isn't COMPLETELY arbitrary, it's based on the size of the earth, but why this planet? Why measured in that way? Well, this historical reason was it just so happened to that that science was in vogue at the time of the French Revolution. Maybe f it had been later it would have been based around the speed of light. I think it's good to have an international agreement on how long a meter actually is, but it gives an illusion that this unit chosen and agreed on by humans has any fundamental significance.

An important thing for pop-science show like this is you must have appreciable units otherwise it doesn't really mean much.

For example, what's the point in saying something is either 900 celcius or 1650 Farenheit?!? No one really knows how hot either of those are as no one really knows what is at that temperature or what happens at that temperature. So give it in the unit "The temperature of red-hot lava".

Also different units are used for different things.

Although I work by distance and speed in kilometres, I still gauge people's height in feet, because it just works better gauging human height in 5 or 6 feet and fractions within rather than 1.79 metres or 1.88 metres. And it's not like it's impossible to convert these units and the units should ALWAYS be stated.

Like in this video if the explosion had pushed the tram 25 millimetres off the ground, wouldn't it be more expedient just to say it rose an inch off the ground?

Treblaine:
My point is it's good to see units for what they are: arbitrary.

Okay, the meter isn't COMPLETELY arbitrary, it's based on the size of the earth, but why this planet? Why measured in that way? Well, this historical reason was it just so happened to that that science was in vogue at the time of the French Revolution. Maybe f it had been later it would have been based around the speed of light. I think it's good to have an international agreement on how long a meter actually is, but it gives an illusion that this unit chosen and agreed on by humans has any fundamental significance.

An important thing for pop-science show like this is you must have appreciable units otherwise it doesn't really mean much.

For example, what's the point in saying something is either 900 celcius or 1650 Farenheit?!? No one really knows how hot either of those are as no one really knows what is at that temperature or what happens at that temperature. So give it in the unit "The temperature of red-hot lava".

Also different units are used for different things.

Although I work by distance and speed in kilometres, I still gauge people's height in feet, because it just works better gauging human height in 5 or 6 feet and fractions within rather than 1.79 metres or 1.88 metres. And it's not like it's impossible to convert these units and the units should ALWAYS be stated.

Like in this video if the explosion had pushed the tram 25 millimetres off the ground, wouldn't it be more expedient just to say it rose an inch off the ground?

I'm not really seeing why the whole arbitrary thing is such a big deal (also from wikipedia: "Since 1983, it has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second").It is a standard agreed upon internationally and used by scientists across the glove, which I think gives it significance.

I disagree with you on not saying 900C or 1650F because no one understands that. Why not say, "900C, which happens to be about the temperature of lava"? You can be precise and give context.

Personally I'd prefer it if they were consistent with their units. Jumping about between imperial and metric is disorienting. And as I have previously said, SI units are the units of science.

pearcinator:
I'm gonna suggest something that I doubt anyone else has...

There are 2 particular scenes in The Jackal (1997) - starring Bruce Willis and Richard Gere - that I want to know if it could possibly happen...some spoilers ahead

I'd imagine with The Jackal you'd have to have a bullet the size of a grapefruit to come anywhere near the mass needed to accomplish that. No matter how fast the bullet is going it just doesn't have the mass to impart on it's target. However I'm not a physicist so I'd welcome them testing that as well so see if my hunch is indeed correct.

So far the weakest episode.

How about a scene from Crank?

Like the last one where he hit's the ground and is still alive.

Anyone knows he would be dead, but it would be fun to hear how dead he actually should be! (as in gravy-dead or minced meat-dead)

Treblaine:

My weather reports all come in Celsius but I too don't have any idea how hot 900 Celsius is either.

See once you get much beyond temperatures you work with it's meaningless. I mean I'd recognise 200C as that's the temperature of my oven, I've been near that heat and seen what happens to things put into that heat. I mean what does quadrupling that temperature mean?

It's like banal facts that the surface of the sun is so many millions of degrees hot, it's meaningless, it's not in any immediately relatable terms and I think most lack the education to know auto-ignition temperatures.

I think any time you quite extreme temperateness you need to put onto a scale of "this temperature will do this thing" as in "auto-ignition of wood" or "Vaporisation of aluminium" which is 2500 C which is quite an image, seeing your sturdy bike get vaporised into a CLOUD OF METAL is a good indication of how damn hot something it. Also the colour it will glow at.

For example 900 C is about the temperature things begin to glow red hot and most rocks will melt. So Lava, that would be 900 degrees. I think that's relatable, we've all likely seen footage of lava from volcanoes, how it's heat affects things.

My favourite property of Lava is that it's still really rock. It looks and moves like treacle but treacle is pretty low density and never sets very hard. Lava is not only hot it's very dense for most fluids we know, it's not just going to burn everything it rolls over it's going to crush it and seal it under thick thick igneous rock. And also, because of it's density, things that won't melt or burn will float on Lava.

While I really do appreciate the context and information you're gave me here, (no sarcasm) I don't know what 280C is either... I just didn't remember what the first figure was, when I commented on the 900 (I had to go to the scene just now in order to pull the 280)

It's not the inexperience of something insanely hot that I'm referring to. It's the fact that I can understand Fahrenheit, but not Celsius. 536F is something I can relate to, because like you, I too have an oven. 280C, what does that mean? Unno...

I stand by F as the superior temperature system, because there are far more degrees of measurement between 32 and 212 than there are 0 and 100. I understand that C can be just as accurate as F when using decimals... but I never see decimals when people talk about C.

Techno Squidgy:

I disagree with you on not saying 900C or 1650F because no one understands that. Why not say, "900C, which happens to be about the temperature of lava"?

Why not, "1650F, which happens to be about the temperature of lava"?

It's the better system anyway.

Techno Squidgy:
I'm not really seeing why the whole arbitrary thing is such a big deal (also from wikipedia: "Since 1983, it has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second").It is a standard agreed upon internationally and used by scientists across the glove, which I think gives it significance.

I can see that, but it's even more obvious now. I mean a number like 1/299'792'458th of a second? What an irregular number.

If I WERE going to define a unit by how far light goes through a vacuum you wouldn't use that number.

Assuming you'd work in seconds (which is arbitrary, but at least it has the advantage in that there aren't any competing units) what fraction would you use? 1 millionth? No, even in a millionth of a second light goes far too far to have a workable unit how about this, 1 billionth. A nanosecond. A light nanosecond, that seems about right.

Now how far is a light nanosecond... almost exactly 1 foot.

Check it yourself, you can do it yourself, just convert speed of light in meters per second to feet-per-second

299 792 458 metres-per-second = 983 571 056.43 feet-per-second

That puts the distance 1 light nano-second within 1.67% of a foot. Now the inch has been redefined by that amount enough times before.

So if you think about it:
1) if you are going to have a unit based on powers of 10 and 1000 (kilo, mega, giga and milli, micro, nano)
2) based around the unit time "a second"
3) to do with the fundamental property of light travelling through a vacuum

Then by cosmic coincidence, we should use feet, and Kilo-feet, and cubic feet. If the "new unit" HAD been defined by the distance light travels in a fraction of a second, if they found it was THAT CLOSE to a Foot, why would they have a "new unit" that's almost identical to a foot? No, they'd just change the foot.

The mile can feck off, 5280 feet? I also think 1000feet (a Kilofoot, kf) is more relatable as it just so happens that 1000 feet (or 304 meters) is the the average maximum distance a person with 20-20 vision can see a standing person on a clear day, this was discovered by the military who were in the business of knowing such things.

And also, all airflight is conducted in feet, and in english. Even in Europe. Maybe this was down to US and British airpower at the end of WWII, who did everything in feet. There, metric is not universal.

So I like the foot. I don't like miles.

Oh and if you are too used to Kilometres per hour here's the best part, feet/sec is almost the same speed.

And I think feet/sec is a HECK of a lot more useful unit for how we approach speed which is highly variable and to do with safety.

Miles or kilometers per hour meant something when people would be walking for HOURS at a pretty steady pace.

But speed today is most seen in vehicles as a safety thing. You can go twice as fast on some roads as opposed to others, but nothing gives a greate impression of speed than how far you move in just a second. Because if your reaction and breaking time is one second, or two, you know you have to leave that much space in front of you.

But with miles per hour, you have to do some conversions to appreciate how far you'll actually move in a second.

You just have to really think about what units ARE and what's useful for this modern world.

Like for example if you know someone is 50 million feet away (about 10'000 miles away) and you are connecting to them through wired communications, you know you cannot possibly get a better ping (internet connection) than 100 milliseconds, as a round trip would be 100 million feet, which is obviously 10% of 1 billion, 10% of 1 second is 100 milliseconds. Now it can never be quicker than that, no matter how much computers improve in speed or a vacuum based light communication.

Anyway, feet, nano-light-seconds. Love em.

I say, save the foot! It's a brilliant unit, and I think it's been horribly neglected by SI.

Draconalis:

While I really do appreciate the context and information you're gave me here, (no sarcasm) I don't know what 280C is either... I just didn't remember what the first figure was, when I commented on the 900 (I had to go to the scene just now in order to pull the 280)

It's not the inexperience of something insanely hot that I'm referring to. It's the fact that I can understand Fahrenheit, but not Celsius. 536F is something I can relate to, because like you, I too have an oven. 280C, what does that mean? Unno...

I stand by F as the superior temperature system, because there are far more degrees of measurement between 32 and 212 than there are 0 and 100. I understand that C can be just as accurate as F when using decimals... but I never see decimals when people talk about C.

Oh, tell me about it. It's an utter shambles the way Farenheit has been treated.

it's not like Celsius is any better, both are just as arbitrary and made to look ridiculous next to Kelvin which actually has some foundation in fundamental properties of ALL materials. But no one uses Kelvin, they may work in Kelvin as it's definitely less cumbersome in equations but they measure in Celsius and give the answers in Celsius.

I think if we aren't going to use Kelvin (and we should) then Fahrenheit is a much more "human" scale.

Knowing that 100 F is close to body temperature, that's good to know, because that's the point where you know ambient temperature has gone above the point where your ability to cool down is greatly diminished. I mean your body produces heat just in it's vital processes in staying alive, being put in a temperature above your critical maximum temperature, that's an immediate threat to your survival. You need to sweat a LOT and be able to sweat to not die.

Okay, Celcius has zero degrees that's pretty much spot on with 0 being the temperature water freezes. I know, not salt water but rain water is distilled. But that isn't so useful. It doesn't need to be freezing for you to get hypothermia this is SUCH an important point and has lead to many people dying in the wilderness because it was cold but not technically cold enough for ice to form, yet high wind or wetness caused them to lose body heat quicker than they could regain it.

So Farenheit, my favoured scale for human temperatures.

And whoever said "they should work in Celsius for SI consistency" no, they should work in Kelvin that NO ONE can relate to.

I mean if your doctor said you had a temperature of 300 Kelvin, would you be worried? I don't even know.

People say Celsius has a foot in because each degree step is the same as Kelvin, but if you're going to convert you're going to have to convert.

I don't think you can win on this, when it comes to temperatures: science says Kelvin, but Fahrenheit is still so common, much more common than imperial units, there is no way you can win choosing either Fahrenheit or Celsius.

And come on, what kind of book name is "232 Celsius"?

Treblaine:

I mean if your doctor said you had a temperature of 300 Kelvin, would you be worried? I don't even know.

I read your entire post... but I have to say... this is the only line that mattered.

I laughed so hard when I read it.

First off I want to say that I have greatly enjoyed all of your videos and have not had any problems with your reasoning so far. You guys definitely do your research.

That having been said, I think you might have oversimplified this scenario a bit. I don't know much about the physics of gas explosions specifically, but I do know that the detonation of a high explosive causes the air surrounding the explosive to be compressed into a shock front that has a much higher density than the surrounding air. These fronts can also travel at much higher than Mach 1.

I do not know if gasoline has a tendency to act as a high explosive or not, and this might not make an appreciable difference considering how ludicrous this scenario is. But, it might be worth a look.

Just a quick note for the creators, since they appear to read these (You guys are pretty awesome). We don't only care about whether something is feasible or not. It is very entertaining to find out exactly HOW unfeasible something is. Proving that this scene is impossible is not as entertaining as demonstrating that the explosion would raise the car a millimeter, assuming some rather crazy, perfect case assumptions. Also, it's entertaining to figure out what would need to be true for a scenario to work.

This has definitely become part of my weekly watching schedule

Wow, that's one big millimeter! Anyone who needs help with the units, 1.17315099 millimeters = 0.04618704685039 inches. Yeah.

The much harder task would be to find a Michael Bay scene with real physics, I think.

Why is metric used instead of imperial for scientific purposes? Simple, Metric has a better scale.

As an example, let's do length and we'll start with imperial:

12 inches = 1 foot
3 feet = 1 yard
1760 feet = 1 mile
1.150779448 miles = 1 nautical mile

Terribly uneven and almost random (note the "almost", i'll go into it later). As well there's too large of a gap between scale points that is measured by either fractions which are just as uneven or decimal which produces some really odd numbers (see the miles -> nautical mile above)

Now let's look at metric and SI therewith length:

10 millimeters = 1 centimeter
10 centimeters = 1 decimeter
10 decimeters = 1 meter
10 meters = 1 decameter
10 decameters = 1 hectameter
10 hectameters = 1 kilometer

Steady, even, and constant in it's measurements. you can measure and convert easily between one scale type and another. With metric, so long as the original measurement is accurate, you can scale up or down with accuracy just by moving the decimal place. That is impossible with imperial and requires an elaborate formula to do the conversion.

This also doesn't factor in some imperial measurements being used incorrectly (pounds and the like being used interchangeably with grams despite the former measures weight and the latter measures mass) or not making sense (what's the point of reference for Fahrenheit for example).

So where did imperial come from? Largely tradition. The "foot" is literal, an inch was the measurement of a finger digit, a yard was the measurement of a stride, etc. Metric and SI subsequently was devised to have a simple, accurate, easy to convert measurement system for objective measurements. Similar systems to metric were used by alchemists for centuries in fact until metric became standardized.

Put simply, Metric and SI is used because though it's standardized and accurate.

Xanadu84:
Just a quick note for the creators, since they appear to read these (You guys are pretty awesome). We don't only care about whether something is feasible or not. It is very entertaining to find out exactly HOW unfeasible something is. Proving that this scene is impossible is not as entertaining as demonstrating that the explosion would raise the car a millimeter, assuming some rather crazy, perfect case assumptions. Also, it's entertaining to figure out what would need to be true for a scenario to work.

This has definitely become part of my weekly watching schedule

This is something that is kind of a case by case basis. Like with the True Lies episode, I was more interested in whether the horse would make it, not whether the motorcycle would, and that made for fun calculations and research. In this episode, we pondered what it would take to raise the trolley to the heights seen here, but honestly it started coming down to something along the lines of a nuclear bomb... and even then we were guessing about the gasoline fumes and treating the gasoline explosion as if it was a sealed container underneath the trolley car with all explosive thrust being vertical without any leaks out of the sides. Even after all of that, it goes up a millimeter... so what would it take to raise it 2 stories in the air? Who the heck can tell!! More gasoline than in every car gas tank in San Francisco I bet... it just ended up being something too hard to calculate because there's just not enough real data to work with. That's why we simplify the data we can truly use from a scene without guessing so far that it becomes ridiculous.

If we truly used the same kind of approach to it that we did here, the amount of gasoline required in a box underneath the trolley would have already raised the trolley higher in the air than when it reached it's apex in this movie! LOL Or maybe we could have shown how there would need to be a 1000 meter hole with the dimensions of the trolley straight down into the Earth below it filled with gasoline fumes to ignite... who knows...

We definitely read every comment and I try to respond to as many as possible and my favorites are where you guys give even more thought to the scene than the episode uses because that's already what we do behind the scenes. You guys see our very summarized approach to keep the show's pace moving as well as keeping the length within reason. No one wants a one-hour physics class here. Or doooo youuuuuuu? HA!

Thanks for watching and for the great feedback. I will keep in mind how we can expand some of the outcomes in future episodes to focus on what it may take to do versus what we had to start with.

Thanks again for supporting us. Remember, it's still a new show and we are trying to find our audience so if you really dig it, share it out and tell your friends so they can discover it too!

Jason Dean
REEL PHYSICS

What I'm taking with after watching this show: "Don't play with Vaseline." Uhm, ok.

LordLundar:
Why is metric used instead of imperial for scientific purposes? Simple, Metric has a better scale.

As an example, let's do length and we'll start with imperial:

12 inches = 1 foot
3 feet = 1 yard
1760 feet = 1 mile
1.150779448 miles = 1 nautical mile

Terribly uneven and almost random (note the "almost", i'll go into it later). As well there's too large of a gap between scale points that is measured by either fractions which are just as uneven or decimal which produces some really odd numbers (see the miles -> nautical mile above)

Now let's look at metric and SI therewith length:

10 millimeters = 1 centimeter
10 centimeters = 1 decimeter
10 decimeters = 1 meter
10 meters = 1 decameter
10 decameters = 1 hectameter
10 hectameters = 1 kilometer

Steady, even, and constant in it's measurements. you can measure and convert easily between one scale type and another. With metric, so long as the original measurement is accurate, you can scale up or down with accuracy just by moving the decimal place. That is impossible with imperial and requires an elaborate formula to do the conversion.

This also doesn't factor in some imperial measurements being used incorrectly (pounds and the like being used interchangeably with grams despite the former measures weight and the latter measures mass) or not making sense (what's the point of reference for Fahrenheit for example).

So where did imperial come from? Largely tradition. The "foot" is literal, an inch was the measurement of a finger digit, a yard was the measurement of a stride, etc. Metric and SI subsequently was devised to have a simple, accurate, easy to convert measurement system for objective measurements. Similar systems to metric were used by alchemists for centuries in fact until metric became standardized.

Put simply, Metric and SI is used because though it's standardized and accurate.

That's no reason to throw out everything. How about keeping the foot and just making multiples of 10 and 1000 from there?

All of aviation works in feet and works very well.

And the metre is NOW defined by being how far light travels through a vacuum in a fraction of a second, well they use an odd fraction like 1/299 792 458 but if they used a round number like 1 billion, or 1 nanosecond, then the answer they'd get is within 1% of 1 Foot. That's actually useful in our world of speed-oflight communications, you know if something is 50 million feet away, the light will take 50 milliseconds to get there.

Steady and even steps isn't a property of the metre, it's a property of how the mere is treated, the foot could be treated in the same way.

"pounds and the like being used interchangeably with grams despite the former measures weight and the latter measures mass)"

Which is accurate because we DON'T DIRECTLY MEASURE MASS! Only it's weight.

Really we can only measure how much gravity of our planet affects some mass, it's weight. Now you can confer it's mass from something weight in a known gravitational field, really you should weight things in pounds (or newtons) then convert to a "mass unit" assuming you've got gravity right and no other forces are acting on the scales except the mass of the object.

You take some gram-scales to the Moon, and they are not doing to be accurate. But pound scales, technically they will be accurate, they'll measure how many pounds force are acting on it.

Now I supposed you could determine the mass of something with a momentum gauge, that pushes something perpendicular to gravity and measures how far a continuous force moves something. I don't know of any of these devices existing, it might be useful in space.

I'm sorry, I mean it might be useful... in spaaaaace.

(what's the point of reference for Fahrenheit for example)

What's the point in referencing Celsius? Both are just as "wrong" compared to Kelvin.

The "foot" is literal, an inch was the measurement of a finger digit

No, an inch is 1/12th of a foot as 12 parts is very useful as it has the most number of divisors for such a low number, divides by 2, 3, 4 and 6, that's twice as many as with 10 that only divides by 2 and 5. That means you can easily find halves, thirds and quarters on measuring, now rule of thirds is very important for anyone doing any design work. How can you be accurate with your work if finding a third you need to find 3.33333-recurring?

So where did imperial come from? Largely tradition.

Where did the metre come from? Just as arbitrary, a convoluted way of measuring the size of the earth and then breaking it up in an odd way... and getting the wrong answer. Now they define it by speed of light in a vacuum... which if they had done at the start, they'd have settled on the foot.

I'm not defending 5280 feet in a mile (which is unwieldy in decimal counting) I'm defending the foot that should have gotten the regular powers-of-10 treatment that Metre got. Instead the foot was made into a forced marriage with the mile, with a awkward conversion factor.

A mile has always been an imprecise measurement, the nautical mile, the Roman mile, it was always meant as a "guestimate", you know how many knots or paces.

The foot, even from the earliest days that was PRECISE. Buildings were made in feet. Parcels of land was separated out in acres which was defined by the foot, not by square miles. People went to war over a foot, not over a mile.

I love metric scales, but hate the metre.

Treblaine:

That's no reason to throw out everything. How about keeping the foot and just making multiples of 10 and 1000 from there?

Because as I said he foot was a traditional measurement which was only standardized by weight of royal decree. The king's foot was the legal definition of a foot. When the king was replaced the new king's foot was a new measurement of it. The same went for every imperial measurement hence the term "Imperial". Had metric not came about it would still be that way and the measurements would fluctuate every 10-12 years, assuming it was even recognized.

Treblaine:
All of aviation works in feet and works very well.

Only because the foot was standardized using metric standards as a comparison. Had metric systems not been invented modern planes simply could not be built properly.

Treblaine:
And the metre is NOW defined by being how far light travels through a vacuum in a fraction of a second, well they use an odd fraction like 1/299 792 458 but if they used a round number like 1 billion, or 1 nanosecond, then the answer they'd get is within 1% of 1 Foot. That's actually useful in our world of speed-oflight communications, you know if something is 50 million feet away, the light will take 50 milliseconds to get there.

Actually the measurement of a meter is the length of a pendulum that can swing from apex to apex in exactly one second and, like every measurement is remeasured every year to ensure it's accuracy.

Treblaine:
Steady and even steps isn't a property of the metre, it's a property of how the mere is treated, the foot could be treated in the same way.

Could be, isn't because it's traditional comparison was the inch which it's legal definition is "three grains of barley, dry and round, placed end to end, lengthwise" (I stand corrected on the original reference, though the legal Scot definition is the width of an average man's thumb). But as I said before, the foot is a traditional measurement based on autocratic rule, while the meter is a measurement based off of scientific evaluation.

Treblaine:
"pounds and the like being used interchangeably with grams despite the former measures weight and the latter measures mass)"

Which is accurate because we DON'T DIRECTLY MEASURE MASS! Only it's weight.

Really we can only measure how much gravity of our planet affects some mass, it's weight. Now you can confer it's mass from something weight in a known gravitational field, really you should weight things in pounds (or newtons) then convert to a "mass unit" assuming you've got gravity right and no other forces are acting on the scales except the mass of the object.

You take some gram-scales to the Moon, and they are not doing to be accurate. But pound scales, technically they will be accurate, they'll measure how many pounds force are acting on it.

Now I supposed you could determine the mass of something with a momentum gauge, that pushes something perpendicular to gravity and measures how far a continuous force moves something. I don't know of any of these devices existing, it might be useful in space.

I'm sorry, I mean it might be useful... in spaaaaace.

Weight is a measurement of gravitational pull while mass is a measure of an object's density. Without having knowledge of an object's mass, you cannot calculate the weight (which in metric terms is referred to as a Newton). Mass scales are constant regardless of gravitational pull and provide a base frame of reference that gravitational pull and subsequently it's affects (aka weight) can be measured and calculated. The common reason weight and mass are interchanged on earth is because the gravitational pull is considered 1.0 at sea level. Get out of that (even a drastic change of altitude on the planet is sufficient and the measurement of weight is less and less inaccurate when needing to calculate anything apart from gravitational pull.

Treblaine:
You take some gram-scales to the Moon, and they are not doing to be accurate. But pound scales, technically they will be accurate, they'll measure how many pounds force are acting on it.

This specifically indicates that you agree with me because you yourself are saying they're not interchangeable.

Treblaine:

(what's the point of reference for Fahrenheit for example)

What's the point in referencing Celsius? Both are just as "wrong" compared to Kelvin.

I didn't say "point in referencing" I said "point of reference" ie it's basis of standard. The point of reference for Celsius/Centigrade is the the point of water will change to it's three states (solid -> liquid ->gas) at a gravity of 1.0 Newtons divided by 100. The point of reference for Kelvin is the point of absolute zero as the zero mark but uses the same scale.

Treblaine:

The "foot" is literal, an inch was the measurement of a finger digit

No, an inch is 1/12th of a foot as 12 parts is very useful as it has the most number of divisors for such a low number, divides by 2, 3, 4 and 6, that's twice as many as with 10 that only divides by 2 and 5. That means you can easily find halves, thirds and quarters on measuring, now rule of thirds is very important for anyone doing any design work. How can you be accurate with your work if finding a third you need to find 3.33333-recurring?

It has been standardized that way as a result of having a constant frame of reference to the metric system. As I said earlier it has no experimental reference that is constant on it's own. Put in other words, you're saying that the inch is always 1/12 of a foot, but what's the measurement of a foot? My foot? Your foot? The foot of a child? Those are all different and not a proper standard. As for the use, it's importance in design is just as traditional as it's formulation. The Japanese for example do not even use imperial measurements in design instead they use the metric system and is much more accurate. Besides, you're the one who said earlier that it could simply be the foot divided by ten instead, so you just fouled your own argument with this statement.

Treblaine:

So where did imperial come from? Largely tradition.

Where did the metre come from? Just as arbitrary, a convoluted way of measuring the size of the earth and then breaking it up in an odd way... and getting the wrong answer. Now they define it by speed of light in a vacuum... which if they had done at the start, they'd have settled on the foot.

As I said earlier the meter came through scientific experimentation and is annually remeasured through the same process and has been constant since it's inception.

Treblaine:
I'm not defending 5280 feet in a mile (which is unwieldy in decimal counting) I'm defending the foot that should have gotten the regular powers-of-10 treatment that Metre got. Instead the foot was made into a forced marriage with the mile, with a awkward conversion factor.

Treblaine:
That means you can easily find halves, thirds and quarters on measuring, now rule of thirds is very important for anyone doing any design work. How can you be accurate with your work if finding a third you need to find 3.33333-recurring?

Oh look, the same argument and the same counter-argument by the exact same person in the exact same post. To add, the mile wasn't put into a "forced marriage", it was formed just as traditionally as the foot and can be changed just as quick.

Treblaine:
A mile has always been an imprecise measurement, the nautical mile, the Roman mile, it was always meant as a "guestimate", you know how many knots or paces.

The foot, even from the earliest days that was PRECISE. Buildings were made in feet. Parcels of land was separated out in acres which was defined by the foot, not by square miles. People went to war over a foot, not over a mile.

All of which is tradition, not scientific. Imperial measurements were by royal and imperial decree, not through constant scientific measurement.

Treblaine:
I love metric scales, but hate the metre.

Accuracy and consistency vs. tradition in scientific works. Hmm, I think I'll go with the former.

Treblaine:

And outside of that one very specific frame of reference it is useless. Base 10 on the other hand is useable regardless of it's frame of reference and when dealing with scientific notation can be adjusted quickly and easily. Otherwise we could use binary, or Octal, or Hexidecimal as measurements in any form of measuring. Or are you suggesting that the entire scientific community (and various other fields of work) overhaul it's entire measurement system just because you don't like how one measurement is done?

I'm going to jump in on this near-dead thread and just say for the record that abhor calculating in imperial units. Whoever came up with the idea of having pound-force, pound-mass, and slugs should be aware that they are responsible for more failed physics and engineering exams than drugs and laziness combined (at least in the US, and by US I mean me).

However, the software we use to calculate the results for the show does not give a flippity flip about what units we input or output in since units are handled automatically. We could do everything in carats and fathoms, or kg/ft^2 if we wanted to, and it would still work.

What units get input largely come down to the source material. Look up the mass of a San Fransisco street car. It's in pounds. Look up the power rating of a Japanese sport bike, it's in kilowatts.

In the end, we are trying to communicate our results in metric and imperial.

Colby Dane
REEL PHYSICS

You rounded it all wrong! It's supposed to be 1,2 mm, not 1,1! See, now it makes MUCH more sense, as 1,2 mm is closer to the actual thing we see in the film!

And seriously now, great show, keep up the good work. If you're doing the TORQUE scene, could you also try to figure out, within reason, how many times he'd die if that happened for real?

ok, so what would have taken for expanding air/heat to propel a street car 10 metres up in the air?

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