290 replies to this topic

[SteelJaws]

They said there would be no maths....they promised!!

I need to take my shoes off for proper maths, can there not be anymore maths....please?

[Major Bill Curtis]

Now, I've seen some calculations, but I'm not yet really convinced; here's why:

A 'mech, according to canon (and not numerous goofy illustrations) usually stands between 10 and 14 meters in height.

Now, let's take anthropomorphic 'mechs only (i.e. generally humanoid), and compare them to a 1.8m, 100kg human.

A 10 meter 'mech has 170 times the volume of our 1.8 meter human (10/1.8 = 5.55, then cubed =~170), so if it has the same density as our human (~1.01 g/cm3), it will also have 170 times the mass, i.e. 17 metric tonnes; ergo, a 10 meter high 20-ton 'mech is denser than a human, coming in at about 1.18g/cm3, which means that the mean density of a 'mech is about the same as epoxy resin (which includes the air spaces in it---keep in mind that every ocean-going vessel has a mean density of less than 1.0g/cm3, including this very heavy object).

Now let's look at the other end of the scale: a 14 meter tall 100-ton 'mech is about 470 times the volume of a 1.8m human (14/1.8 = 7.77, then cubed =~470); ergo, a 14 meter tall human will scale up to a weight of 47,000 kg, or 47 metric tonnes; thus a 100-ton 'mech at this height has a mean density of ~2.15g/cm3, including the air spaces, which is the density of things like Opal and Teflon.

TL;DR? 'mechs sink in water, as they have a mean density somewhere between that of epoxy resin and rocks, depending on the tonnage.

Anyone seeing any issue with this anthropomorphic calculation of volume and extrapolation of mass? (and I'm not talking about "'mechs aren't shaped like people --- plenty of them roughly are, and this is reasonable for estimating volume).

Cheers.

Edited by Major Bill Curtis, 14 June 2012 - 06:47 PM.

[Wraith 1]

Answer to all Battletech-related physics conundrums: Blame it on Comstar!

[Major Bill Curtis]

Wraith 1, on 14 June 2012 - 06:54 PM, said:

Answer to all Battletech-related physics conundrums: Blame it on Comstar!

Never a truer thing has been written: you have won the forums.

[Boymonkey]

Wow I started a thread with Maths in pity I don't understand it but thanks my old maths teacher would be proud.

[Siebzhen]

BDU Havoc, on 13 June 2012 - 07:40 PM, said:

People are aware that this is FICTION, right?

Make believe?

Pretend?

Not real?


Any of this getting through?

Well actually In real life we just recently came up with a method to do what you see in the BT universe.

the material produced is 99.9% air yet able to carry a load. the example i saw was the material was light enough to sit ontop of a seeding dandylion puff with out crushing the puffball yet able to take a load of three apple stacked ontop of each other with out being crushed.

The article is in June 2012 issue of National Geographic page 30 something (pages are not allways numbered).

Hell we are very quickly heading in the same direction that the BT universe went.

We are very very close to being able to create powered armor ie: Elementals. I think at this point we are only lacking a viable power supply.

Edited by Siebzhen, 14 June 2012 - 09:02 PM.

[Boymonkey]

Do you mean graphene? http://en.wikipedia.org/wiki/Graphene

[Siebzhen]

Boymonkey, on 14 June 2012 - 08:53 PM, said:

Do you mean graphene? http://en.wikipedia.org/wiki/Graphene

No i dont think so. What they do is make a mock up of what they want with a resin. Then they Nickel plate that resin. Then they use a chemical that disolves the resin leaveing the nickle in place in a very strong structure yet very light weight.

[Hyperius]

Just gotta ask. Why are there so many people in this thread that seem to be confusing Science Fiction and Science Fantasy?

Science Fiction DOES need a plausible explanation. That's a staple of the genre. eg.Star Trek (mostly)

Science Fantasy DOESN'T need to be explained, and in fact, is usually more effective when it isn't. eg.Star Wars

At least that's always been my understanding of it.

[Gakky]

Even though were talking about things that don't actually exist I thought I would throw this out there.

A Caterpillar D11 dozer weighs 230,000 Lbs or 140,000 Kg (104 Tonne), They're approx. 10 meters long, 4 meters wide/tall. If you were to stand it on its "nose" it would stand 10 meters tall (Approx. 3 storey building). So it's 104 tonnes of mass take up less than 160 cubic meters of space, would actually be less due to the 4m height is top of the cab and most of the heavy structure is below 3m in height from the ground so lets say more likely 120 cubic meters as a ball park figure.

Just to give you an idea of perspective, not sure exactly how tall an Atlas is but again.....they're not real.

Edited by Gakky, 14 June 2012 - 09:47 PM.

[ORIGINAL SteelWolf]

Frostiken, on 13 June 2012 - 02:42 PM, said:

Also, jumpjets. Jumpjets put mechs under a lot of acceleration - I honestly can't picture a heavyweight mech activating the jumpjets and dealing with the high G-forces from acceleration and landing without breaking things.

Under a mere 2g, which you'd experience after simply falling 20 meters, your Archer weighs 140 tons o_O

The mind boggles.

Physics? Really?
THIS.. IS.. SCI-FI! [Battlemaster chest kicks the Atlas off the cliff.]

[Kasiagora]

Hyperius, on 14 June 2012 - 09:39 PM, said:

Just gotta ask. Why are there so many people in this thread that seem to be confusing Science Fiction and Science Fantasy?

Science Fiction DOES need a plausible explanation. That's a staple of the genre. eg.Star Trek (mostly)

Science Fantasy DOESN'T need to be explained, and in fact, is usually more effective when it isn't. eg.Star Wars

At least that's always been my understanding of it.

The way I take it is as Hard Sci-fi, Standard Sci-fi, and Science Fantasy. In the way I figure it, hard sci-fi is anything written by Kim Stanley Robinson such as the Mars Trilogy, or Arthur C. Clarke's Rendezvous With Rama. These novels have quite a bit of real physics and geology written into them and can at times be rather bland because of it. I'd consider Frederik Pohl to be a hard sci-fi writer even though his focus usually is on the psychology of his characters rather than on mathematical theories or scientific law. A good example of hard sci-fi in film would be Sunshine. Watch the DVD with the Physicist commentary. Toward the end it becomes more standard sci-fi and the physicist gives up I think. lol

In Standard Sci-fi you'll find things like the Aliens movies, Robert Heinlein's novels. He'll give the bare minimum of how things work in layman's terms to appeal to a large audience and keep from getting bogged down. John Scalzi is a terrific, newer author of standard sci-fi that follows in the footsteps of, and in many ways is an anti-Robert Heinlein. If you like sci-fi that takes you for a ride, check him out.

Battletech falls into the harder end of standard sci-fi because although it's mostly just sci-fi, there's a little pseudo-physics to semi-explain things enough to keep the imagination going. It's got plausibility. Kind of like Heinlein, but without so much moral debate.

Science fantasy to me, you're right on with Star Wars. There's standard sci-fi, but also magic in the form of the force. Many authors will go from one form into another like Heinlein's "Magic, Inc." which is a good example of sci-fant.

Anyway, that's just my own perspective and I want it to be some brain food for ya, and if anyone checks out any of the things I mentioned, I sincerely hope you enjoy them. I grew up on this stuff.

Edited by Kasiagora, 14 June 2012 - 11:14 PM.

[Hyperius]

Kasiagora, on 14 June 2012 - 11:11 PM, said:

The way I take it is as Hard Sci-fi, Standard Sci-fi, and Science Fantasy. In the way I figure it, hard sci-fi is anything written by Kim Stanley Robinson such as the Mars Trilogy, or Arthur C. Clarke's Rendezvous With Rama. These novels have quite a bit of real physics and geology written into them and can at times be rather bland because of it. I'd consider Frederik Pohl to be a hard sci-fi writer even though his focus usually is on the psychology of his characters rather than on mathematical theories or scientific law. A good example of hard sci-fi in film would be Sunshine. Watch the DVD with the Physicist commentary. Toward the end it becomes more standard sci-fi and the physicist gives up I think. lol

In Standard Sci-fi you'll find things like the Aliens movies, Robert Heinlein's novels. He'll give the bare minimum of how things work in layman's terms to appeal to a large audience and keep from getting bogged down. John Scalzi is a terrific, newer author of standard sci-fi that follows in the footsteps of, and in many ways is an anti-Robert Heinlein. If you like sci-fi that takes you for a ride, check him out.

Battletech falls into the harder end of standard sci-fi because although it's mostly just sci-fi, there's a little pseudo-physics to semi-explain things enough to keep the imagination going. It's got plausibility. Kind of like Heinlein, but without so much moral debate.

Science fantasy to me, you're right on with Star Wars. There's standard sci-fi, but also magic in the form of the force. Many authors will go from one form into another like Heinlein's "Magic, Inc." which is a good example of sci-fant.

Anyway, that's just my own perspective and I want it to be some brain food for ya, and if anyone checks out any of the things I mentioned, I sincerely hope you enjoy them. I grew up on this stuff.

Makes sense. I've never really thought of Sci-Fi being broken down into "hard" and "standard" but that actually makes a lot more sense than lumping it all together. I'll definitely check out John Scalzi. I'm just surprised at all the people equating sci-fi and magic when they are really quite different. Oh well.

[Full Metal Monte]

Hyperius, on 14 June 2012 - 09:39 PM, said:

Just gotta ask. Why are there so many people in this thread that seem to be confusing Science Fiction and Science Fantasy?

Science Fiction DOES need a plausible explanation. That's a staple of the genre. eg.Star Trek (mostly)

Science Fantasy DOESN'T need to be explained, and in fact, is usually more effective when it isn't. eg.Star Wars

At least that's always been my understanding of it.

Personally I don't care if an Atlas can shoot lightning bolts out of it's Arse. The question was, or turned into, can an Atlas float. Which was followed by a bunch of bad math with attitude. Can't let that go just because "Dude, I just woke up and all this mathy stuff makes my head hurt and don't you get it...it's not real!".

The Chinese forums would have been.
American exchange student: Can an Atlas float?
Chinese 6 year old: No.

Yeah I said it! But who cares. in a month we all get to shoot each other in the faces with lazooorz!

[Hyperius]

Full Metal Monte, on 15 June 2012 - 12:03 AM, said:

Personally I don't care if an Atlas can shoot lightning bolts out of it's Arse. The question was, or turned into, can an Atlas float. Which was followed by a bunch of bad math with attitude. Can't let that go just because "Dude, I just woke up and all this mathy stuff makes my head hurt and don't you get it...it's not real!".

The Chinese forums would have been.
American exchange student: Can an Atlas float?
Chinese 6 year old: No.

Yeah I said it! But who cares. in a month we all get to shoot each other in the faces with lazooorz!

No! This game is postponed until we figure this out dammit! How can I play unless I know whether or not my mechs can float?

[GHQCommander]

Hyperius, on 14 June 2012 - 09:39 PM, said:

Just gotta ask. Why are there so many people in this thread that seem to be confusing Science Fiction and Science Fantasy?

Science Fiction DOES need a plausible explanation. That's a staple of the genre. eg.Star Trek (mostly)

Science Fantasy DOESN'T need to be explained, and in fact, is usually more effective when it isn't. eg.Star Wars

At least that's always been my understanding of it.

I agree overall, but not on this matter. They used "ton" which is real life, so the canon invites us to compare that to reality

[RedDragon]

Major Bill Curtis, on 14 June 2012 - 06:43 PM, said:

Now, I've seen some calculations, but I'm not yet really convinced; here's why:

A 'mech, according to canon (and not numerous goofy illustrations) usually stands between 10 and 14 meters in height.

Now, let's take anthropomorphic 'mechs only (i.e. generally humanoid), and compare them to a 1.8m, 100kg human.

A 10 meter 'mech has 170 times the volume of our 1.8 meter human (10/1.8 = 5.55, then cubed =~170), so if it has the same density as our human (~1.01 g/cm3), it will also have 170 times the mass, i.e. 17 metric tonnes; ergo, a 10 meter high 20-ton 'mech is denser than a human, coming in at about 1.18g/cm3, which means that the mean density of a 'mech is about the same as epoxy resin (which includes the air spaces in it---keep in mind that every ocean-going vessel has a mean density of less than 1.0g/cm3, including this very heavy object).

Now let's look at the other end of the scale: a 14 meter tall 100-ton 'mech is about 470 times the volume of a 1.8m human (14/1.8 = 7.77, then cubed =~470); ergo, a 14 meter tall human will scale up to a weight of 47,000 kg, or 47 metric tonnes; thus a 100-ton 'mech at this height has a mean density of ~2.15g/cm3, including the air spaces, which is the density of things like Opal and Teflon.

TL;DR? 'mechs sink in water, as they have a mean density somewhere between that of epoxy resin and rocks, depending on the tonnage.

Anyone seeing any issue with this anthropomorphic calculation of volume and extrapolation of mass? (and I'm not talking about "'mechs aren't shaped like people --- plenty of them roughly are, and this is reasonable for estimating volume).

Cheers.

Thanks. Finally some right numbers.

I don't like it how guys like Kartr create such nonsense as floating mechs with absurd formulars:

Kartr, on 13 June 2012 - 05:09 PM, said:

Using the stated max height of a BattleMech from sarna, which is 14m and doing a quick estimation the Atlas has a volume of roughly 378m^3. Which is roughly 265kg/m^3 which means it falls somewhere between cork and lithium and just over 1/4 the density of water.

That would be the volume for an Atlas with the proportions of a box with the sizes 14mx5mx5m. That's like estimating the volume of a human by calculating with a box of 1,8x0,65x0,65m. That would be a VERY broad shouldered and VERY VERY fat guy. And by 100 kilos such a person would indeed float, even if you put a weight belt on him.
A humanoid mech (or any humanoid shape for that matter) has MUCH less volume and therefore Major Bill Curtis' numbers are way better estimates.

Edit: You don't even have to calculate with density etc.
Simple way to visualize it:
The human body has approx. the density of water.
A normal man of 1,8m weights let's say 80kg. If you take his size x10, he is 18m tall and has the weight of 80x10³kg=80.000kg=80 tons. But he has still approx. the density of water, i.e. he has a near neutral buoyancy. A 14m mech with 100 tons is a lot smaller and weights a lot more, therefore its density would be higher than that of the human. Ergo it would sink. Q.e.d.

Edited by RedDragon, 15 June 2012 - 05:35 AM.

[Viperise152]

Very interesting convo.

[Hyperius]

GHQCommander, on 15 June 2012 - 03:00 AM, said:

I agree overall, but not on this matter. They used "ton" which is real life, so the canon invites us to compare that to reality

I agree. I think Battletech is Science Fiction not Science Fantasy. I was merely observing that some people, the ones saying "it's science fiction you don't have to explain it", don't seem to recognize the distinction between sci-fi and sci-fant.

[RedDragon]

Hyperius, on 15 June 2012 - 10:50 AM, said:

I agree. I think Battletech is Science Fiction not Science Fantasy. I was merely observing that some people, the ones saying "it's science fiction you don't have to explain it", don't seem to recognize the distinction between sci-fi and sci-fant.

Good thing then that we can explain it, doing our maths right