search results matching tag: combustion

» channel: learn

go advanced with your query
Search took 0.000 seconds

    Videos (77)     Sift Talk (0)     Blogs (6)     Comments (255)   

Samantha Bee on Orlando - Again? Again.

RedSky says...

@Mordhaus

The idea of US being a gun violence culture just makes no sense to me. A gun ownership culture among a subset of the population sure, but a culture of resolving conflict with violence? No, it's a product of gun availability. The numbers ChaosEngine quoted on guns / 100 people really is the unique differentiator that makes murder rates some 5-20x the developed country average.

Poverty leading to crime, poor mental health treatment are the tinder but the easy access to weapons is what leads to the death tolls to combust incomparable to any other developed country. Also if legislators can't pass gun control after Sandy Hook, or even restrict people on or previously on the terrorist watch-list from buying guns then the idea of any kind of slippery slope is farcical.

Is Spontaneous Combustion Real?

newtboy says...

I know I've seen this done by someone else where it was done slightly differently with better, more thorough cremation. I think they put the pig in the chair and let it smolder naturally, with the fat melting, wicking into the cloth, and feeding the fire for hours like an oil lamp. This video really looked like the cloth just burned and scorched the pig, but not really '(non)spontaneous pork combustion'.

The Rotary Engine is Dead - Here's Why.

MilkmanDan says...

***update -- I was wrong about P-47 having a rotary engine, confused *radial* with rotary. Other than noting that mistake here, I'll leave my original comment unedited below (in which I draw erroneous conclusions based on that brain fart):

@eric3579 and @newtboy -

I was also quite interested in the "advantages" question. My grandfather was an armorer on P-47 "Thunderbolt" aircraft in WW2, and I knew that rotary engines were used in those.

Both of your answers tie in to the strengths of P-47s during the war. They were considered very reliable and resistant to damage (sorta like a WW2-era A-10; they could take a beating and make it back home). And of course, in internal combustion powered aircraft, power to weight ratio is even more important than in automobiles.

So, I'm sure that some of those strengths were at least partially due to the use of a radial engine. Not entirely, because other things in the design played a big role also -- like the fact that the P-47 engine was air cooled, so it didn't need a radiator system. As I understand it, comparatively light damage to a liquid-cooled aircraft like a P-51 that happened to damage the cooling system could disable or force them down for repairs... Not to knock the amazing piece of engineering that the Mustang was, but for sheer ability to take a beating and stay in the air, the Thunderbolt may have been the best US fighter in the war.

Kuhn SW 4014 Bale Wrapper

oritteropo says...

The idea of the wrap is to stop rain from damaging the hay, so I doubt it would let moisture out either. The bale shouldn't rot though, since part of the process is that you only bale dry grass (or you risk a haystack fire).

The other way of storing grass is to cut it green and ferment it into silage.

bobknight33 said:

I found that oddly mesmerizing.

I do wonder about the wrap. Does it allow the moister out or would the bail develop rot?

Amazing footage of 150,000 tyres on fire in Australia

Working Miniature V8 Paper Engine

Khufu says...

a real engine just an air pump. The combustion is what gives the air the force needed to move the cylinder.

This is the same thing, but because it's paper it only needs a bit of forced air, so if you were a mouse, you could put this in your tiny mouse car and work a little pump to drive around....

very impressive!

Sagemind said:

No it isn't.
It's a small paper box with paper-folded valves that make an engine sound when an exterior energy source is applied.

Rhys Millen Wins Pikes Peak First Electric Car Victory

Jinx says...

No power loss at altitude helps quite a bit I imagine. Would be interesting to see the splits compared to a combustion engine as it climbs, well, if it hadn't lost a motor half way up.

60k HP shockwave jet engine dragracing

SFOGuy says...

5.38 second quarter mile...fast ride---
Oddly, the top fuel dragsters (internal combustion engines) can run it faster (4.5 seconds, with a trap speed of 332 mph...)

Bugatti Veyron around 10.1 seconds at 139 mph
Corvette Z06 runs 11.2 to 11.6 seconds...
VW GTE runs 15.2
and a 2013 Prius about 18 seconds...

Elon Musk introduces the TESLA ENERGY POWERWALL

MilkmanDan says...

One more thought that I had:

Before Tesla, electric cars were niche marketed as adequate. In the sense that if you were a person very highly motivated to be "green", you could get one, drive around short distances, and in general enjoy a small subset of the versatility of an internal combustion gas guzzling car. You could get by, but in general life with an electric car was a step back from life with a gas car.

The reason Tesla is amazing is that it flipped that on its head. You're not sacrificing anything, you don't need an attitude of "I can use a bit less and take one for the team" for a Tesla to appeal to you. Everything I watch about the Model S says it is a fast, high-performance, fun to drive, luxurious car -- objectively BETTER than a similarly priced gas-powered car to most users (who can afford one, but that will include more and more people over time).


Same thing goes for home solar and other "green energy". Adoption rates are NEVER going to soar when solar is "adequate". And then only adequate if you make very big lifestyle changes like cutting back on heating and cooling, using low-draw appliances, etc. etc.

But as Tesla is doing to cars, maybe this can do to energy. Musk is saying NO, you don't have to cut back. You don't have to settle for less. You don't have to take one for the team. Install some (currently fairly expensive) solar panels and 1, 2, or however many of our power packs, and you can have a BETTER experience than being on the grid, paying high bills every month and dealing with the occasional outage, etc.

I guarantee that pitch will do more to push the adoption of green energy than 10 years of Al Gore living in a mansion and flying around constantly on a private jet to give $100,000 lectures explaining why everybody else needs to cut back or we're all going to melt...

Elon Musk introduces the TESLA ENERGY POWERWALL

MilkmanDan says...

Thank you very much for your answers -- here's a couple more questions maybe you can give thoughts on if you have time:

Quick googling says the average US home uses a bit under 12,000 kWh per year. Divide that by 365 and get ~33 kWh per day, divide that by 24 and get ~1.4 kW per hour (rounding up in all instances). Of course, that's going to be higher in the day and lower at night, but one of the points of the batteries is to help smooth out that usage curve and make it transparent to the homeowner / user.

Anyway, questions related to those figures:
*Do those numbers sound ballpark to your experience?

*You've got 1kWh of lead acid batteries. Ignoring the fact that night usage would tend to be lower than daytime, an "average home" draw of 1.4 kW per hour would give you about 40 minutes of off-the-grid power (without help from the solar). That would probably require lifestyle changes to deal with; it seems like an average home couldn't get through a night without fully draining the batteries. True?

A 10 kWh pack like shown in the video would give 7+ hours, not accounting for lower drain at night. Seems like an average US house might well be able to go a whole night with that kind of battery without any lifestyle adjustments (assuming solar can handle 100% of the load during daytime PLUS charge up the batteries).

* Could your existing solar cells handle daytime load and charging of 1 or 2 of these 10 kWh packs so that you could be comfortably 100% off-grid?

* How much area do your solar cells cover?


I'm been very impressed with Tesla as a car company, even though I've never driven or even seen one in person (only a very few super-rich people have imported Teslas to Thailand). I thought that electric cars were going to be impractical toys for really out-there tree huggers, but everything I read about the Model S and other Tesla cars tells me that they are the real deal, actually superior to internal combustion for MOST use cases.

Hopefully without sounding too much like Howard Hughes, I believe that baseline practicality will let economy of scale take over and make Tesla and other electrics the way of the future. And this makes me likewise optimistic that Musk can similarly revolutionize the future of energy in general. Pretty exciting stuff!

newtboy said:

I have solar now, so I'll answer.
Today, if you want battery power at home for storage of solar, wind, even micro hydro generated power, you have one real choice....lead acid batteries.
Pros (compared to lead acid)-At best, lead acids are large, unsightly, need an enclosure, need a charger, have a 1000 cycle life span, need maintenance, can't be frozen or allowed to get too hot, use acid, are expensive to dispose of, and are more expensive than this (better?) technology by almost a factor of 4. I recently replaced my battery bank of just over 1KWH for around $1200-$1400, while he's advertising 10KWH for $3500!
Cons-likely lots of 'rare earth minerals' needed, which cause massive pollution where they're refined (China), unknown rate of failure/fire, other unknown problems, and anti-renewable energy people's heads exploding trying to come up with new reasons that renewable energy sucks.

Awesome Chemistry Demonstration ...Cos FIRE!

Actual footage from inside a 4-stroke engine. Wow, cool!

The Newsroom's Take On Global Warming-Fact Checked

newtboy says...

I'm there with you partially, but if we must wait 50-100 years for the tech to START solving this problem, humanity as we know it has no chance.
I say that because 1. We're still rising the rate at which we add CO2, not lowering it 2. Even if it dropped to 0 tomorrow, we still see 3-5 degree temperature rise in the 100 years before even the extra CO2 already in the atmosphere is absorbed (and that's if the natural processes that absorb CO2 don't completely fail before then, the ocean system is, forests are disappearing, I'm not sure what's left to do the job nature has done for all history) 3. Assuming we do see even just that minimal rise, and not a catastrophic cycle that releases methane causing it to be more like 10 degrees minimum, the disruption of commerce, production (food and other), the loss of natural food sources, useable water, etc. could easily make solving the problem exponentially more difficult to solve in the even near future, and impossible 50 years farther down this road, and 4.Unexpected side effects of solving this problem could easily make things worse...for instance, if we just shut down all coal plants and combustion engines tomorrow, we could easily see a rapid 3+ degree C rise in temperature globally because we would stop adding the particulates that cause 'global dimming' (which is assumed to be causing approximately 3 degrees of cooling today).

(wow, that might be the longest run on sentence I've ever written!)

Chairman_woo said:

My hope is that this will take the form of progressive revolutions. When the food and energy start to become scarce people might start to recognise that the ONLY people who can get us out of this mess are engineers, inventors and scientists.

Maybe we will even be smart enough to put them in charge and ditch the whole idea of politics for the sake of politics all together.

A man can hope anyway. The alternative seems to be extreme left and right wing movements fighting over metaphorical ash and bones.

Co2, methane and other undesirables in the atmosphere could probably be shifted if there was a concerted global effort, doubly so if we factor in 50-100 years of technological advancement. I'm sure the task would be herculean but it would probably also be the greatest thing we ever achieved as a species! ("screw your ancient wonders, we built an air scrubber the size of Missouri!")

Doubt - How Deniers Win

newtboy says...

You gave a few examples, I did not ever disagree that it happens, I disagreed that it's happening today in Africa (or worldwide) at a level that's worse than the lack of water on a global scale. I will concede that, in certain areas, it is, but worldwide, even continent wide, it's less of an issue than useable water by far.
You give up pretty easily.
Historically, there have not been 'men with guns'. Guns are a fairly new construct. If it were historical fact that men with 'overwhelming force' (so forget the guns quip) drive farmers out of farming, why are we still here farming?

Yes, the two statements about technology are not mutually exclusive...your point? You 'give up' a lot.

Yes, and I clearly stated I believe they ignored some factors to get their numbers, as most 'predictions' I've seen in the last 20 years have done. I also clearly stated that even their lower range numbers were disastrous and unsurvivable and their high numbers even more so, I just went on to say my educated guess is that they are likely also on the low side because they don't account for everything AND they assume we'll stop rushing to make things worse at some point. I just think that's wishful thinking, based on my estimations of human behavior.

I do listen to fact, reason, data, hypothesis, innuendo, lies, insanity, and more (proven by the fact that I'm still here discussing this, and it's funny that you now wish to no longer 'listen' to facts or reason yourself because you 'give up'), then do my best with my degree in science and scientific mind to work out what hypothesis is closest to the data, and see if I can determine where it's imperfect and why. You can call it 'personal belief', I call it educated guess work, because I've paid attention and most models were on the low side of reality because they don't include all factors (they can't, we don't know all factors involved yet to program them into the models) and because they all expect humans to stop adding to the problem at some point in their equations, which I say from experience is wishful thinking and bad science/math, and I think it's nearly always added to actual science lately for political reasons on one side or the other.
EDIT: For instance, I've never seen a model that includes 'global dimming', but it's a factor that has kept up to 3 degrees C of warming from happening. it happens when particulates in the upper atmosphere deflect sunlight, stopping it from entering the system as light or heat. It has also added to a decline in global food production, but I've yet to see a climate study that includes it in their model. If we shut down all coal plants and combustion engines tomorrow, we would see a rapid spike in temperature as a result, another thing no one ever mentions.

I note you aren't defending your 'facts' about Texas producing more food than California, were you as certain of that as you are about these 'facts'? If so, perhaps more research could be warranted?

Oh, never mind, I forgot you decided to stop listening to facts and hypothesis and give up. I think your children would be disappointed you care so little about their future....I have none, so I have no dog in the fight. Nothing done today will effect things either way in my lifetime. As I see it, that means I'm one of the few with no agenda either way, I'm only interested in reality, and the data I have seen has consistently been worse than the worst predictions when everything is considered in totality (not cherry picked).

bcglorf said:

This is getting old.
If production were simple, ie not requiring extra water and fertilizer, everyone who's hungry would farm, and there would be 'bush taca' (wild food) to gather and eat. You can't make a living stealing from subsistence farmers, you go hungry between farms that way.
I point out that historically you are wrong. I cite specific examples illustrating that you are wrong. Still you come back insisting that somehow men with guns can't starve people out who want to farm. That somehow the mass starvations under Stalin, Mao, and North Korea weren't even related to the mass theft at gunpoint of farm crops and land from farmers. You insist that it's not what is today stopping farmland from productivity in places like the DRC, Liberia, Sudan, Somalia, Yemen, and many more. I give up.

the tech to replace oil and coal and gas exist today
But also
we can't get to the moon with NASA today, or get on a concord
I give up.

78% less glacier doesn't mean ...
I think those numbers are small, and it's likely that there will be less than 22% of glaciers left in 100 years
I cited the actual science from the IPCC with their own projections. You take the very, very worst of the multiple scenarios the IPCC run. Not content with that, you take the most extreme range of error within that extreme scenario. Not content with that, you then inject your PERSONAL BELIEF that even that position of science is likely to optimistic.

I give up. If you refuse to listen to fact and reason that's up to you. Just don't pretend your any better than the other side ignoring the actual science just from a different end of the spectrum.

Nicolas Prost sends Nick Heidfeld into a violent crash

EMPIRE says...

it's not silent. It's actually louder than a regular car. But it's not a combustion engine sound obviously. It's that high pitch noise of an electric engine.

edit: by regular car, I mean a road car. not a formula 1 car.



Send this Article to a Friend



Separate multiple emails with a comma (,); limit 5 recipients






Your email has been sent successfully!

Manage this Video in Your Playlists

Beggar's Canyon