I hold here a bag of popcorn.
The microwave kind.
Just how close to the sun would it have to be before it started popping?
Not very close. Once the ambient temperature reaches about 200c, I’d say you’re good to go…
Thanks, but I’m looking for something in kilometers or miles.
Inches or centimeters would be handy.
And no, I’m not saying why.
In the sun the temperture on the moon gets to about 130[sup]o[/sup]C. Not quite there but you can see it is already pretty hot up there. Someone else would have to figure how much closer you need to be to get to 200. I’m just throwing this out as a starting point.
Well not as far as Mercury. The surface temp of Mercury ranges from 90 - 700 Kelvin. What we need is about 473K. So, Earth gets up to say (max) 330K, Mercury gets up to (max) 700k, so the range of Max Temp between the two is 370k. We need to go 143K up this range - so about 38.6% of the distance from Earth to Mercury, where we should reach 473K. The distance from Earth to Mercury is about 57,000,000 miles, so going about 22,002,000 miles towards Mercury. The distance of Mercury to the Sun varies from about 27,000,000 miles to about 41,000,000. Since we are talking about Max temp, we’ll take the closest 27,000,000. This would leave you a total of 27,000,000 miles + 34,998,000 miles (57,000,000 - 22,002,000) = ** 61,998,000 miles **
I majored in Latin so there is probably a million flaws in those calculations… let the ripping apart begin…
Well not as far as Mercury. The surface temp of Mercury ranges from 90 - 700 Kelvin. What we need is about 473K. So, Earth gets up to say (max) 330K, Mercury gets up to (max) 700k, so the range of Max Temp between the two is 370k. We need to go 143K up this range - so about 38.6% of the distance from Earth to Mercury, where we should reach 473K. The distance from Earth to Mercury is about 57,000,000 miles, so going about 22,002,000 miles towards Mercury. The distance of Mercury to the Sun varies from about 27,000,000 miles to about 41,000,000. Since we are talking about Max temp, we’ll take the closest 27,000,000. This would leave you a total of 27,000,000 miles + 34,998,000 miles (57,000,000 - 22,002,000) = ** 61,998,000 miles from the sun.**
I majored in Latin so there is probably a million flaws in those calculations… let the ripping apart begin…
Shit, I let my popcorn get to 62,000,000 miles from the sun and it burst into flames. Where were you when I had the munchies achilles? Charred popcorn it really foul tasting. Upham, I would try adjusting this distance by several thousand feet, maybe more (unless your using Butter Lover’s), then all bets are off.
Isn’t Popcorn Supernova the name of a song by some BritPop band? Maybe Blur or The Lightning Seeds?
If it isn’t, it should be.
Mangetout - I think you’re thinking of “Champagne Supernova” by Oasis…
Uh, which ambient temperature are we talking about here? The one in airless space? Somehow I don’t think that’s a very good index.
I think the temperature of the popcorn would depend much more on the thermal radiation absoption and radiative properties of the bag holding it more than the actual distance from the sun. I mean, if you had a container that absorbed all the radiation incident on it, and reradiated none, I think you’d eventually pop the corn at virtually any distance. It’s really just a matter of time.
Also, why have we set the (hypothetical, ambient temp in a vaccuum) benchmark at 200C? Popcorn pops because the miosture (i.e.water) forms vapor pressure inside the shell. Eventually, the shell bursts and - viola! - popcorn, but this shouldn’t take a temperature much more than that needed to boil water. OR should it? Does anyone know what the average pressure inside an average popcorn kernel is? Any, estimates of strength of the shell would be helpful?
in a vacuum the water would boil at a very low temperature, unless it froze first- in which case it might sublime.
Depending on the amount of radiation flux you would end up with frozen popcorn,
freeze dried popcorn
or frozen and popped dried popcorn,
but you wouldn’t get charred popcorn in a vacuum.
Right, but the popcorn shell is relatively impermeable to gas, that’s why the pressure build when you reach the boiling point of water and the whole popping process works. So, as long as the kernels weren’t ruptured, the external pressure wouldn’t affect the boining temperature of the water inside the kernels (much).
Take it from me, boining temp is pretty much constant regardless of pressure. Boiling temp, however varies greatly.
Now you know too, and science marches on!
The thread title lead me to another train of thought.
When I cook popcorn, I always nuke it for 2:35. The first kernal probably pops somewhere between 60-90 seconds. Then more progressively pop, and most are then done by 2:35.
So what causes the variation in explosion time? I suspect it’s the minor variations in moisture and shell thickness. Is it possible to create a hyrid, or genetically engineered popcorn, in which each kernal was absolutely identical? Then each kernal would pop at the exact same moment, causing a Popcorn Supernova.
Way cool.
But this is just a thought experiment only. Please do not devote any more time thinking about it. We must focus all remaining energy to Upham’s original post. Thank you.
In addition to having identical kernels, you’d hae to tweak the microwave to hear each one at exactly the same rate.
As for the identical kernels, I can think of at least two ways to do it taht wouldn’t involve all those messy genes: matter editation and Star Trek replicators.
With matter editation, we have the added bonus of being able to build the Clinical Immortality project (and get +1 talent and double votes for governor and supreme leader) , but with replicators we could also replicate pretty much anything we felt like, such as, say, styrofoam packing kernels. We could then compress the kernels into a light but risilient building material for use in humanitarian aid. Frankly, I’m torn.
RE: the OP
I have my trusty heat transfer book ready, but we need the specs on the material and the contents before we can get down to business.
Upham ,
Playing devil’s advocate.
I don’t think you are asking the right question. I believe the question is “would the popcorn pop at all ?” Because the popcorn would be in a vacuum in space I’m not sure the process it takes to pop corn would take place.
In the event that it would pop I don’t think the tempurature of the surrounding planets is an indicator of the tempurature the bag of popcorn would be. The planets have atmosphere which creates a whole different tempurature environment.
Because tempurature in space is caused by radiant energy from the sun, the side of the bag closest to the sun would be much hotter than the one away from the sun. I guess you could spin it when you released it to try and cook evenly.
I think there are alot more problems than I have identified in your question,and even though I didn’t answer it maybe it will turn the course of this string in a new direction
:dubious:
But wouldnt the water boil at any temperature in an absolute vacuum so the popcorn would pop regardless of temperature? Of course, there most likely to be what I call squibs which are ones which are slightly popped but still hard and inedible.
The problem there, Shalmanese, is that as long as the shells were in one piece, the contents of the kernels wouldn’t be in a near absolute vaccuum (absolute vaccuum doesn’t exist , even in space). Think of it like this: the shell acts as a little pressure vessel, keeping the contents from being exposed to the very low pressure outside.
That does raise an interesting question, though. Since we’re concerned with the gage pressure (the difference in pressure between the inside of the kernel and the surrounding environment), the pressure already in the kernels might be enough to burst them, assuming the shells are exposed to the vaccuum. No heating may be neccessary.
(BTW, sorry about all the typos in the previous few posts. Too little sleeeeezzzzzzzzzzzzzzzzzzz.)
The temperatures cited for planets in this thread have been for Mercury and the Moon…neither of which has an atmosphere so you are measuring the radiant energy of the sun at that point. Venus, which is further from the sun than Mercury, is hotter than Mercury but that is due to its having an atmosphere.