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Lava Lamp

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Lava Lamp

What if I made a lava lamp out of real lava? What could I use as a clear medium? How close could I stand to watch it?

Kathy Johnstone, 6th Grade Teacher (via a student)

This is a surprisingly reasonable idea, by What If standards.

I mean, it's not that reasonable. At the very least, I'm guessing you would lose your teaching license, and possibly some of the students in the front row. But you could do it.

Just a warning: I'm going to be linking to a lot of videos of lava flowing and people poking it with sticks, so you may have a hard time getting to the end of the article without getting sidetracked into watching a bunch of them like I did while writing it.

You have a few choices for transparent materials that could hold the lava without rupturing and splattering half the classroom with red-hot droplets. Fused quartz glass would be a great choice. It's the same stuff they use in high-intensity lamp bulbs, the surface of which can easily get up to mid-range lava temperatures.[1] This bulb, [This bulb], for example, can supposedly handle bulb temperatures of up to 1000°C, which is hotter than many types of lava. Another possibility is sapphire, which stays solid up to 2,000°C, and is commonly used as a window into high-temperature chambers.[2]That link wasn't a lava video, but this is.

The question of what to use for the clear medium is trickier. Let's say we find a transparent glass that melts[3]Some people say glass is a liquid that flows very slowly. Other people smugly point out that this is actually wrong. Then another group of people dissects how we know it's wrong, and where this incorrect idea got started. And then at the end of the chain, a Metafilter user steps back and asks some supremely insightful questions about what's really going on here as we variously repeat and debunk these kinds of factoids. at low temperatures. Even if we ignore the impurities from the hot lava that would probably cloud the glass, we're going to have a problem.[4]And later, when the school board finds out, we'll have another.

Molten glass is transparent. So why doesn't it look transparent?[5]Which sounds sorta contradictory. "This music is loud, but it doesn't sound loud." The answer is simple: It glows. Hot objects give off blackbody radiation; molten glass glows just like molten lava does, and for the same reason.

So the problem with a lava lamp is that both halves of it will be equally bright, and it will be hard to see the lava. We could try having nothing in the top half of the lamp—after all, when it's hot enough, lava bubbles pretty well on its own. Unfortunately, the lamp itself would also be in contact with the lava. Sapphire might not melt easily, but it will glow, making it hard to see whatever the lava was doing inside.

Unless you hooked it up to a really bright bulb, this lava lamp would cool down quickly. Just like individual blobs of lava, the lamp would solidify and stop glowing within the first minute, and by the end of the class period you'd probably be able to touch it without being burned.

A solidified lava lamp is just about the most boring thing in the world. But the scenario made me wonder: If making a lamp out of molten lava wouldn't be very exciting, then what about a volcano made of lamps?

This is probably the most useless calculation I've ever done,[6]Ok, there's no way that's true. but ... what if Mount Saint Helens erupted again today, but instead of tephra,[7]The technical term for "whatever crap comes out of a volcano." it spewed compact fluorescent bulbs?

Well, if it did, the mercury released into the atmosphere would be several orders of magnitude larger than all manmade emissions combined.[8]45% of which come from gold mining.

All in all, I think making a lava lamp out of lava would be kind of anticlimactic, and would much rather go find some actual lava and poke it with a stick. I also think that it's probably good that Mount Saint Helens didn't erupt compact fluorescent bulbs. And I think that if I were in Ms. Johnstone's class, I'd try to sit toward the back of the room.

Lastly, for old time's sake, I'd like to share one final link with you: The music video for Rick Astley's "Never Gonna Give You Up."

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4 public comments
llucax
19 hours ago
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Lava EVERYWHERE!!!
Berlin
Repton
1 day ago
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"Not found" :-(
rclatterbuck
1 day ago
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It is very important that you watch the video on the mercury hyperlink.
ridingsloth
1 day ago
That is a lie that Ross is telling :|
sandge
1 day ago
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Wait, is the lava having a sword fight *with itself*?!
Atlanta, GA, USA

Animierte Infografik: wie ein Mensch entsteht

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Toll, was GIFs alles so können. Eleanor Lutz von Tabletop Whale hat mit ihnen eine Infografik erstellt, die den Weg eines befruchteten Eis bis zum Tag der Geburt zeigt. Dazu hat sie die verschiedenen Stadien erklärt. Klasse! Hier in groß und hier auch als Poster.


(via reddit)

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Payloads

5 Comments and 13 Shares
With a space elevator, a backyard full of solar panels could launch about 500 horses per year, and a large power plant could launch 10 horses per minute.
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5 public comments
mareino
3 days ago
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Alt text: With a space elevator, a backyard full of solar panels could launch about 500 horses per year, and a large power plant could launch 10 horses per minute.
Washington, District of Columbia
thelem
3 days ago
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What's the unlabelled one? I doubt it's a mistake.
Brighton, UK
Ironica
3 days ago
I don't see any that are unlabeled. Some of them have the label at the bottom instead of the top, maybe you just are missing it?
thelem
3 days ago
Bottom left of 2000s
Ironica
3 days ago
Sure enough. Huh, interesting.
ChuckMcM
3 days ago
Ariane 5 (Ariane 4 is 16 horses, original 5 is 21 horses)
JayM
3 days ago
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.
Boston Metro Area
skittone
3 days ago
I'd rather have a space elevator than tethered surveillance blimps and whatnot.
sfrazer
4 days ago
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Just in time for the KSP beta!
Chicago
Cafeine
4 days ago
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<3
Paris / France
mchahn
2 days ago
Where can I get a version of the graphic big enough to read?

Medical Marijuana Suddenly A Whole Lot Less Illegal Nationwide

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Congress passed a massive omnibus government spending bill over the weekend. And while most of the attention is on the fact that lawmakers have managed to avoid the mess of another government shutdown, the 1600-page, $1.1 trillion bill has a lot in it. Particularly of note? After many long years, the federal government has effectively lifted its prohibition on medical marijuana nationwide.

As the Los Angeles Times explains, the bill makes the federal government’s implicit policy of the past year into its explicit policy, and marks the first time Congress has taken a significant national move toward legalization.

Marijuana has been illegal for both medical and recreational use at the federal level for decades, despite a spate of state-level laws approving its use. Since the 1990s, 32 states and D.C. have passed approving the use of medical marijuana. But even in those states where medical use is legal, federal agencies have been able to raid and shut down marijuana buying, selling, and growing operations.

Last year, the Obama administration instructed federal prosecutors to stop enforcing federal-level marijuana laws that contradicted state policies. Now, that policy is law — or at least will be once President Obama signs the bill sometime this week.

Marijuana legalization advocates have been hailing the measure as a major win. “By approving this measure, Congress is siding with the vast majority of Americans who are calling for change in how we enforce our federal marijuana laws,” said Mike Liszewski, government affairs director for Americans for Safe Access.

Of course, Congress is still standing in the way of some other pot laws. D.C. voters overwhelmingly passed a measure in favor of legalizing recreational marijuana in the District, but legislators have tacked on an amendment to the very same bill that would prevent that change from moving forward.

Congress quietly ends federal government’s ban on medical marijuana [LA Times]

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December 15, 2014

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OH GOD IT'S MOVING DAY AAAHAHAAAAA
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Deer stranded on top of 176 feet high ski jump killed as there was no safe way to remove it

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A deer that was stranded on top of the Pine Mountain Ski Jump earlier this week had to be killed after Michigan Department of Natural Resources (DNR) personnel determined that there was no safe way to remove it from the structure.



DNR Public Information Officer Debbie Munson Badini said that a DNR officer and biologist located the young deer on the platform at the top of the scaffold on Tuesday evening. "We have no idea how it got up there or how long it was there," she said.

According to Badini, the officer and biologist looked at all available options on how to remove the deer. They could not find a way to do it without endangering their own safety or the safety of the deer. Badini added that the deer was starving and "not in good shape physically."



After considering all of these factors, DNR personnel dispatched the deer on Wednesday. The Pine Mountain Ski Jump, which is located in Breitung Township near Iron Mountain, is one of the highest artificial ski jumps in the world. It is is 176 feet high, and 380 feet in length.
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