Wrong. You can't scale logs much. logs are 16 MJ/kg
this post was submitted on 09 Apr 2025
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Uranium generates that energy by fission. The hydrogen in sugar could generate huge amounts of energy if fused.
For comparison:
- Chemical combustion of uranium: ~4.7 MJ/kg
- Nuclear fission of uranium-235: ~83.14 TJ/kg (or $ 83.14 \times 10^6 , \text{MJ/kg} $)
Do you have a Lemmy client that supports mathematical functions?
With ollama, having smart local bots for your lemmy instance should be easy
Did you reply to the wrong comment?
Built-in LaTeX support would be so cool (and not that hard, Mathstodon has it)
How much more energy would you get if you fused uranium?
Ask Hiroshima and Nagasaki.
In alphabetical order.
Those are fission. Fusion bombs don't fuse uranium. They use a fission bomb to fuse Lithium.
Fusion bombs use a fission bomb to fuse Hydrogen, which is why they're called H-bombs.
I mean if we really want to be technically accurate here, the lithium is just a moderater for the hydrogen isotopes to fuse.
But for me it gets fuzzy when looking at the reaction.
LiD is 4 protons, 8 neutrons. Add a new neutron, and bam, you have 4 protons and 9 neutrons. But that's where it gets weird to me. The lithium needs to decay or something into a tritium and dueterium which forces the tritium to fuse with the existing dueterium in the LiD molecule? Clearly the neutron has enough energy to transfer into one of the atoms to increase the chance of tunneling actually occuring.
The only real purpose of the lithium deuteride is that it's a dry, shelf-stable, room-temperature fuel. The very first hydrogen "bomb" (actually a building-sized device) used supercooled liquid hydrogen as the fusion fuel, but this was obviously not practical for a deliverable bomb.
Oh, they do, but not as the primary or secondary. You can wrap depleated uranium around the core to capture fast neutrons that are leftover from the rest of the process. Changing the number of layers is how you can dial in a desired yield.
For that matter, even the Nagasaki bomb ("Fat Man") didn't use Uranium at all - its fuel was Plutonium.
That's fissed, not fused.
I stand corrected, because I done forgetted.
Using the rule of thumb, anything heavier than iron requires energy input to fuse. So you lose energy fusing uranium.
Serious answer: A huge negative amount. Anything above iron requires energy to fuse (which is why it produces energy from fission.) and I'm pretty sure nothing with 184 protons could be stable enough to count as being produced - the nuclei would be more smashed apart than merging at that point.
Whilst I get your point, their point is still valid in the sense that you just can't extract that energy from gasoline in a more efficient manner than just burning it. For practical purposes, gasoline truly is that much less energy dense.
It's disappointing that natural selection didn't figure out fusion.
There is still time
I mean, technically it already has.
We have fusion (hydrogen) bombs. We just haven't figured out how to maintain and efficiently harness it for energy.
It figured out photosynthesis instead. Why do your own fusion when you can just take advantage of the fusion that's already happening?
It's good it didn't, otherwise it's possible that all the hydrogen in the ocean would be fused into helium by now
Well, more likely it would significantly heat up earth due to the amount of energy released first, cooking everything/starting an endless cooking->extinction->cooling cycle
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In theory, yes. In practice, of those two only fission is currently viable.
And this boulder could generate huge amounts of energy if I pushed it up to the top of Mt. Kilimanjaro and let it roll down.
44 upvotes and 0 downvotes for a comment that doesn't understand that energy density measurements like this tend to measure the useful energy of a system.
and all would generate the same if thrown to something capable of lossless e=mc^2 conversion (maybe a black hole)
sadly black holes go to something like 42% conversion (source: some minute physics video i think)
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Copy pasta without source. Book! https://xkcd.com/1162/
*Boo
(But having a book instead is always nice.)
I choose to believe it was meant as a warning, because GP is going to yeet a book at your head. But with a fair warning.
Maybe it's like a yellow card and they've been booked.
I always use “book” as an insult. Especially since my phone autocorrect was updated…
which is bigger? TREE(3) vs
((...(1 room of stacked papers ) room of paper) room of paper)...)) room of paper
The number of brackets in above expression is, eh, ok, you got the idea.
/s
I love book.
Yes boss, I did work out the dynamic range of that log amplifier we wanted to use in our next product's sensor PCB, it's 80dB.
The results are over here. (points to a roll of A-4 paper)
It has 40 data points and only took me 1 week, 10 pencils, and 20 erasers to plot the chart. Yeah I can present it, it'll take me 10 minutes to roll it out, pin it down, and fetch the A-frame ladder.
This is the real big brain hack with decibels
you can use a linear scale, it's just that the units are logarithmic instead.
(Yes I know most people would call a dB axis logarithmic, it's just a silly comment.)
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If we could consume uranium, you could have a teaspoon's worth and be done with eating for the rest of your life.
I think that's technically true regardless.
I wonder if that's actually factual or not. Uranium by itself isn't too terribly dangerous. It's the whole fission byproducts thing that's the buzz kill.
Also it depends on the isotope of uranium. Something you could find naturally isn't too dangerous, but something enriched too be used as fuel or for wepons is significantly more radioactive.
You would get heavy metal poisoning, same as if you ate a chunk of lead
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Incorrect, if you aren't a bitch about it. Fuse that gasoline!
I was thinking the same thing. It's unfair compare chemical energy to nuclear energy. Coal still kind of sucks, but the hydrogen in the others could definitely be used in fusion...
It is perfectly fair in the context of "fuel", a resource used to produce energy. Whether energy is generated via chemical or nuclear reaction is irrelavent in this case.
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