One gram of uranium has 20 billion calories – radiation aside, would that many calories at once kill you?

3.41K views
0

One gram of uranium has 20 billion calories – radiation aside, would that many calories at once kill you?

In:

If you put radiation aside, a gram of uranium won’t have many calories. And none of those calories are likely to be bioavailable, so your body wouldn’t absorb them anyway. The’d just be excreted.

Assuming that the radiation didn’t matter at all, of course.

Different kind of calories mate. You also wouldn’t absorb it either it would pass through you and if radiation is aside it’d be like eating a grain of sand.

Bizarrely, this has been asked before and answered very clearly.

Check it out [here](https://www.reddit.com/r/NoStupidQuestions/comments/3xl78p/a_gram_uranium_is_roughly_20_billion_calories_if/). Short answer is no, because (a) they’re energy calories (a food calorie is 1 kcal), (b) they’re not bioavailable, and (c) there’s no matter to add to your body.

Interesting question.

So to pick apart your question.

We need to address a few things.

First, Calorie is a unit of energy. When they say 1 gram of uranium has 20 billion calories. They mean that when it *under goes fission* it will release 20 billion calories. Not that if you eat it you will get that many calories.

Two, your body can only extract energy from certain things. That’s why you can build a fire with wood and release a lot of energy. But you wouldn’t be able to just eat the wood and get the same.amount of energy. In fact, your body cant do.anything with it. You would get zero calories out of eating wood.

The same thing would happen here. You get zero calories because the process your body is using wont release that energy.

On a similar note, can i drink a gallon of gasoline and not have to eat for the rest of the year?

So leaving aside the obvious answers of “No, it’s not food so you’re body won’t absorb it”, the answer is yes.

A calorie is a unit of energy. While you can’t take in 20 billion calories from uranium, we can still work out what 20 billion calories would do to the human body.

I’m going to assume those are small (thermochecmial) calories (equal to about 4 joules), instead of food calories, not that it really matters here. It just changes the size of the final crater by a bit

Napkin math. You weigh 80kg. about 50kg of that is water. body temp is 37. Starting from body temp, it takes about 2500 kilojoules of energy to convert 1 kg of water to steam. So about 125 megajoules to flash all the water in your body into steam. 20 billion calories is about 80 gigajoules. of energy. Which means after introducing 20 billion calories of energy into your body, you would still have about 79.9 gigajoules of energy left to expect, after you vaporize.

The answer is you explode, and take out a significant area of your local neighbourhood.

I feel like her question is if that many calories can kill you, assuming it can be absorbed.

**Please read this entire message**

Your submission has been removed for the following reason(s):

* Straightforward or factual queries are not allowed on ELI5. ELI5 is meant for simplifying complex concepts (Rule 2).

r/theydidthemath

* Recommended subreddit(s): /r/Answers


If you would like this removal reviewed, please read the [detailed rules](https://www.reddit.com/r/explainlikeimfive/wiki/detailed_rules) first. If you still feel the removal should be reviewed, please [message the moderators.](http://www.reddit.com/message/compose?to=%2Fr%2Fexplainlikeimfive&subject=Can%20you%20review%20my%20thread?)