[gus_massa]

Try to remain here. As a self appointed Em-Drive denier, I can ensure that the level of discussion in Physics and Math is sometimes not so high.

If the post has less than 20 or 30 comments, it is possible to reply to the interesting comments that are wrong or are asking for more information. Sometimes the article has big mistakes, and it is still possible to make a toplevel comment explaining the errors.

When the post already has 100 comment, usually the conversation derrailed and the main discussion is if it's possible to use an Em-Drive inside a Warp-Drive bubble to make a Start Treck teleporter, or something like that.

I'm not an specialist in Biology, so repliying in biologial threads is more difficult. Please ramian here and answer questions in your area of knowdledge.

[jryb]

I've been mulling writing a general "Common misunderstandings HN has about CRISPR" blog post. I'd like to see if confronting everything head-on can change the general nature of conversations here. Maybe you could try something similar for Em-Drives.

[gus_massa]

I prefer to adapt the explanation for each thread. The main problem is that people is not too attached to the conservation of momentum, so each thread has a different excuse to explain why it is broken and why it doesn't break the current laws of Physics.

(For some reason people is not so happy with explanations that break the conservation of energy.)

[pretzell]

I'm definitely your target audience. For the past few months ive been super curious about crispr and just enrolled in OChem to try to really understand this stuff. I probably have all those misunderstandings. Any pointers?

[jryb]

First, ochem is good and there are aspects of cas proteins that you need ochem to understand, but you'll probably want to take biochemistry as well since it deals directly with proteins and nucleic acids (though I assume ochem is a pre-req wherever you are anyway).

I really need to sit down and be thorough about this, but off the top of my head, here are some things I frequently see misunderstood:

1) not all diseases can be cured by changing the genome, even in principle

2) delivery is an unsolved problem! we can't get CRISPR into every cell, or necessarily any arbitrary tissue. This is probably the main roadblock right now for CRISPR therapeutics. For some genetic diseases this is fine. For example, there are some conditions where fixing only 20% of cells is enough to get a clinically-meaningful improvement, but for others this won't work. There are ex vivo techniques, where you remove some cells, modify them in vitro, and transplant them back, but that can't be done with all (most?) cell types.

3) Most traits aren't controlled by a single gene, and those interactions can get very complicated.

4) We don't know what every gene does

5) Even when a gene has been thoroughly characterized, we don't necessarily know what effect a particular modification will have

6) Biology is complicated af. Every change could potentially have unanticipated side effects.

7) Even if God descended from the clouds and granted us the ability to modify any genome in any and all cells of our choosing without any negative side effects, we wouldn't be able to cure every disease even when there's clearly a genetic component. Aging comes up on HN a lot but it's probably the least tractable disease I can think of.

I could go on, but I'm going to stop here and save it for the blog. To be sure, the technology is being developed rapidly, but there are some problems where it's just a matter of iterative engineering, and others where it's going to take a century of dedicated effort.