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by sushibowl 755 days ago
> Better superconductors means better magnets, which means cheaper fusion.

Notably, what is required for this is superconductors with a higher critical field strength. A higher critical temperature eases cooling requirements somewhat but does not in itself make fusion easier.

Also, quite a few other advances are required before home appliance-sized fusion reactors become feasible. After all, the largest part of most fission plants has to do with generating power from steam, not so much the nuclear reaction itself.

> If anyone could get highly detailed MRI scans whenever they wanted, a huge amount of disease could be prevented.

I think this is oversold. Regular MRI screening without any indication is generally regarded as unproductive not because of the cost of the scan, but because of the high number of false positives. Any normal human body is bound to contain some number of benign growths.

4 comments

Isn't the high number of false positives not just a symptom of us using it almost always on sick people? I would imagine if everyone got their monthly MRI we would learn far more about healthy bodies and the false positive rate would drop.
If you scan everyone, the prior probability is the rate of occurrence within your population. So the test has to be more sensitive than that. For things that have an occurrence of less than 1%...
> Also, quite a few other advances are required before home appliance-sized fusion reactors become feasible. After all, the largest part of most fission plants has to do with generating power from steam, not so much the nuclear reaction itself.

RTGs are not very large, so the technology already exists.

More financially available MRIs would be pretty nice for sports/exercise injuries.

Find out cheaply and quickly if something's a break, a sprain, a connective tissue injury, or something else.

Not to mention that MRIs represent a significant portion of a person's yearly allowable radiation dose. Not worth it to irradiate people without having a reason.

There's also a recent trend in some medical diagnostics of having a lighter touch, instead of running all the tests and potentially drawing the wrong conclusion from heaps of data.

There is no ionizing radiation in MRI. Only strong low-frequency magnetic fields.
You're thinking of CT scans. MRIs use Magnets and Radios to make Images, not radiation. you're thinking of CT scans, which use X-rays. we can't get random MRI scans done because they're very expensive.
> we can't get random MRI scans done because they're very expensive.

How come then that outside of Western Europe and US it costs $100-200? Or is it because the MRI machines were amortized in EU/US first?

The R stands for Resonance, not for Radio.
Since it's a resonance of radio-frequency waves, the parent's not really in error.
And why is that? How does resonance alter the fact that the radiation is non ionizing and therefore not cancer causing.
The comment you're replying to isn't debating that point, I think. They're saying "you got the precise acronym wrong, but what you did write is still technically correct".