Recent comments in /f/askscience

Natolx OP t1_j81wfiq wrote

Reply to comment by Redwoo in Can the Radiation from a Sample of Depleted Uranium Sterilize? by Natolx

>The dose rate seems to be very high for DU gamma radiation. I calculated 400nSv/h using 0.7 Sv/Gy on contact for 0.2 w/o U235 for newly depleted material. The dose rate will increase a bit as daughter products accumulate over thousands of years, but that isn’t particularly relevant.

This is just the default calculation of cpm to microsieverts by my radiation counter (GM500) so I suppose it could be that the calculation is wrong.

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Natolx OP t1_j81vyay wrote

Reply to comment by [deleted] in Can the Radiation from a Sample of Depleted Uranium Sterilize? by Natolx

>Without being replenished by new protein, the GFP would photobleach pretty quickly anyways, so I don't think the necklace is worth trying to sterilize. While GFP is stable to protease digestion, it doesn't really remain fluorescent in a purified solution for more than a few days if you just leave it our like you would with normal jewelry. Plus, killing the bacteria probably won't improve the appearance, as they likely broke down a lot of your GFP for food and their corpses will keep making the solution cloudy even if they're no longer alive. Honestly, it's probably easier to write this one off and make a new one.

I think you underestimate how much fluorescent protein we are talking about... This is milligrams. This is many orders of magnitude more protein than you are seeing photobleached in an immunofluorescence assay.

To put this in perspective, this liquid containing fluorescent protein entirely absorbs a 473nm laser I have. None of it makes it out the other side.

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willun t1_j81up2b wrote

Reply to comment by Cheshire-Kate in Why is the Oort cloud spherical? by Outliver

Would the dark matter provide drag? I wonder what the movements of dark matter would be in galaxies like that. I assume for the Milky Way it just rotates in line with the movement of stars (or more accurately, the stars move in line with the dark matter)

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Redwoo t1_j81up1z wrote

Reply to Can the Radiation from a Sample of Depleted Uranium Sterilize? by Natolx

The dose rate seems to be very high for DU gamma radiation. I calculated 400nSv/h using 0.7 Sv/Gy on contact for 0.2 w/o U235 for newly depleted material. The dose rate will increase a bit as daughter products accumulate over thousands of years, but that isn’t particularly relevant.

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beef-o-lipso t1_j81s5gl wrote

Reply to Are there lots of comets coming by? by Mindless_Fill_3473

Comets are rather common. They can have very different periods some very long, others shorter.

What is rare are comets that are visible to the naked eye. Been over 20 years, I think, since the last one.

What you are observing is an uptick in interest from MSM in all things space due to the JWST, Space X, happenings on the ISS and other interesting things. That means more stories and more awareness. It just seems like an uptick.

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