Recent comments in /f/askscience

wakka55 t1_j4hivxi wrote

Reply to comment by r2k-in-the-vortex in Is time divided up into discrete quanta? Is time "quantized"? by NulloK

Just to add clarity to "analog resolution" - film, optics, and analog signal resolution is generally measured similar to pixel pitch.

You take a card with two black squares with a white square between, and a card with just a grey rectangle, then see how far away you can tell the cards apart, on your photograph, thru the optics eyepiece, or on the oscilloscope. In other words, what angle does 2 dots look like 1 dot. Then how many of said angles fit on a rectangle - there's your megapixels equivilent.

The cards look something like this https://en.wikipedia.org/wiki/EIA_1956_resolution_chart

It's kind of funny that some people don't realize that a lot of 1960s photos and movies are higher resolution than 4k movies are today. Good IMAX and 35mm film was very high res.

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Durable_me OP t1_j4hibox wrote

Reply to comment by Nescio224 in What is the smallest possible black hole? by Durable_me

But if you 'feed' them, will that prolong their lives?
Is there a formula that states how much matter needs to be added in what timeframe to sustain the black hole?

I suppose the smallest black hole will evaporate in 1 Plack second. Faster is not possible, so that is in fact the limit of the smallest black hole if I am right?
so the lifespan of 5,3891 x 10E-44 seconds

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Traditional_Story834 t1_j4hdse8 wrote

Reply to Is there an upper limit on the size of a ship? by LilyFish-

There are material limits to how large you could make something. The compressive strength and the tensile strength of materials would be the main limiting factor. Going beyond those limits and the structure would collapse or fall apart under it's own weight. If you went to space you could theoretically make much larger ships, but they would have the same limits in their material properties and would have to be mindful of the inertial forces when maneuvering the ship. The wrong gravity well and everything would rip itself apart.

Just think about the largest buildings in the world, why is it so difficult to build the tallest building? Now imagine that building moving around bobbing on the ocean.

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askoemnzviwcasf t1_j4hdmuq wrote

Reply to What would happen if we took an organism's DNA, separated each and every couple of DNA that coded for ONE SINGLE PROTEIN and jumbled it up in a different order? by heartless-tramp

Yes but the result would be a little boring. It would without doubt create a nonviable organism.

The reason is that DNA contains critical regions outside of the protein coding part. These include promoters, repressors, enhancers, and numerous RNA transcripts that serve a wide array of functions. Divorcing the part of the DNA that codes for a protein from all the other parts that regulate the expression of that gene would result in dysregulated expression and would certainly be lethal if applied to all genes simultaneously.

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123frogman246 t1_j4h81iz wrote

Reply to comment by menooby in Do antibodies get constantly gobbled up by the immune system or does it only get gobbled it up if it binds to something? if so why. by menooby

Yes, if an antibody on the surface of a B-cell binds to the target, then the B-cell will proliferate and attract other immune cells to it to respond to the disease. If it's an antibody that's been secreted, then there are immune cells monitoring the body, looking out for them, and the immune cells will then find them and respond appropriately.

In general (in a healthy individual), the immune is brilliant at knowing when to respond and when not to - T cells and B cells develop in lymph nodes/follicles in your body and go through both negative and positive selection steps - so they bind to foreign substances (ie diseases) but don't respond to your own body (ie they don't attack your own cells).

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