Is Black Widow Silk Stronger Than Steel?

WHERE IS THE SPIDER NOW

Hi James! As others have mentioned, you did your first ultimate tensile strength calculation wrong -- you need to take into account the angles of the two threads. I measured a screenshot taken right before failure and found the thread on the left was 30deg. from horizontal and the thread on the right was 24deg. from horizontal. I'm a physics/math teacher and have a degree in mechanical engineering so I had some fun re-doing the calculations. The actual ultimate tensile strength is 1.37GPa -- better than you thought! Let me know if you'd like a link to the PDF. (I don't think I can post a dropbox link here.) :) IMO the biggest sources of error is your diameter measurement -- it doesn't look like you had very high resolution in the microscope capture, and there's always a possibility that the thread had a weaker/thinner spot somewhere you didn't look. Also note that for the pulling-up-from-jar method, any tiny spikes in tension force due to slight shakiness of your hand will not be picked up by the reading on the scale, due to the inertia of the heavy glass jar and scale bed. If you want to try the pulling-up-from-jar method again for a more accurate result, I would recommend using the duct tape to attach the silk to a stretchy material like a strand of spandex from old underwear/socks, to absorb shocks and allow you to turn translational motion with your hand into a slow, steady force increase.

2:34 "Now I have one single strand of black widow silk" You also have a black widow running free in your house...

Bros videos keep getting more dangerous

I love how you just let the widow walk off. DUDE - CAPTURE THE WIDOW!

"deadliest spider in the US" continues to poke it

Sets world’s brightest flashlight down, without turning it off. I was half expecting the desk to burst into flames

There is a problem in your calculation. You did not take into acount the angle of the silk. When you are lifting heavy equipment, if you use 1 ton slings, and you have them at a 45° angle, you can only lift 500kg with them.

Angle made of strand between supports changes horizontal tension force. The less the angle the greater the horizontal force which can be far far greater than the vertical weight of the hooks you placed on strand. In Statics physics. At 45° horizontal and vertical forces are equal. An accurate strength test can only be made using pure vertical strand . Or measurement of angle of strand upon failure.

When calculating the tension in the spider silk in the first experiment, you also need consider the angle the silk is making (because it is slacking due to the weight). From the video I estimated this to be around 30° with respect to the horizontal, resulting in an estimate of the tensile strength of 1.2 GPa.

As someone from Texas, Black widows are actually sorta chill. Not so chill I'd invite them to my house for coffee, but they aren't bothering me either

You did the test a bit wrong - you're only supposed to calculate the tensile strength from a certain amount of deformation usually labeled at the failure point. When it deforms too much you should stop counting. I think the deformation was certainly past the critical failure point at around 8 - meaning it would've snapped after being left alone for a few more minutes. The failure point was 6 or 7.

your experiment measures tangential stress. The thread breaks due to tangential forces, not normal forces. The tensile strength, due to normal forces, is usually at least 10 times larger than the tangential stress limit.

"...when the females are really hungry." Well, that will surely put Mr. Widow at ease.

Man, them spiders be acting like engineers at this point

1:09 POV ME GETTING ON THE WRONG SIDE OF THE INTERNET 💀💀

I love the fact that at the start he says "it's the deadlist spider" then proceed to touch it

i love it when you explain the methods you use, measuring pixels and all!

Next video be like: My friend found a crocodile in his backyard, and I'm going to test if it really has the strongest bite

Now I get why Spiderman's web could lift an entire School bus