Intimidator 305 Media Day

But as Eric just pointed out, there are many other ways to help determine velocity. Back in my sky diving days, I once had a very minor malfunction where two of the nine nacelles on my canopy didn't inflate. This probably reduced my forward speed by about 3 mph and my drop rate by about 5 mph. But believe me, I knew the difference coming down.

We all notice small changes in speed when a coaster has more air. This is why we like the good train and the late night rides. However I did not think greasing the track did so much to the top speed as much as it helped maintain speed. That was just my theory anyway.

We sense proprioception in three ways, with our eyes, our touch, and our vestibular system. When its dark we lose our vision, and the other two systems tend to overestimate which is why everything seems faster at night.

You are defiantly right about the maintaining speed vs faster speed, while the loss of some friction on the first drop will help slightly increase the speed, the combined loss of friction over the rest of the track is far greater.

Here is what I was looking for: The drag force on an object is proportional to the square of its velocity. That's why even a small increase in velocity can feel so much more forceful. So (going back to where this started I think) if you took 25 laps on MF all day long at 93 mph, and then suddenly hit 100 mph on the 26th trip, I would be surprised if you could not feel the difference in the force of the wind the 26th time; especially since the force doesn't increase linearly.

Chafed nipples? Lube? Tensed butts?
Whatever happened to Coasterbuzz?

The only thing I could possibly find unusual is Moosh wasn't the one who said it.. Otherwise, its still the same CoasterBuzz.

I'm surprised nobody's brought up assless chaps yet. ;)

^ What you wear to ride coasters is your own business.

Ensign Smith said:
...I once had a very minor malfunction where two of the nine nacelles on my canopy didn't inflate. ...I knew the difference coming down.

Were you aware of the malfunction during your descent? If so, I'd attribute any speed change perception to the heightening of your senses, which happens when your adrenaline is pumping.

Eric Hossfield said:
...if you took 25 laps on MF all day long at 93 mph, and then suddenly hit 100 mph on the 26th trip, I would be surprised if you could not feel the difference in the force of the wind the 26th time; especially since the force doesn't increase linearly.

Or, maybe there was a 7mph breeze.

Seriously - there's virtually no way for a human to determine what amounts to a 7.5% change in velocity without instrumentation (especially in an uncontrolled environment - i.e. outside). You may think you can, but I'd love to see you put to the test.

It really wasn't a huge adrenalin surge. I was flying a Goliath, a sort of 'Big Boy' student canopy, since I was over 200 pounds. This was like my 8th or 9th jump, so I wasn't exactly freaking out about it. I knew those 7 remaining cells would get me down just fine. But I could definitely tell a difference.

You are right, though, it could be a perception bias. I was expecting to come down faster, so maybe that's why I observed it.

What is your "base" velocity under those conditions? That is, what is the drop velocity from which you noticed a ~5mph increase? It's one thing to notice a change from, say, 50-55mph, and quite another to notice a change from 95-100mph.

Under normal conditions, a large canopy with a medium weight diver will descend at a rate of 10 - 15 feet/sec. Since I was a little bigger, call it 15 feet/sec = about 10 mph downward. So 5mph would be a 50% increase in descent rate.

I dunno. Maybe it really wasn't that much. Maybe half or more of it really was psychological.

If your speed increased by 50% (or even ~30+%), I'd be concerned if you didn't feel it.

Or, maybe there was a 7mph breeze.

Seriously - there's virtually no way for a human to determine what amounts to a 7.5% change in velocity without instrumentation (especially in an uncontrolled environment - i.e. outside). You may thinkyou can, but I'd love to see you put to the test.

I was wondering if someone was going to say that. I was implying that all other variables are constant. There is a big difference b/t noticing the change in force of the wind when comparing 30 to 35 mph than is there is 95 to 100 mph. It would not be very difficult to tell the difference b/t 95 and 100 mph if all variables are constant.

If you pay for my expenses I would gladly be put to the test :)

But how do you know the other variables (most importantly, wind) were constant? Did you have someone standing beside the track with an anemometer where you felt the "extra" speed, so they could measure it just as you went by?

You're right that it would be easier to feel such a difference if all other variables were constant. So let me know when someone builds a MF-sized coaster in a vacuum, and I'll gladly pay for whatever testing you like. :)

The issue is that the human body doesn't sense things linearly either. It's true that the difference in drag force between 95 MPH -> 100 MPH is greater than the difference between 50 MPH -> 55 MPH but the human body is going to be much better at telling the difference between 60 degrees and 70 degrees vs. 200 degrees and 250 degrees (well, other than the part when you start to boil).

On a similar note, I would bet that the human body is better at telling the difference between 50 Newtons and 60 Newtons compared to the difference between 200 Newtons and 250 Newtons.

ApolloAndy said:

On a similar note, I would bet that the human body is better at telling the difference between 50 Newtons and 60 Newtons compared to the difference between 200 Newtons and 250 Newtons.

But after eating those 50 newtons I am pretty full.

http://www.j2fi.net/wp-content/uploads/2009/03/fig_newtons.jpg

If you're skydiving while wearing assless chaps, I bet your body is more sensitive to all kinds of sensations.

See, that's another great idea I wish I had thought of.

I would guess the sensations involved would depend on whether you were skydiving solo...or in tandem. ;)

Sounds like it would chap my ass.